Magnetic device and method for selective capture, modification, release, and sensing of biological particles

Abstract

The invention relates to a method for selectively capturing, modifying, releasing, and / or sensing biological particles, such as extracellular vesicles, from a liquid sample. The method involves contacting the sample with a surface provided by a fiber section comprising electrically conductive fibers functionalized with receptor molecules for specific binding of the biological particle. A magnetic section induces motion in response to an external magnetic field to enhance interaction. The bound particle is optionally washed, modified by loading with cargo molecules through application of a loading voltage, and released by applying a release potential to the fiber section. The invention further relates to a device comprising the fiber section as a working electrode, optionally embedded in a non-electrically conductive polymer matrix, a magnetic section for motion induction, an optional insulation layer, and electrical connections to a voltage source, with optional counter and / or reference electrodes. The device enables high-throughput isolation, modification, and electrochemical sensing for applications in biomedical, chemical, and environmental fields.

Description

[0001] MAGNETIC DEVICE AND METHOD FOR SELECTIVE CAPTURE, MODIFICATION, RELEASE, AND SENSING OF BIOLOGICAL PARTICLES

[0002] Background of the Invention

[0003] In embodiments, the present invention relates to devices and methods for the rapid and specific capture, separation, and analysis of biological particles from biological samples. More specifically, the invention pertains to a device that combines functionalized carbon fibers with magnetic components to isolate and release biological particles, such as extracellular vesicles, exosomes, viruses, and bacterial particles, for applications in diagnostics, therapeutics, and laboratory processes.

[0004] In further embodiments, the present invention provides a method and a device for selectively capturing, modifying, releasing, and / or sensing biological particles, particularly extracellular vesicles, from a liquid sample. The device comprises a fiber section including electrically conductive fibers functionalized with receptor molecules for specific binding to the biological particles, and a magnetic section responsive to an external magnetic field to induce motion and enhance interaction with the sample. The method involves contacting the sample with the device, optionally washing the bound particles, optionally modifying them by loading with cargo molecules, and releasing them by applying a release potential to the fiber section. The device is configured as a standalone system, with the fiber section serving as a working electrode, optionally including counter and / or reference electrodes, to enable high-throughput isolation, modification, and electrochemical sensing for applications in biomedical, chemical, and environmental fields.

[0005] The capture and analysis of biological particles such as exosomes and extracellular vesicles are essential for advancing diagnostics, developing innovative therapies, and conducting research. Biological particles, such as extracellular vesicles (EVs) ranging from 30-5000 nm (e.g., exosomes: 30-150 nm, microvesicles: 100-1000 nm, apoptotic bodies: 500-5000 nm), viruses (20-300 nm), bacterial particles (0.5-5 pm), protein aggregates, liposomes, and cellular organelles, are critical in intercellular communication, disease progression, and biomarker discovery. EVs have emerged as promising therapeutic agents and substitutes for cell therapy due to their stability, safety, bioactivity, and low immunogenicity. They also serve as key biomarkers in physiological and pathological processes, carrying molecular cargo (e.g., proteins, lipids, nucleic acids) that reflects the state of their originating cells. These properties make EVs and other biological particles valuable for non-invasive liquid biopsies in cancer detection, infectious disease monitoring, neurodegenerative disorder diagnostics, and therapeutic applications like drug and gene delivery. Despite their potential, current isolation techniques limit research and clinical applications due to inefficiencies. Current methods for bioparticle isolation, including ultracentrifugation, precipitation, and immunoaffinity capture, face significant limitations:

[0006] 1 . Time-Consuming Processes: Conventional techniques often require hours or even days to isolate biological particles from samples, making them impractical for rapid diagnostics. Techniques like ultracentrifugation, the gold standard for EV isolation, require multiple high-speed spinning steps (often >100,000 x g for 4-24 hours), making them impractical for rapid diagnostics or high-throughput settings. Some protocols involve up to five centrifugation steps, extending processing times to several hours or days.

[0007] 2. Low Specificity: Many existing methods lack the specificity needed to isolate biological particles of interest, leading to contamination by unwanted particles or debris. Many methods, such as ultracentrifugation and filtration, co-isolate contaminants like protein complexes, lipoproteins (e.g., HDL, LDL), and cellular debris, resulting in low purity (often <50% exosomal content) and inconsistent yields (5-25% recovery). These methods lack the specificity to isolate target particles, especially rare ones like tumor-derived exosomes.

[0008] 3. Complex and Expensive Equipment: Isolation procedures often involve complex, large- scale equipment that is costly and challenging to operate, limiting accessibility for smaller labs or point-of-care settings. Ultracentrifugation and density gradient centrifugation require specialized, costly equipment and large sample volumes (milliliters to liters), limiting accessibility for smaller labs or point-of-care settings. Even filtration-based methods, such as ExoMir™ with dual-pore-size filters (US 2013 / 0052647A1), rely on bulky setups prone to clogging or shear stress-induced particle damage.

[0009] Inefficient Release of Captured Particles: Many existing capture systems do not efficiently release biological particles after isolation, resulting in loss of material and reduced downstream usability. Immunoaffinity methods, such as Dynabeads® using antibody-coated magnetic beads (US8901284B2), provide specificity but require centrifugation and eluting buffer exchange for particle release, often resulting in low yield or particle damage that hinders downstream applications like proteomics or RNA sequencing. Centrifugation-based methods, including ultracentrifugation and density gradient centrifugation with sucrose or iodixanol, improve purity but exacerbate time and complexity issues, often requiring overnight runs. Filtration methods, such as ultrafiltration or tangential flow filtration, are faster but suffer from membrane clogging and non-specific retention of contaminants. Size-exclusion chromatography (SEC) using crosslinked polymers like Sephadex, Sepharose, or Sephacryl offers gentle isolation but is limited by low throughput, sample dilution, and incomplete separation from similarly sized impurities. Immunoaffinity capture, using antibodies against tetraspanins (e.g., CD9, CD63, CD81), provides high specificity but is constrained by high antibody costs, epitope variability, and incomplete particle release under harsh conditions. For instance, Dynabeads® (US8901284B2) require multiple steps and are unsuitable for large samples. Precipitation methods, such as ExoQuick (LIS20130337440) and Total Exosome Isolation Reagent (LIS20130273544), use volume-excluding polymers like poly(ethylene glycol) for particle sedimentation but often co-precipitate aggregates and proteins, requiring additional centrifugation. Microfluidic platforms, leveraging size, immuno-affinity, or densitybased sorting (e.g., dielectrophoresis, acoustic waves), offer fast, portable, and low-cost solutions. However, they are limited by low sample capacity, biofouling, and lack of validation for large-scale clinical samples. The main hurdle in EV isolation is their sparseness in biofluids, necessitating significant volume reduction to achieve sufficient concentrations, which current methods struggle to accomplish efficiently for sample volumes ranging from 0.005 mL to 500 mL. For therapeutic applications, modifying captured particles (e.g., loading with nucleic acids or drugs) is challenging. Classical electroporation, used for microorganisms, requires high- voltage pulses that can damage EVs and electrodes, retaining impurities (WO2012162563A2). Microfluidic electroporation, such as the comb electrode design in polydimethylsiloxane and glass (Adamo et al., Anal. Chem. 2013, 85, 1637-1641) or cell electroporation devices (EP2940120), is difficult to integrate with purification on a single platform. These limitations — prolonged processing times (>1-2 hours), low recovery of rare particles, particle damage, lack of reusability, and incompatibility with high-throughput or large-scale systems (e.g., 100 L bioreactors) — hinder diagnostic and therapeutic advancements.

[0010] Given these limitations, there is a critical need for a device that can rapidly and selectively isolate biological particles with minimal contamination, while providing a simple and efficient method for their release. Such a device would streamline workflows in diagnostic labs, enable faster therapeutic development, and open new possibilities for personalized medicine. The present invention addresses these challenges by providing a compact, efficient, and multifunctional device for the capture and release of biological particles. This device employs carbon fibers functionalized with specific receptors (e.g., antibodies or aptamers) to ensure high selectivity. It integrates a magnetic component for mixing biological solutions, enhancing particle capture efficiency. The device also supports the controlled release of captured particles through the application of an electrical potential, enabling easy recovery for downstream applications. Furthermore, the invention facilitates additional processes such as particle analysis and transformation (e.g., drug or gene loading) for advanced therapeutic applications. This innovative device significantly reduces the time required for bioparticle isolation to approximately 10 minutes and offers high selectivity, versatility, and ease of use. Its capabilities make it a powerful tool for rapid disease diagnosis, therapeutic development, and advanced laboratory research, while also enabling potential applications in gene delivery and targeted drug delivery systems. This device reduces isolation time to approximately 10 minutes, supports sample volumes from 0.1 pL to 100 L, and enables on-device analysis (e.g., electrochemical sensing) and modification (e.g., drug or gene loading), making it a versatile tool for rapid diagnostics, therapeutic development, and advanced research.

[0011] US10948451 B2 and all other patent documents cited herein are incorporated by reference.

[0012] Summary of the Invention

[0013] The present invention provides a novel device and method for the rapid, selective, and efficient isolation, separation, and analysis of biological particles from biological samples. The invention combines functionalized carbon fibers with magnetic components to achieve high specificity in capturing biological particles, such as extracellular vesicles, exosomes, viruses, and bacterial particles. This innovative device is compact, versatile, and suitable for use in diagnostics, therapeutic development, and laboratory workflows.

[0014] In one aspect, the invention provides a method for isolating a biological particle from a liquid sample, comprising contacting the liquid sample containing the biological particle with a surface provided by a fiber section of a device, wherein the fiber section comprises electrically conductive fibers functionalized with receptor molecules capable of specifically binding to the biological particle; wherein the device further comprises a magnetic section configured to induce motion in response to an external magnetic field, thereby enhancing interaction between the surface and the biological particle; optionally washing the surface to remove impurities subsequent to binding; applying a release potential to the fiber section to release the biological particle into a release solution; and collecting the biological particle.

[0015] In certain embodiments, the motion induced by the magnetic section comprises rotational, translational, or oscillatory movement; the receptor molecules are selected from antibodies, aptamers, peptides, ligands, and combinations thereof; and the release potential ranges from -3 V to +3 V, preserving the integrity of the biological particle.

[0016] In another aspect, the invention provides a method for loading a biological particle with a cargo molecule, comprising contacting a surface provided by an electrically conductive fiber section with an aqueous medium containing the biological particle and the cargo molecule; and applying a loading voltage to the surface to facilitate entry of the cargo molecule into the biological particle; wherein the loading voltage ranges from -350 V to -50 V or +350 V to +50 V, applied in bursts, and is opposite in polarity to the release potential; and wherein the surface is provided by electrically conductive fibers with micro- or nanoscale features, integrated with a magnetic section for enhanced capture and manipulation, enabling selective modification without compromising particle integrity.

[0017] It is believed that the present invention overcomes the above shortcomings by exhibiting one or more of the following main features and advantages: 1 . Rapid Operation: The device isolates biological particles from samples in approximately 10 minutes, significantly faster than conventional techniques such as ultracentrifugation.

[0018] 2. High Specificity: Functionalized carbon fibers with receptor molecules (e.g., antibodies or aptamers) selectively bind target biological particles, minimizing contamination.

[0019] 3. Efficient Release: Captured particles are released into a solution through the application of a controlled electrical potential, preserving their integrity for downstream applications.

[0020] 4. Integrated Mixing Mechanism: A magnetic component enables the device to rotate in the presence of a magnetic field, enhancing particle capture by ensuring thorough mixing.

[0021] 5. Versatility: The device can be used for various applications, including particle identification through electrochemical analysis and particle transformation for therapeutic formulations.

[0022] 6. Scalability: The device is adaptable for a wide range of biological solutions, from microfluidic systems to larger-scale industrial applications.

[0023] As explained in more detail below, the device comprises two primary components:

[0024] 1 . Fiber Section: A set of carbon fibers functionalized with specific receptors that bind target biological particles. These fibers act as both a capture mechanism and an electrode for particle release.

[0025] 2. Magnetic Section: A magnetic material that enables the device to move within a solution under an external magnetic field, functioning as a stirrer to maximize contact with particles.

[0026] As explained in more detail below, the device is used as follows:

[0027] 1. First, it is introduced into a biological sample, where its magnetic section facilitates mixing. The functionalized fibers bind to the biological particles of interest with high specificity.

[0028] 2. The device is then washed to remove non-specific material, and captured particles are released into a separate solution by applying an electrical potential.

[0029] 3. The released particles can be analyzed or further processed, such as being loaded with therapeutic agents, to thereby making the device as described herein a versatile tool for advanced biomedical applications.

[0030] In certain aspects, the invention provides a separation and modification method and device having high-throughput capabilities. In certain embodiments, the device comprises conductive fibers, such as carbon fibers or carbon nanotube fibers, with high surface area, optionally in a mesh or fabric form, conjugated with affinity agents for specific capture of biological particles like extracellular vesicles. The magnetic section enables dynamic mixing without additional mechanical components, and controlled release or loading is driven by electrical potentials. Isolation and modification of biological particles directly from biological fluids enable therapeutic investigations, drug delivery applications, and sensing of biomarkers. In contrast to current isolation methods, the device is tailored for processing small to large volumes of raw samples within approximately 10 minutes or less. The device operates by bringing the fiber section, with its micro- or nanoscale features and high packing density, into contact with the sample; inducing magnetic motion to enhance binding; optionally washing bound particles; and applying electrical potentials to enable release or loading. The expected yield depends on the device configuration; for example, a device with a 2 mm exposed fiber length functionalized with anti-CD9 antibodies can isolate extracellular vesicles yielding 1-100 pg of protein from 1- 200 mL of sample. The system and methods disclosed herein provide a fast, robust, and reusable methodology for capturing, modifying, and releasing biological particles, with high selectivity, flexible sample volumes, simplicity, and portability. The device is a compact, rodlike structure, with minimized dimensions, weight, and costs, suitable for automation and integration into chemical, biomedical, or environmental applications. The device allows integration of capture, modification, release, and sensing on a single platform in sequential steps, or can interface with upstream processes. In contrast to classical methods for particle manipulation, which often require high voltages that risk damaging particles or devices or lack integration of magnetic enhancement, the device utilizes low to moderate voltages that maintain integrity, incorporates robust conductive fibers resistant to degradation, and requires only a simple voltage source and magnetic field, enabling portability and reusability. Affinity to the surface allows easy solution exchange and sequential loading with multiple cargos, while the release step permits control over the elution buffer. The cargo molecules can be therapeutic agents, diagnostic probes, nucleic acids, proteins, or small molecules, facilitating applications in drug delivery, immunotherapy, gene therapy, and theranostics. This invention addresses critical shortcomings in current bioparticle isolation techniques by offering a fast, efficient, and specific solution, with potential applications in disease diagnosis, therapeutic development, and laboratory research.

[0031] Terms and definitions

[0032] For the purposes of interpreting the present specification, the definitions provided herein shall govern. Terms expressed in the singular shall encompass the plural, and vice versa, where appropriate. In the event of a conflict between any definition herein and a definition in a document incorporated by reference, the definition in this specification shall prevail.

[0033] As used herein, the terms "comprising," "having," "containing," "including," and grammatical variants thereof are open-ended and equivalent, such that one or more elements following any such term do not constitute an exhaustive enumeration or restrict the scope to the enumerated elements only. For example, a composition "comprising" elements A, B, and C may consist of A, B, and C alone, or include A, B, and C along with one or more additional elements. Thus, "comprises" and analogous expressions encompass embodiments "consisting essentially of" or "consisting of." When a range of values is recited, every intervening value, to the tenth of the unit of the lower limit (unless the context clearly indicates otherwise), between the upper and lower bounds, as well as any stated or intervening value within the range, is encompassed, subject to any expressly excluded limit. Ranges excluding either or both recited limits are also encompassed.

[0034] The term "about" as applied to a value or parameter encompasses embodiments directed to that value or parameter per se. For instance, "about X" encompasses and describes "X."

[0035] As used herein, including in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the relevant art (e.g., molecular biology, biochemistry, electrochemistry, materials science, nanotechnology, and biomedical engineering). Conventional techniques are used for molecular, genetic, and biochemical procedures (see, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual, 4th ed. (2012) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; Ausubel et al., Short Protocols in Molecular Biology (2002) 5th Ed, John Wiley & Sons, Inc.) and for chemical procedures.

[0037] 1. Binding; Receptor Molecules; Specific Binding

[0038] “Specific binding” refers to the selective and preferential interaction of a receptor molecule with a target biological particle or a biomarker thereof. Specific binding is characterized by a measurable affinity and distinguishable selectivity relative to structurally related non-target analytes. In certain embodiments, specific binding is indicated by a dissociation constant (K_D) of about 10-5mol / L or lower for the target, and by a binding affinity for a structurally related non-target analyte that is at least about three orders of magnitude weaker. Unless otherwise stated, specific binding encompasses equilibrium and kinetic binding parameters.

[0039] “Dissociation constant” or “K_D” denotes the equilibrium constant for reversible dissociation of a receptor-target complex. For a 1 :1 binding interaction, it is expressed as:

[0040] K_D = ([R] x [P]) I [R-P], where [R], [P], and [R-P] represent the equilibrium concentrations of receptor, target particle, and receptor-particle complex, respectively.

[0041] “On-rate” (k_on) and “off-rate” (k_off) refer to the association and dissociation rate constants, respectively, of receptor-target interactions. These kinetic constants may be determined using methods including, but not limited to, surface plasmon resonance, biolayer interferometry, or equivalent kinetic binding techniques. The relationship K_D = k_off / k_on applies for a 1 :1 binding interaction. In certain embodiments, k_on may have an upper practical limit of approximately 109L mol“1s“1.

[0042] 1. 2. Aptamers, Antibodies, and Antibody-Like Molecules

[0043] “Aptamer” refers to a nucleic-acid-based or peptide-based oligomer capable of binding a designated target with high affinity and specificity. Aptamers may be isolated from randomized libraries, including by SELEX or comparable selection procedures, or may be synthetically designed or modified. For purposes of this disclosure, aptamers are considered functional equivalents of antibodies.

[0044] “Antibody” includes intact immunoglobulins (e.g., IgG, IgA, IgD, IgE, IgM), antigen-binding fragments (e.g., Fab, F(ab’)2, Fv), single-chain constructs (e.g., scFv), engineered variants, and derivatives thereof. Antibodies comprise at least one variable heavy (V_H) and variable light (V_L) domain and may additionally include one or more constant domains (e.g., C_H1 , C_H2, C_H3, and / or C_L). The term further includes single-domain antibodies, nanobodies, and other antibody formats retaining antigen-binding capability.

[0045] “Antibody-like molecule” means a non-immunoglobulin binding protein that exhibits antigenbinding affinity comparable to that of an antibody (e.g., a K_D of about 10'6mol / L or lower). Antibody-like molecules include, but are not limited to, designed ankyrin repeat proteins (DARPins), armadillo-repeat proteins, leucine-rich repeat proteins, tetratricopeptide repeat proteins, fibronectin type III scaffolds (including consensus FN3 domains), lipocalins, zinc- finger scaffolds, SH2 and SH3 domains, PDZ domains, y-crystallin derivatives, ubiquitin variants, cystine-knot proteins, Sac7d proteins, coiled-coil constructs, Kunitz domains, carbohydrate-binding modules, and other engineered or synthetic binding scaffolds.

[0046] 1. 3. Receptor Molecules

[0047] “Receptor molecule” denotes any molecule capable of specifically binding a biological particle or a biomarker thereof. Receptor molecules include, without limitation, antibodies, antibody fragments, antibody-like molecules, aptamers, peptides, ligands, enzymes, nucleic acids, and combinations or conjugates thereof.

[0048] 2. Biological Particles; Extracellular Vesicles

[0049] “Biological particle” denotes any particulate biological or biologically derived entity, natural, synthetic, or hybrid, that can be selectively bound by a receptor molecule and is capturable and releasable by the device. Biological particles include, without limitation, extracellular vesicles (EVs), exosomes, microvesicles, apoptotic bodies, viruses, viral fragments, bacterial particles, spores, ribonucleoprotein complexes, protein aggregates, lipoproteins, organelles, cell fragments, liposomes, prions, cell-free nucleic-acid complexes, nanobacteria, biodebris, circulating tumor cells, fetal-derived vesicles, environmental particles, and combinations thereof. Biological particles may range from approximately 1 nm to 10 pm or greater.

[0050] “Extracellular vesicle” (EV) denotes a lipid-bilayer-enclosed particle released by cells and containing proteins, nucleic acids, lipids, metabolites, or organelles reflective of its cellular origin. EVs typically range from 20-30 nm to about 10 pm, with exosomes generally below 200 nm.

[0051] “Exosome” refers to an endosomal-derived EV typically having a diameter of 30-150 nm.

[0052] 3. Conductive Fibers; Fiber Section

[0053] “Conductive fibers” denote electrically conductive filaments suitable for use as electrodes or electrode components. Conductive fibers include, without limitation, carbon fibers (PAN- or pitch-derived), graphene fibers, graphene oxide fibers, carbon-nanotube fibers, metallic fibers (e.g., Ag, Cu, Au, Ni, W, Co), semiconducting nanowires (e.g., Si, GaAs, ZnO, InP), transition- metal-dichalcogenide fibers (e.g., MoS2, WS2, WSe2), conductive polymers (e.g., PEDOT:PSS, polyaniline, polypyrrole), conductive oxides (e.g., ITO, AZO, FTO), MXene fibers (e.g., Ti3C2Tx, Nb2CTx), and combinations thereof. Conductivities may range from 10° to 108S / m, with characteristic dimensions from ~0.1 nm to 1 mm.

[0054] “Fiber section” refers to a segment comprising one or more conductive fibers, optionally arranged as bundles, meshes, fabrics, papers, or composites. The fiber section may be receptor-functionalized and typically has a diameter of 1-10 pm and an exposed length of 1 nm to 1 m or more, depending on the device embodiment. The fiber section may exhibit an area density of 30-200 g / m2, resistivity of 10“6-10“3Q m, and may be compatible with electrochemical potentials between -0.8 V and +0.8 V versus a reference electrode.

[0055] 4. Magnetic Section; Insulation Layer

[0056] “Magnetic section” denotes a component configured to respond to an externally applied magnetic field and produce rotational, translational, or oscillatory motion of the device. The magnetic section may comprise neodymium magnets (e.g., NdFeB), ferrite magnets, iron, cobalt-based alloys, magnetizable composites, or combinations thereof.

[0057] “Insulation layer” denotes a material layer positioned between conductive and magnetic components to prevent undesired electrical or chemical interactions. Suitable materials include silicone, elastomers, or aqueous-resistant polymers. Length may range from 1-10 mm or greater.

[0058] 5. Electrical Parameters: Release, Loading, and Retention Potentials “Release potential” refers to an electrical potential applied to the fiber section to disrupt receptor-particle binding and facilitate intact particle release. The potential may range from -300 V to +300 V, preferably within ±3 V.

[0059] “Loading voltage” denotes a potential applied to promote entry or incorporation of cargo molecules into captured biological particles. In certain embodiments, the loading voltage has polarity opposite to the release potential and may range from -350 V to -50 V or +350 V to +50 V, optionally delivered in 0.5-5 ms pulses for 2-20 cycles.

[0060] “Retention potential” refers to an applied potential that enhances receptor-particle attachment, generally of polarity opposite the release potential and within ±3 V, preferably ±2 V.

[0061] “Counter electrode” denotes an electrode paired with the fiber section for electrochemical operation, and may comprise Pt, Au, C, or equivalent conductive materials.

[0062] “Reference electrode” denotes a stable reference electrode such as Ag / AgCI, optionally prepared by applying and curing Ag / AgCI paste.

[0063] Potential may be applied progressively in increments (e.g., 0.5-5 V) to enable size-selective release of particles.

[0064] 6. Cargo Molecules, Hybrid Particles, and Polyplexes

[0065] “Cargo molecule” refers to any agent intended for incorporation into biological particles. Cargo includes, without limitation, therapeutic agents, proteins, nucleic acids (e.g., siRNA, shRNA, antisense oligonucleotides), dyes, small molecules, polymeric gene-delivery constructs, ligands, immunomodulators (e.g., cytokines), photodynamic or photothermal agents, diagnostic probes, and combinations thereof.

[0066] “Polyplex” denotes a complex formed between a cationic polymer and a nucleic-acid molecule (e.g., polylysine-siRNA), optionally prepared at predetermined mass or molar ratios.

[0067] “Hybrid particle” denotes a biological particle incorporating cargo molecules or complexes. Exemplary hybrid particles include EVs loaded with hydrophobic dyes, polymers, polyplexes, or other cargoes via incubation, diffusion, electrostatic association, or voltage-assisted loading.

[0068] Cargo incorporation may occur with or without application of a loading voltage.

[0069] 7. Biological Sample

[0070] “Biological sample”, “biosample”, or “biological solution” denotes any sample of biological origin or containing biological material that may contain biological particles. The term includes, without limitation, blood, plasma, serum, urine, saliva, cerebrospinal fluid, lymph, mucus, catamenial fluid, perspiration, tears, semen, tissue lysates, cell-culture supernatants, environmental samples (e.g., fresh or saltwater), agricultural samples, and reagent-containing fluids. Sample volumes may range from >0.1 pL to 10 L or more. “Liquid sample” refers to any fluid sample containing or suspected of containing biological particles.

[0071] 8. Surface Activation, Silanization, and Functionalization

[0072] “Surface activation” denotes modification of the fiber surface to introduce reactive groups (e.g., hydroxyl, carboxyl). Methods include plasma treatment (e.g., 10-100 W, 1-5 min).

[0073] “Silanization” denotes attachment of silane molecules to activated fiber surfaces to enable subsequent receptor immobilization. Exemplary methods include vapor-phase exposure to aminosilanes such as APDMES.

[0074] “Functionalized” or “functionalization” refers to covalent or non-covalent attachment of receptor molecules or ligands to the fiber surface.

[0075] 9. Device Components

[0076] “Device” or “device (10)” denotes the rod-shaped particle-isolation device comprising at least: (a) a fiber section, (b) a magnetic section, and (c) a voltage-source contact.

[0077] “Fiber section (100)” is as defined above and is the portion that directly interacts with the biological sample.

[0078] “Magnetic section (102)” denotes the magnetic or magnetizable component that enables movement under a magnetic field.

[0079] “Voltage source contact (106)” denotes the conductive interface through which electrical potential is supplied to the fiber section. In certain embodiments, the magnetic section serves simultaneously as a voltage-source contact.

[0080] “Insulation section (101)” denotes a protective and electrically isolating layer surrounding selected device portions, typically 1-4 mm thick.

[0081] 10. Device Geometry and Motion

[0082] “Rod-shaped” refers to an elongated, substantially cylindrical or prismatic geometry having a length of 1-100 mm and a width or diameter of 3-5 mm.

[0083] “Rotational motion” means rotation or spinning of the device within a sample, induced by an externally applied rotating magnetic field.

[0084] 11 . Analytical Methods

[0085] “Proteomics analysis” denotes analytical workflows for protein identification or quantification, including extraction, digestion, chromatographic separation, and mass-spectrometric detection. “Western blot analysis” denotes protein separation, transfer, and immunodetection by electrophoresis, membrane transfer, antibody binding, and chemiluminescent or equivalent visualization.

[0086] 12. Small Molecules

[0087] “Small molecule” refers to an organic or inorganic compound typically having a molecular weight below 1 ,500 Da, including therapeutic agents, dyes, metabolites, and non-polymeric chemical entities suitable for incorporation into biological particles.

[0088] 13. Washing Solution

[0089] “Washing solution” refers to any aqueous or aqueous-compatible fluid used to rinse, cleanse, or remove unbound or non-specifically associated materials (including biological particles, cargo molecules, reagents, or contaminants) from the fiber section, device components, or processed samples. The washing solution may consist of or comprise, without limitation:

[0090] • deionized water (DI water), including ultrapure water (e.g., >18 MQ cm resistivity), distilled water, filtered DI water, or sterilized DI water;

[0091] • physiological or buffered solutions (e.g., phosphate-buffered saline (PBS), Tris-buffered saline (TBS), HEPES buffer);

[0092] • low-ionic-strength rinsing solutions;

[0093] • surfactant-containing washes (e.g., Tween-20, Triton X-100) at non-denaturing concentrations;

[0094] • salt solutions, chelating solutions, or reagent-containing washes appropriate for removing nonspecifically bound components while maintaining integrity of captured biological particles.

[0095] Unless otherwise indicated, the term encompasses any formulation suitable for gentle or stringent washing under operational conditions of the device, including electrically assisted washing.

[0096] 13. Interpretation

[0097] “Comprising”, “including”, and “having” are open-ended terms and do not exclude the presence of additional elements or steps. “Preferably”, “particularly”, and similar expressions denote optional, non-limiting features. Numeric ranges are inclusive of their endpoints, and endpoints may be combined unless context dictates otherwise. “Approximately” or “about” refers to ±20% of the referenced value unless otherwise specified. These definitions apply throughout the specification and claims unless explicitly stated otherwise. Detailed Description of the Invention

[0098] Introduction

[0099] The invention pertains to a novel device and method for the rapid and specific isolation, separation, and analysis of biological particles from biological samples. The invention addresses limitations in existing technologies by providing a compact and efficient solution that combines functionalized carbon fibers and magnetic components. The device facilitates the capture, release, and potential transformation of biological particles such as extracellular vesicles, exosomes, viruses, and bacterial particles. This invention is particularly useful for rapid diagnostics, therapeutic development, and advanced laboratory research. The device and method are suitable for applications in chemical, genetic, biochemical, pharmaceutical, biomedical, medical, radiological, and environmental fields.

[0100] Background Art

[0101] Existing methods for isolating biological particles, including ultracentrifugation, precipitation, and immunoaffinity techniques, are often slow, complex, and require expensive equipment. For instance, ultracentrifugation, while widely used, can take hours to days and often leads to contamination with other particles. Precipitation-based methods are faster but lack the specificity needed for pure particle isolation. Immunoaffinity techniques, though specific, are labor-intensive and yield limited quantities of particles. These limitations highlight the need for a device that can perform rapid, efficient, and highly specific particle isolation, while being versatile and cost-effective.

[0102] Summary of the Invention

[0103] The invention provides a device composed of two main components:

[0104] 1. Fiber Section: Carbon fibers, functionalized with specific receptors (e.g., antibodies or aptamers), that can selectively bind biological particles from a biological sample. The functionalization enables specific interaction with biological particles, including extracellular vesicles, exosomes, viruses, and bacteria. When a voltage is applied, the fibers can release the captured particles into a chosen solution, enabling recovery.

[0105] 2. Magnetic Section: A magnetic material that enables the device to rotate within a solution when subjected to an external magnetic field, functioning like a magnetic stirrer. This movement enhances the interaction between the fibers and the particles in the sample, improving capture efficiency. The integration of these components allows the device to:

[0106] ■ Rapidly capture biological particles within 10 minutes.

[0107] ■ Cleanly release captured particles using an applied electrical potential.

[0108] ■ Facilitate electrochemical or other forms of analysis for adsorbed particles. ■ Enable the transformation of isolated particles by introducing them to drug-loaded or gene- loaded materials for therapeutic purposes.

[0109] The device is versatile, scalable, and compatible with a wide range of biological solutions and experimental conditions. The invention relates to the purification, capture, and release of biological particles, including exosomes, extracellular vesicles, proteins, aggregates, viruses, bacteria, platelets, microvesicles, and apoptotic bodies. Where alternatives for features such as receptor molecules or fiber types are described as embodiments, they may be combined freely.

[0110] Device (10), Structure

[0111] Exemplary embodiments of the device 10 are illustrated in the figures, exemplary and nonlimiting methods of its manufacturing and of its use is described in the examples. As mentioned above, the device comprises, or is composed of, the following key sections, designed to work synergistically for the capture, release, and analysis of biological particles:

[0112] Fiber Section 100:

[0113] This section is made of carbon fibers with diameters in the micrometer range.

[0114] The fibers are functionalized with specific receptors, such as antibodies, aptamers, or other biomolecules, enabling selective binding to target biological particles, including extracellular vesicles, viruses, or bacteria.

[0115] The functionalization process ensures high specificity and efficiency in particle capture while maintaining compatibility with a range of biological samples. The fiber section comprises conductive fibers configured to provide electrical connectivity for subsequent steps. The conductive fibers are selected from the group consisting of carbon fibers (e.g., polyacrylonitrilebased or pitch-based, electrical conductivity of 104to 106S / m, thickness of 10 nm to 1 mm), graphene fibers (electrical conductivity of 105to 107S / m, thickness of 0.3 nm to 1 mm), carbon nanotube fibers (electrical conductivity of 105to 107S / m, thickness of 1 nm to 1 mm), metallic fibers (e.g., silver, copper, gold, nickel, tungsten, cobalt, electrical conductivity of 106to 108S / m, thickness of 0.1 nm to 1 mm), semiconducting nanowire fibers (e.g., silicon, gallium arsenide, zinc oxide, indium phosphide, electrical conductivity of 102to 105S / m, thickness of 0.5 nm to hundreds of micrometers), molybdenum disulfide fibers (electrical conductivity of 102to 104S / m, thickness of 0.6 nm to 0.5 mm), transition metal dichalcogenide fibers (e.g., tungsten disulfide, tungsten diselenide, molybdenum ditelluride, electrical conductivity of 102to 104S / m, thickness of 0.6 nm to several hundred micrometers), conductive polymer fibers (e.g., PEDOT:PSS, polyaniline, polypyrrole, electrical conductivity of 10° to 104S / m, thickness of 50 nm to 1 mm), conductive oxide fibers (e.g., indium tin oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide, electrical conductivity of 102to 105S / m, thickness of 1 nm to 1 mm), MXene fibers (e.g., Ti3C2Tx, Nb2CTx, Mo2CTx, electrical conductivity of 104to 106S / m, thickness of 1 nm to hundreds of micrometers), and combinations thereof. The fiber section is characterized by individual fibers having a diameter ranging from 1 to 10 pm, particularly approximately 7 pm, and an exposed length ranging from 1 nm to 1 mm, 1 mm to 1 cm, or up to 1 m or more, particularly approximately 2 mm. The conductive fibers exhibit a density of less than 1 .5 g / cm3, particularly from 0.1 to 1 .1 g / cm3, an area density of 30 to 200 g / m2, an in-plane electrical resistance (measured by the van der Pauw method) of 0.015 to 1.5 Q mm, a resistivity of 10“6to 10“3Q m at 20°C, suitability for electrochemical analysis (e.g., cyclic voltammetry between -0.8 V and +0.8 V versus a reference electrode), and a resistance per unit length of approximately 30 Q / m for carbon fibers.

[0116] In certain embodiments, the conductive fibers are carbon fibers comprising elemental carbon (e.g., graphite) in filament form, with a microscale or nanoscale diameter ranging from 1 to 500 pm, particularly 5 to 200 pm, 5 to 100 pm, 5 to 50 pm, or 5 to 20 pm, and a length ranging from 100 pm to 50 mm, particularly 100 pm to 1 mm or 100 to 800 pm.

[0117] In certain embodiments, the fiber section is gas-permeable, exhibiting a through-plane air permeability at 200 Pa (DIN EN ISO 9237) of 100 to 1000 L / m2s, or as determined by Gurley (ISO 5636-5). The fiber section has a thickness at 1 MPa ranging from 10 to 10000 pm, particularly 100 to 300 pm, and a mass per unit area (DIN EN ISO 29073-1) ranging from 1 to 1000 g / m2, particularly 30 to 200 g / m2. The through-plane electrical resistance at 1 MPa ranges from 0.1 to 100 mfi cm, particularly 2 to 20 mfi cm2, and the in-plane electrical resistance ranges from 0.05 to 20 Q, particularly 0.5 to 2 Q.

[0118] In certain embodiments, the fiber section is made of a carbon fabric or carbon paper, particularly gas-permeable, such as ELAT — Hydrophilic Plain Cloth, 1071 HCB, Panex 30, Freudenberg H23, Spectracarb, Sigracet 39 AA, or AvCarb P75. Such carbon fabric or carbon paper has the same function as fiber-shaped material and may thus be used as an alternative to carbon fibers.

[0119] The fiber section provides a surface area of at least 10 to 50 cm2per geometrical cm2and may be electrically connected via conducting wires, needles (e.g., steel), or foils (e.g., nickel, aluminum, copper).

[0120] In certain embodiments, the fiber section is embedded in a polymer matrix, with an exposed portion ranging from 0.01 pm to 10 mm, particularly 0.5 pm to 1 mm, protruding into the sample. The polymer matrix may comprise an elastomer, thermoplastic, or thermosetting material, such as polystyrene, polycarbonate, polyacrylate, PMMA, PEGDA, polyethylene, polyurethane, ABS, nylon, PLA, PBI, PES, POM, PEEK, PEI, PPO, PPS, PP, PVC, PVDF, PTFE, or resins such as polyester, polyurethane, vulcanized rubber, bakelite, urea-formaldehyde, DAP, epoxy, novolac, benzoxazine, polyimide, bismaleimide, cyanate ester, furan, silicone, Thiolyte, or vinyl ester.

[0121] The fiber section 100 of the device 10 comprises an attachment layer configured for the immobilization of receptor molecules, which may be covalently attached or non-covalently immobilized via electrostatic, hydrophobic, van der Waals, or other intermolecular interactions. In certain embodiments, the surface of the fiber section 100 is functionalized with one or more moieties selected from C2-C20 alkyl chains comprising cationic groups (e.g., amino, C1-C4 alkylamino, carbamoyl), anionic groups (e.g., carboxyl, phosphate, phosphonate, sulfate), or neutral groups such as hydroxyl, C1-C20 alkyl, carbonyl, or sulfhydryl. Such functionalization may be achieved through methods known in the art, including but not limited to those described in Steeno et al. (Chem. Mater. 2020), Zhang et al. (J. Am. Chem. Soc. 2019), Nayak et al. (Springer 2018), and Khan and Nishina (Nanoscale 2021), which are incorporated herein by reference in their entirety for their teachings on surface modification techniques.

[0122] In various embodiments, the receptor molecules are covalently attached to the surface of the fiber section 100, enabling specific engagement with a biological particle (e.g., exosomes, cells, viruses, or other analytes) to facilitate effective capture and recovery. The attachment may be mediated via a hydrocarbon chain crosslinker having a length of 1 to 10A6 atoms, preferably 1 to 100 atoms or 1 to 20 atoms, wherein the crosslinker backbone may be hydrophobic (e.g., alkyl chains) or hydrophilic (e.g., polyethylene glycol) or PEG derivatives). The average density of receptor molecules on the surface is at least 10A10 to 10A13 moieties per cm2, although higher or lower densities may be employed depending on the application. In alternative embodiments, receptor molecules may be adsorbed onto the surface via physical spreading, potentially achieving higher densities than covalent attachment alone, and may interact with surface modifications such as amino-silanes (e.g., (3- aminopropyl)dimethylethoxysilane (APDMES) or (3-aminopropyl)triethoxysilane (APTES)) through ionic or other non-covalent bonds. For instance, IgG antibodies (approximately 156 kDa, with dimensions of about 14.5 x 8.5 x 4 nm) can provide a surface coverage of approximately 2.6 mg / m2in a side-on orientation, as calculated based on molecular footprint and packing efficiency.

[0123] In some embodiments, the surface of the fiber section 100 is coated with cationic moieties, such as alkylamines or aminoalkylsilanes (e.g., APTES, APMDES, APDMES), forming a monolayer, multilayer, or gradient coating to enhance receptor adhesion. Conjugation of receptor molecules may be achieved covalently or electrostatically using functional groups including, but not limited to, carboxylic acids, esters, amines, azides, carbonyls, hydroxyls, sulfonyls, epoxides, or N-hydroxysuccinimide (NHS) esters, as exemplified in Dennler et al. (Antibodies 2015), incorporated herein by reference for its disclosure of bioconjugation strategies. Electrostatic conjugation approaches may further involve conductive polymers such as polyaniline or polycationic peptides like polylysine to facilitate charge-based immobilization.

[0124] The receptor molecules immobilized on the fiber section 100 are selected to target specific markers on the biological particle. In exemplary embodiments for exosome capture, such markers include tetraspanins (e.g., CD9, CD63, CD81 , CD82, or CD86) or non-specific surface proteins and components such as CD16, CD18, CD14, CD13, monocarboxylate transporter 1 (MCT-1), Na / K ATPase, CD11b / Mac-1 , major histocompatibility complex (MHC) l / ll, interleukin-1 p (IL-1 |3), Flotillin-1 , integrins, annexins, or lipid-raft constituents (e.g., sphingolipids, cholesterol, ceramides). The fiber section 100 may comprise conductive materials suitable for electrode applications, including but not limited to carbon fibers, carbon nanotube yarns, graphene fibers, gold fiber microelectrodes, or combinations thereof, with surface immobilization strategies tailored to the substrate properties.

[0125] To enable robust and versatile immobilization of receptor molecules (e.g., antibodies, aptamers, peptides, or other binding agents) on the fiber section 100, a variety of chemical strategies may be employed. These strategies are categorized below for clarity, with conceptual applicability to the fiber materials described herein. One skilled in the art will appreciate that these methods can be adapted and combined as needed to optimize binding specificity, orientation, density, and stability without undue experimentation.

[0126] A. Classical Organic Surface-Functionalization Chemistries

[0127] 1. Silane Chemistry (Silanization): Organosilanes such as APTES, (3- glycidyloxypropyl)trimethoxysilane (GPTMS), or (3-mercaptopropyl)trimethoxysilane (MPTMS) form covalent Si-O-Si networks on hydroxylated surfaces, introducing functional groups like -NH2, -SH, -epoxy, or -COOH. These enable amide formation, epoxy-amine coupling, thiol chemistry, or electrostatic attraction for antibody immobilization. For carbon fibers, surfaces may be oxidized (e.g., via plasma or UV- ozone) to generate -OH groups for silane attachment. For gold fibers, silica coatings or sol-gel layers may be applied to support silanization.

[0128] 2. Epoxy-Functional Surface Chemistry: Epoxide-bearing surfaces react with nucleophilic residues (e.g., lysines) on antibodies. Epoxy groups may be introduced via functional polymers or silanes on carbon fibers, or self-assembled monolayers (SAMs) with thiol- linkers on gold fibers.

[0129] 3. Carbodiimide Chemistry (EDC / NHS-Type Coupling): Carboxyl groups are activated (e.g., using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and NHS) to form amide bonds with amines. Oxidized carbon fibers inherently provide -COOH groups, while gold fibers may use COOH-terminated thiol SAMs. 4. Aldehyde-Amine Coupling: Surface aldehydes react with antibody amines to form Schiff bases, optionally stabilized by reduction. Aldehydes may be generated on oxidized carbon or carbohydrate coatings (e.g., dextran, chitosan) for carbon fibers, or via aldehyde- functional thiol SAMs on gold.

[0130] 5. Maleimide-Thiol Chemistry: Maleimides selectively react with thiols from cysteines or reduced disulfides. Functional coatings (e.g., maleimide-PEG) suit carbon fibers, while maleimide-terminated thiol SAMs are applicable to gold.

[0131] 6. Isothiocyanate or NHS-Ester Functional Groups: These react with amines to form thiourea or amide linkages. Polymer layers with NHS-esters or isothiocyanates may be applied to carbon fibers, or SAMs of corresponding thiol derivatives to gold.

[0132] B. Bio-Orthogonal “Click” Reactions

[0133] 7. Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC): Azides and terminal alkynes form triazoles selectively. Azide- or alkyne-functional polymers coat carbon fibers, while functional thiols suit gold.

[0134] 8. Copper-Free Click (SPAAC): Strained cyclooctynes (e.g., dibenzocyclooctyne (DBCO), bicyclo[6.1.0]nonyne (BCN)) react with azides without copper. DBCO-PEG or azide-PEG coatings apply to carbon; DBCO-thiol SAMs to gold.

[0135] 9. Tetrazine-TCO Ligation: Tetrazines react rapidly with trans-cyclooctenes via inverseelectron demand Diels-Alder. TCO- or tetrazine-modified polymers for carbon; corresponding SAMs for gold.

[0136] C. Metallophilic & Coordination-Based Immobilization

[0137] 10. Gold-Thiol (Au-S) Bonding: Thiols bind strongly to gold for direct immobilization of thiolated antibodies or linkers. Applicable primarily to gold fibers; not directly to carbon unless gold-coated.

[0138] 11. Ni2+ / NTA or Co2+ / IDA I His-Tag Binding: His-tagged antibodies bind to metal-chelated surfaces. NTA-functional polymers or silanes for carbon; NTA-thiol SAMs loaded with Ni2+for gold.

[0139] 12. Metal-Phosphate (Zr*+Coordination): Zr(IV) coordinates phosphates on modified antibodies or linkers. Zr4+-binding polymers for carbon; phosphate-terminated SAMs with Zr4+for gold.

[0140] D. Polymer-Based Immobilization Strategies

[0141] 13. Polydopamine (Mussel-Inspired Coating): Dopamine polymerizes to polydopamine (PDA), providing catechols, quinones, and amines for reaction with antibodies. PDA adheres via TT-TT interactions to carbon and robustly to gold. 14. Electropolymerized Films: Conducting polymers (e.g., polyaniline, polypyrrole, PEDOT, polyphenols, polytyramine) grow directly on conductive fibers, enabling antibody entrapment or covalent attachment with tunable functionality.

[0142] 15. Layer- by- Layer (LbL) Polyelectrolytes: Alternating polycations (e.g., poly-L-lysine (PLL), polyethyleneimine (PEI)) and polyanions (e.g., polystyrene sulfonate (PSS), poly(allylamine hydrochloride) (PAH)) build multilayers for electrostatic or covalent antibody binding.

[0143] 16. PEG-Based Spacer Polymers: PEG minimizes nonspecific binding and provides functional ends (e.g., -NH2, -COOH, -biotin, -maleimide, -azide, -alkyne). PEG-silanes or polymers for carbon; PEG-thiol SAMs for gold.

[0144] 17. Polymer Brushes: Dense brushes (e.g., polyacrylic acid, polymethacrylate, poly(2- hydroxyethyl methacrylate) (polyHEMA), zwitterionic polymers) via grafted-from / to methods offer high loading. Initiators anchor to oxidized carbon or thiolated gold for polymerization (e.g., ATRP, SI-RAFT).

[0145] E. Biological & Affinity- Based Immobilization

[0146] 18. Protein A I Protein G Binding: These bind antibody Fc regions for oriented immobilization. Attached via linkers (e.g., amine-carboxyl, click) to carbon polymers or gold thiol- SAMs / NTA-His.

[0147] 19. Biotin-Streptavidin I Avidin Systems: High-affinity non-covalent binding for tunable orientation. Biotinylated surfaces or linkers for carbon; biotin-thiol SAMs or streptavidin on SAMs for gold.

[0148] 20. Lectin-Glycan Binding: Lectins target antibody glycans (e.g., Fc region). Immobilized on polymer coatings for carbon or lectin-functional thiol SAMs for gold.

[0149] F. Nanostructure-Assisted Immobilization

[0150] 21. Nanoparticle-Enhanced Binding: Pre-functionalized nanoparticles (e.g., AuNPs, carbon nanodots, polymer NPs) increase surface area. Attached electrochemically or covalently to carbon or gold fibers.

[0151] 22. Carbon Nanotube (CNT) or Graphene Coatings: Provide -OH, -COOH, epoxide groups. Covalent integration or deposition on carbon; polymer-mediated adhesion on gold.

[0152] G. Surface Activation & Oxidation Approaches

[0153] 23. Plasma or UV-Ozone Activation: Generates oxygen functionals (-COOH, -OH, -C=O) on carbon (effective for basal / edge planes); limited on gold but supports oxide / polymer attachment. 24. Electrochemical Activation: Anodic oxidation produces carboxylic acids on carbon electrodes; forms gold oxide films on gold for further chemistry.

[0154] 25. Diazonium Grafting: Aryl diazonium salts graft covalently, introducing groups like -NH2, - COOH, - N3, -alkyne, -biotin. Strong for carbon; forms multilayers on gold.

[0155] H. Less Common but Useful Immobilization Strategies

[0156] 26. Cyclodextrin Host-Guest Chemistry: Cyclodextrins host hydrophobic antibody anchors. Cyclodextrin-carbon composites or thiolated cyclodextrin SAMs.

[0157] 27. Imidoester Crosslinkers: React with amines for amidinium linkages (mild, reversible). On amine-primed surfaces for carbon polymers or aminated gold SAMs.

[0158] 28. Hydrazone I Oxime Ligations: Carbonyls react with hydrazides / aminooxy groups. Aldehyde / ketone coatings for carbon; SAMs with carbonyls for gold.

[0159] 29. Supramolecular Assemblies: Host-guest (e.g., cucurbiturils, calixarenes) or TT-TT stacking. Direct TT-TT on carbon; polymer linkers on gold.

[0160] I. Physical & Noncovalent Immobilization

[0161] 30. Hydrophobic Adsorption: Antibodies adhere to hydrophobic surfaces (e.g., polystyrene coatings). Innate on carbon; hydrophobic SAMs on gold.

[0162] 31. Electrostatic Adsorption: Exploits charge differences using charged polymers (e.g., PLL, poly(acrylic acid) (PAA)) on carbon or charged SAMs on gold.

[0163] 32. Entrapment in Porous or Gel Layers: Sol-gel matrices, hydrogels, or nanoporous oxides encapsulate antibodies. Silica coatings or hydrogels on carbon; patterned hydrogels on gold.

[0164] These immobilization strategies may be selected and optimized based on factors such as the fiber material, desired receptor orientation (e.g., Fab-outward for enhanced binding kinetics), environmental stability, and scalability for manufacturing. In preferred embodiments, combinations of these methods (e.g., initial surface activation followed by polymer coating and bio-orthogonal conjugation) are employed to achieve multifunctional surfaces with minimal nonspecific binding and high capture efficiency.

[0165] Insulation Section 101:

[0166] Advantageously, a protective layer of insulation 101 surrounds and isolates the fiber section 100 and the magnetic section 102.

[0167] This layer prevents undesired electrical interactions or cross-contamination during operation, ensuring the integrity of the particle capture and release processes. An optional insulation layer, disposed between the fiber section and the magnetic section, prevents electrical interference and comprises materials resistant to aqueous solutions, such as silicone, polymers, or flexible insulators, with a length ranging from 1 mm to 10 mm or more.

[0168] Magnetic Section 102:

[0169] This section allows the device to be manipulated in a solution using an external magnetic field, enabling effective mixing, positioning, and retrieval of the device during operation.

[0170] The magnetic section facilitates dynamic interaction with biological samples, enhancing the capture efficiency of the fibers.

[0171] A magnetic material, such as a neodymium magnet, forms the core of this section. In embodiments, the magnetic section comprises materials selected from the group consisting of neodymium iron boron, neodymium magnets, iron, and combinations thereof.

[0172] In embodiments, the magnetic section has a diameter of approximately 2 mm, a thickness of approximately 2 mm, and a weight ranging from 30 milligrams to 3 kilograms.

[0173] In embodiments, the magnetic section is positioned at a distance of 0 to 1 m, particularly 0 to

[0174] 1 pm or more, from the fiber section 100 while maintaining electrical conductivity.

[0175] Voltage Contact:

[0176] A dedicated contact point connects the device to an external voltage source.

[0177] This contact enables the application of controlled electrical potentials (positive or negative) to the carbon fibers, which facilitates the release of bound biological particles into a solution.

[0178] The contact is designed for reliable electrical connectivity and ease of integration with standard laboratory equipment. The electrical contact is connected directly, via a conductive magnetic section, or through an intermediate conductive element.

[0179] Integrated or Modular Design:

[0180] ■ The magnetic section and voltage contact can be combined into a single, integrated component or implemented as separate, discrete elements, depending on the application requirements.

[0181] ■ In various embodiments of the invention, the magnetic section and the voltage source contact may be integrated into a single unitary component or provided as separate, discrete components, depending on the requirements of the particular application.

[0182] In certain embodiments, the magnetic section and the voltage source contact are combined into one integrated component, wherein at least a portion of the surface of the magnetic section itself serves as the voltage source contact. In other embodiments, the magnetic section and the voltage source contact are implemented as separate components, particularly in applications where the magnetic section does not make direct electrical contact with the voltage source.

[0183] The magnetic section may be configured to induce rotational motion, translational motion, oscillatory motion, or any combination thereof in a target object or component.

[0184] Additionally or alternatively, the device (10) may comprise one or more of the following features, alone or in combination:

[0185] • the voltage source contact comprises a surface of the magnetic section; and / or

[0186] • the voltage source contact is a separate entity distinct from the magnetic section, particularly when the magnetic section is electrically isolated from the voltage source; and / or

[0187] • the magnetic section is configured to induce rotational, translational, and / or oscillatory motion, or combinations thereof.

[0188] These configurations provide manufacturing flexibility, reduce part count when integration is desired, and enable optimized electrical and magnetic performance in applications requiring physical or electrical separation of the magnetic and conductive functions.

[0189] This flexible design allows for easy customization of the device for specific use cases, such as batch or continuous operation in laboratory or clinical settings. In certain embodiments, the device is rod-like and has a length of about 1 mm to 12 mm or more. It is suitable for use in low sample volumes (approximately 0.1 pL to 1 mL) as well as larger volumes (approximately 1 mL to 100 L), including applications involving multi-well plates. The device may further include a counter electrode and / or a reference electrode, which may be integrated with or separate from the device body and positioned at a distance of approximately 1 pm to 1000 mm, preferably about 10 pm to 10 mm, from the fiber section. This configuration enables electrochemical analyses such as cyclic voltammetry. In certain embodiments, the fiber section functions as a working electrode with an area of approximately 10 mm2and is paired with a counter electrode having an area of approximately 1 mm2and a reference electrode having an area of approximately 0.24 cm2. The counter electrode may comprise a platinum wire, while the reference electrode may include a silver / silver-chloride coating. In some embodiments, the device comprises an insulating tube of approximately 1 cm in length encasing conductive fibers of approximately 1 cm in length and about 7 pm in diameter, assembled together with a neodymium magnet measuring approximately 2 mm x 2 mm. In certain embodiments, the silver / silver-chloride coating on the reference electrode is dried at approximately 60 °C for about 30 minutes. In additional embodiments, the device (10) is integrated into an electrochemical system as a working electrode, facilitated by the low resistivity of the fiber section (e.g., less than approximately 30 Q / cm). In certain embodiments, the device is further incorporated into a system comprising a magnetic field source — such as a magnetic stirrer, plate, or coil — capable of providing a magnetic field of approximately 0.01 T to 1 T at rotational speeds between about 100 and 10,000 RPM.

[0190] Operation in a Biological Sample

[0191] The device is introduced into a biological sample, see e.g. FIG. 7. These biological fluids include, but are not limited to: cell culture, Blood, Plasma, Serum, Lymph, Urine, Sweat, Seminal Fluid (Semen), Vaginal Secretions, Amniotic Fluid, Saliva, Gastric Juice, Bile, Pancreatic Juice, Intestinal Fluid, Chyme, Mucus (from respiratory tract), Pleural Fluid, Cerebrospinal Fluid (CSF), Aqueous Humor (in the eye), Vitreous Humor (in the eye), Pus, Synovial Fluid (in joints), Milk, Tears, Sebum (from sebaceous glands), Cerumen (earwax), Pericardial Fluid, Peritoneal Fluid, Ascitic Fluid.).

[0192] A magnetic stirrer or similar apparatus is used to generate a rotating magnetic field, which induces the device to rotate and mix the biological solution. This mixing enhances the interaction between the device's functionalized carbon fibers and the biological particles in the sample.

[0193] Targeted biological particles in the solution, such as extracellular vesicles, exosomes, viruses, bacterial particles or other particles of interest, bind specifically to the functionalized carbon fibers through receptor-ligand interactions.

[0194] Alternatively, the device can effectively capture biological particles without relying on an external magnetic field. This can be achieved by:

[0195] Manually stirring the biological solution containing the device.

[0196] Utilizing mechanical mixing tools such as rockers, rotators, orbital shakers, or mixers.

[0197] Employing other suitable equipment to agitate the solution and facilitate interaction between the device and the biological sample.

[0198] These alternative methods ensure efficient mixing and thorough exposure of the functionalized carbon fibers to the biological sample, enabling effective capture of the targeted biological particles regardless of the mixing mechanism. The receptor-particle interaction is characterized by a dissociation constant (K_D) of < 10'5M, particularly < 10'6M to < 10'15M.

[0199] Washing and Cleaning

[0200] The device is transferred to washing solutions to remove non-specifically bound materials, ensuring high specificity in the isolated particles.

[0201] Washing can include rinsing with phosphate-buffered saline (PBS) or similar solutions to eliminate residual biological materials and minimize contamination. Additional washes with distilled water or deionized water can be performed to remove salts or other dissolved impurities that might interfere with downstream applications.

[0202] The device can also be cleaned with detergents or surfactants, such as Triton X-100, when necessary, to eliminate lipid residues or tightly adhered particles.

[0203] Acidic or basic cleaning solutions can be used to neutralize and remove stubborn contaminants while maintaining the integrity of the functionalized carbon fibers.

[0204] For reusability, the device can undergo cleaning cycles in ethanol or other sterilizing agents to decontaminate and prepare it for subsequent use.

[0205] Ultrasonic cleaning in appropriate washing solutions can be employed for thorough removal of particles from the fiber surface without damaging the functional coating.

[0206] In specialized applications, enzymatic cleaning solutions may be used to degrade and remove protein-based impurities from the device. This comprehensive washing and cleaning protocol ensures that the device maintains high performance, specificity, and reusability across multiple cycles of use.

[0207] Particle Release

[0208] The device is placed in a small volume of release solution.

[0209] A negative voltage is applied to the carbon fibers, causing the release of bound particles into the solution.

[0210] Alternatively, a positive voltage can be applied to the carbon fibers to induce the release of bound particles, depending on the electrochemical properties of the particles and their interaction with the receptor molecules on the fiber surface.

[0211] The release process is optimized to maintain the integrity and functionality of the biological particles, making them suitable for downstream applications such as diagnostics, therapeutic development, or research.

[0212] The device can be used to release captured extracellular vesicles, exosomes, viruses, or bacterial particles for subsequent characterization using techniques such as dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), or flow cytometry.

[0213] The released particles can be processed for biochemical or genetic analysis, such as protein profiling or RNA / DNA extraction, to enable detailed molecular characterization. In addition to simple particle release, the device can be employed in biofunctionalization workflows, where released particles can interact with secondary agents like drug-loaded carriers or gene-editing systems for therapeutic applications. The device allows for controlled sequential release, enabling the selective elution of different particle populations based on their specific binding properties. This functionality is particularly useful in applications requiring the separation of particle subpopulations.

[0214] The device can also be integrated into microfluidic systems to enable continuous or automated release and collection of particles for high-throughput analysis.

[0215] The electric potential applied during the release process can be adjusted to modulate the interaction strength between the fibers and the particles, providing a customizable release mechanism for diverse particle types. The release potential ranges from -3 V to +3 V, -30 V to +30 V, or -300 V to +300 V or more, while preserving the integrity of the biological particle. For negatively charged particles, a potential of -1 .6 V is preferred, with potentials below -3 V risking particle destruction; suitable ranges are -0.1 V to -2.0 V, particularly -0.2 V to -1.8 V. For positively charged particles, potentials above +2 V risk destruction; suitable ranges are +0.1 V to +2.0 V, particularly +0.2 V to +1.8 V. Local pH changes due to electrolysis may contribute to release by inducing conformational changes in the receptor-particle complex. Higher potentials risk decomposition of the biological particle. A retention potential, ranging from +3 V to -3 V, particularly +2 V to -2 V, +1.5 V to -1.5 V, or +1 V to -1 V, opposite in polarity to the release potential, may be applied to enhance binding.

[0216] Optional Analysis

[0217] The device can be utilized for a wide range of biological analyses, including but not limited to:

[0218] Electrochemical Analysis: The device can function as an electrode in a multi-electrode setup to identify bound particles based on their unique electrochemical signatures.

[0219] Microscopy-Based Analysis: Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Confocal Microscopy, Fluorescence Microscopy

[0220] Spectroscopy and Scattering Techniques: Dynamic Light Scattering (DLS), Multi-Angle Light Scattering (MALS), Static Light Scattering (SLS), Nanoparticle Tracking Analysis (NTA), Nuclear Magnetic Resonance (NMR) Spectroscopy.

[0221] Molecular and Omics Analysis: Proteomics (e.g., protein profiling, Western blot), Genomics (e.g., DNA analysis, Southern blot), Transcriptomics, Lipidomics, Multiomics Integration.

[0222] Immunoassays and Molecular Detection: Enzyme-Linked Immunosorbent Assay (ELISA), All blotting techniques, including Northern blot, Southern blot, and Western blot

[0223] Mass Spectrometry-Based Analysis: Tandem Mass Spectrometry (MS-MS), Matrix-Assisted Laser Desorption / lonization (MALDI) Other Advanced Techniques: Raman Spectroscopy, Surface Plasmon Resonance (SPR), Flow Cytometry, Isothermal Titration Calorimetry (ITC), Cryo-Electron Microscopy (Cryo-EM). The versatility of the device enables its use in diverse research applications, including molecular diagnostics, particle characterization, therapeutic development, and advanced analytical workflows in biological and chemical sciences. In certain embodiments, the system enables on-device analysis, selectively detecting low-abundance biomarkers without requiring centrifugation, desalting, or affinity columns, with a processing time of less than 24 hours, preferably less than 180 minutes, 30 minutes, 10 minutes, 5 minutes, or 1 minutes.

[0224] Particle Transformation

[0225] The device can be immersed in a solution containing drug- or gene-loaded materials, such as liposomes, nanoparticles, or cationic polymers. These materials interact with the captured biological particles, facilitating the creation of therapeutic formulations.

[0226] Excess unreacted materials are washed away, and the modified particles are released into a clean solution, ready for downstream applications.

[0227] The device can also be used for surface functionalization of captured particles, where the particles are exposed to specific ligands, peptides, or targeting molecules. These functionalized particles can then be used for targeted drug delivery, imaging, or diagnostic purposes.

[0228] The captured particles can undergo biochemical labeling by immersing the device in a solution containing fluorescent dyes, isotopic labels, or enzymatic tags. This transformation is particularly useful for bioimaging and tracking studies.

[0229] The device enables genetic modification of particles, such as transfection of captured extracellular vesicles with specific plasmids, RNA, or CRISPR-Cas components for gene therapy or research applications.

[0230] The captured particles can be subjected to encapsulation processes, where they are integrated into biocompatible carriers such as hydrogels or polymeric microspheres. These carriers enhance particle stability and control the release profile for therapeutic use.

[0231] The device allows co-delivery customization, where captured particles are combined with complementary payloads, such as adjuvants or co-stimulatory agents, to enhance therapeutic efficacy, especially in vaccine development.

[0232] The device can facilitate enzymatic modification of particles by immersing them in enzymecontaining solutions, enabling processes such as glycosylation, deglycosylation, or protease cleavage for research or therapeutic applications. The device may also enable composite particle formation, where captured particles are combined with inorganic materials such as gold nanoparticles, quantum dots, or magnetic nanoparticles, creating multifunctional hybrid particles for diagnostics, therapy, or theranostics.

[0233] Specific Embodiments or Variations

[0234] Material Variations

[0235] Fiber Section:

[0236] While carbon fibers are the primary material for the fiber section, other conductive and functionalizable materials may be used. These include:

[0237] Graphene sheets or graphene oxide, offering high surface area and electrical conductivity.

[0238] Carbon nanotubes (CNTs), which provide structural flexibility and enhanced conductivity.

[0239] Metal nanowires, such as gold, silver, or platinum, which are biocompatible and support electrochemical modifications.

[0240] Conductive polymers, such as polyaniline (PAN I) or polypyrrole, which are tunable and offer electrochemical activity. ■ Functionalized synthetic fibers coated with conductive materials or bio-compatible surfaces.

[0241] Magnetic Section:

[0242] The magnetic section may incorporate various materials to enhance magnetic responsiveness, including: ■ Neodymium or ferrite materials for strong and stable magnetic properties. ■ Iron or iron oxide nanoparticles embedded in a polymer matrix to provide flexible and lightweight magnetic properties. ■ Cobalt alloys or samarium-cobalt for high-temperature stability and robust magnetic fields. ■ Soft magnetic composites (SMCs), which minimize eddy current losses for dynamic applications.

[0243] Structural Materials:

[0244] The insulation and structural components of the device may utilize: ■ Silicone, for its flexibility and chemical resistance. ■ Polymeric materials such as polyethylene terephthalate (PET) or polycarbonate for strength and transparency. ■ Biodegradable polymers, such as polylactic acid (PLA) or polycaprolactone (PCL), for single-use applications. ■ Glass or quartz for chemically inert and heat-resistant components. These material variations allow the device to be customized for specific applications, including improved biocompatibility, enhanced sensitivity, and tailored operational environments.

[0245] Functionalization Adaptations

[0246] Receptor Customization: Receptors on the fibers can be tailored for specific applications, including: ■ Antibodies: For targeting specific disease biomarkers, tissue, cells, viral particles, bacterial particles or extracellular vesicles such as exosomes. ■ Aptamers: For high-affinity binding to viral particles, proteins, or nucleic acids. ■ Peptides: For interaction with bacterial cells or specific protein domains. ■ Small Molecule Ligands: For capturing metabolites or environmental toxins. ■ Nucleic Acids: For hybridization-based capture of DNA, RNA, or microRNA molecules. ■ Enzymes: For binding substrates of interest or detecting enzymatic activity.

[0247] Surface Modifications for Enhanced Functionality:

[0248] Electrostatic Functionalization: Using charged polymers or groups to interact with oppositely charged particles such as polyanionic exosomes or cationic proteins.

[0249] Hydrophobic Interactions: Functionalizing with hydrophobic molecules to enhance interaction with lipid-based particles or amphiphilic compounds.

[0250] Magnetic Nanoparticles: Incorporating additional functionalized magnetic particles for dualfunction capture and enhanced device manipulation.

[0251] Multiplexed Functionalization: Coating the fibers with multiple receptor types to enable simultaneous capture of diverse target particles within a single sample.

[0252] Environment-Specific Adaptations: Tailoring receptors to operate effectively in complex matrices, such as blood plasma, cerebrospinal fluid, or environmental water samples.

[0253] Catalytic Functionalization: Incorporating catalytic receptors to not only capture but also chemically transform target particles (e.g., enzymatic cleavage of biomarkers for signal amplification). ■ Therapeutic Applications: Functionalizing the fibers with drug-loaded liposomes or gene delivery vehicles for applications in targeted delivery or in vitro therapeutic modeling.

[0254] Signal Reporting Functionalization: Attaching fluorophores, electrochemical probes, or nanoparticles for real-time monitoring of capture efficiency or target identification. Receptor molecules may include antibodies, antibody-like molecules, aptamers, or DARPins. If the biomolecule is an antibody, the antigen is attached. Antibodies may be gamma immunoglobulins, Fab fragments, diabodies, or nanobodies. In certain embodiments, the biomolecule is a membrane protein within an extracellular vesicle membrane. In certain embodiments, the receptor molecules comprise antibodies specific to biomarkers such as CD171, CD3, or combinations thereof with other antibodies, such as anti-CD9 or anti-CD81. The surface may be functionalized with a mixture of receptor molecules targeting multiple biomarkers, such as anti-CD81 , anti-CD9, anti-CD171, and anti-CD3 antibodies, to capture subpopulations of extracellular vesicles. Device Scaling

[0255] The device is versatile and can be adapted to various scales and applications: ■ Larger Samples: The device can be scaled up for industrial applications, enabling the processing of larger biological samples in batch or continuous flow systems. ■ Miniaturized Systems: The device can be miniaturized for integration into microfluidic platforms, allowing for precise and automated handling of small sample volumes in high-throughput settings. ■ Multi-Well Applications: The device can be configured for use in multi-well plates, enabling parallel separation of multiple samples simultaneously. This adaptation is particularly beneficial for high-throughput analysis in research and clinical diagnostic settings. ■ Array Configurations: The device can be deployed in arrayed systems, where multiple devices operate concurrently under a single magnetic stirring mechanism, increasing throughput without significantly increasing operational complexity. ■ Automated Systems: The device can be incorporated into robotic or automated platforms, enhancing efficiency and reproducibility in laboratory or industrial workflows. ■ Disposable and Single-Use Designs: For specific applications, the device can be fabricated as a disposable unit, ensuring sterility and reducing crosscontamination risks. These scaling options make the device suitable for a wide range of applications, from small-scale laboratory experiments to large-scale industrial processes.

[0256] Integration with Analytical Systems:

[0257] ■ The device may be integrated into automated systems for real-time diagnostics or therapeutic production. Therapeutic Loading Applications ■ The device can separate biological particles, such as extracellular vesicles, exosomes, or viruses, and load them with therapeutic agents, including but not limited to DNA, RNA, proteins, peptides, small-molecule drugs, or CRISPR components. The modified particles can then be released for use in gene therapy, targeted drug delivery, or regenerative medicine. ■ The device can encapsulate therapeutic agents into biological particles to improve their stability, bioavailability, and cellular uptake for enhanced therapeutic outcomes. ■ The device can facilitate the conjugation of biological particles with targeting ligands, such as antibodies, aptamers, or other receptor-specific molecules, to enhance precision targeting in cancer therapy, immune modulation, or other disease treatments. ■ The device can be used to load nanoparticles, such as liposomes or polymeric carriers, onto biological particles, creating hybrid delivery vehicles for complex therapies, such as combination treatments of drugs and genetic material. ■ The device enables the attachment or integration of immunomodulatory agents, such as cytokines or checkpoint inhibitors, to biological particles for use in immune therapy applications. ■ The device can facilitate the preparation of functionalized biological particles for use in vaccines, where therapeutic payloads can be delivered to specific cells to stimulate a controlled immune response. ■ The device can enable the incorporation of photodynamic or photothermal therapeutic agents into biological particles, providing novel tools for cancer treatment using light-activated therapies. ■ The device can be employed in loading exosomes or other vesicles with diagnostic probes, such as fluorescent markers or imaging agents, for combined therapeutic and diagnostic (theranostic) applications.

[0258] Types of Biological Particles Captured, Released, Modified, and Sensed by the Device The device described in this patent application is designed for versatile application across a wide range of biological particles. Its innovative combination of functionalized carbon fibers, magnetic motion, and controlled voltage application enables the following types of biological particles to be effectively captured, released, modified, and sensed: 1. Extracellular Vesicles (EVs): Includes subtypes such as exosomes, microvesicles, and apoptotic bodies. These particles are released by cells and play significant roles in intercellular communication. Applications: Diagnostics (e.g., cancer biomarkers), therapeutic delivery, and basic research. 2. Viruses: Encompasses enveloped and non-enveloped viruses, such as HIV, influenza, SARS-CoV-2, and others. Applications: Viral detection and identification, vaccine development, and therapeutic targeting. 3. Bacteria and Bacterial Particles: Includes whole bacterial cells, outer membrane vesicles (OMVs), and bacterial fragments. Applications: Bacterial detection, antimicrobial testing, and environmental monitoring. 4. Nucleic Acid-Bound Complexes: DNA- and RNA-associated particles such as ribonucleoproteins (RNPs) or chromatin fragments. Applications: Genomic studies, epigenetic research, and nucleic acid therapeutic delivery. 5. Lipoproteins: Includes low-density lipoproteins (LDL), high-density lipoproteins (HDL), and other lipid-protein complexes. Applications: Cardiovascular disease research and lipidomics. 6. Protein Complexes and Aggregates: Examples: Amyloid fibrils, heat shock protein aggregates, and receptor-ligand complexes. Applications: Neurodegenerative disease research, drug screening, and protein-protein interaction studies. 7. Cellular Organelles and Fragments: Includes mitochondria, nuclei, lysosomes, and other cellular components. Applications: Organelle-specific research, cellular metabolism studies, and drug development. 8. Pathogenic Particles: Includes prions, fungal spores, and protozoan cysts. Applications: Pathogen detection, environmental surveillance, and infectious disease research. 9. Synthetic and Hybrid Biological Particles: Includes synthetic nanoparticles functionalized with biological molecules (e.g., liposomes, dendrimers, and polymeric particles). Applications: Drug delivery systems, nanomedicine, and hybrid therapeutic development. 10. Biodebris and Cellular Waste Products: Includes apoptotic blebs, necrotic cell debris, and oxidized macromolecules. Applications: Cell death research, immune response studies, and bioremediation. 11. Therapeutically Modified Particles: Particles modified with therapeutic agents, such as drug-loaded exosomes or gene-edited vesicles. Applications: Precision medicine, genetic therapies, and drug discovery. 12. Rare and Specialized Particles: Includes fetal-derived extracellular vesicles, circulating tumor cells (CTCs), and parasite-derived vesicles. Applications: Prenatal diagnostics, cancer monitoring, and parasitology. 13. Environmental and Agricultural Samples: Bioparticles found in environmental or agricultural samples, including plant-derived vesicles and microbial spores. Applications: Environmental monitoring, agricultural biotechnology, and bioengineering. The biological particles may include extracellular vesicles (30-5000 nm), exosomes (30-150 nm), microvesicles (100-1000 nm), apoptotic bodies (0.5-5 pm), viruses (20-300 nm), bacterial particles (0.5-5 pm), bacterial membrane vesicles (20-400 nm), spores (0.5-2 pm), ribosomes (20-30 nm), protein aggregates or amyloid fibrils (5-200 nm width), liposomes (50-1000 nm), mitochondria (0.5-3 pm), lysosomes or endosomes (50-500 nm), nanobacteria (80-200 nm), cell-free nucleic acid complexes (<10-100 nm), prions (10-100 nm), lipoproteins (e.g., LDL, HDL), cellular organelles (e.g., nuclei), biodebris (e.g., apoptotic blebs, necrotic debris), rare particles (e.g., circulating tumor cells, fetal-derived vesicles), and combinations thereof. In certain embodiments, the isolated biological particle is an extracellular vesicle, a eukaryotic or prokaryotic cell, a virus, or another particle presenting a biomolecule. The device is configured to separate and / or detect at least one biomarker, up to 100, 1000, 10000, or more biomarkers.

[0259] Method for Isolating Biological Particles According to a first aspect of the present invention, there is provided a method for isolating a biological particle from a liquid sample. The biological particle may be suspended in the liquid sample and may include an extracellular vesicle, a microvesicle, an apoptotic body, a virus, a bacterial particle, a spore, a ribosome, a protein aggregate, a liposome, a mitochondrion, a lysosome, an endosome, a nanobacterium, a cell- free nucleic acid complex, a prion, a lipoprotein, a cellular organelle, biodebris, or a rare particle such as a circulating tumor cell or a fetal-derived vesicle. The method comprises a binding step, an optional washing step, and a release step, and may further include a modification or loading step. In the binding step, the liquid sample containing the biological particle is contacted with a surface provided by a fiber section. The surface is configured to retain the biological particle through chemical functionalization, such as attachment of receptor molecules enabling specific binding. The receptor molecules are selected from the group consisting of antibodies, aptamers, peptides, ligands specific to the biological particle, and combinations thereof. To facilitate interaction, a magnetic section is provided to induce motion in response to an external magnetic field, such as rotational, translational, or oscillatory motion. In certain embodiments, the surface comprises receptor molecules configured for specific, non-covalent binding to the biological particle, such as antibodies immobilized on the surface. The fiber section functions as an electrode, wherein the specific receptor-particle interaction may be disrupted by applying a release potential to facilitate release of the biological particle. During the binding step, the biological particle binds to the surface via the receptor molecules. Motion may be induced without magnetic fields through physical mixing, such as by rockers, rotators, orbital shakers, or static diffusion. In an optional washing step, the liquid sample is removed, and the surface is contacted with a washing solution selected from the group consisting of phosphate-buffered saline, distilled water, deionized water, detergents (e.g., Triton X-100), ethanol, sterilizing agents, acidic or basic solutions, enzymatic cleaners, and combinations thereof, to remove impurities and enable reusability. A release solution is provided to collect the biological particle. In the release step, a release potential is applied to the surface via an electrical contact connected to a voltage source, thereby releasing the biological particle. The biological particle is collected in the release solution, completing the isolation process in approximately 10 minutes or less. According to the invention, the surface is provided by an electrically conductive fiber section with microscale or nanoscale features, enabling high packing density for receptor molecule attachment and efficient recovery of biological particles. In certain embodiments, the method further comprises a loading step to incorporate cargo molecules into the biological particle, wherein the cargo molecules are retained without diffusion absent disruption. The loading step is performed after binding and before release, wherein the surface is contacted with a loading solution comprising therapeutic agents selected from the group consisting of drug-loaded liposomes, gene-delivery polymers, targeting ligands, immunomodulatory agents (e.g., cytokines, checkpoint inhibitors), photodynamic agents, photothermal agents, diagnostic probes, and combinations thereof. A loading voltage, opposite in polarity to the release potential and ranging from -300 V to +300 V, is applied to facilitate incorporation of the cargo molecules. The modified biological particles are subsequently released for downstream applications, including drug delivery, vaccination, immunoactivation, chemotherapy, immunotherapy, gene delivery, cancer therapy, immune modulation, theranostics, and combinations thereof. The method establishes a reversible affinity system wherein biological particles bound by receptor molecules are captured and released through application of an electrical potential.

[0260] Method for Loading Biological Particles According to another aspect of the present invention, there is provided a method for loading a biological particle, such as an extracellular vesicle, with a cargo molecule. The method comprises contacting a surface provided by an electrically conductive fiber section with an aqueous medium containing the biological particle and the cargo molecule, and applying a loading voltage to the surface to facilitate entry of the cargo molecule into the biological particle. In certain embodiments, the cargo molecule is selected from the group consisting of pharmaceutical drugs, proteins, nucleic acids, dyes, small molecule drugs, nucleic acid oligomers (ranging from 10 to 150 nucleotides, including siRNA, shRNA, antisense oligonucleotides with thioate bonds or Locked Nucleic Acid moieties), and combinations thereof. In certain embodiments, the loading voltage ranges from -350 V to -50 V or +350 V to +50 V, particularly -300 V to -100 V or +300 V to +100 V, applied as bursts of 0.5 ms to 5 ms, particularly 1 ms, with 2 to 20 bursts.

[0261] Device for Isolating Biological Particles According to a second aspect of the present invention, there is provided a device for isolating a biological particle, comprising a fiber section configured to receive the liquid sample, wherein the surface comprises conductive fibers, optionally embedded in an insulating matrix, functionalized with receptor molecules. The device further comprises a magnetic section for inducing motion, an electrical contact for connection to a voltage source, and optional counter and / or reference electrodes.

[0262] Advantages and Applications The device provides high-throughput purification using three- dimensional microfibers with a high surface area within a fluidic channel. The fibers are conjugated with affinity agents, such as antibodies, antibody fragments, nanobodies, DARPins, lectins, or aptamers, enabling specific separation. Release is achieved by applying a voltage, requiring no additional steps. The design prevents blockage and allows processing within 10 minutes, with optimization for automation. Advantages include ease of use, rapid processing, high throughput, high yield, reproducibility, cost-effectiveness, and the ability to process both small and large clinical samples with high purity. The method and device enable therapeutic investigation and manipulation for drug delivery applications, providing a fast, efficient, and cost-effective solution for particle isolation, purification, and modification across a broad range of sample types and volumes, with potential as a standard for laboratory comparisons.

[0263] Description of the Figures

[0264] The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.

[0265] FIG. 1 is a schematic illustration of an exemplary side view of a device 10 for capturing biological particles, according to embodiments of the present invention. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section.

[0266] FIG. 2 is a schematic illustration of an exemplary cross-section of a device for capturing biological particles, according to embodiments of the present invention. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section.

[0267] FIG. 3 is a schematic illustration showing an exemplary top view (top) and bottom view (bottom) of a device for capturing biological particles, according to embodiments of the present invention. The labeled components are: 100 - fiber section, 101 — insulation section, 102 - magnetic section.

[0268] FIG. 4 is an image of the side view of the device standing on its magnetic section. The labeled components are: 100 - fiber section, 101 - insulation section.

[0269] FIG. 5 is an image of the device lying on its side with the magnetic section facing the camera. The labeled components are: 101 - insulation section, 102 - magnetic section.

[0270] FIG. 6 is an image of the device lying on its side with the fiber section facing the camera. The labeled components are: 100 - fiber section. FIG. 7 is an image of device in a biological sample, specifically urine, capturing biological particles. The magnetic field from a stirrer causes the device to rotate in the solution like a magnetic stirrer, while the carbon fibers capture biological particles such as extracellular vesicles. The labeled components are: 100 - fiber section, 101 — insulation section, 102 - magnetic section, 103 - magnetic stirring plate, 104 - biosample, 105 - test tube containing the biosample.

[0271] FIG. 8 is an image of the device next to a connecting cable for the power source that supplies voltage. The device attaches to the power source receiver via magnetic attraction. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section, 106 - voltage source contact, 107 - insulation for voltage source wire.

[0272] FIG. 9 is an image of the device attached to the voltage source wire using magnetic attraction. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section, 106 - voltage source contact, 107 - insulation for voltage source wire.

[0273] FIG. 10 is an image of the device placed inside an Eppendorf tube containing 50 microliters of a solution for releasing biological particles, such as deionized water, biological particles are released by applying a negative voltage to the device and a positive voltage to a counter electrode. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section, 106 - voltage source contact, 107 - insulation for voltage source wire, 108 - counter electrode, 109 - counter electrode insulation, 110 - Eppendorf tube, 111 - solution for released biological particles.

[0274] FIG. 11 is an image of the device connected to a voltage source during the release of biological particles. A current flows between the carbon fibers of the device, connected to the negative terminal, and a counter electrode, connected to the positive terminal. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section, 106 - voltage source contact, 107 - insulation for voltage source wire, 108 - counter electrode, 109 - counter electrode insulation, 110 — Eppendorf tube, 111 - solution for released biological particles, 112 - device for applying voltage and measuring current, 113 - positive voltage wire, 114 - negative voltage wire, 115 - current measured during bioparticle release.

[0275] FIG. 12 is an image of the device in a three-electrode electrochemical cell array, containing a solution for electrolysis, a reference electrode, and a counter electrode. This setup allows identification of biological particles adsorbed to the device’s fibers. The labeled components are: 100 - fiber section, 101 - insulation section, 102 - magnetic section, 106 - voltage source contact, 107 - insulation for voltage source wire, 108 - counter electrode, 109 - counter electrode insulation, 116 - reference electrode.

[0276] FIG. 13 depicts a Dynamic Light Scattering (DLS) measurement of particles released from the device. The device captured biological particles from urine for 10 minutes, and these particles were released into deionized water by applying a negative potential. The DLS result shows a single peak around 100 nm, indicative of nanosized particles such as exosomes, a subgroup of extracellular vesicles. The device was conjugated with anti-CD9 antibodies, enabling specific capture of extracellular particles from the biological solution. The plot presents the hydrodynamic diameter (nm) along the horizontal axis and the number intensity (%) along the vertical axis. In this example, 50 mL of urine served as the biological sample.

[0277] FIG. 14 illustrates representative dynamic light scattering (DLS) measurements of extracellular vesicles (EVs) released from the device after EV capture from various biological samples and subsequent release into deionized water upon application of a 3 V potential between the device and a counter-electrode. The horizontal axis indicates hydrodynamic diameter (nm), and the vertical axis indicates particle number (%). (A) DLS profile of particles captured from 500 mL of milk over 30 minutes using a device functionalized with anti-CD81 antibodies and subsequently released into deionized water, showing a single peak at approximately 113 nm. (B) DLS profile of particles captured from 20 pL of whole blood over 10 minutes using a device functionalized with anti-CD9 antibodies and subsequently released into deionized water, showing a single peak at approximately 84 nm. (C) DLS profile of particles captured from 200 pL of plasma over 10 minutes using a device functionalized with anti-CD9 antibodies and subsequently released into deionized water, showing a single peak at approximately 83 nm.

[0278] FIG. 15 illustrates representative SEM (panel A) and cryo-TEM (panel B) images of extracellular vesicles (EVs) purified using the disclosed device. (A) SEM image of urine-derived EVs captured on the device’s micro-carbon fibers and visualized using a secondary electron detector. Nanoparticles of approximately 100 nm in diameter are observed on the fiber surfaces. (B) Cryo-TEM image of plasma-derived EVs. Particles having diameters of approximately 100 nm are visible, and their characteristic double-membrane morphology is evident, as typical for cryo-TEM imaging of EVs.

[0279] FIG. 16 illustrates DLS measurements of particle populations sequentially released from a single device in response to incrementally increased applied voltages. The horizontal axis represents hydrodynamic diameter (nm), and the vertical axis represents particle number (%). Biological particles were captured from 500 mL of milk over a 30-minute capture interval and subsequently released into deionized water by applying potentials between 0.25 V and 4.4 V across the device and a counter electrode. The DLS profiles show voltage-dependent particle size distributions, including populations exhibiting peaks at approximately 80 nm at 0.25 V and 1.85 V, and populations exhibiting peaks at approximately 228 nm and 361 nm at 3.0 V and 4.4 V, respectively.

[0280] FIG. 17 Characterization of EVs loaded with Nile red using the disclosed device. (A) Fluorescence spectra of free Nile red (line 1 , ▲) and Nile red associated with EVs captured on an anti-CD81 -modified device (line 2, •). The horizontal axis represents wavelength (nm) and the vertical axis represents fluorescence intensity. The device was sequentially incubated in milk to capture EVs and in a Nile-red loading solution, followed by application of a release voltage to elute Nile-red-loaded EVs into deionized water. A spectral maximum shift from approximately 620 nm (free Nile red) to approximately 670 nm (EV-associated Nile red) indicates incorporation of Nile red into the EV lipid membranes. (B) DLS measurement of Nile-red-loaded EVs released into deionized water following sequential incubation of the anti-CD81 -modified device in milk and the Nile-red loading solution. The horizontal axis represents hydrodynamic diameter (nm) and the vertical axis represents number intensity (%). The DLS profile exhibits a single peak at approximately 270 nm, which is larger than the typical size of milk-derived EVs (approximately 113 nm, FIG. 14A).

[0281] FIG. 18 illustrates representative western blot analyses comparing raw biological samples with extracellular vesicles (EVs) purified using the disclosed device. Panels (A), (B), and (C) show western blot results for samples derived from blood, urine, and milk, respectively. In each panel, lane 1 corresponds to the raw (unprocessed urine or plasma) biological sample, and lane 2 corresponds to the EV fraction purified from the corresponding sample. In panels (A) and (B), the EV marker CD9 is detected in the purified EV fractions (A2, B2) but is not detected in the respective raw samples (A1 , B1). In panel (C), the EV marker TSG101 is detected in the EV fraction purified from milk (C2). A prominent albumin band is present in the raw plasma sample (A1) and is absent in the corresponding purified EV fraction (A2)

[0282] FIG. 19 (A) Dynamic light scattering (DLS) analysis of polylysine:siRNA-loaded extracellular vesicles (EVs) released into deionized water following sequential incubation of an anti-CD81 -modified capture device in milk and subsequently in a polylysine:siRNA loading solution. The horizontal axis represents hydrodynamic diameter (nm) and the vertical axis represents number percentage. The DLS profile shows a single population with a peak centered at approximately 74.33 nm and a standard deviation of 51.96 nm. (B) Zeta potential measurement of the polylysine:siRNA-loaded EVs in deionized water, exhibiting a zeta potential of 27.8 mV and a zeta deviation of 5.71 mV.

[0283] FIG. 20 illustrates LC-MS / MS proteomic profiling of extracellular vesicles (EVs) isolated from raw urine and raw blood obtained from the same individual. A total of 968 proteins were identified in urine-derived EVs, and 1 ,138 proteins were identified in blood- derived EVs. Analysis of protein overlap, as represented in the Venn diagram, revealed 651 proteins common to both urine- and blood-derived EVs. Among the identified proteins, 680 proteins from urine-derived EVs and 663 proteins from blood- derived EVs were annotated as extracellular vesicle-associated proteins (G0:0031982). Notably, canonical EV and exosome markers, including CD9, TSG101 , and CD63, were consistently detected in both urine- and blood-derived EVs. These data demonstrate both shared and distinct protein signatures in EVs derived from urine and blood, providing a basis for distinguishing source-specific EV proteomes and potential biomarker applications.

[0284] FIG. 21 is a scanning electron microscope (SEM) image of a micro-carbon fiber section of the device, acquired using a secondary-electron detector at approximately 997* magnification, with an accelerating voltage of 2 kV and a probe current of 100 pA.

[0285] FIG. 22 Representative characterization of extracellular vesicles (EVs) isolated from urine. Left: Dynamic light scattering (DLS) profile of EVs captured from 300 mL of urine using a device functionalized with anti-CD9 antibodies and subsequently released into deionized water. The profile exhibits a single peak at approximately 152.6 nm with a standard deviation of 96.66 nm. Right: Scanning electron microscope (SEM) image of urine-derived EVs retained on carbon fibers of the device. After capture, the fibers were washed with phosphate-buffered saline (PBS) and deionized water, air-dried, and imaged using a secondary-electron detector. Nanoparticles of approximately 100 nm in diameter are visible on the fiber surfaces.

[0286] FIG. 23 Schematic illustration (cross section left, side view right) of a further variation of the device in which the magnetic component is positioned so as not to directly contact the fibers and may be fully enclosed within an insulating portion of the assembly. In this configuration, a conductive element provides contact with the fibers and functions as the electrical interface between the voltage source and the fibers.

[0287] FIG. 24 Schematic illustration (cross section left, side view right) of a further alternative embodiment of the device, wherein the magnetic component is not necessarily in direct contact with the fibers and may be partially enclosed within, or disposed externally relative to, the insulation-related portion. In certain embodiments, the magnetic component may be secured to the insulating material. In this configuration, the conductive fibers themselves serve as the electrical contact with the voltage source, thereby enabling the release of captured particles upon application of an electric potential to the fibers.

[0288] FIG. 25 illustrates an alternative embodiment of the device (10) in which the counter electrode (108), or alternatively another electrode such as the reference electrode (116), is integrated within the device (10); an additional insulation layer (117) may be provided, and (100) designates the fiber section. This configuration achieves further miniaturization of the electrochemical release architecture and enables electrochemical analyses to be performed using reduced sample volumes.

[0289] FIG. 26 illustrates one exemplary mode of using the device (10) according to the present disclosure. The device (10), comprising fibers functionalized with anti-CD9 antibodies, is placed within a pipette tip-shaped plastic cartridge or housing (119). The housing (119) is first filled with 20 pL of phosphate-buffered saline (PBS). Subsequently, 20 pL of whole blood (118) containing extracellular vesicles is injected into the housing (119). Upon contact with the functionalized fibers, the extracellular vesicles are passively adsorbed onto the fiber surfaces and retained within the fiber matrix without requiring agitation, mixing, or application of an external magnetic field.

[0290] FIG. 27 is a schematic illustration showing the parallel operation of a plurality of devices (10) on a single magnetic mixing plate (103), wherein each device (10) is immersed in a respective biological sample (118) contained within an 1.5 mL tube, thereby enabling simultaneous capture of target biological particles in multiple samples. This configuration facilitates high-throughput processing of large sample volumes and seamless integration with automated liquid-handling and robotic systems.

[0291] Examples

[0292] Example 1: Materials and Instruments

[0293] All reagents and materials were obtained from commercial suppliers and used as received unless otherwise stated. Deionized water (DIW) was produced using a Purelab Ultra water purifier (Labtech Services).

[0294] Antibodies

[0295] • Mouse monoclonal anti-CD9 antibody (IgG 1 K, clone C-4, catalog no. sc-13118, Santa Cruz Biotechnology)

[0296] • Mouse monoclonal anti-CD81 antibody (lgG2b K, clone B-11 , Santa Cruz Biotechnology)

[0297] • Mouse monoclonal anti-TSG101 antibody (catalog no. sc-7964, Santa Cruz Biotechnology)

[0298] • Mouse monoclonal anti-albumin antibody (catalog no. sc-271605, Santa Cruz Biotechnology)

[0299] • Horseradish peroxidase (HRP)-conjugated polyclonal goat anti-mouse IgG secondary antibody (Dako) Reagents and consumables

[0300] • Western Blotting Luminol Reagent (Santa Cruz Biotechnology)

[0301] • Phosphate-buffered saline (PBS, 1 *, pH 7.4, premixed granules, catalog no. BAL102, Apollo Scientific)

[0302] • Poly-L-lysine (PLL, 99 %, catalog no. OR1014790-100 g, Apollo Scientific; or AS53057, Apollo Scientific)

[0303] • Nile Red (catalog no. BIN0465-250 mg, Apollo Scientific)

[0304] • MISSION® siRNA Fluorescent Universal Negative Control #1 , Cyanine 5 (catalog no. SIC005-1 NMOL, Sigma-Aldrich / Merck)

[0305] • 3-Aminopropyldimethylethoxysilane (APDMES, 95 %, catalog no. S00750-5G, Fluorochem)

[0306] • Pasteurized full-fat cow’s milk (3.9 % fat, “Retour aux Sources Bio” Vollmilch or equivalent commercial pasteurized milk)

[0307] • Micro BCA Protein Assay Kit (Thermo Fisher Scientific)

[0308] • RIPA lysis buffer (commercially available or prepared according to standard protocols) Device components and related materials

[0309] • Carbon fibers prepared from polyacrylonitrile (PAN) precursors by spinning, oxidative stabilization in air, and carbonization in an oxygen-free environment (diameter » 7 pm)

[0310] • Silicone rubber tubing (outer diameter 3 mm, wall thickness 1 mm)

[0311] • Neodymium permanent magnets (NdFeB, N35 grade, 2 mm diameter x 2 mm length)

[0312] • Platinum wire (counter electrode, exposed length 2 mm)

[0313] Biological samples

[0314] • Fresh human urine from healthy donors

[0315] • Pasteurized cow’s milk (3.9 % fat)

[0316] • Fresh human whole blood from healthy donors

[0317] • Human plasma from healthy donors

[0318] Instruments

[0319] • Dynamic light scattering (DLS) / zeta potential analyzer: Zetasizer Nano-ZS (Malvern Panalytical, formerly Malvern Instruments)

[0320] • Scanning electron microscope: Merlin field-emission SEM (Carl Zeiss Microscopy)

[0321] • Cryo-transmission electron microscope: Titan Krios (Thermo Fisher Scientific)

[0322] • Metal sputter coater: CCU-010 (Safematic)

[0323] • Water purifier: Purelab Ultra (Labtech Services / Elga)

[0324] • Plate reader: Infinite M200 Pro (Tecan)

[0325] • Lyophilizer: Epsilon 2-4 LSCpIus (Martin Christ)

[0326] • Gel imaging system: ChemiDoc MP Imaging System (Bio-Rad)

[0327] All other reagents and solvents were of analytical grade and used as received. All experiments were performed at room temperature unless otherwise specified. Example 2: Typical device dimensions and characteristics:

[0328] In this example, a representative embodiment of the device according to the invention was fabricated and characterized to demonstrate typical dimensions, materials, electrical conductivity, and functional performance as an electrode in a capture-and-release workflow for biological particles.

[0329] The device (10) was rod-shaped with an overall length of 12 mm and comprised three main sections:

[0330] • Fiber section (100): consisting of carbon fibers prepared from polyacrylonitrile (PAN) polymer by spinning into fibers, followed by oxidative stabilization in air and carbonization in an oxygen-free environment. The carbon fibers had a diameter of approximately 7 pm and a total length of 10 mm, of which 2 mm was exposed to the sample solution for interaction with biological particles.

[0331] • Insulation section (101): consisting of silicone rubber that encased the carbon fibers except for the exposed 2 mm portion, with an insulation thickness of 1 mm and an outer diameter of approximately 3 mm (provided by a silicone rubber tube).

[0332] • Magnetic section (102): a neodymium (NdFeB, N35 grade) permanent magnet measuring 2 mm (diameter) x 2 mm (length). In this embodiment, the magnetic section was integrated to serve simultaneously as the voltage source contact (106), enabling direct electrical connection to the carbon fiber section through magnetic attachment to the power supply wire (as shown in FIGS. 8 and 9).

[0333] The overall device thickness was in the range of 3-5 mm, with the magnetic section diameter being 2 mm.

[0334] The electrical conductivity of the complete device (10) was measured using a digital multimeter and found to be lower than approximately 30 Q (total resistance per device), confirming that the carbon fiber surface, even after assembly and insulation, remained highly conductive and fully suitable for operation as a working electrode.

[0335] In a typical release protocol (FIGS. 10 and 11), the device was placed in an Eppendorf tube (110) containing 50 microliters of deionized water (111) together with a platinum wire counter electrode (108, exposed length 2 mm). The carbon fiber device was connected to the negative terminal of a DC voltage source and the platinum counter electrode to the positive terminal. Application of an electrical potential in the range of -300 V to +300 V, and specifically at -3 V, resulted in a measured current of 0.5-200 microamperes (as displayed on the ammeter in FIG. 11). This current range confirmed effective electrical coupling through the integrated magnetic / voltage-contact section and demonstrated that the applied potential was sufficient to disrupt receptor-particle interactions and release bound biological particles while preserving particle integrity (no detectable damage observed in downstream analysis in related experiments).

[0336] The described dimensions (overall length preferably 10-12 mm, magnetic section diameter preferably about 2 mm, device thickness preferably 3-5 mm) enable the device to operate efficiently in very small sample volumes (down to 50 pL or less) while providing robust magnetic manipulation (rotation akin to a micro-stirrer when placed on a magnetic stirring plate, as shown in FIG. 7) and simple, reliabile electrical connection via magnetic attachment. The high conductivity (less than approximately 30 Q / cm) and low operating voltage (<3 V absolute) for release constitute key technical advantages, as they allow efficient, non-destructive release of sensitive biological particles such as extracellular vesicles in minimal solution volumes without requiring complex wiring or large electrochemical cells.

[0337] The same or equivalent electrochemical performance can also be achieved with alternative fiber materials subjected to similar chemical activation / functionalization protocols, including gold fibers and carbon nanotubes. Broader working ranges for the device, while maintaining functionality, include overall length 1-100 mm, magnetic section diameter 1-90 mm, and device thickness 1-90 mm.

[0338] Example 3: two-electrode setup for biological particles release

[0339] This example demonstrates the release of biological particles captured on the fiber section of the device using a two-electrode electrochemical setup, wherein the device itself serves as the working electrode and a platinum wire serves as the counter electrode. The setup enables release of bound biological particles by application of a controlled electrical potential that disrupts receptor-particle interactions while preserving particle integrity, with the magnetic section of the device simultaneously functioning as the voltage source contact.

[0340] The device (10) was constructed as follows. Carbon fibers having a diameter of approximately 7 pm were prepared from polyacrylonitrile (PAN) polymer through spinning the polymer into fibers, stabilizing the fibers by heating in air, and carbonizing the stabilized fibers at high temperatures in an oxygen-free environment. The resulting carbon fibers had a total length of 10 mm and exhibited a total resistance of less than approximately 30 Q / cm per device, confirming high conductivity suitable for electrode use, as measured using a multimeter. Approximately 2 mm of the carbon fiber section (100) was left exposed. The fibers were partially enclosed in a silicone rubber insulation section (101) having a thickness of 1 mm and an outer diameter of 3 mm. A neodymium magnet (N35 grade, NdFeB, 2 mm x 2 mm) formed the magnetic section (102) having a diameter of 2 mm. The resulting rod-shaped device had an overall length of 12 mm and a thickness in the range of 3-5 mm (see also FIGS. 1-6). In various embodiments, the overall device length may be in the range of 1-100 mm, the magnetic section diameter may be in the range of 1-90 mm, and the device thickness may be in the range of 1-90 mm.

[0341] The carbon fibers were functionalized with specific receptor molecules capable of binding target biological particles.

[0342] Following capture of biological particles onto the exposed carbon fiber section (100), the device was placed into an Eppendorf tube (110) containing 50 microliters of deionized water (111) as the release solution (FIG. 10). A platinum wire counter electrode (108) with an exposed length of 2 mm was positioned within the same tube.

[0343] The device was connected to the negative pole of a voltage supply (112) via direct contact between the voltage source contact (106) and the surface of the magnetic section (102), with connection achieved by magnetic attraction (FIGS. 8, 9 and 11). The platinum wire counter electrode (108) was connected to the positive pole of the voltage supply via wire (113), while the device was connected via wire (114).

[0344] An electrical potential of -3 V was applied to the carbon fiber section (working electrode), corresponding to a positive potential on the counter electrode. During application of the potential, current flowing between the carbon fiber device and the counter electrode was measured using an ammeter and ranged from 0.5 microamperes to 200 microamperes in deionized water (115; FIG. 11).

[0345] The applied negative electrical potential of -3 V (within the broader operable range of -300 V to +300 V) disrupted receptor-particle interactions, thereby releasing the bound biological particles into the deionized water while preserving particle integrity. The observed low current (0.5-200 pA) in the low-conductivity deionized water release medium confirms that release occurs under mild electrochemical conditions that avoid excessive electrolysis or thermal effects that could damage the biological particles.

[0346] This two-electrode configuration (FIGS. 10 and 11) further illustrates the technical advantage provided by the integration of the magnetic section (102) and voltage source contact into a single component, enabling simple, wire-free electrical connection via magnetic attachment and facilitating release in small-volume (microliter-scale) setups. Comparable electrochemical performance for release is achievable with alternative fiber materials subjected to similar chemical activation, including gold fibers and carbon nanotubes.

[0347] The results of this example thus support the ability of the device to function effectively as a working electrode in a two-electrode system for controlled, integrity-preserving release of captured biological particles using low applied potential under mild conditions.

[0348] Example 4: Three-electrode device set up of electrochemical analysis

[0349] This example demonstrates the configuration of the device according to the invention as the working electrode in a three-electrode electrochemical cell, thereby enabling electrochemical analysis (including cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry, and the like) of particles adsorbed onto the carbon fiber section.

[0350] The device (10) used in this example comprised as described in “Example 3: two-electrode setup for biological particles release".

[0351] The three-electrode electrochemical cell was assembled in a 1.5 mL Eppendorf tube serving as the cell (FIG. 12). The device was employed as the working electrode and was connected to the working electrode terminal of a potentiostat via magnetic contact at the magnetic section (102). A platinum wire was used as the counter electrode (108) and connected to the counter electrode terminal. An Ag / AgCI micro reference electrode (4 mm, 116) was connected to the reference terminal of the potentiostat.

[0352] Following assembly, the electrochemical cell (containing the device with the adsorbed particles on the exposed 2 mm carbon fiber section) was subjected to cyclic voltammetry using the potentiostat.

[0353] The cell was successfully characterized by cyclic voltammetry, confirming that the device functions effectively as the working electrode in a three-electrode configuration. The low resistance (<30 Q / cm) and high conductivity of the carbon fiber section enabled precise current collection and supported a wide range of electrochemical techniques, including linear sweep voltammetry, cyclic voltammetry, and differential pulse voltammetry. This configuration permits direct electrochemical analysis of biological particles adsorbed onto the fiber section, allowing their identification via unique electrochemical signatures without requiring prior release of the particles from the device.

[0354] The magnetic section simultaneously provided (i) mechanical manipulation capability, (ii) electrical connection to the potentiostat via magnetic contact, and (iii) in embodiments where the magnetic section and voltage source contact are integrated, the ability to apply release potentials, thereby illustrating the multifunctional integration claimed in the present invention (e.g., claims 1 , 2, and 10). Similar electrochemical performance can be achieved with devices fabricated using alternative conductive fiber materials, such as gold fibers or carbon nanotubes, subjected to analogous chemical activation.

[0355] Example 5: fibers surface activation for Antibody immobilization

[0356] This example describes a procedure for activation of the carbon fiber (CF) surface of the device (10) and subsequent immobilization of antibodies specific for EV surface markers (anti-CD81 or anti-CD9).

[0357] Prior to surface modification, the device (10) was washed with 20 mL of ethanol followed by 20 mL of deionized water. The device was then dried in a vacuum oven at 80 °C for 30 min.

[0358] To activate the carbon fiber surface for silanization, oxygen plasma treatment was applied at 60 W for 2 min under an oxygen pressure of 30 Pa. An amino-silane monolayer was then formed on the activated carbon fiber surface by gasphase chemical adsorption of APDMES. The device was placed in a covered glass Petri dish together with a 2 mL glass vial containing 150 pL of APDMES. The Petri dish was placed in a vacuum oven preheated to 95 °C. The oven was evacuated to 0 Pa, after which pumping was stopped to allow APDMES vapors to saturate the chamber. The device was incubated under these conditions for 16 h. Thereafter, the pump was restarted to remove residual APDMES vapor, the APDMES vial was removed, and the device (still in the Petri dish) was heated under vacuum at 100 °C for an additional 2 h.

[0359] The silanized device was then washed with 20 mL of ethanol and dried at 80 °C in the vacuum oven.

[0360] Immediately thereafter, antibody immobilization was performed by immersing the carbon fiber section of the device in 20 pL of antibody solution (anti-CD81 or anti-CD9, 200 pg / mL) for 24 h at 4 °C. After immobilization, the device was washed with 20 mL of phosphate-buffered saline (PBS) at a flow rate of 2 mL / s to remove unadsorbed antibody.

[0361] The foregoing procedure provides the carbon fiber section (100) of the device (10) with a covalently anchored amino-functional monolayer that facilitates stable immobilization of anti- CD81 or anti-CD9 antibodies. These antibodies specifically recognize CD81 or CD9 tetraspanins present on the surface of EVs, thereby functionalizing the conductive carbon fibers with receptor molecules capable of selective binding of EV biological particles as required by the device of the invention. The resulting antibody-functionalized device is suitable for subsequent capture of EVs from biological samples and electrically induced release of the captured particles while maintaining the conductivity required for the electrical release mechanism.

[0362] To enable robust and versatile immobilization of receptor molecules (such as antibodies, aptamers, peptides, or other binding agents) on the fiber section 100, various chemical strategies may be employed, as detailed in the section entitled "Fiber section 100."

[0363] Example 6: Separation and Release of Extracellular Vesicle-Type Biological Particles from a Urine Sample and Characterization Using PLS

[0364] In this example, the device is constructed using carbon fibers (approximately 7 microns in diameter), a silicone tube (3 mm outer diameter, made of silicone rubber), and a neodymium magnet (2 mm x 2 mm, N35 grade, NdFeB). Figures 1-6 illustrate the device components.

[0365] After assembly, the surface of the carbon fibers is activated using a gas-phase silanization process with (3-aminopropyl)dimethylethoxysilane (APDMES) as the reagent, as follows: All glassware used in the modification process was cleaned with ethanol and dried in a vacuum oven at 85 °C for 30 minutes. Prior to surface modification, the device was washed with 30 mL of ethanol, followed by 30 mL of deionized water. The device was then placed in a vacuum oven (connected to an oil pump) and dried for 90 minutes at 85 °C. To activate the carbon fiber surface for the silanization process, plasma treatment was applied at 60 W for 2 minutes under a pressure of 30 Pa using oxygen gas. The amino-silane monolayer on the carbon fibers was formed by performing a gas-phase chemical adsorption of APDMES in a vacuum oven, as follows: The carbon fibers of the device were exposed to 150 pL of APDMES inside a 2 mL glass vial for 16 hours at 85 °C in a covered glass Petri dish. The vacuum oven was then pumped until the pressure gauge read 0 Pa, after which the pumping was stopped, allowing the APDMES vapors to saturate the oven chamber. After 16 hours of incubation, the vacuum pump was turned on again to remove the APDMES vapors. The vial with the APDMES was then removed, and the Petri dish containing the device was placed back into the heated oven under vacuum at 100 °C for an additional 90 minutes. Once the modification process was complete, the devices were washed with 30 mL of ethanol and dried in the vacuum oven at 85 °C.

[0366] To achieve selectivity for extracellular vesicles (EVs) in urine, the carbon fiber surface was functionalized with 4 pg of anti-CD9 (sc-13118) monoclonal antibody. This was accomplished by incubating the device with the antibody for 24 hours at 4°C. After incubation, the device was rinsed with phosphate-buffered saline (PBS) to remove any unbound antibody residues.

[0367] The functionalized device was then introduced into a fresh 50 ml urine sample and placed on a magnetic stirring plate (FIG. 7). The sample was stirred at 300 RPM for 10 minutes to facilitate the capture of extracellular vesicles by the carbon fibers. Following this, the device was transferred to a clean PBS solution and stirred for 1 minute using the magnetic mixing plate to remove residual urine. Subsequently, the device was rinsed in 50 ml of deionized water, stirring for 1 minute to remove any adsorbed salts. This rinsing process with deionized water was repeated two additional times to ensure that the device was free of contaminants and unwanted residues.

[0368] The cleaned device was then placed in an Eppendorf tube containing 50 pl of deionized water alongside a counter electrode (FIG. 10). A voltage of 3 volts was applied for 1 minute between the device and the counter electrode. This voltage generated an electric current of several microamperes, facilitating the release of biological particles from the surface of the carbon fibers. The current was monitored using an ammeter. (FIG. 11)

[0369] Following particle release, 20 pl of the solution containing the released particles was collected and diluted to 1 ml for dynamic light scattering (DLS) analysis. The DLS results revealed a uniform particle population with a peak size of approximately 100 nm, characteristic of exosomes — a specific subset of extracellular vesicles. (FIG. 13)

[0370] This example demonstrates the ability of the device to selectively capture extracellular vesicles, efficiently release them using electrical stimulation, and confirm their presence and size distribution using DLS. Example 7 Purification of EVs from Urine Using Device with Anti-CD9 Antibody

[0371] The purpose of this example is to demonstrate the use of a device according to the invention for the isolation of extracellular vesicles (EVs) from a urine sample. This includes capture of EVs on carbon fibers functionalized with anti-CD9 antibodies, subsequent release of the captured EVs by application of an electrical potential, and characterization of the released EVs by dynamic light scattering (DLS) and zeta potential measurements, as well as imaging of captured EVs by scanning electron microscopy (SEM).

[0372] The device (10) employed in this example comprised a fiber section (100) composed of carbon fibers functionalized with anti-CD9 antibodies as receptor molecules for binding EVs, a magnetic section (102) configured to induce rotational motion in response to an external magnetic field, an insulation section (101), and a voltage source contact configured to enable application of an electrical potential for release of captured EVs, in accordance with the device of claims 1-10. The device was immersed in urine as the biological sample contained within a 1 L glass bottle and subjected to rotational motion via a magnetic stirring plate (103), as illustrated in FIG. 7. For release of captured EVs, the device was connected to a voltage source via a voltage source contact (106) and insulation for voltage source wire (107), with a counter electrode (108) and counter electrode insulation (109) placed in a 1.5 mL tube (110) containing a release solution (111), deionized water, as illustrated in FIG. 10. Voltage application and current measurement were performed using a device for applying voltage and measuring current (112), with positive voltage wire (113), negative voltage wire (114), and current measured during bioparticle release (115), as illustrated in FIG. 11.

[0373] Materials used included 300 mL of human urine from a healthy donor as the biological sample, 30 mL of phosphate-buffered saline (PBS) as a washing solution, deionized water (DIW) for additional washing (30 mL) and as the release solution (100 pL per release, with an additional 300 pL for zeta potential measurement), and 1.5 mL tubes for collection of released EVs. Characterization was performed using a NanoZX instrument (Malvern Instruments) for DLS and zeta potential measurements, and SEM imaging was conducted using a secondaryelectron detector.

[0374] The procedure was as follows: The device functionalized with anti-CD9 antibodies was incubated in 300 mL of human urine from a healthy donor for 30 minutes under stirring induced by an external magnetic field from a magnetic stirring plate. The device was then removed from the urine sample and washed with 30 mL of PBS, followed by washing with 30 mL of DIW. EVs attached to the device surface were released into an Eppendorf tube containing 100 pL of DIW by application of a potential of 3.0 V between the device (connected to the negative terminal) and a counter electrode (connected to the positive terminal). A second release was carried out in a similar manner into a separate Eppendorf tube containing 100 pL of DIW, with the device washed with DIW prior to the second release. A third release was carried out in a similar manner into a separate Eppendorf tube containing 100 pL of DIW, with the device washed with DIW prior to the third release. The contents of the three Eppendorf tubes were combined and subjected to size measurement by DLS. Subsequently, 300 pL of DIW was added to the combined sample, and zeta potential measurement was performed.

[0375] Separately, for SEM imaging, EVs captured on the device surface prior to the release step were prepared by air-drying the device after washing with PBS and DIW. The device with the adsorbed EVs was then coated with 4 nm of chromium (Cr) using a metal sputter coater. The coated device with the EVs on the surface was imaged using a secondary-electron detector at approximately 150,000* magnification, with an accelerating voltage of 2 kV and a probe current of 100 pA, using a Zeiss Merlin ultra-high resolution FE-SEM (FIG. 22B).

[0376] FIG. 22A is a DLS measurement of the released EVs, yielding an average hydrodynamic diameter by number distribution of 152.6 nm with a standard deviation of 96.66 nm. The zeta potential measurement yielded a value of -20.5 mV with a zeta deviation of 7.22 mV. FIG. 22B is a scanning electron microscope (SEM) image of urine-derived EVs. The EVs from urine were captured on the carbon fibers of the device, followed by a subsequent wash with phosphate-buffered saline (PBS) and then DI water. The carbon fibers with captured EVs were then allowed to air-dry, coated with 4 nm of chromium, and imaged using an SEM under a secondary electron detector. Nanoparticles having a diameter of approximately 100 nm are shown on the surface of the fibers.

[0377] The results demonstrate that the device enables specific capture of EVs from urine via anti- CD9 antibodies on the carbon fibers and controlled release of the captured EVs by application of a low electrical potential (3.0 V) while preserving EV integrity, as evidenced by the DLS profile exhibiting a uniform particle population with a hydrodynamic diameter characteristic of exosomes (a subset of EVs) and the zeta potential indicative of stable, negatively charged particles. The SEM imaging confirms the presence of nanosized EVs on the fiber surfaces prior to release. These findings support the technical advantage of the invention in providing a method for isolating EVs from large-volume biological samples with minimal non-specific binding, as facilitated by the rotational motion during capture and the electrochemical release mechanism, in accordance with the method of claims 11-15.

[0378] Example 8: Purification of EVs from Milk Using Device with Anti-CD81 Antibody

[0379] The objective of this example is to demonstrate the use of a device functionalized with anti- CD81 antibodies for the isolation and purification of extracellular vesicles (EVs) from a milk sample, including capture under stirring conditions, washing, electrochemical release, and characterization of the released EVs by dynamic light scattering (DLS) and zeta potential measurements. The device (10) employed in this example comprised a fiber section (100) composed of carbon fibers functionalized with anti-CD81 antibodies as receptor molecules for specific binding of EVs, an insulation section (101) comprising a silicon rubber, and a magnetic section (102) configured to induce rotational motion in response to an external magnetic field and to serve as a voltage source contact for application of an electrical potential. The device configuration is as illustrated in FIGS. 1-3, with exemplary images provided in FIGS. 4-6. The carbon fibers in the fiber section had a diameter in the range of 1-10 microns. The magnetic section comprised a neodymium material. The overall device was rod-shaped with a length of approximately 12 mm, the magnetic section having a diameter of approximately 2 mm, and the insulation section having a thickness of approximately 3-4 mm. An electrical releasing unit was used to supply the potential for EV release, comprising a voltage source connected via a voltage source contact (106) and insulation for the voltage source wire (107), with a counter electrode (108) and counter electrode insulation (109), as illustrated in FIGS. 8-11. Measurements were performed using a NanoZS instrument (Malvern Instruments) for DLS and zeta potential analyses.

[0380] The procedure was conducted as follows: A 500 mL sample of pasteurized milk (3.9% fat, Retour aux sources) was pre-heated to 37 °C. The device functionalized with anti-CD81 antibodies was introduced into the milk sample and incubated for 30 min under stirring conditions induced by an external magnetic field applied via a magnetic stirring plate (103), promoting interaction between the functionalized carbon fibers and EVs in the sample, as illustrated in FIG. 7. The device was then removed from the milk sample and transferred to a washing solution consisting of 30 mL of phosphate-buffered saline (PBS) to remove non- specifically bound material, followed by a second wash with 30 mL of deionized water (DIW). For release, the device was placed into an Eppendorf tube (110) containing 100 pL of DIW (111), and an electrical potential of 3.0 V was applied between the device (connected to the negative terminal via the magnetic section / voltage source contact) and the counter electrode (connected to the positive terminal) using the electrical releasing unit (112), with current measured (115) during release, as illustrated in FIG. 11. The released EVs were collected in the DIW solution.

[0381] To the released EV solution, 200 pL of DIW was added, and the sample was subjected to DLS measurement using the NanoZS instrument (Malvern Instruments) to determine the size distribution, as shown in FIG. 14A. The average hydrodynamic diameter by number distribution was 113.1 nm, with a standard deviation of 75.40 nm, exhibiting a single peak at approximately 113 nm. Subsequently, an additional 300 pL of DIW was added to the sample, and zeta potential was measured using the NanoZS instrument (Malvern Instruments). The zeta potential was -19.6 mV, with a zeta deviation of 7.77 mV. These results demonstrate that the device enables efficient capture of EVs from a large- volume milk sample via specific binding to anti-CD81 -functionalized carbon fibers under magnetically induced rotational motion, followed by gentle electrochemical release at a low potential of 3.0 V, which preserves EV integrity as evidenced by the DLS profile showing a single population of nanosized particles consistent with EV dimensions (approximately 100 nm) and the negative zeta potential indicative of stable, negatively charged EV surfaces. This supports the innovative feature of the invention wherein the integrated magnetic and electrical functionalities of the device allow for scalable, motion-enhanced capture and voltage- controlled release of biological particles in a manner that minimizes damage and facilitates downstream characterization, as claimed in claims 1 , 8, 11 , and 15.

[0382] Example 9: Purification of EVs from Raw Blood Using Device with Anti-CD9 Antibody

[0383] This example demonstrates the capture, purification, and release of extracellular vesicles (EVs) from a small volume of raw whole blood using the device functionalized with anti-CD9 antibodies, followed by characterization of the released EVs by dynamic light scattering (DLS) and zeta potential measurements.

[0384] The device employed in this example comprised a fiber section (100) composed of carbon fibers functionalized with anti-CD9 antibodies for specific binding of EVs, an insulation section

[0385] (101) comprising a polymeric material resistant to aqueous solutions, and a magnetic section

[0386] (102) serving as both a magnetic component for potential motion induction and a voltage source contact for application of electrical potential. The device was configured in a rod-shaped form with an overall length of approximately 10 mm to 12 mm, wherein the fiber section had a diameter in the range of 1-10 microns, the magnetic section had a diameter of approximately 2 mm, and the insulation section had a thickness of approximately 3 mm to 4 mm and a length configured to partially separate the fiber section from the biological sample while maintaining exposure of a portion of the fiber section. The device was placed within a pipette tip-shaped plastic housing (119) for the capture step. Other materials included phosphate-buffered saline (PBS), deionized water (DIW), fresh whole blood (118) as the biological sample, a 50 mL Falcon tube for washing, a 1.5 mL Eppendorf tube (110) for release, and an electrical releasing unit comprising a voltage source (112) with a counter electrode (108) for applying potential. Characterization was performed using a DLS instrument and a NanoZS zeta potential analyzer (Malvern Instruments).

[0387] The procedure was conducted as follows: The device, modified with anti-CD9 antibodies, was first washed with PBS. Subsequently, 20 pL of PBS was added to the carbon fiber part within the housing to prevent blood coagulation. Then, 20 pL of fresh whole blood was added onto the carbon fiber with the PBS and incubated for 10 minutes at room temperature, allowing passive adsorption of EVs onto the functionalized fiber surfaces without agitation or application of an external magnetic field (FIG. 26). The device was then transferred to a Falcon tube containing 30 mL of PBS and washed under stirring for 2 minutes to remove non-specific material. This was followed by two additional washes with DIW in a similar manner. For release, the device was placed in an Eppendorf tube containing 300 pL of DIW, and EVs were eluted by applying a potential of 3.0 V between the device (negative terminal) and the counter electrode (positive terminal) using the electrical releasing unit.

[0388] The released solution was subjected to DLS measurement for size characterization (FIG. 14B). The DLS profile exhibited a single peak, with an average hydrodynamic diameter by number distribution of 83.7 nm and a standard deviation of 48.49 nm. Subsequently, an additional 300 pL of DIW was added to the solution, and zeta potential was measured using the NanoZS instrument. The zeta potential was -6.2 mV with a zeta deviation of 5.98 mV.

[0389] These results indicate that the device enables isolation of a population of nanoparticles from 20 pL of raw whole blood with a hydrodynamic diameter consistent with that of EVs, such as exosomes (typically in the range of approximately 30-150 nm), as evidenced by the single peak at approximately 84 nm in the DLS profile. The negative zeta potential is characteristic of EVs due to their lipid membrane composition. The absence of albumin in the purified EV fraction, as confirmed by western blot analysis where CD9 (an EV marker) was detected in the EV fraction but not in the raw centrifuged blood, and albumin was present only in the raw sample (FIG. 18A), supports the specificity and purity of the isolation. This demonstrates the technical advantage of the device's functionalized carbon fibers and electrochemical release mechanism in achieving rapid, low-volume purification of intact EVs while disrupting receptorparticle interactions without compromising particle integrity, as preserved for downstream analytical techniques.

[0390] Example 10: Purification of EVs from Plasma Using Device with Anti-CD9 Antibody

[0391] The objective of this example is to describe the purification of extracellular vesicles (EVs) from plasma using a device functionalized with anti-CD9 antibody, followed by characterization of the captured and released EVs by dynamic light scattering (DLS), zeta potential measurement, scanning electron microscopy (SEM), and cryo-transmission electron microscopy (cryo-TEM).

[0392] The device comprised a fiber section composed of carbon fibers functionalized with anti-CD9 antibodies, a magnetic section, and an insulation section, as described with reference to FIGS. 1-3. The device was configured to enable rotational motion in response to an external magnetic field and to serve as an electrode for application of electrical potential. Additional materials and equipment included phosphate-buffered saline (PBS), deionized water (DIW), 0.5 mL of plasma pre-heated to 37 °C, an Eppendorf tube, an electrical releasing unit for applying voltage, a NanoZX instrument (Malvern Instruments) for DLS and zeta potential measurements, a metal sputter coater for chromium coating, a Zeiss Merlin ultra-high resolution field emission SEM for imaging, 300-mesh lacey carbon-coated copper grids (Quantifoil Micro Tools GmbH, Germany), an Emitech K100X glow discharge system (Quorum Technologies Ltd., UK), a Vitrobot Mark IV (Thermo Fisher Scientific) for vitrification, AutoGrid specimen carriers (Thermo Fisher Scientific), and a TFS Titan Krios (Thermo Fisher Scientific) equipped with a Gatan Quantum LS Energy Filter and a Gatan K2 Summit direct electron detector (AMETEK Inc.) for cryo-TEM imaging.

[0393] The procedure was conducted as follows: The device, modified with anti-CD9 antibody, was washed with PBS. The device was then inserted into 0.5 mL of plasma pre-heated to 37 °C and incubated under stirring for 10 min at room temperature. The device was washed with PBS (30 mL) and with DIW (30 mL). EVs were released into an 1.5 mL tube containing 200 pL of DIW at a potential of 3.0 V supplied by the electrical releasing unit.

[0394] The released EV solution was subjected to size measurement using DLS with the NanoZX instrument (Malvern Instruments), as shown in FIG. 14C. The DLS profile exhibited a single peak at approximately 83 nm, with an average hydrodynamic diameter by number distribution of 83.39 nm and a standard deviation of 52.47 nm. Subsequently, 300 pL of DIW were added to the solution, and zeta potential was measured using the NanoZX instrument (Malvern Instruments). The zeta potential was -11.0 mV with a zeta deviation of 3.76 mV.

[0395] For SEM imaging of surface-captured EVs prior to the release step, the EVs from plasma were captured on the carbon fibers of the device, followed by a wash with PBS and then DIW. The carbon fibers with captured EVs were allowed to air-dry using an air gun. The device with the adsorbed EVs was coated with 4 nm of chromium (Cr) using a metal sputter coater. The 4 nm- coated device with the EVs on the surface was imaged using a secondary-electron detector at approximately 150,000* magnification, with an accelerating voltage of 2 kV and a probe current of 100 pA, using the Zeiss Merlin ultra-high resolution field emission SEM, as shown in FIG. 15A. Nanoparticles having a diameter of approximately 100 nm were observed on the surface of the fibers.

[0396] For cryo-TEM imaging of purified EVs after release into water, 300-mesh lacey carbon-coated copper grids were glow-discharged for 45 s using the Emitech K100X glow discharge system. Then, 3.6 pL of the EV solution in PBS were dropped on the grid. Excess liquid was removed by blotting for 2 s at 100% relative humidity before immersion of the grids into a mixture of liquid ethane and propane using the Vitrobot Mark IV. The vitrified grids were clipped into AutoGrid specimen carriers. The prepared grids were examined in bright-field mode using the TFS Titan Krios operated at 300 kV acceleration voltage and equipped with a Gatan Quantum LS Energy Filter using a 20 eV slit width and a Gatan K2 Summit direct electron detector. The microscope was maintained at a temperature of =-180 °C during observations. Micrographs were acquired in energy filtered TEM (EFTEM) operation mode using the TFS EPU software (up to 105,000x magnification, at most =40 e per A2total electron dose, K2 camera in a linear mode, within 2-4 pm defocus range), as shown in FIG. 15B. Particles having diameters of approximately 100 nm were visible, with characteristic double-membrane morphology evident.

[0397] These results demonstrate that the device enables specific capture of EVs from plasma via the functionalized carbon fibers and their subsequent release by application of a controlled electrical potential while preserving EV integrity, as evidenced by the DLS-measured size distribution consistent with typical EV dimensions, the negative zeta potential indicative of EV surface charge properties, and the cryo-TEM-observed double-membrane morphology confirming structural preservation post-release. This supports the technical advantage of the invention in providing a method for isolating biological particles, such as EVs, from smallvolume biological samples through magnetically induced motion during capture and electrically mediated release, thereby facilitating downstream characterization without compromising particle viability for applications in diagnostics or therapeutics.

[0398] Example 11: Potential-Induced Release According to EV Size

[0399] The objective of this example was to demonstrate the sequential release of captured extracellular vesicles (EVs) from the device in a size-dependent manner by applying incrementally increasing negative electrical potentials, thereby illustrating the voltagedependent fractionation of EVs based on their hydrodynamic diameters.

[0400] A device according to the invention, comprising a fiber section composed of carbon fibers functionalized with anti-CD81 antibodies, an insulation section, and a magnetic section serving as a voltage source contact, was employed. The biological sample consisted of 500 mL of pasteurized milk (3.9% fat, Retour aux sources). Additional materials included phosphate- buffered saline (PBS), deionized water (DIW), 1.5 mL tubes, and an electrical releasing unit configured to apply negative electrical potentials to the device relative to a counter electrode. Dynamic light scattering (DLS) measurements were performed using a NanoZS instrument (Malvern Instruments).

[0401] The milk was pre-heated to 37 °C. The device was then incubated in the pre-heated milk for 30 minutes under stirring to capture EVs on the functionalized carbon fibers. Following incubation, the device was removed from the milk, washed with 30 mL of PBS, and then washed with 30 mL of DIW to remove non-specifically bound material. The captured EVs were sequentially released into separate 1.5 mL Eppendorf tubes, each containing 300 pL of DIW, by applying increasing negative potentials supplied by the electrical releasing unit. After each release step, the device was washed with DIW prior to the subsequent release. The released EVs in each tube were analyzed by DLS to determine the size distribution by number. The applied release voltages and the corresponding average hydrodynamic diameters of the released EVs, along with standard deviations, as determined by DLS measurements, are summarized in Table 1.

[0402] Table 1 : A summary of the potential used for the release of extracellular vesicles (EVs), the average hydrodynamic diameter of the released EVs, and the standard deviation, as determined by DLS measurements.

[0403] FIG. 16 illustrates DLS measurements of the particle populations sequentially released from the device in response to the incrementally increased applied voltages. The DLS profiles show voltage-dependent particle size distributions, with the horizontal axis representing hydrodynamic diameter (nm) and the vertical axis representing particle number (%).

[0404] The results demonstrate that the average size of the released EVs decreases with increasing magnitude of the applied negative potential on the device (10), ranging from larger EVs (approximately 361 nm) at -1 .25 V to smaller EVs (approximately 80 nm) at -4.40 V. This size- selective release supports the innovative feature of the invention wherein the electrical potential applied to the fiber section disrupts the interactions between the receptor molecules (anti-CD81 antibodies) and the bound biological particles in a manner dependent on particle size, enabling fractionation of EVs without compromising their integrity for downstream applications such as DLS analysis.

[0405] Example 12: Purification of EVs and Subsequent Loading with Small Molecules

[0406] The purpose of this example is to illustrate the isolation of extracellular vesicles (EVs) from a biological sample using a device functionalized with anti-CD81 antibodies, followed by loading of the captured EVs with the lipophilic dye Nile Red, and subsequent release and characterization of the loaded EVs.

[0407] The materials used in this example included: a device (10) comprising a fiber section composed of carbon fibers functionalized with anti-CD81 antibodies, an insulation section, and a magnetic section, as described in “Example 3: two-electrode setup for biological particles release" pasteurized milk (3.9% fat, Retour aux sources); phosphate-buffered saline (PBS); deionized water (DIW); Nile red (BIN0465-250mg, Apollo); dimethyl sulfoxide (DMSO); an electrical releasing unit capable of supplying a potential of 3.0 V; Eppendorf tubes; a magnetic stirring plate; and analytical instruments including a fluorometer for measuring fluorescence emission spectra, a dynamic light scattering (DLS) instrument (NanoZX, Malvern Instruments) for size and zeta potential measurements.

[0408] The procedure was conducted as follows: A loading solution was prepared by dissolving Nile red in DMSO to a concentration of 2 mg / mL, followed by dilution at a ratio of 1 :20 in PBS to achieve a final concentration of 0.1 mg / mL. The anti-CD81 -functionalized device was incubated in 500 mL of pasteurized milk pre-heated to 37 °C for 30 minutes under stirring induced by an external magnetic field applied via the magnetic stirring plate to promote interaction between the fiber section and EVs in the sample. The device was then removed from the milk and washed with 30 mL of PBS. The washed device, with captured EVs retained on the fiber section, was inserted into an Eppendorf tube containing 1 mL of the Nile red loading solution and incubated at room temperature under stirring for 1 hour to allow incorporation of Nile red into the EV lipid membranes. Following incubation, the device was washed with 30 mL of PBS and then with 30 mL of DIW. The loaded EVs were released from the device into an Eppendorf tube containing 100 pL of DIW by applying a potential of 3.0 V using the electrical releasing unit, with the device connected to the negative terminal and a counter electrode connected to the positive terminal.

[0409] The released EVs were characterized as follows: Fluorescence emission spectra were measured for the released Nile red-loaded EVs in DIW and compared to free Nile red (7.5 pg / mL in water). The spectrum of free Nile red exhibited a maximum emission wavelength at approximately 620 nm, while the spectrum of Nile red associated with the released EVs showed a maximum emission wavelength at approximately 670 nm (FIG. 17A). To the released EV solution, 200 pL of DIWwas added, and the sample was subjected to DLS analysis, yielding an average hydrodynamic diameter by number distribution of 269.3 nm with a standard deviation of 80.84 nm, presenting as a single peak (FIG. 17B). For quantification of Nile red loading, 20 pL of the released EV solution was mixed with 80 pL of DMSO to dissolve the vesicles, and fluorescence emission intensity was measured against a linear calibration curve of Nile red in 80% DMSO in water (y = 76.53X + 1075.5, R2= 0.9965). The loaded EVs exhibited a fluorescence emission intensity of 4,589, corresponding to a Nile red concentration of 0.7 pg / mL, whereas unloaded EVs showed an intensity of 1 , comparable to background levels. Additionally, 300 pL of DIW was added to the diluted EV solution, and zeta potential was measured, resulting in a value of -21.9 mV with a zeta deviation of 8.17 mV.

[0410] The observed shift in the maximum emission wavelength of Nile red from approximately 620 nm in aqueous solution to approximately 670 nm when associated with the released EVs indicates successful incorporation of the lipophilic small molecule into the lipid-rich environment of the EV membranes, thereby demonstrating the device's capability to facilitate on-device loading of captured EVs with small molecules while preserving EV integrity for release via controlled electrical potential. The increase in hydrodynamic diameter from approximately 113 nm for unloaded milk-derived EVs (as shown in FIG. 14A) to approximately 270 nm for the loaded EVs further supports the modification of EVs through small molecule incorporation, highlighting a technical advantage of the invention in enabling efficient purification, loading, and recovery of modified biological particles suitable for downstream applications such as diagnostics or therapeutics. This approach can be extended to loading with other small molecules, such as fluorescent dye (like fluorescein), chemotherapy medication (like cisplatin), Cannabinoid, and to targeting different EV subpopulations via functionalization with receptors specific to markers including CD9, CD63, CD171 , CD3, MOG, or other membrane proteins, for research, analytical, diagnostic, theranostic, or therapeutic purposes.

[0411] Example 13: Protein Amount and Purity of the Purified EV Samples

[0412] The objective of this example is to quantify the total protein content in extracellular vesicle (EV) samples purified from various biological samples using the device of the present invention and to assess the purity of such EV samples based on the total protein.

[0413] EV samples were purified from 300 mL urine using a device (10) functionalized with anti-CD9 antibodies, from 500 mL milk using a device functionalized with anti-CD81 antibodies, from 0.04 mL blood using a device functionalized with anti-CD9 antibodies, and from 0.200 mL plasma using a device functionalized with anti-CD9 antibodies. The purification process involved introducing the device into the respective biological sample, applying a magnetic field to induce rotational motion of the device to promote interaction between the functionalized carbon fibers and the EVs, allowing the functionalized carbon fibers to bind the EVs, transferring the device to a washing solution to remove non-specific material, and applying an electrical potential to release the bound EVs into a release solution.

[0414] For protein quantification, 25 pL of each purified EV sample was added to 6.25 pL of RIPA buffer supplemented with protease inhibitor and incubated for 30 min at 4 °C. The samples were then sonicated twice for 1 min at room temperature. Subsequently, 3 pL of each sample was loaded onto a 96-well plate and added to 200 pL of Micro BCA assay reagent (Thermo Fisher Scientific). The samples were positioned near a calibration curve prepared from a stock solution of bovine serum albumin (BSA) that had been treated in a similar manner, with measurements performed in triplicates. A linear correlation was fitted using the least squares method, yielding the equation y = 0.2102x + 0.1356 with R2= 0.9977. The plate was incubated at room temperature for 24 h, after which absorbance was measured using an Infinite M200 Pro plate reader (Tecan) with the preset setup for BCA assay via the Tecan i-control software.

[0415] Table 2: The results are presented in Table 2, which details the protein quantities in the various EV samples based on the Micro BCA assay, including the total protein amount purified from each biosample.

[0416] These results demonstrate that the device enables the purification of EV samples with quantifiable protein content from diverse biological samples, including large volumes such as 300 mL urine and 500 mL milk, as well as small volumes such as 0.04 mL blood and 0.200 mL plasma. The total protein, supports the technical advantage of the invention in achieving high- purity EV isolates through specific receptor-mediated capture on functionalized carbon fibers and controlled electrical release, which minimizes non-specific protein binding and contamination while preserving EV integrity for downstream applications.

[0417] Example 14: Protein Markers and Impurities of the Purified EV Samples

[0418] The objective of this example was to evaluate the presence of extracellular vesicle (EV)- specific protein markers and a common protein impurity in EV samples purified from milk, urine, and blood using the device of the invention, in comparison to unpurified biological samples.

[0419] EV samples were purified from milk (approximately 10 pg protein), urine (approximately 3.5 pg protein), and blood (approximately 2 pg protein) using the device as described in previous examples. Unpurified urine (approximately 3.4 pg protein, as measured by microBCA assay) and plasma (approximately 3.5 pg protein, as measured by microBCA assay) served as control samples. The EV samples and control samples were lyophilized using an Epsilon 2-4 LSCpIus Lyophilizer (Christ). Each lyophilized sample was dissolved in 30 pL of deionized water (DIW), to which 7.5 pL of sample buffer (1 M Tris HCI, 10% (w / v) SDS, 30% (v / v) glycerol, 0.02% (w / v) bromophenol blue, pH 6.8) was added. The mixtures were heated for 5 minutes at 95 °C.

[0420] Samples were loaded onto a 12% polyacrylamide gel and electrophoresed at 90-100 V in running buffer (3% (w / v) Tris base, 14.4% (w / v) glycine, 1% (w / v) SDS). Proteins were transferred to 0.2 pm pore-sized Immun-Blot PVDF membranes (Bio-Rad Laboratories Inc.) using the Trans-Blot Turbo Transfer system for 10 minutes at 17 V and 1.3 A. The membranes were blocked with 5% (w / v) skim milk in Tris-buffered saline with Tween (TBST: 20 mM Tris, 150 mM NaCI, 1 % (v / v) polysorbate 20) for 1 hour at room temperature (RT). The membranes were then incubated with primary antibodies — mouse monoclonal anti-CD9 (sc-13118, Santa Cruz Biotechnology), mouse monoclonal anti-TSG101 (sc-7964, Santa Cruz Biotechnology), and mouse monoclonal anti-albumin (sc-271605, Santa Cruz Biotechnology) — diluted 1 :200 (v / v) in TBST overnight at 4 °C. Following incubation, the membranes were washed three times with TBST (10 minutes each, RT) and incubated with secondary HRP-conjugated polyclonal goat anti-mouse antibody (Dako) diluted 1 :1000 (v / v) in TBST for 3 hours at RT. The membranes were washed three times with TBST (10 minutes each, RT), incubated with Western Blotting Luminol reagent (Santa Cruz Biotechnology) according to the manufacturer's protocol, and imaged using a ChemiDoc MP Imaging System (Bio-Rad).

[0421] Western blot analysis revealed bands corresponding to the CD9 protein in the EV samples purified from blood and urine, but not in the corresponding unpurified samples. A band corresponding to the TSG101 cytosolic protein was observed in the EV sample purified from milk. A high-intensity band corresponding to albumin was observed solely in the unpurified plasma sample. These results are shown in FIG. 18, where panels (A), (B), and (C) correspond to samples derived from blood, urine, and milk, respectively. In each panel, lane 1 corresponds to the unpurified biological sample, and lane 2 corresponds to the EV fraction purified from the corresponding sample. In panels (A) and (B), the EV marker CD9 was detected in the purified EV fractions (A2, B2) but not in the respective unpurified samples (A1 , B1). In panel (C), the EV marker TSG101 was detected in the EV fraction purified from milk (C2). A prominent albumin band was present in the unpurified blood sample (A1) and absent in the corresponding purified EV fraction (A2).

[0422] The presence of EV-specific markers such as CD9 and TSG101 in the purified EV fractions, coupled with their absence or reduced detection in unpurified samples, demonstrates the device's capacity to selectively capture and enrich EVs from complex biological matrices. Furthermore, the absence of albumin in the purified EV fraction from blood indicates effective depletion of abundant protein impurities, thereby supporting the technical advantage of the invention in providing high-purity EV isolates suitable for downstream analytical applications.

[0423] Example 15: Hybrid Particles: Loading siRNA via Cationic Polymer

[0424] The objective of this example is to demonstrate the preparation of hybrid particles comprising extracellular vesicles (EVs) loaded with siRNA via complexation with a cationic polymer, using a device functionalized with anti-CD81 antibodies for EV capture and subsequent loading.

[0425] Polyplexes of polylysine (AS53057, Apollo Scientific) and Cy5-conjugated siRNA (SIC005, Merck) were prepared as follows. 6 mg of polylysine were dissolved in phosphate-buffered saline (PBS). 1 nmol of siRNA were dissolved in 100 pL of deionized water (DIW). 170 pL of DIW were combined with 10 pL of the siRNA solution and 20 pL of the polylysine solution, pipetted to mix, and allowed to complex for 1 hour at room temperature.

[0426] EVs were purified from 500 mL of pasteurized milk using a device modified with anti-CD81 antibody by incubating the device in the milk for 30 minutes at room temperature, followed by washing with PBS. The device with captured EVs was then transferred to the loading solution comprising the polyplex prepared as described above. The captured EVs were allowed to complex with the polyplex for 30 minutes at room temperature on a stirring plate. The device was then removed, washed with PBS and DIW, and the loaded EVs were released into 100 pL of DIW by applying a release voltage.

[0427] 200 pL of DIW were added to the released solution, and particle size was measured by dynamic light scattering (DLS) using a NanoZX instrument (Malvern Instruments). The average hydrodynamic diameter by number distribution was 74.33 nm with a standard deviation of 51.96 nm (FIG. 19A). An additional 300 pL of DIW were added, and zeta potential was measured using the NanoZX instrument. The zeta potential was 27.8 mV with a zeta deviation of 5.71 mV (FIG. 19B).

[0428] Quantification of loaded Cy5-siRNA was performed against a calibration curve of Cy5-siRNA in water using an Infinite M200 Pro plate reader (Tecan) at an excitation wavelength of 645 nm and an emission wavelength of 670 nm. The calculated concentration of siRNA in the EVs:polylysine:siRNA solution was approximately 0.9 nM, with an estimated number of 5-50 siRNA molecules per single EV.

[0429] The zeta potential of the loaded EVs (27.8 mV) represented an increase in positive surface charge relative to the negative charge of unloaded milk-derived EVs (-19.6 mV). This shift, together with the single-peak distributions observed in both size and zeta potential measurements, indicated successful complexation of the polylysine:siRNA payload with the EVs. Modification of biological particles using positively charged polymers enables the loading of negatively charged molecules, such as DNA and RNA, into hybrid particles. The low immunogenicity of vesicles, along with their natural role in intercellular communication and their receptor-mediated targeting capabilities, can be leveraged to develop advanced drugdelivery systems capable of targeted delivery. In general, this strategy can be used to load various biological particles that bind to the device surface — not only for drug delivery but also for other biomedical applications. This approach enables the creation of particles with different charges or receptors tailored for specific purposes in the body, or for analysis and theranostic applications. Similar hybrid particles have been reported to exhibit cellular RNA uptake and gene silencing. These results support the capability of the device and method to facilitate the transformation of captured biological particles into modified biological particles adapted for therapeutic applications, including gene delivery, by enabling surface functionalization and loading with genetic material while preserving particle integrity for downstream release and use.

[0430] Example 16: Purification of EVs from Urine and Blood Followed by LC-MS / MS Proteomics

[0431] This Example demonstrates the isolation of extracellular vesicles (EVs) from human urine and human blood using the device according to the present invention, followed by quantitative protein determination and comprehensive proteomic analysis by liquid chromatographytandem mass spectrometry (LC-MS / MS). The results confirm that the device enables efficient capture and electrically triggered release of EVs from both large-volume urine samples and minimal-volume blood samples, yielding sufficient pure EV material to permit identification of approximately 1 ,000 proteins per sample, including hundreds of annotated extracellular vesicle proteins and canonical EV markers.

[0432] EV Isolation from Urine: the device (10), functionalized with anti-CD9 antibody on the carbon fiber section, was placed in 300 mL of human urine and incubated for 30 minutes at room temperature with constant stirring induced by the magnetic section of the device. The device was removed, washed with 30 mL of phosphate-buffered saline (PBS) followed by 30 mL of deionized water (DIW). Captured EVs were released by immersing the device in an Eppendorf tube containing 200 pL of DIW and applying a potential of 3.0 V using the electrical releasing unit. Second and third releases were performed identically, with DIW rinsing of the device between releases. The three 200 pL fractions were combined, yielding a total volume of 600 pL of purified urine-derived EVs.

[0433] EV Isolation from Blood: the device (10), functionalized with anti-CD9 antibody, was placed in 40 pL of whole human blood diluted in 500 pL of PBS and incubated for 15 minutes at room temperature with constant stirring induced by the magnetic section. Captured EVs were released exactly as described above for urine (three successive 200 pL DIW releases at 3.0 V, with DIW rinsing between releases), and the fractions were combined to yield 600 pL of purified blood-derived EVs.

[0434] Protein Quantification: For each EV preparation, 20 pL was mixed with 5 pL of RIPA buffer and incubated for 30 minutes at 4 °C, followed by sonication (twice for 1 minute each at room temperature). Samples and BSA standards (treated identically, in triplicate) were loaded onto a 96-well plate and 150 pL of Micro BCA Protein Assay reagent (Thermo Fisher Scientific) was added to each well. The plate was incubated at 37 °C for 2 hours, and absorbance was measured using an Infinite M200 Pro plate reader (Tecan) with the manufacturer’s preset BCA protocol via i-control software. Measured total protein amounts were:

[0435] • Blood-derived EVs: 7.3 pg • Urine-derived EVs: 3.2 pg

[0436] LC-MS / MS Proteomic Analysis: The remaining EV samples were subjected to in-solution tryptic digestion and LC-MS / MS analysis as follows. Samples were dissolved in 1% sodium deoxycholate in 50 mM ammonium bicarbonate buffer, pH 8, reduced with 1 mM dithiothreitol, and alkylated with 5.5 mM iodoacetamide for 10 minutes at room temperature. Proteins were digested overnight with trypsin (Promega). Sodium deoxycholate was precipitated with 50% trifluoroacetic acid, and peptides were desalted using STAGE tips. Peptides were separated on a 20 cm self-packed Reprosil-Pur 120 C18-AQ 1.9 pm column using an EasyLC 1000 nano- HPLC and analyzed on an Orbitrap Astral mass spectrometer (both Thermo Fisher Scientific) in data-independent acquisition (DI A) mode (survey scan m / z 350-1200; 28 DI A windows of 31.4 m / z width; resolution 120,000 / 30,000; AGC 3 x 106; NCE 27%). Data were processed using Spectronaut 15.7 (Biognosys) in directDIA mode against the UniProt Homo sapiens reference proteome plus contaminants, followed by further analysis in Perseus.

[0437] Results: In urine-derived EVs, 968 proteins were identified. In blood-derived EVs, 1 ,138 proteins were identified. Of these, 651 proteins were common to both samples (FIG. 20).

[0438] Among the Gene Ontology term G0:0031982 (vesicle), 680 proteins in the urine-derived EVs and 663 proteins in the blood-derived EVs were annotated as extracellular vesicle-associated. Canonical EV / exosome markers CD9, TSG101 , CD63 and additional established markers were detected in both urine- and blood-derived EVs. Table 3 summarizes the tissue-origin annotation of identified proteins:

[0439] These results demonstrate that the device of the present invention enables the isolation of sufficient quantities of highly pure EVs from clinically convenient samples (300 mL urine or only 40 pL whole blood) to permit deep proteomic characterization by state-of-the-art LC- MS / MS, resulting in the identification of approximately 1 ,000 proteins per sample, including several hundred annotated vesicle proteins and canonical EV markers. The substantial overlap of 651 proteins between urine- and blood-derived EVs as well as the detection of tissuespecific proteins from organs such as brain, heart, liver, and kidney confirm the high sensitivity and low contamination of the isolation method and illustrate its suitability for non-invasive or minimally invasive liquid biopsy applications requiring comprehensive EV proteome profiling.

[0440] Example 17: Scanning electron microscope images of the fiber section 100

[0441] The fiber section 100 of the device according to the present invention was characterized by scanning electron microscopy (SEM) in order to visualize the morphology and confirm the dimensions of the micro-carbon fibers.

[0442] SEM imaging was performed using a Zeiss Merlin ultra-high resolution field-emission scanning electron microscope (FE-SEM). The sample was imaged using a secondary-electron detector at a magnification of approximately 997*, with an accelerating voltage of 2 kV and a probe current of 100 pA.

[0443] Figure 21 presents a representative scanning electron microscope (SEM) image of the microcarbon fiber section 100 of the device. The image clearly shows the bundled arrangement of the carbon fibers. Individual carbon fibers exhibited a diameter of approximately 7 microns.

[0444] The approximately 7-micron diameter of the carbon fibers, which falls within the preferred range of 1-10 microns recited in the claims, provides a high surface area-to-volume ratio and a densely packed yet accessible fibrous matrix. These structural features enable efficient functionalization with receptor molecules (e.g., antibodies, aptamers, or other ligands) and subsequent high-capacity binding of target biological particles, including extracellular vesicles, exosomes, viruses, and other nanosized entities, thereby contributing to the superior capture performance of the device. Example 18: device 10 variation and different uses

[0445] This example illustrates further variations of the device according to the present invention as well as alternative modes of operation that demonstrate the versatility, miniaturization potential, and high-throughput capability of the disclosed technology.

[0446] 18.1 Device Variations

[0447] FIGS. 23-25 depict additional embodiments of the device (10) that provide structural flexibility while preserving the core functionality of magnetic actuation, specific capture on the fiber section (100), and electrically triggered release of bound biological particles.

[0448] In the embodiment shown in FIG. 23, the magnetic component (102) is positioned so as not to directly contact the carbon fibers of the fiber section (100) and is fully enclosed within an insulating portion (101) of the assembly. A separate conductive element is provided that establishes physical and electrical contact with the fibers and serves as the electrical interface between the voltage source and the fiber section (100). This configuration electrically isolates the magnetic component from the conductive fibers and the sample medium during both capture and release steps.

[0449] In the embodiment shown in FIG. 24, the magnetic component (102) is not required to be in direct contact with the fibers and may be partially enclosed within the insulation-related portion (101) or disposed externally relative thereto. In certain implementations, the magnetic component is secured to the insulating material. In this arrangement, the conductive carbon fibers themselves function as the direct electrical contact with the voltage source, thereby permitting release of captured biological particles upon application of an electric potential directly to the fibers.

[0450] The embodiment illustrated in FIG. 25 integrates the counter electrode (108) (or alternatively another electrode such as the reference electrode (116)) within the device (10) itself. An additional insulation layer (117) is provided to isolate the integrated electrode from the fiber section (100). This configuration achieves further miniaturization of the electrochemical release architecture and enables electrochemical analyses or release to be performed using substantially reduced sample volumes compared to setups requiring an external counter electrode.

[0451] 18.2 Exemplary Modes of Use: Passive capture in a miniature cartridge (FIG. 26)

[0452] A device (10) comprising carbon fibers of the fiber section (100) functionalized with anti-CD9 antibodies was placed within a pipette tip-shaped plastic cartridge or housing (119). The housing (119) was first filled with 20 pL of phosphate-buffered saline (PBS). Subsequently, 20 pL of whole blood (118) containing extracellular vesicles was injected into the housing (119). Upon simple contact with the functionalized fibers, the extracellular vesicles were passively adsorbed onto the fiber surfaces and retained within the fiber matrix. Notably, capture occurred efficiently without any agitation, mixing, or application of an external magnetic field. This mode of operation demonstrates that the device can achieve high-efficiency capture of target biological particles in very small sample volumes (total 40 pL) and in a completely passive manner, eliminating the need for active magnetic stirring in certain applications and enabling integration into microfluidic or point-of-care formats.

[0453] 18.3 Exemplary Modes of Use: Parallel high-throughput processing (FIG. 27)

[0454] A plurality of devices (10) were simultaneously placed on a single magnetic mixing plate (103), with each device (10) immersed in a respective biological sample (118) contained within a separate 1.5 mL tube. Application of a rotating magnetic field from the magnetic mixing plate (103) induced rotational motion in all devices concurrently, thereby promoting interaction between each fiber section (100) and the biological particles present in the corresponding sample. This parallel configuration enabled simultaneous capture of target biological particles from multiple samples in a single run. The setup facilitates high-throughput processing of large sample volumes per device while maintaining compatibility with standard laboratory tubes and seamless integration with automated liquid-handling and robotic systems.

[0455] The variations and operational modes described in this example collectively demonstrate that the device (10) can be structurally adapted (e.g., separation of magnetic and electrical functions, integration of electrodes, altered positioning of the magnetic component) without loss of performance, while supporting diverse use cases ranging from passive, ultra-low- volume capture to fully automated, high-throughput magnetic processing. These features enhance the device’s applicability across point-of-care, laboratory, and industrialized settings.

Claims

Claims1. A device (10), adapted for isolating biological particles from a biological sample (104, 118), the device comprising:• a fiber section (100) composed of carbon fibers, wherein the carbon fibers are functionalized with specific receptor molecules to bind biological particles;• a magnetic section (102) configured to induce rotational motion of the device in response to an external magnetic field; and• a voltage source contact configured to enable the application of an electrical potential to release captured biological particles from the fiber section.

2. The device of claim 1 , where• the magnetic section and voltage contact are combined into a single, integrated component (102); or• the magnetic section and voltage contact are present as separate, discrete elements (202, 302).

3. The device of claim 1 or 2, wherein the receptor molecules are selected from the group consisting of antibodies, aptamers, peptides, or other ligands specific to biological particles.

4. The device of claim 1 to 3, wherein the biological particles are selected from the group consisting of extracellular vesicles, exosomes, viruses, bacterial particles, and combinations thereof; or wherein the biological particles are selected from the group consisting of bacteria and bacterial particles, nucleic acid-bound complexes, lipoproteins, protein complexes and aggregates, cellular organelles and fragments, pathogenic particles, synthetic and hybrid biological particles, biodebris and cellular waste products, therapeutically modified particles, rare and specialized particles, environmental and agricultural samples, and combinations thereof.

5. The device of claim 1 to 4, wherein the fiber section (100)• has a diameter in the range of 1-10 microns; and / or• comprises material selected from graphene sheets, graphene oxide, carbon nanotubes, metal nanowires, conductive polymers and functionalized synthetic fibers.Sr The device of claim 1 to 5, further comprising an insulation section (101), wherein the insulation section is present in a form of a protective layer that surrounds and isolates the fiber section and the magnetic section to thereby prevent undesired electrical interactions or cross-contamination during operation.

7. The device of claim 1 to 6, wherein the magnetic section (102)• comprises a magnetic material, preferably selected from (i) Neodymium or ferrite materials, (ii) Iron or iron oxide nanoparticles embedded in a polymer matrix, (iii) Cobalt alloys including samarium-cobalt; and (iv) Soft magnetic composites; and I or• enables the device to move, particularly to rotate, within a solution under an external magnetic field.

8. The device of claim 1 to 7, wherein the electrical potential applied to the fiber section is configured to release the bound biological particles by disrupting receptor-particle interactions.

9. The device according to any one of claims 1 to 8, wherein:• the device is rod-shaped and has an overall length of 1 - 100 mm, preferably 10 - 12 mm;• the magnetic section has a diameter of 1 - 90 mm, preferably about 2 mm;• the insulation section has:- a length of 1 - 100 mm, and- a thickness of 1 - 90 mm, preferably 3 - 4 mm;• the insulation section is configured to:- at least partially separate the fiber section from the biological sample such that a portion of the fiber section remains exposed to the biological sample; and- partially or completely separate the magnetic section and / or the voltage-source contact from the biological sample so as to maintain structural integrity of the device;• the insulation section comprises a material resistant to aqueous solutions, including silicone rubber or a polymeric material.

10. The device of claim 1 to 9, wherein the device can function as an electrode in a multielectrode setup, particularly to thereby identify bound biological particles based on their unique electrochemical signatures.

11. A method for isolating biological particles from a biological sample, comprising the steps consecutive steps a. to f. : a. introducing the device (10) of any of claims 1 to 10 into the biological sample (104); b. applying a magnetic field to induce motion, particularly rotational motion, of the device and promote interaction between the fiber section and the biological particles; c. allowing the functionalized carbon fibers to bind the biological particles; d. transferring the device to a washing solution to remove non-specific material; and e. applying an electrical potential to release the bound biological particles into a release solution.

12. The method of claim 11 , where• the biological sample in step a has a volume in the range of volumes of more than 0.1 pL and preferably in the range of 0.1 pL to 10 L; and / or• the electrical potential applied to the device in step e is in the range of -300 V to +300 V; and I or• the absolute value of the applied electrical potential in step e is 3 V or less.

13. The method of claim 11 to 12, further comprising f. analyzing the released biological particles using electrochemical methods, dynamic light scattering, or other analytical techniques, to thereby identify or quantify the released biological particles.

14. The method of any one of claims 11 to 13, further comprising step g : g-1. exposing the captured biological particles to a solution comprising one or more small molecules selected from drugs, labeling agents, hydrophilic molecules, amphiphilic molecules, and lipophilic molecules; g-2. optionally applying a loading voltage to promote uptake of the small molecules into the biological particles; and g-3. recovering the resulting modified biological particles by applying an electrical potential; to thereby obtain modified biological particles loaded with small molecules.

15. The method of claim 11 to 14, wherein the captured particles are released into a solution through the application of a controlled electrical potential, preserving their integrity for downstream applications.

16. A system for capturing and releasing biological particles, comprising: the device of claim 1 to 10; a magnetic stirring apparatus to provide a rotating magnetic field; a voltage source configured to apply an electrical potential to the fiber section of the device; and an analytical instrument configured to analyze captured or released biological particles, and wherein the system is optionally integrated into automated systems for real-time diagnostics or therapeutic production.

17. Use of the device according to any one of claims 1 to 10 for the transformation of captured biological particles into modified biological particles, the transformation comprising at least one of surface functionalization of the captured particles, biochemical labeling, genetic modification of the particles, encapsulation, co-delivery customization, enzymatic modification, or composite-particle formation, wherein the resulting modified biological particles are adapted for therapeutic applications, including drug delivery, vaccination, immunotherapy, gene delivery.

18. Use of the device according to any one of claims 1 to 10 for downstream characterization of biological particles captured by the device, wherein the downstream characterization preferably comprises at least one technique selected from the group consisting of: electrochemical analyses; microscopy-based analyses; molecular and omics-based analyses; immunoassays; molecular detection assays; mass-spectrometry-based analyses.

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