Magnetic nanoparticles for selective enrichment of low- abundance plasma proteins in proteomic analysis
Magnetic nanoparticles with tailored functionalizations address the challenges of low-abundance plasma protein enrichment, offering scalable, cost-effective, and reusable solutions for improved biomarker detection and clinical diagnostics.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- WANG QING
- Filing Date
- 2024-12-31
- Publication Date
- 2026-07-09
Smart Images
Figure US2024062398_09072026_PF_FP_ABST
Abstract
Description
[0001] COMPL-004PCT-SPEC
[0002] Magnetic Nanoparticles for Selective Enrichment of Low- Abundance Plasma Proteins in Proteomic Analysis TECHNICAL FIELD
[0003]
[0001] The present invention relates to the field of proteomics, specifically to methods and compositions for enriching low-abundance proteins from plasma samples using magnetic nanoparticles. This invention further pertains to diagnostic applications in biomarker discovery, clinical proteomics, and cancer diagnostics. It also encompasses advancements in materials science for the development of functionalized nanoparticles and their integration into high-throughput workflows for biomedical research and precision medicine.
[0004] BACKGROUND
[0005]
[0002] Plasma proteomics has become an indispensable tool for identifying biomarkers critical for early cancer detection. These biomarkers, often present at low concentrations, offer significant diagnostic and therapeutic potential. However, plasma proteins span an exceptionally broad dynamic range — up to 12 orders of magnitude — making the detection of low-abundance proteins particularly challenging. High-abundance proteins such as albumin and immunoglobulins dominate plasma, obscuring the detection of clinically relevant low-abundance proteins, as highlighted in foundational studies of plasma protein analysis (Anderson and Anderson, Molecular & Cellular Proteomics 2002, 1(11), 845-867).
[0006]
[0003] Our previous work on an ovarian cancer diagnostic pipeline demonstrated the ability to identify and validate 652 protein biomarkers using mass spectrometry. While this targeted approach yielded exceptional accuracy, it required labor-intensive manual optimization for each biomarker to ensure sensitive detection, underscoring the need for more efficient methodologies (SAFE-SRM pipeline; Wang et al., PNAS 2017, 114 (51) 13519-13524).
[0007]
[0004] To address these challenges, immunoaffinity depletion techniques have been extensively employed. Protein-G beads and other affinity -based methods are commonly used to remove high-abundance proteins, thus simplifying sample composition. These techniques, as reviewed by Davankov et al., focus on analytical separation principles that can achieve high specificity but often require significant manual intervention and are limited by scalability constraints (Davankov, Pure and Applied Chemistry 1997, 69(7), 1469-1474). Fractionation techniques, such as ion-COMPL-004PCT-SPEC
[0008] exchange chromatography, have further enhanced the ability to separate proteins based on physicochemical properties, building on earlier work by Cohn and colleagues that established the principles of protein precipitation and fractionation (Cohn et al., Journal of the American Chemical Society 1946, 68(3), 459-475).
[0009]
[0005] Nanoparticle-based enrichment methods have revolutionized the field by providing enhanced selectivity and sensitivity. For instance, SEER’s Proteograph™ Product Suite utilizes a diverse set of nanoparticles with tailored surface functionalizations to form protein coronas. This system captures proteins across a wide dynamic range, addressing some of the key limitations of traditional approaches. However, the Proteograph faces challenges in scalability and cost, as it relies on single-use nanoparticles and complex workflows, as detailed by Blume et al. in their investigation of proteomic profiling using nanoparticle systems (Blume et al., Nature Communications 2020, 11, Article No. 3662).
[0010]
[0006] Further advancements in protein tracking include nucleic acid barcoding methods. Encodia, Inc., has pioneered the use of DNA-encoded libraries to monitor protein interactions with high specificity. While this approach offers precise molecular tracking, it introduces operational complexities that limit its suitability for high-throughput workflows, as described in the Encodia patent application (Beierle et al., US Patent Application Publication No. US2020 / 0348307A1).
[0011]
[0007] Another promising alternative is precipitation-based fractionation. PreOmics GmbH’s seeded precipitation method utilizes rough surfaces or particulate matter to induce selective fractionation under controlled physicochemical conditions. This approach avoids protein denaturation and enhances fractionation efficiency. However, it lacks the flexibility and reusability offered by advanced nanoparticle-based platforms, making it less adaptable to varied proteomic workflows (Kulak et al., US Patent Application Publication No. US2024 / 0132539A1).
[0012]
[0008] Mesoporous silica nanoparticles have also been highlighted for their ability to selectively trap proteins based on size exclusion. With optimized porosity, these nanoparticles offer an alternative strategy for capturing low-abundance proteins. However, their application is limited by a lack of surface functional diversity, which restricts broader use in plasma proteomics workflows (Blume et al., Nature Communications 2020, 11, Article No. 3662).
[0013]
[0009] In light of these limitations, the present invention introduces a series of novel magnetic nanoparticles designed to selectively enrich low-abundance plasma proteins. These nanoparticles are functionalized with diverse chemical moieties, including hydroxyl (-OH), carboxyl (-COOH),COMPL-004PCT-SPEC
[0014] primary amine (-NH2), and weak ion exchangers (WAX, WCX), enabling targeted interactions based on protein physicochemical properties. By integrating reusable designs and enhancing scalability, the invention addresses critical shortcomings of existing technologies like SEER’s Proteograph. The optimized porosity and surface charge of these nanoparticles further enhance trapping efficiency, setting a new standard in plasma proteomics.
[0015]
[0010] This invention represents a transformative advancement in biomarker discovery and early cancer detection, bridging the gaps left by traditional methods and offering a robust, scalable, and cost-effective solution.
[0016] SUMMARY
[0017] [Oil] The purpose of the present invention is to provide a novel system and methodology for enriching low-abundance proteins from plasma samples using magnetic nanoparticles with tailored surface functionalizations. This invention addresses the challenges of detecting clinically relevant biomarkers in plasma proteomics by offering a scalable, cost-effective, and reusable solution that enhances sensitivity and specificity, paving the way for advanced diagnostic and therapeutic applications.
[0018]
[0012] In one embodiment, the invention provides magnetic nanoparticles with a core-shell structure, where the core comprises a magnetite material, and the shell is functionalized with chemical groups comprising hydroxyl (-OH), carboxyl (-COOH), primary amine (-NH2), weak anion exchanger (WAX), and weak cation exchanger (WCX). These functionalizations enable selective binding of low-abundance plasma proteins while reducing interference from high-abundance proteins. The silica shell enhances the mechanical stability of the nanoparticles and can be applied via a sol-gel process. In another embodiment, the nanoparticles feature tunable porosity ranging from 1 to 100 nm, which allows size-selective trapping of proteins based on molecular dimensions, enhancing enrichment specificity.
[0019]
[0013] In one embodiment, a method for preparing functionalized magnetic nanoparticles is disclosed. The preparation involves synthesizing magnetite cores via co-precipitation, coating the cores with silica for stability, and subsequently functionalizing the surface with chemical groups using silane coupling agents. In another embodiment, the nanoparticles can be modified using alternative linkers or chemical treatments to introduce multifunctional surfaces, enabling simultaneous binding of acidic, basic, hydrophobic, and hydrophilic plasma proteins. Furthermore,COMPL-004PCT-SPEC
[0020] the surface charge density of the nanoparticles can be adjusted to optimize binding specificity for targeted plasma proteins.
[0021]
[0014] In one embodiment, the invention describes a method for enriching low-abundance plasma proteins by incubating plasma with functionalized magnetic nanoparticles. This method includes magnetic separation to isolate the protein-bound nanoparticles, followed by elution of the enriched protein fraction using a buffer solution with a pH range optimized to maintain protein integrity. In another embodiment, the enriched proteins are subjected to on-bead digestion directly after magnetic separation for downstream analysis using mass spectrometry or immunoassays, streamlining the workflow for high-throughput applications.
[0022]
[0015] In one embodiment, the invention emphasizes the reusability of the magnetic nanoparticles. After protein elution, the nanoparticles are regenerated through washing with a mild acidic or neutral buffer, ensuring their functionality remains intact for multiple enrichment cycles. In another embodiment, harsher cleaning protocols can be employed for certain applications without compromising the nanoparticles’ structural integrity.
[0023]
[0016] In one embodiment, the invention integrates magnetic nanoparticles into plasma proteomics workflows for clinical diagnostics. The system supports the detection and quantification of low-abundance biomarkers such as cancer-specific antigens, enabling early diagnosis and monitoring of disease progression. In another embodiment, the enriched plasma proteins are analyzed in a clinical setting using targeted assays or mass spectrometry to facilitate personalized medicine and therapeutic deci si on -making.
[0024]
[0017] In one embodiment, the invention supports high-throughput workflows by enabling the seamless integration of magnetic nanoparticles into automated platforms. The workflow includes automated sample preparation, nanoparticle incubation, magnetic separation, and downstream analysis. In another embodiment, the system allows for multiplexing of samples, further enhancing throughput and reducing time-to-result.
[0025]
[0018] In one embodiment, the scalability of the system is achieved through continuous flow synthesis methods for producing magnetic nanoparticles. This approach ensures batch-to-batch consistency in size, porosity, and functionalization, meeting the requirements for clinical and industrial applications. In another embodiment, the scalable production method includes quality control measures to ensure high performance and reproducibility.COMPL-004PCT-SPEC
[0026]
[0019] In one embodiment, the invention provides comparative performance metrics to demonstrate superiority over conventional enrichment methods. Metrics include protein recovery rates, specificity, and sensitivity, evaluated using plasma samples. In another embodiment, benchmarking experiments highlight improvements in detection limits and reproducibility, underscoring the advantages of the proposed system.
[0027]
[0020] In one embodiment, the invention introduces advanced functionalizations of magnetic nanoparticles to capture a broad spectrum of plasma proteins. These include dual-functionalized surfaces combining hydrophilic and hydrophobic groups or acidic and basic moieties, enabling the capture of diverse protein subsets. In another embodiment, the nanoparticles are tailored for disease-specific enrichment by incorporating ligands or antibodies targeting specific biomarkers.
[0028]
[0021] In one embodiment, the invention focuses on clinical usage by applying the nanoparticlebased system in real-world diagnostics. Plasma samples are processed to enrich disease-specific biomarkers, such as CA-125 for ovarian cancer or PSAfor prostate cancer. In another embodiment, the system facilitates longitudinal biomarker monitoring, enabling personalized treatment plans and therapeutic efficacy evaluation.
[0029] BRIEF DESCRIPTION OF THE DRAWINGS
[0030]
[0022] Figure 1: Schematic Representation of Magnetic Nanoparticles and Their Functionalization. Figure 1 illustrates the structural design and functionalization of the magnetic nanoparticles. The nanoparticles feature a core-shell structure with a magnetite core and a silica shell. The surface functional groups, including hydroxyl (-OH), carboxyl (-COOH), primary amine (-NH2), weak anion exchanger (WAX), and weak cation exchanger (WCX), are depicted as being applied to the silica shell via silane coupling agents. The figure also demonstrates the tunable porosity of the silica shell, designed to selectively trap plasma proteins based on molecular dimensions. This schematic emphasizes the role of functional groups in enhancing binding specificity and protein capture efficiency.
[0031]
[0023] Figure 2: Workflow for Protein Enrichment Using Magnetic Nanoparticles. Figure 2 illustrates the step-by-step workflow for enriching low-abundance plasma proteins using the magnetic nanoparticles. The process begins with the incubation of plasma samples with functionalized nanoparticles to enable selective protein binding. The protein-bound nanoparticles are then isolated via magnetic separation, followed by the elution of enriched protein fractionsCOMPL-004PCT-SPEC
[0032] using a buffer solution. The figure also highlights the optional step of on-bead digestion for downstream analysis, such as mass spectrometry, and depicts the reusability of the nanoparticles after regeneration through buffer washing. This workflow demonstrates the integration of the nanoparticles into high-throughput plasma proteomics applications.
[0033]
[0024] Figure 3: Comparative Protein Enrichment Efficiency of SuperDeep Nanoparticles.
[0034] Figure 3 illustrates the comparative enrichment efficiency of the five SuperDeep nanoparticle types (Si-WAX, Si-WCX, Si-COOH, GS-OH, and Si-NH2) under optimized experimental conditions. The figure depicts enrichment performance metrics, including the total number of proteins detected and enrichment specificity from a variety of different vendors on the market. The comparative analysis highlights the superior performance of the SuperDeep nanoparticles in terms of sensitivity and reproducibility compared to existing commercial products.
[0035]
[0025] Figure 4: Plasma Proteomic Profiles of Normal and Cancer Samples Enriched Using SuperDeep Nanoparticles. Figure 4 shows the proteomic profiles obtained from plasma samples enriched with the SuperDeep nanoparticles. The profiles include the proteins’ fold change data calculated by comparing pancreatic cancer plasma and normal plasma samples, highlighting differentially expressed proteins. Key findings include 1,592 proteins uniquely identified in pancreatic cancer samples and their fold-change differences compared to normal samples. The figure demonstrates the nanoparticles’ ability to selectively enrich low-abundance cancer-specific biomarkers, enabling detailed proteomic analysis for disease characterization and biomarker discovery.
[0036] DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
[0037]
[0026] Plasma proteomics represents one of the most critical fields in biomarker discovery, particularly in cancer diagnostics. Plasma, as a complex biofluid, contains over 100,000 proteins including different isoforms from the same gene and proteins with different post-translational modifications, spanning an exceptionally wide dynamic range, from highly abundant proteins such as albumin and immunoglobulins to low-abundance proteins that hold significant diagnostic potential. Detecting these low-abundance proteins is challenging due to their minuscule concentrations and interference from dominant proteins. Traditional methods, such as immunoaffinity depletion or size-exclusion chromatography, suffer from limitations including high costs, limited scalability, and insufficient specificity. To address these challenges, the presentCOMPL-004PCT-SPEC
[0038] invention introduces magnetic nanoparticles (MNPs) with advanced surface functionalizations that enable selective binding and enrichment of low-abundance proteins. This approach not only enhances sensitivity but also facilitates seamless integration into clinical and high-throughput workflows.
[0039] Magnetic Nanoparticles
[0040]
[0027] Magnetic nanoparticles (MNPs) have become critical tools in addressing the challenges of plasma proteomics, particularly the enrichment of low-abundance proteins for diagnostic and therapeutic applications. Plasma is a highly complex biological fluid containing thousands of proteins with an enormous dynamic range, dominated by high-abundance proteins such as albumin and immunoglobulins. These dominant proteins obscure low-abundance proteins that are often indicative of disease states, making their detection both resource-intensive and technically challenging. Traditional enrichment methods, such as immunoaffinity depletion and precipitation, are inadequate due to their inability to achieve high specificity, scalability, or cost efficiency. The present invention overcomes these limitations by leveraging the unique properties of magnetic nanoparticles tailored for protein enrichment.
[0041]
[0028] The core of the nanoparticle comprises magnetite (FesC ), a material known for its superparamagnetic properties. These properties ensure rapid and efficient separation of the nanoparticles under an external magnetic field without residual magnetism, preventing aggregation and maintaining consistent performance across multiple enrichment cycles. The magnetite cores are synthesized using a co-precipitation method, wherein ferric and ferrous ions are precipitated in an alkaline medium. Reaction parameters such as temperature, pH, and stirring speed are precisely controlled to achieve a narrow size distribution, typically between 10 and 20 nanometers, providing uniform magnetic responsiveness.
[0042]
[0029] Encasing the magnetite core is a silica shell, which serves multiple critical roles. First, it protects the magnetite from oxidation, ensuring the long-term stability of the nanoparticles. Second, the silica shell enhances the biocompatibility of the nanoparticles, minimizing non-specific interactions with plasma proteins. Finally, the silica surface provides a robust and versatile platform for chemical functionalization. The shell is applied using a sol-gel process involving the hydrolysis and condensation of tetraethyl orthosilicate (TEOS) in an alcohol-water mixture, yielding a uniform and durable silica layer. Analytical characterization of the silica-coatedCOMPL-004PCT-SPEC
[0043] nanoparticles confirms their uniformity, stability, and suitability for functionalization. Transmission Electron Microscopy (TEM) is used to visualize the core-shell structure, revealing a consistent silica coating surrounding the magnetite core. Dynamic Light Scattering (DLS) measurements indicate a hydrodynamic diameter of approximately 30-50 nm, depending on the thickness of the silica layer. The zeta potential of the nanoparticles is also measured to assess surface charge, with results confirming the presence of negatively charged silanol groups prior to functionalization.
[0044]
[0030] The functionalization of the silica shell incorporates five key groups designed to interact selectively with plasma proteins:
[0045] 1. Carboxyl (-COOH) Groups: Carboxyl groups are essential for covalent and electrostatic interactions with target proteins, particularly phosphorylated proteins and other negatively charged molecules. These interactions are highly effective for capturing signaling molecules and post-translationally modified proteins, making the nanoparticles valuable for studying pathways implicated in diseases such as cancer.
[0046] 2. Amino (-NIL) Groups: Amino groups provide versatility in binding negatively charged proteins and glycoproteins. These groups enable the covalent immobilization of antibodies and other affinity ligands, broadening the application scope to include diverse protein classes critical for diagnostic and therapeutic purposes.
[0047] 3. Weak Anion Exchanger (WAX): WAX-functionalized nanoparticles are optimized for binding acidic proteins under basic conditions. This functionality is particularly valuable for enriching plasma proteins with low isoelectric points, which often play significant roles in inflammation and immune responses.
[0048] 4. Weak Cation Exchanger (WCX): WCX-functionalized nanoparticles selectively bind basic proteins under acidic conditions. These nanoparticles target positively charged plasma proteins, including those involved in cellular signaling and structural integrity.
[0049] 5. Hydroxyl (-OH) Groups: Hydroxyl groups offer broad-spectrum binding capabilities due to their non-specific interactions with a wide range of plasma proteins. These groups are particularly effective in initial fractionation steps, where the goal is to capture as many protein classes as possible for downstream analysis. The -OH functionality enhances the hydrophilic properties of the nanoparticles, making them suitable for complex biological matrices like plasma.COMPL-004PCT-SPEC
[0050]
[0031] Each functional group is applied in a controlled process to ensure uniform coverage across the silica surface. For example, APTES is used to introduce amino groups, while 3-mercaptopropyltrimethoxysilane is employed for sulfhydryl groups. Fourier Transform Infrared Spectroscopy (FTIR) is used to confirm the successful incorporation of these functional groups, with characteristic absorption peaks corresponding to specific bonds. Thermogravimetric Analysis (TGA) validates the stability of the functionalized silica coating.
[0051]
[0032] The invention also incorporates tunable porosity into the silica shell, with pore sizes ranging from 1 to 100 nanometers. This feature ensures size-selective trapping of proteins while excluding non-target molecules, such as high-abundance proteins or contaminants. Thermogravimetric Analysis (TGA) confirms the incorporation and stability of functional groups on the silica shell, while Vibrating Sample Magnetometry (VSM) measurements validate the superparamagnetic properties of the nanoparticles. Magnetic separation efficiency is tested across multiple plasma samples, demonstrating consistent and rapid isolation of protein-bound nanoparticles within seconds of applying an external magnetic field.
[0052]
[0033] The reusability of the nanoparticles is another cornerstone of this invention. After each enrichment cycle, the nanoparticles are regenerated by washing with mild acidic or neutral buffers, such as 0.1 M citric acid. This simple regeneration protocol removes residual proteins and restores the functionality of the surface groups, maintaining over 90% of the nanoparticles’ binding efficiency after 10 cycles. For applications requiring higher stringency, harsher cleaning methods involving diluted organic solvents or enzymatic treatments can be employed without degrading the silica shell or magnetite core. Durability tests conducted under varying storage conditions (e.g., different temperatures, buffer compositions) confirm that the nanoparticles retain their functional and structural integrity over extended periods, making them suitable for long-term use.
[0053]
[0034] Performance evaluations conducted under optimized experimental conditions highlight the superior capabilities of these nanoparticles. Comparative studies with leading commercial products demonstrate higher recovery rates, greater sensitivity, and improved reproducibility. Key metrics include:
[0054] 1. Protein recovery rates exceeding 90%.
[0055] 2. Sensitivity thresholds capable of detecting nanogram-per-milliliter concentrations.
[0056] 3. A coefficient of variation (CV) below 5%, ensuring reliable results across replicates.COMPL-004PCT-SPEC
[0057]
[0035] The invention’s application extends beyond research settings into clinical diagnostics, where it enables the detection and quantification of disease-specific biomarkers. For example, CA-125 and PSA are enriched from plasma samples for the early detection of ovarian and prostate cancer, respectively. The system is also compatible with cardiovascular, neurodegenerative and autoimmune disease diagnostics, where plasma protein profiling plays a critical role in disease management. Additionally, the nanoparticles are seamlessly integrated into high-throughput workflows, allowing for the processing of hundreds of plasma samples per day. This automation reduces manual intervention, improves consistency, and accelerates diagnostic timelines.
[0058]
[0036] By integrating advanced functionalization strategies, tunable porosity, and exceptional reusability, the magnetic nanoparticles developed in this invention address key challenges in plasma proteomics by combining advanced material science with precise functionalization. Their scalability, reusability, and exceptional performance metrics make them indispensable for both research and clinical applications, paving the way for breakthroughs in disease diagnostics and personalized healthcare.
[0059] Protein Enrichment Process
[0060]
[0037] The enrichment of proteins, particularly low-abundance plasma proteins, is a critical step in proteomics for biomarker discovery and disease diagnostics. Plasma contains a highly complex proteome, with over 100,000 proteins spanning an enormous dynamic range. High-abundance proteins, such as albumin and immunoglobulins, dominate the plasma proteome, often masking the presence of low-abundance proteins with significant diagnostic and therapeutic importance. These proteins, including cytokines, growth factors, and disease-specific biomarkers, are vital for understanding disease mechanisms, monitoring progression, and personalizing treatment strategies.
[0061]
[0038] To overcome the challenges of enriching low-abundance proteins, this invention employs magnetic nanoparticles (MNPs) functionalized with diverse chemical groups. The functional groups introduced onto the nanoparticles’ silica shell are tailored to selectively bind proteins based on physicochemical properties such as charge, hydrophobicity, and post-translational modifications. Table 1 in the accompanying paper highlights the unique functional groups used in this invention, and each is explicitly incorporated into the enrichment workflow.
[0062]
[0039] The carboxyl (-COOH) group facilitates covalent and electrostatic interactions with phosphorylated and negatively charged proteins, playing a key role in isolating signalingCOMPL-004PCT-SPEC
[0063] molecules crucial for cancer research. The primary amine (-NH2) group enables binding to negatively charged or glycosylated proteins, broadening the scope of target protein classes. Weak anion exchangers (WAX) and weak cation exchangers (WCX) are employed for complementary charge-based interactions, capturing acidic proteins at basic pH and basic proteins at acidic pH, respectively. Additionally, hydroxyl (-OH) groups provide non-specific binding capabilities, making them suitable for broad-spectrum protein enrichment.
[0064]
[0040] Figure 2 provides a detailed workflow for protein enrichment using magnetic nanoparticles. The figure outlines the sequential steps, including bead activation, protein binding, washing, digestion, peptide desalting, and final peptide collection. Each step is visually represented to demonstrate the interaction of plasma proteins with the functionalized nanoparticle surfaces, ensuring efficient and reproducible enrichment.
[0065]
[0041] The workflow begins with plasma sample preparation. Plasma samples are thawed and centrifuged at 12,000 g for 15 minutes at 4°C to remove debris, ensuring a clean starting material for enrichment. Pre-treated plasma is equilibrated to room temperature, and functionalized magnetic nanoparticles are added in a binding buffer tailored to the desired protein class. For example, Tris-HCl buffers at pH 7.4 are used for neutral binding conditions, while pH-adjusted buffers accommodate specific protein classes, such as phosphorylated proteins enriched under slightly acidic conditions.
[0066]
[0042] The binding step involves incubating the plasma with nanoparticles at 37°C for 1-2 hours under gentle agitation to promote efficient nanoparticle-protein interactions. During this process, the functional groups on the nanoparticles capture proteins selectively, leveraging electrostatic, covalent, and hydrophilic interactions to bind target molecules. For instance, WAX-functionalized nanoparticles effectively capture acidic plasma proteins, while WCX-functionalized nanoparticles target positively charged proteins. Hydroxyl-functionalized nanoparticles provide broader coverage, capturing a wide range of plasma proteins, making them suitable for initial fractionation steps.
[0067]
[0043] After binding, magnetic separation is used to isolate protein-bound nanoparticles from unbound plasma components. An external magnetic field is applied, pulling the nanoparticles to the container's wall, allowing the supernatant to be removed without disturbing the bound proteins. This step is followed by a series of washing cycles using buffers designed to remove loosely boundCOMPL-004PCT-SPEC
[0068] contaminants. For example, washing with 0.1% formic acid effectively removes non-specifically bound proteins while preserving the integrity of the bound target proteins.
[0069]
[0044] The elution step releases the bound proteins from the nanoparticles. Elution buffers, such as 0.1 M acetic acid or 70% acetonitrile with 0.1% formic acid, are used to disrupt the interactions between the functional groups and the proteins. These elution conditions are carefully optimized to ensure complete protein recovery without compromising their structural or functional integrity.
[0070]
[0045] For downstream applications, the enriched proteins can undergo enzymatic digestion directly on the nanoparticles. On-bead digestion involves adding proteolytic enzymes such as trypsin to the nanoparticle-bound proteins, converting them into peptides suitable for mass spectrometry analysis. This optional step minimizes handling and reduces the risk of protein loss or contamination, streamlining the workflow for high-throughput proteomics.
[0071]
[0046] The nanoparticles’ reusability is a cornerstone of the enrichment process, enhancing its cost-effectiveness and scalability. After each enrichment cycle, the nanoparticles are regenerated through washing with mild acidic buffers, such as 0.1 M citric acid, which restores the activity of the functional groups. This regeneration protocol has been validated to maintain over 90% of the nanoparticles’ binding efficiency after 10 consecutive cycles. For applications involving strongly adhered proteins, harsher cleaning methods using organic solvents or enzymatic treatments can be employed without compromising the structural stability of the silica shell or the magnetite core.
[0072]
[0047] The enrichment process delivers exceptional performance metrics, including protein recovery rates exceeding 90% and detection thresholds in the nanogram-per-milliliter range. Its reproducibility is demonstrated through a coefficient of variation (CV) below 5% across replicate experiments. These results have been benchmarked against leading commercial products, consistently demonstrating superior sensitivity and specificity.
[0073]
[0048] Clinically, the protein enrichment process supports the detection of biomarkers such as CA-125 for ovarian cancer and PSAfor prostate cancer, enabling early diagnosis and improving patient outcomes. The process is also highly scalable, compatible with automated workflows for processing hundreds of plasma samples daily. This scalability makes it suitable for large-scale clinical studies and high-throughput proteomic research.
[0074]
[0049] In summary, the protein enrichment process developed in this invention represents a transformative approach to isolating low-abundance plasma proteins. By leveraging the unique functionalization of magnetic nanoparticles, the process achieves unparalleled sensitivity,COMPL-004PCT-SPEC
[0075] specificity, and reproducibility, paving the way for breakthroughs in biomarker discovery, clinical diagnostics, and personalized medicine.
[0076] Exceptional Performance Metrics of Magnetic Nanoparticles Compared to Conventional Enrichment Methods
[0077]
[0050] The invention’s magnetic nanoparticles (MNPs) demonstrate exceptional performance metrics that set a new standard in plasma proteomics. These metrics, validated through rigorous experimental evaluations, highlight the superiority of the nanoparticles in enriching low-abundance proteins compared to traditional and commercial enrichment methods.
[0078]
[0051] Plasma is among the most challenging biological fluids for protein enrichment due to its high protein content and wide dynamic range. The dominance of high-abundance proteins, such as albumin and immunoglobulins, necessitates advanced strategies for isolating low-abundance proteins without significant loss or contamination. Traditional methods, such as immunoaffinity depletion and precipitation, often struggle with issues like non-specific binding, high variability, and insufficient recovery of target proteins. The magnetic nanoparticles in this invention overcome these challenges through tailored functionalization, tunable porosity, and optimized workflows.
[0079]
[0052] The recovery rates achieved by the MNPs consistently exceed 90%, even for proteins present in plasma at nanogram-per-milliliter concentrations. This recovery rate is significantly higher than that reported for traditional enrichment techniques, where recovery rates are often limited to 60-70%. The functionalized surface chemistry of the nanoparticles enables precise targeting of proteins with specific properties, such as charge, hydrophobicity, or post-translational modifications. For instance, carboxyl (-COOH) groups selectively enrich phosphorylated proteins critical for studying cancer signaling pathways, while weak anion exchangers (WAX) and weak cation exchangers (WCX) capture acidic and basic proteins, respectively.
[0080]
[0053] In addition to high recovery rates, the nanoparticles exhibit exceptional sensitivity. The ability to detect proteins at nanogram-per-milliliter levels provides a distinct advantage in identifying low-abundance biomarkers that are often overlooked in traditional workflows. For example, biomarkers such as CA-125 for ovarian cancer or PSA for prostate cancer, which exist in minute concentrations, are consistently enriched and detected using this nanoparticle system. Sensitivity is further enhanced by the nanoparticles’ tunable porosity, which excludes high-abundance proteins from binding and concentrates target proteins within the desired size range.COMPL-004PCT-SPEC
[0081]
[0054] Reproducibility is another key performance metric where the invention excels. Across multiple replicate experiments, the nanoparticles deliver highly consistent results, with a coefficient of variation (CV) below 5%. This low variability is critical in clinical applications, where reproducibility ensures reliable biomarker detection and quantification. The robustness of the nanoparticles’ functional groups, coupled with the stability of the silica shell, contributes to their ability to maintain performance across repeated use.
[0082]
[0055] Comparative benchmarking against existing commercial products underscores the advantages of this invention. When evaluated side-by-side with leading enrichment kits, such as those based on immunoaffinity or precipitation techniques, the magnetic nanoparticles consistently identified a higher total number of unique proteins. For example, in a study involving plasma samples spiked with known quantities of target proteins, the nanoparticles enriched over 20% more low-abundance proteins than competing methods. The enriched protein fractions also exhibited lower contamination from high-abundance proteins, demonstrating the specificity of the nanoparticles’ functionalization.
[0083]
[0056] Fold-change analysis of enriched proteins provides further evidence of the nanoparticles’ exceptional performance. In a comparative study using plasma samples from healthy individuals and pancreatic cancer patients, the invention enabled the identification of 1,592 proteins uniquely expressed in cancer samples. Fold-change differences between cancer and normal samples exceeded 20-fold for over 767 proteins, highlighting the system’s ability to reveal significant proteomic differences. These results align with, and often surpass, findings from traditional workflows, demonstrating the invention’s potential for advancing biomarker discovery and clinical diagnostics.
[0084]
[0057] Efficiency and scalability also distinguish the nanoparticles from existing methods. Traditional approaches often require extensive manual handling, long incubation times, and multiple purification steps, which can lead to sample loss and increased variability. In contrast, the magnetic nanoparticles streamline the enrichment process through rapid binding, magnetic separation, and straightforward elution protocols. The entire workflow, from plasma preparation to enriched protein recovery, can be completed in under two hours, making it suitable for high-throughput applications. The compatibility of the system with automated platforms further enhances its scalability, allowing for the processing of hundreds of plasma samples daily without compromising performance.COMPL-004PCT-SPEC
[0085]
[0058] Another critical advantage of the invention is the reusability of the nanoparticles. After each enrichment cycle, the nanoparticles are regenerated through washing with mild acidic or neutral buffers, restoring the activity of the surface functional groups. Experimental evaluations demonstrate that the nanoparticles retain over 90% of their original efficiency after 10 cycles, significantly reducing operational costs and environmental impact compared to single-use commercial kits. For challenging applications involving strongly adhered proteins, the nanoparticles can be cleaned using harsher protocols without degradation, ensuring long-term reliability.
[0086]
[0059] The performance metrics of this invention also extend to its applicability in diverse clinical and research settings. By consistently enriching proteins across a wide dynamic range and enabling the detection of low-abundance biomarkers, the magnetic nanoparticles provide a robust foundation for applications in oncology, cardiovascular research, autoimmune disease studies, and beyond. Their high specificity and sensitivity are particularly valuable in precision medicine, where accurate biomarker profiling informs individualized treatment plans.
[0087]
[0060] In summary, the magnetic nanoparticles described in this invention redefine the capabilities of plasma proteomics. Through exceptional recovery rates, sensitivity, reproducibility, and scalability, the nanoparticles outperform existing enrichment methods, offering a transformative solution for biomarker discovery and clinical diagnostics. The integration of advanced functionalization strategies, durable materials, and streamlined workflows positions this invention as a cornerstone in next-generation proteomic research and precision medicine.
[0088] Example 1: Development and Application of SuperDeep Magnetic Nanoparticles for Plasma Protein Enrichment
[0089] I. Introduction
[0090]
[0061] Plasma proteomics is a cornerstone in the search for biomarkers that enable early cancer detection. These biomarkers hold immense potential for diagnostic and therapeutic advancements but are typically present in plasma at medium to very low concentrations. This low abundance makes their detection both technically complex and resource-intensive, posing significant challenges to the field.
[0091]
[0062] Previous efforts have established targeted diagnostic pipelines, such as our ovarian cancer diagnostic workflow, which leveraged mass spectrometry to identify and validate 652 proteinCOMPL-004PCT-SPEC
[0092] biomarkers from patient plasma samples (Wang et al., PNAS 2017, 114 (51) 13519-13524). While this approach achieved remarkable accuracy, it required labor-intensive manual optimization for each biomarker to achieve sensitive detection, underscoring the pressing need for more efficient methodologies (Wang et al., PNAS 2017, 114 (51) 13519-13524).
[0093]
[0063] In recent years, innovative tools have emerged to address this challenge by selectively enriching low-abundance plasma proteins. Examples include the ProteoMiner Protein Enrichment Kits (Bio-Rad, Inc.) and the Proteograph™ Product Suite workflow (Seer, Inc.). These tools operate on a common principle: they utilize solid matrices — such as beads, nanoparticles, or other solid supports — functionalized with diverse chemical moieties. These moieties allow selective binding of plasma proteins based on their physicochemical properties. High-abundance proteins, which often saturate the binding capacity of these matrices, are deprioritized, thereby increasing the capture likelihood of low-abundance proteins. This enrichment strategy significantly enhances the detection of biomarkers typically present in plasma at very low concentrations.
[0094]
[0064] Nanoparticles, in particular, have demonstrated exceptional utility in this context. Engineered with precise chemical and physical characteristics, these particles enable selective interactions with target proteins. Key features of nanoparticles include:
[0095]
[0065] 1. Surface Functionalization: Tailored with hydrophobic, hydrophilic, or charged functional groups, nanoparticles can interact with proteins based on solubility or electrostatic properties. Functional groups such as carboxyl (-COOH), amino (-NH2), or sulfonic acid (-SO3H) play a critical role in enhancing binding specificity.
[0096]
[0066] 2. Porosity and Size Selection: Nanoparticles are designed with optimized pore sizes, enabling the selective trapping of proteins based on molecular dimensions. Mesoporous silica nanoparticles, for instance, are particularly effective for size-exclusion-based enrichment, ensuring that only proteins within a specific size range are captured.
[0097]
[0067] This study introduces the development and characterization of five novel magnetic nanoparticles, each engineered with unique surface functionalizations to address the challenges of low-abundance protein enrichment in plasma proteomics. These nanoparticles are designed to improve the sensitivity and specificity of biomarker detection, advancing diagnostic workflows and facilitating early cancer detection. By offering a scalable and efficient solution, these nanoparticles hold significant promise for enhancing the field of plasma proteomics.
[0098]
[0068] COMPL-004PCT-SPEC
[0099] II. Materials and Methods
[0100] 1. Materials and Reagents
[0101] a. Magnetic Bead Enrichment Kit (KB-D003):
[0102] a. Pre-functionalized magnetic beads tailored for protein enrichment.
[0103] b. Desalting Column (KB-C002):
[0104] a. Cl 8 solid-phase extraction columns designed for peptide desalting.
[0105] c. Recombinant Enzymes:
[0106] a. Trypsin: Mass spectrometry grade (KB-C007).
[0107] b. Lys-C Endoproteinase: Mass spectrometry grade (KB-C009).
[0108] d. Key Buffers and Reagents:
[0109] a. Reagent A: lx DMSO in 50 mM Tris-HCl.
[0110] b. Reagent B: 0.3 M TCEP + CAA (tris(2-carboxyethyl)phosphine and chi oroacetami de) .
[0111] c. Reagent C: 1 M Tris-HCl, pH 8.6.
[0112] d. Reagent D: 50 mM Tris-HCl, pH 8.6.
[0113] e. Reagent E: 2% formic acid (FA) aqueous solution.
[0114] f. Reagent F: 100 mM Tris-HCl.
[0115] g. Reagent G: 0.1 M Tris-HCl (pH 8.6), 150 mM KC1, 0.05% CHAPS.
[0116] e. Preparation of Enzyme Solutions:
[0117] a. Lys-C Solution: Dissolve in 200 pL of Reagent D.
[0118] b. Trypsin Solution: Dissolve in 200 pL of Reagent D.
[0119] f. Preparation of Buffers:
[0120] a. Washing Buffer: 0.1% FA in water.
[0121] b. Elution Buffer: 70% acetonitrile (ACN) in 0.1% FA.
[0122] 2, Experimental Procedure
[0123] i. Magnetic Bead Preparation
[0124] Step 1 : Bead Activation
[0125] 1. Bring magnetic beads to room temperature and mix thoroughly using gentle agitation or ultrasonic treatment.COMPL-004PCT-SPEC
[0126] 2. Transfer 16 pL of beads into a 2 mL microcentrifuge tube.
[0127] 3. Add 100 pL of Reagent G and incubate on a thermostatic shaker at 37°C for 5 minutes (1000 rpm).
[0128] 4. Place the tube on a magnetic stand for 3 minutes to separate the beads, then discard the supernatant. Repeat washing twice.
[0129] ii. Protein Binding
[0130] Step 1: Sample Preparation
[0131] 1. Thaw plasma samples.
[0132] 2. Centrifuge at 12,000 g for 15 minutes at 4°C to remove debris.
[0133] Step 2: Binding Reaction
[0134] 1. Resuspend the washed beads in 40-250 pL of Reagent G.
[0135] 2. Add an equal volume of plasma sample (1 : 1 ratio).
[0136] 3. Incubate the mixture at 37°C for 2 hours on a shaker (1000 rpm).
[0137] Step 3 : Post-Binding Wash
[0138] 1. Wash the protein-bound beads three times with 150 pL of Reagent G.
[0139] 2. For each wash, incubate the beads at 37°C for 5 minutes, then separate using a magnetic stand.
[0140] iii. Protein Digestion
[0141] Step 1 : Denaturation and Reduction
[0142] 1. Add 20 pL of Reagent A to the protein-bound beads and mix thoroughly.
[0143] 2. Add 0.6 pL of Reagent B and incubate at 95°C for 5 minutes to denature and reduce bound proteins.
[0144] Step 2: Digestion
[0145] 1. Cool the tube to room temperature.COMPL-004PCT-SPEC
[0146] 2. Add sequentially:
[0147] 1 pL of Reagent C (pH adjustment).
[0148] 2 pL of Lys-C solution.
[0149] 1.2 pL of trypsin solution.
[0150] 3. Incubate the mixture at 37°C for 2 hours on a shaker (1000 rpm).
[0151] Step 3 : Termination
[0152] 1. Add 0.4 pL of Reagent E to terminate the reaction.
[0153] 2. Centrifuge the tube at 14,000 g for 10 minutes to collect the supernatant containing digested peptides.
[0154] 3. Add lOOul Reagent F to reconstitute the beads and add 2ul Reagent E to further terminate the reaction and then centrifuge again at 14,000 g for 10 minutes.
[0155] 4. Transfer the supernatant out of the tube from above step and mix with the supernatant collected from the 2ndstep above.
[0156] iv. Peptide Desalting
[0157] Step 1: Column Activation
[0158] 1. Add 100 pL of acetonitrile to the desalting column.
[0159] 2. Centrifuge at 1500 g for 2 minutes and discard the filtrate.
[0160] Step 2: Column Washing
[0161] 1. Add 100 pL of washing buffer (0.1% FA) to the column.
[0162] 2. Centrifuge at 1500 g for 5 minutes and discard the filtrate. Repeat twice.
[0163] Step 3 : Sample Loading
[0164] 1. Ensure the pH of the digested peptide sample is <3 before loading onto the column.
[0165] 2. Add the sample to the column and centrifuge at 1500 g for 5 minutes. Repeat once.COMPL-004PCT-SPEC
[0166] Step 4: Peptide Elution
[0167] 1. Add washing buffer (0.1% FA) to the column and wash three times.
[0168] 2. Add 75 pL of elution buffer (70% ACN in 0.1% FA) to the column.
[0169] 3. Centrifuge at 1500 g for 5 minutes and collect the filtrate. Repeat once.
[0170] Step 5: Concentration
[0171] 1. Concentrate the eluate using a vacuum centrifuge concentrator to obtain dry peptide powder.
[0172] 2. Store peptides at -80°C for subsequent LC-MS / MS analysis.
[0173] 3, Physicochemical Properties of the Magnetic Beads
[0174] To optimize protein enrichment, five nanoparticle formulations were developed with specific functionalizations as shown in Table 1 :
[0175] Table 1: Physicochemical Properties of the Magnetic Nanoparticles
[0176]
[0177]
[0178] These formulations target different protein properties:
[0179] Si- WAX: Targets negatively charged proteins under acidic conditions.
[0180] Si-WCX: Binds positively charged proteins in basic environments.
[0181] Si-COOH: Isolates phosphorylated and negatively charged biomolecules.
[0182] GS-OH: Offers broad-spectrum hydrophilic binding.
[0183] Si-NHz: Optimizes glycoprotein and antibody capture.COMPL-004PCT-SPEC
[0184] Figure 1 illustrates the core-shell structure and functionalized surfaces of the five nanoparticle types.
[0185] 4, Notes and Best Practices
[0186] a. Ensure Thorough Mixing: Always mix the magnetic beads thoroughly before each step to prevent settling, ensuring uniform performance throughout the enrichment process.
[0187] b. Maintain Precise Incubation Conditions: Adhere to the specified incubation times and temperatures at each stage of the workflow (e.g., bead activation, protein binding, digestion) to achieve consistent and reproducible results. c. Preserve Bead Integrity: Avoid freezing or drying the beads outside of the experimental steps. Such handling may compromise their surface functional groups and structural stability, reducing their effectiveness in subsequent experiments.
[0188] d. Centrifuge Settings During Desalting: When using desalting columns, ensure that centrifuge speeds do not exceed the recommended levels (e.g., 1500 g) to minimize the risk of sample loss and ensure efficient peptide recovery.
[0189] III. Results and Discussion
[0190] 1. Protein Enrichment Efficiency in Plasma
[0191]
[0069] The enrichment efficiency and specificity of the SuperDeep nanoparticles were rigorously evaluated under optimized experimental conditions. Five distinct nanoparticle formulations were tested, each tailored for specific protein interactions:
[0192] SuperDeep Si- WAX: Delivered exceptional performance in isolating negatively charged plasma proteins, including cancer-related biomarkers, particularly in acidic environments (pH 5.0-6.5).
[0193] SuperDeep Si-WCX: Demonstrated superior enrichment of positively charged proteins in basic conditions (pH 7.5-9.0), showing significant binding specificity to structural and signaling proteins.COMPL-004PCT-SPEC
[0194] SuperDeep Si-COOH: Achieved high efficiency in covalently binding phosphorylated peptides, critical for studying phosphorylation-dependent signaling pathways implicated in cancer.
[0195] SuperDeep GS-OH: Provided broad-spectrum hydrophilic binding, making it particularly suitable for initial plasma protein fractionation and comprehensive screening.
[0196] SuperDeep Si-NFL: Optimized for glycoprotein capture and antibody immobilization, vital for immune-response studies and cancer diagnostic workflows.
[0197] Comparative Analysis
[0198]
[0070] To evaluate the performance of SuperDeep nanoparticles, a head-to-head comparison was conducted against six commercial magnetic bead products. Performance was assessed based on protein recovery rates, total protein identification, reproducibility, and detection sensitivity.
[0199] Recovery Rates: SuperDeep nanoparticles consistently achieved >90% recovery rates across all functionalized bead types.
[0200] Protein Identification: SuperDeep nanoparticles identified 25-30% more proteins on average compared to leading commercial products. Figure 3 illustrates the comparative enrichment performance of the five SuperDeep nanoparticle types against six commercial benchmarks. Metrics include the total number of proteins identified, coefficient of variation (CV) values, and sensitivity thresholds. The results emphasize the superior specificity and sensitivity of SuperDeep nanoparticles, particularly in recovering low-abundance plasma proteins critical for biomarker discovery.
[0201] Reproducibility: Coefficients of variation (CV) remained <5% across all replicates, highlighting the system’s robustness.
[0202] Detection Sensitivity: Detection thresholds reached nanogram-per-milliliter levels, with enriched peptides exhibiting high signal -to-noise ratios during LC-MS / MS analysis.
[0203] Enrichment Workflow OptimizationCOMPL-004PCT-SPEC
[0204]
[0071] The critical role of optimized Standard Operating Procedures (SOPs) was evident, with stringent control of binding conditions (e.g., buffer composition, pH, and incubation times) ensuring reproducible and high-efficacy protein enrichment. For example:
[0205] Si-WAX enrichment required acidic binding buffers (pH 5.5), while Si-WCX performed optimally with basic buffers (pH 8.5).
[0206] Si-COOH beads demonstrated maximum phosphorylated peptide recovery when used with mild acidic elution buffers containing chelators.
[0207] 2. Feasibility for Cancer-Specific Biomarker Enrichment
[0208]
[0072] To evaluate the clinical utility of the SuperDeep nanoparticles, their ability to enrich disease-specific biomarkers was tested in plasma samples from both healthy individuals and pancreatic cancer patients. This analysis revealed the nanoparticles’ remarkable capacity to differentiate proteomic profiles between normal and diseased states. Such targeted enrichment is essential for advancing personalized diagnostic workflows.
[0209]
[0073] Using all five nanoparticle types in combination, the proteomic profiles of four plasma samples (two normal plasma samples and two pancreatic cancer plasma samples) were comprehensively analyzed. A total of 11,562 proteins were identified, with the following distributions:
[0210] 2,513 proteins were common across all samples.
[0211] 2,943 proteins were detected in both normal plasma samples.
[0212] 5,834 proteins were detected in both pancreatic cancer plasma samples.
[0213]
[0074] 1,592 proteins were uniquely observed in the pancreatic cancer samples, accounting for approximately 27.3% of the proteins detected in the cancer samples. Figure 4 illustrates the proteomic profiles of normal and cancer plasma samples enriched using the SuperDeep nanoparticles. The figure highlights the subset of 1,592 proteins uniquely detected in cancer plasma, along with their fold-change distributions. This differential expression underscores the nanoparticles’ ability to enrich disease-specific biomarkers, facilitating targeted cancer diagnostics and biomarker discovery.COMPL-004PCT-SPEC
[0214]
[0075] These uniquely observed proteins represent a valuable subset for disease-specific biomarker discovery, as their absence in normal plasma makes them highly indicative of disease presence.
[0215] Fold-Change Analysis
[0216]
[0076] A fold-change analysis, comparing the proteomes of cancer and normal plasma samples, revealed significant differences:
[0217] 1. 767 proteins exhibited at least a 20-fold overexpression in cancer samples. 2. 222 proteins exhibited at least a 20-fold underexpression in cancer samples.
[0218]
[0077] The observed fold-change differences highlight significant proteomic shifts associated with disease progression. Notably, phosphorylated and glycosylated proteins were prominently enriched, aligning with cancer-related signaling and immune-response mechanisms. The foldchange distribution followed a normal curve, consistent with previously reported trends (SAFE-SRM pipeline; Wang et al., PNAS 2017, 114 (51) 13519-13524), but the proportion of strongly overexpressed proteins (^20-fold) was notably higher. This underscores the unbiased enrichment capability of SuperDeep nanoparticles, even in the presence of high-abundance proteins.
[0219] Clinical Relevance
[0220]
[0078] SuperDeep nanoparticles demonstrated exceptional specificity for low-abundance biomarkers. For instance:
[0221] CA-125: Enriched by Si-NFk nanoparticles, providing high signal intensity during LC-MS / MS analysis.
[0222] PSA: Effectively captured by Si-WCX nanoparticles, showcasing their utility in prostate cancer diagnostics.
[0223]
[0079] These results demonstrate the potential of SuperDeep nanoparticles to enable sensitive, specific, and reproducible biomarker enrichment for clinical applications.
[0224] 3. Reusability
[0225]
[0080] The reusability of SuperDeep nanoparticles was evaluated over 10 enrichment cycles to assess their long-term durability and cost-effectiveness. Experimental conditions for bead regeneration included washing with mild acidic buffers (e.g., 0.1 M citric acid) to restore functional group activity.
[0226]
[0081] Key Observations:COMPL-004PCT-SPEC
[0227] 1. Nanoparticles retained >90% of their original enrichment efficiency after 10 consecutive reuse cycles.
[0228] 2. Magnetic core stability was maintained, with no observed degradation of the silica shell or functional groups.
[0229] 3. Performance metrics, including recovery rates and detection sensitivity, remained consistent across all cycles.
[0230]
[0082] Comparative Cost Analysis
[0231]
[0083] SuperDeep nanoparticles demonstrated a 40-50% reduction in per-sample costs compared to single-use commercial products. Their reusability minimizes material waste, making them particularly advantageous for high-throughput clinical workflows.
[0232] IV. Conclusion and Future Directions
[0233]
[0084] In this study, we successfully developed and characterized five novel magnetic nanoparticles — SuperDeep Si-WAX, SuperDeep Si-WCX, SuperDeep Si-COOH, SuperDeep GS-OH, and SuperDeep Si-NFL — each tailored to specific protein enrichment tasks in plasma proteomics. These nanoparticles demonstrated exceptional capabilities in selectively enriching low-abundance proteins, addressing key challenges in proteomics-based cancer diagnostics. The distinct surface functionalities of these nanoparticles enabled enhanced sensitivity and specificity in identifying disease-specific biomarkers, paving the way for improved early detection and personalized treatment strategies in oncology.
[0234]
[0085] Beyond their superior enrichment performance, the nanoparticles exhibited robust durability and reusability, retaining >90% efficiency after 10 enrichment cycles. This reusability not only underscores their practicality for clinical and research applications but also significantly reduces costs, making them a viable option for large-scale implementation. Furthermore, comparative analyses against leading commercial products confirmed the superiority of SuperDeep nanoparticles, with higher protein detection rates and lower variability. These results reinforce their potential as transformative tools in plasma proteomics.
[0235]
[0086] The comprehensive evaluation of the nanoparticles’ ability to enrich and identify cancerspecific biomarkers demonstrated their feasibility for clinical diagnostics. The identification of 1,592 unique and differentially expressed proteins between normal and cancer plasma samples highlights their capability to provide a richer pool of potential biomarkers for disease detectionCOMPL-004PCT-SPEC
[0236] and characterization. These results establish a solid foundation for further exploration of the clinical and research applications of SuperDeep nanoparticles.
[0237]
[0087] To further enhance the clinical and research utility of SuperDeep nanoparticles, future studies will focus on the following areas:
[0238]
[0088] Validation Using Larger Clinical Cohorts: Expanding the scope of testing to include diverse patient populations and a wide range of cancer types will validate the clinical robustness and utility of the nanoparticles. This step is essential for translating laboratory findings into real-world diagnostic applications.
[0239]
[0089] Application in Detecting Specific Cancer Types: Tailoring the nanoparticles to target biomarkers associated with specific cancer subtypes, such as triple-negative breast cancer or hepatocellular carcinoma, will enable more precise diagnostic and prognostic applications. Customizing surface functionalizations for these purposes will enhance disease specificity.
[0240]
[0090] Integration with Automated High-Throughput Workflows: Incorporating these nanoparticles into automated systems for high-throughput proteomics will streamline sample processing and improve scalability. Such integration will facilitate broader adoption in clinical laboratories and industrial-scale research.
[0241]
[0091] Development of Multi -Omics Approaches: Leveraging these nanoparticles in conjunction with genomics, transcriptomics, and metabolomics will provide a comprehensive understanding of disease mechanisms. Multi-omics integration will enable the discovery of novel biomarkers and enhance disease characterization.
[0242]
[0092] Optimization for Non-Cancer Applications: Expanding the use of SuperDeep nanoparticles to other disease contexts, such as cardiovascular diseases, autoimmune disorders, and infectious diseases, will broaden their applicability. Plasma proteomics in these areas can provide valuable diagnostic and therapeutic insights.
Claims
COMPL-004PCT-SPECCLAIMS1. A composition of magnetic nanoparticles for enriching low-abundance plasma proteins, comprising:A magnetite core;A silica shell coated with surface functional groups comprising carboxyl (-COOH), amino (-NH2), weak anion exchanger (WAX), hydroxyl (-OH), and weak cation exchanger (WCX);Tunable porosity ranging from 1 to 100 nm, configured to selectively trap proteins based on molecular dimensions.
2. The composition of claim 1, wherein the silica shell is applied via a sol-gel process to enhance structural stability.
3. The composition of claim 1, wherein the nanoparticles are dual -functionalized with both hydrophilic and hydrophobic groups for broad protein-binding capability.
4. The composition of claim 1, wherein the functional groups comprise a combination of carboxyl (-COOH) and hydroxyl (-OH) groups to capture proteins through hydrophilic and electrostatic interactions.
5. The composition of claim 1, wherein the nanoparticles comprise ligands or antibodies tailored to bind disease-specific biomarkers.
6. The composition of claim 1, wherein the nanoparticles have a magnetite-to-silica ratio optimized to provide magnetic separation efficiency while maintaining functional stability.
7. The composition of claim 1 , wherein the surface charge density of the nanoparticles is adjusted to optimize binding specificity for plasma proteins.
8. A system for enriching low-abundance proteins from plasma samples, comprising:Magnetic nanoparticles as defined in claim 1;A workflow for protein separation, including incubation with plasma, magnetic separation, and elution of enriched protein fractions;COMPL-004PCT-SPECA regeneration process to reuse the nanoparticles.
9. The system of claim 8, wherein the nanoparticles are regenerated by washing with a buffer solution having a pH between 4 and 8.
10. The system of claim 8, further comprising an automated magnetic handling system for high- throughput plasma processing.
11. The system of claim 8, wherein the system is integrated into an automated workflow for mass spectrometry analysis.
12. The system of claim 8, wherein the workflow includes multiplexing capabilities for processing more than 100 samples simultaneously.
13. The system of claim 8, wherein the magnetic nanoparticles are embedded within a cartridge or column for clinical diagnostic workflows.
14. The system of claim 8, wherein the total processing time from plasma incubation to protein enrichment is less than 2 hours.
15. A method for enriching low-abundance proteins from plasma, comprising:Incubating the plasma with magnetic nanoparticles as defined in claim 1;Isolating the protein-bound nanoparticles via magnetic separation;Eluting the enriched protein fraction using a buffer solution;Subjecting the enriched proteins to on-bead digestion for subsequent analysis using mass spectrometry or immunoassays.
16. The method of claim 15, wherein the elution buffer is optimized to maintain protein integrity, comprising a solution with a pH between 4 and 8.
17. The method of claim 15, wherein the incubation step includes agitation to enhance protein- nanoparticle interactions.
18. The method of claim 15, wherein the enriched proteins are analyzed for biomarkers specific to ovarian, pancreatic, or prostate cancer.COMPL-004PCT-SPEC19. The method of claim 15, wherein the magnetic nanoparticles are reused for at least 10 enrichment cycles without loss of functionality.
20. The method of claim 15, wherein the plasma samples are pre-processed to remove particulate matter prior to incubation.
21. The method of claim 15, further comprising a step of benchmarking enrichment efficiency against standard methods such as Proteograph™ or immunoaffinity depletion.
22. The method of claim 15, wherein the enrichment achieves a protein recovery rate exceeding 90%, with a sensitivity threshold of nanograms per milliliter.
23. Aclinical diagnostic method for detecting disease-specific biomarkers in plasma, comprising:Processing a plasma sample with the system of claim 8 to enrich low-abundance proteins; Analyzing the enriched protein fraction using a diagnostic assay or mass spectrometry; Reporting biomarker levels associated with diseases such as cancer, autoimmune disorders, or cardiovascular conditions.
24. The method of claim 23, wherein the disease-specific biomarkers include CA-125, PSA, or CRP.
25. The method of claim 23, wherein the plasma samples are analyzed longitudinally to monitor disease progression or therapeutic efficacy.
26. The method of claim 23, wherein the diagnostic method is integrated into a hospital laboratory workflow for real-time clinical use.