Fiber-spinning process for the application of metal nanoparticles in polymeric devices

Abstract

Disclosed are polymer fibers incorporating metal nanoparticles and medical devices made therefrom. The disclosed polymer fibers can be used to form medical devices, including implantable medical devices, that have effective antimicrobial properties. The disclosed polymer fibers incorporate metal nanoparticles that function without releasing metal (e.g., silver) ions.

Description

[Technical field]

[0001] The present disclosure relates to polymer compositions containing antimicrobial nanoparticles, devices formed therefrom, and fiber spinning manufacturing processes for forming such polymer compositions and devices. [Background technology]

[0002] Polymers used in medical and other applications are typically inexpensive and can be used for many different functions. Polymeric products can be manufactured using an injection molding process. One challenge with injection molded polymers is that the surface finish of the product can be spongy with pores that may extend several microns deep into the product. For example, FIG. 1 is a scanning transmission electron microscope (STEM) image of a polystyrene surface from a hot extrusion pellet. The surface of the polymer is highly porous, which can harbor bacteria and other microorganisms. Such microbial growth can be a concern in hospitals and elsewhere in the medical field. The maintenance of polymers used in sensitive areas, including many medical applications, requires expensive and rigorous sterilization and preservation procedures. Even so, tissue and infection deterioration is known to result from the use of infectious polymers used to deliver materials to or implanted in patients. Drug-resistant microbial infections can also result from the use of infectious polymer products, resulting in expensive medical care and even death.

[0003] Overuse of antibiotics has in some cases contributed to antibiotic-resistant bacteria and other treatment-resistant microorganisms. There is concern that the increase in antibiotic resistance may lead to microorganisms that cannot be treated with conventional techniques. At present, there are few methods of disinfection and microbial control that do not require the use of traditional antibiotics. Medical devices incorporating antibiotics may not be able to prevent biofilm formation and / or prevent infection from antibiotic-resistant bacteria. In such cases, the use of antibiotics in polymeric materials may not protect patients from infection and may even provide a false sense of security.

[0004] There have been attempts to incorporate ionic colloidal silver and silver nanoparticles into polymeric materials to introduce antimicrobial activity into the polymer, but antimicrobial resistance has now been found for colloidal silver (i.e., silver nanoparticles produced by conventional chemical reduction processes, typically with some form of capping agent) and ionic silver. McNeilly et al., “Emerging Concern for Silver Nanoparticle Resistance in Acinetobacter baumannii and Other Bacteria,” Front. Microbiol., 16 April 2021, discusses the emergence of several antibiotic-resistant bacteria, including Acinetobacter baumannii, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. Of these, A. baumannii is of particular concern and has been found to have established resistance to colloidal silver nanoparticles, as have E. coli, Enterobacter cloacae, S. typhimurium, B. subtilis, S. aureus, P. aeruginosa, K. pneumoniae, Serratia marcescens, and Acinetobacter spp.

[0005] Silver, “Bacterial silver resistance: molecular biology and uses and misuses of silver compounds,” FEMS Microbiology Reviews, Volume 27, Issue 2-3, June 2003, Pages 341-35, discusses silver-resistant Salmonella and E. coli. Elkrewi, et al., “Cryptic silver resistance is prevalent and readily activated in certain Gram-negative pathogens,” J. Antimicrob.Chemother., 2017 Nov 1;72(11):3043-3046, discloses resistance to colloidal silver nanoparticles by Gram-negative pathogens such as Enterobacter spp., Klebsiella spp., E. coli, Pseudomonas aeruginosa, Acinetobacter spp., Citrobacter spp., and Proteus spp. Hosney, “The increasing threat of silver-resistance in clinical isolates from wounds and burns,” Infect Drug Resist.2019; 12: 1985-2001, discusses colloidal silver-resistant Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Percival, et al., “Bacterial resistance to silver in wound care, J. Hospital Infection, Vol. 60, Issue 1, May 2005, pp. 1-7, discusses the threat and potential of colloidal silver-resistant microorganisms in wounds.Kedziora, et al., “Consequences Of Long-Term Bacteria's Exposure To Silver Nanoformulations With Different PhysicoChemical Properties,” Intl. J. of Nanomedicine, 2020:15 199-213, discusses colloidal silver resistance in gram-positive and gram-negative bacteria.

[0006] The paper, titled “Are Silver Nanoparticles a Silver Bullet Against Microbes?” July 13, 2021, https: / / news.engineering.pitt.edu / are-silver-nanoparticles-a-silver-bullet-against-microbes / (accessed October 12, 2022), discusses colloidal silver nanoparticle-resistant E. coli and states: “Initially, the bacteria could only survive low concentrations of silver nanoparticles, but as the experiments continued, the authors found that the bacteria could survive higher doses. (...) Interestingly, the authors found that the bacteria developed resistance to silver nanoparticles, but not to the silver ions released from the nanoparticles alone.” The group sequenced the genome of E. coli exposed to silver nanoparticles and found mutations in genes that correspond to efflux pumps that push heavy metal ions out of the cell. "It's possible that some form of silver gets inside the cells, and once there, the cells mutate in a way that quickly pumps it out... Further work is needed to determine whether researchers might be able to overcome this mechanism of resistance through particle design." Silver nanoparticles made by conventional chemical synthesis have external bond angles and edges that allow silver ions to be released even when the bulk nanoparticles are in the ground state. The addition of ion-releasing metal nanoparticles into polymers results in nanoparticle-impregnated polymers and plastics that are a source of unwanted metal ions, such as silver ions, which can be toxic to human and animal tissues under excessive exposure. Furthermore, the release of ions can decrease over time. Thus, even if there is a beneficial antimicrobial effect associated with the release of silver ions, such effect decreases over time as the ions are leached out of the bulk polymer material. If the release of silver ions is the primary mode of antimicrobial action, as is the case with conventional colloidal silver products, the antimicrobial activity of the polymer will similarly decrease over time.

[0007] In addition, exposure to solar radiation can cause weakening and other structural damage to polymers. When absorbed by a polymer, UV energy can excite electrons to produce free radicals that can lead to plastic degradation. Polymers affected by UV radiation can have a chalky appearance, the surface of the polymer can become brittle, and noticeable discoloration can occur on the surface of the polymer. UV-induced degradation can cause polymer products to crack and can lead to complete failure of the product. For example, UV radiation hitting polypropylene and / or low density polyethylene can interact with tertiary carbon bonds in its structure, which can then interact with oxygen in the atmosphere. This can create carbonyl groups in the backbone of the structure, making the plastic product more susceptible to cracking or discoloration.

[0008] Ultraviolet B radiation ("UVB radiation") is generally considered to be in the wavelength range of about 280 to about 315 nanometers. Ultraviolet A radiation ("UVA radiation") is generally considered to be in the wavelength range of about 315 to about 400 nanometers. Ultraviolet C radiation (UVC) is generally considered to be in the wavelength range of about 100 to about 280 nanometers.

[0009] In view of the above, there remains a need to find improved polymeric materials that exhibit effective antimicrobial properties and are useful for use in medical devices, including implantable medical devices. Summary of the Invention

[0010] Disclosed are polymer compositions incorporating metal nanoparticles, medical devices made therefrom, and fiber spinning methods for forming such polymer compositions and devices. The disclosed polymer compositions can be used to form medical devices, including implantable medical devices, that have effective antimicrobial properties. The disclosed polymer compositions incorporate metal nanoparticles that function without releasing metal (e.g., silver) ions. The disclosed polymer materials can also effectively resist UV damage when exposed to sunlight and / or other UV light sources.

[0011] In some embodiments, the disclosed polymer compositions include wavelength-shifting metal nanoparticles that function to protect exposed surfaces from UV radiation. For example, the polymer compositions can downconvert incident UV light to longer wavelength light that is less or non-damaging to polymer bonds.

[0012] The disclosed polymer compositions containing metal nanoparticles also have antimicrobial properties to prevent microbial colonization on the composition, including preventing microbial colonization within the pores of the polymeric material and structures formed therefrom. Such nanoparticle-modified polymers are less susceptible to the establishment of silver nanoparticle antibiotic resistance, as occurs more frequently with conventional colloidal silver made via chemical synthesis. Surprisingly and unexpectedly, it has been found that non-ionic silver nanoparticles formed by laser ablation do not cause silver nanoparticle resistance, at least to the same extent, as compared to conventional colloidal silver or silver nanoparticles made by chemical synthesis, which are known to release silver ions as their primary mode of antimicrobial activity.

[0013] Metal (e.g., silver) nanoparticles produced by laser ablation (and with smooth spherical morphology and narrow size distribution) can be incorporated into polymers to inhibit bacterial or other microbial colonization. Unexpectedly, the spherical silver nanoparticles produced by laser ablation and with narrow size distribution do not confer microbial resistance to the same extent as conventional colloidal silver or silver nanoparticles formed via chemical synthesis.

[0014] In some embodiments, the spherical metal (e.g., silver) nanoparticles have an average diameter and a size distribution in which at least 99% of the spherical metal nanoparticles have a diameter within 30% of the average diameter, or within 20% of the average diameter, or within 10% of the average diameter, and / or at least 99% of the spherical metal nanoparticles have a diameter within ±3 nm of the average diameter, or within ±2 nm of the average diameter, or within ±1 nm of the average diameter.

[0015] In some embodiments, the composition may include coral-shaped metal nanoparticles instead of or in addition to spherical metal nanoparticles. Coral-shaped metal (e.g., gold) nanoparticles have a non-uniform cross-section and a spherical structure formed by multiple non-linear strands joined together with no right angles.

[0016] In some embodiments, the metal nanoparticles may include spherical metal (e.g., silver) nanoparticles and / or coral-shaped metal (e.g., gold) nanoparticles. In some embodiments, coral-shaped metal nanoparticles may be used in conjunction with spherical metal nanoparticles. The coral-shaped nanoparticles may beneficially enhance the spherical metal nanoparticles.

[0017] In some embodiments, the metal nanoparticles may comprise at least one metal selected from the group consisting of silver, gold, platinum, palladium, rhodium, osmium, ruthenium, rhenium, molybdenum, copper, iron, nickel, tin, beryllium, cobalt, antimony, chromium, manganese, zirconium, tin, zinc, tungsten, titanium, vanadium, lanthanum, cerium, heterogeneous mixtures thereof, and alloys thereof. Nanoparticles comprising silver, gold, and mixtures and alloys thereof may be particularly effective.

[0018] In some embodiments, the polymer composition may be made from a liquid polymer composition having metal nanoparticles incorporated therein, such as by mixing the metal nanoparticles into an uncured polymer solution or polymer melt and drawing polymer fibers therefrom using an electrospinning or wet spinning process, where the metal nanoparticles become mixed throughout the formed polymer fiber.

[0019] The metal nanoparticles on the surface of the polymeric material and / or embedded within the pores provide antimicrobial activity to prevent microbial growth on the polymeric material. The metal nanoparticles also protect the polymeric material from damage by UV radiation by down-converting the incident UV energy to lower energy wavelengths that are less or not damaging to the polymeric material.

[0020] The polymer compositions disclosed herein advantageously can provide antimicrobial and UV protection benefits for extended periods of time without nanoparticle depletion, even after abrasion or machining. For example, because the embedded nanoparticles do not rely on ion release as the primary means of antimicrobial activity, the polymer compositions disclosed herein can provide this functionality for longer than similar polymer compositions that utilize conventional nanoparticles formed via chemical synthesis.

[0021] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.

[0022] Various objects, features, characteristics and advantages of the present invention will become apparent and be more readily understood from the following description of embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification, in which like reference numerals may be used to designate corresponding or similar parts in the various views, and the various elements illustrated are not necessarily drawn to scale. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a scanning transmission electron microscope image of the polystyrene surface from hot extrusion pellets. [Figure 2A] 2A-2C show a thermoplastic containing Ag nanoparticles. [Figure 2B] 2A-2C show a thermoplastic containing Ag nanoparticles. [Figure 2C] 2A-2C show a thermoplastic containing Ag nanoparticles. [Figure 3A] 3A and 3B are schematic diagrams showing the microorganism after absorbing the spherical metal nanoparticles from the substrate, and the disulfide bonds that have been catalytically modified by the spherical nanoparticles. [Figure 3B] 3A and 3B are schematic diagrams showing the microorganism after absorbing the spherical metal nanoparticles from the substrate, and the disulfide bonds that have been catalytically modified by the spherical nanoparticles. [Figure 4] FIG. 4 shows STEM images of Ag nanoparticles inside MRSA SA62 drug-resistant bacteria. [Figure 5A]5A-5C show STEM images of Tecoflex EG-93A-B20 thermoplastic impregnated with nanoparticles. [Figure 5B] 5A-5C show STEM images of Tecoflex EG-93A-B20 thermoplastic impregnated with nanoparticles. [Figure 5C] 5A-5C show STEM images of Tecoflex EG-93A-B20 thermoplastic impregnated with nanoparticles. [Figure 6A] 6A-6C show STEM images of Isoplast 2510 thermoplastic impregnated with nanoparticles. [Figure 6B] 6A-6C show STEM images of Isoplast 2510 thermoplastic impregnated with nanoparticles. [Figure 6C] 6A-6C show STEM images of Isoplast 2510 thermoplastic impregnated with nanoparticles. [Figure 7A] 7A-B show magnified STEM images of Ag nanoparticles embedded in thermoplastic. [Figure 7B] 7A-B show magnified STEM images of Ag nanoparticles embedded in thermoplastic. [Figure 8A] 8A-8B are schematic diagrams showing examples of electrospinning and wet spinning processes, respectively. [Figure 8B] 8A-8B are schematic diagrams showing examples of electrospinning and wet spinning processes, respectively. [Figure 9] Figure 9 is a rendering of nanoparticles embedded in electrospun fibers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] I. Overview The term "nanoparticle" often refers to a particle whose largest dimension is less than 100 nm. Bulk materials typically have consistent physical properties regardless of size, but at the nanoscale, size-dependent properties are often observed. Thus, the properties of a material change as its size approaches the nanoscale and as the proportion of atoms at the surface of the material increases. For bulk materials larger than 1 micrometer (or micron), the proportion of atoms at the surface relative to the number of atoms in the bulk of the material is not important. Thus, the interesting and sometimes unexpected properties of nanoparticles are primarily due to the large surface area of ​​the material, which dominates the contribution of the relatively small bulk of the material.

[0025] The polymer compositions disclosed herein can be made from liquid polymer compositions having metal nanoparticles incorporated therein, such as by mixing metal nanoparticles into an uncured polymer solution or polymer melt and drawing polymer fibers therefrom using an electrospinning or wet spinning process, where the metal nanoparticles become mixed throughout the formed polymer fibers.

[0026] As used herein, "polymer composition" refers to a polymer fiber product resulting from the disclosed electrospinning or wet spinning process and may be used synonymously with terms such as "polymer fiber." "Polymer solution" or "polymer melt" refers to a liquid and / or uncured composition prior to being drawn into a fiber through one of the aforementioned processes. A "polymer solution" may be an uncured solution containing monomers and / or oligomers that undergo polymerization and / or crosslinking when drawn into a fiber, while a "polymer melt" may be a polymer that is heated until it melts and then resolidifies when drawn into a fiber.

[0027] Some examples may refer to a polymer solution and other examples may refer to a polymer melt, but it is understood that the same principles apply to either embodiment. As disclosed herein, the metal nanoparticles may be mixed with a polymer solution or melt prior to the fiber spinning process such that the metal nanoparticles are incorporated into the resulting polymer composition.

[0028] Examples of polymer compositions that may be used in the disclosed embodiments include silicones, polysiloxanes, epoxies, polystyrene (PS), polyethylene (PE) (including low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE)), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), polycarbonate (PC), polyurethane (PU), polyether ether ketone (PEEK), polylactic acid (PLA), polyhydroxyalkanoates (PHA), polyesters (PES), polyethylene terephthalate (PET), polymethyl methacrylate (PHA), and the like. MMA), polybutylene terephthalate (PBT), phenol-formaldehyde (PF), nylon / polyimide (PA), melamine formaldehyde (MF), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinylpyrrolidone (PVP), acrylonitrile butadiene styrene terpolymer (ABS), styrene block copolymer (SBC), rubber latex (natural or synthetic), nitriles such as nitrile-butadiene rubber (NBR), medical grade thermoplastic elastomers (TPE), aramid fibers such as Kevlar®, carbon fiber reinforced polymers, and combinations thereof.

[0029] II. Nanoparticles The metal nanoparticles used in the disclosed polymer compositions may be in a non-ionic ground state, with no external edges or bond angles that would cause the release of metal ions. Typically, spherical metal nanoparticles are used to kill microorganisms, but coral-shaped metal nanoparticles may provide antimicrobial activity, typically in combination with spherical metal nanoparticles.

[0030] In some embodiments, the metal nanoparticles may comprise or consist essentially of non-ionic, ground state metal nanoparticles with no external edges or bond angles that would cause the release of metal ions. Examples include spherical metal nanoparticles, coral-shaped metal nanoparticles, and blends of spherical and coral-shaped metal nanoparticles.

[0031] Conventional silver nanoparticles produced via chemical reduction (typically with a capping agent) tend to be clustered, crystalline, faceted, or polyhedral in shape, rather than truly spherical with rounded, smooth surfaces. Such nanoparticles are often clusters and can have a relatively broad particle size distribution. In some cases, conventional silver nanoparticles are formed as a shell of silver formed on a non-metallic seed material.

[0032] In contrast, the spherical nanoparticles that may be included in the polymer compositions disclosed herein may exhibit one or more of the following: (1) solid metal morphology, (2) substantially non-clustered state, (3) exposed / uncoated surface, (4) smooth surface morphology, and / or (4) narrow particle size distribution. As used herein, an "exposed" or "uncoated" surface is one in which the capping agent is omitted and instead the metal surface is directly exposed to the environment.

[0033] The metal nanoparticles of the disclosed polymeric compositions, including spherical and coral-shaped nanoparticles, may comprise any desired metal, mixture of metals, or metal alloy, including at least one of silver, gold, platinum, palladium, rhodium, osmium, ruthenium, rhenium, molybdenum, copper, iron, nickel, tin, beryllium, cobalt, antimony, chromium, manganese, zirconium, tin, zinc, tungsten, titanium, vanadium, lanthanum, cerium, heterogeneous mixtures thereof, or alloys thereof. Nanoparticles comprising silver, gold, and mixtures and alloys thereof may be particularly effective.

[0034] In some embodiments, gold (Au) nanoparticles are included in the polymer composition and function to downshift incident UV radiation. The gold nanoparticles can downconvert light waves to longer wavelength, less energetic and less harmful light. The gold nanoparticles can downconvert the wavelength of light towards the red zone of the light spectrum. In some embodiments, the gold nanoparticles are spherical in shape. In some embodiments, the gold nanoparticles have a diameter of approximately 1-40 nm.

[0035] The nanoparticle composition may include spherical metal nanoparticles, coral-shaped metal nanoparticles, or a combination of the two. Typically, the spherical metal nanoparticles have greater antimicrobial activity, but the coral-shaped metal nanoparticles can also provide antimicrobial activity and when combined, can enhance the antimicrobial activity of the spherical metal nanoparticles.

[0036] Non-ionic, ground state, spherical metal nanoparticles having no external edges or bond angles, and compositions comprising such nanoparticles, may be made according to the disclosures of U.S. Patent Nos. 9,849,512, 10,137,503, and 10,610,934. Non-ionic, ground state, coral-shaped metal nanoparticles having no external edges or bond angles, and compositions comprising such nanoparticles, may be made according to the disclosures of U.S. Patent No. 9,919,363. Compositions comprising a mixture of spherical and coral-shaped metal nanoparticles are disclosed in U.S. Patent No. 9,434,006. Each of the foregoing patents is incorporated herein by reference in its entirety.

[0037] The liquid medium into which the nanoparticles are mixed (e.g., a polymer solution or polymer melt) may contain a concentration of nanoparticles ranging from about 50 ppb to about 100 ppm, or from about 100 ppb to about 50 ppm, or from about 200 ppb to about 20 ppm, or from about 400 ppb to about 10 ppm, or from about 600 ppb to about 6 ppm, or from about 800 ppb to about 4 ppm, or from about 1 ppm to 3 ppm, or about 2 ppm, or a combination of any of the foregoing values ​​using as endpoints, based on the weight of the liquid medium applied to the polymer composition.

[0038] The nanoparticles may be incorporated into the polymer by known means, such as those disclosed in U.S. Patent Application Nos. 17 / 969,299 and 17 / 970,172, which are incorporated by reference. In some embodiments, the polymer composition may be made from a thermoplastic material having the metal nanoparticles incorporated therein, such as by coating polymer beads or pellets that are then thermoplastically formed into an article of manufacture of the desired structure. In other embodiments, the polymer composition may be made from a two-component composition in which the metal nanoparticles are included in one or both components of the composition. In either case, the metal nanoparticles become mixed throughout the polymer composition, either in the molten state before molding and cooling, or in the liquid state before molding and heat curing. The nanoparticles may be added to the monomers or oligomers that form the desired polymer or copolymer. The nanoparticles may be applied to the spun polymer fibers through a coagulation bath containing the nanoparticles.

[0039] After the nanoparticles are incorporated into the polymer composition (e.g., after they are incorporated into formed fibers), the nanoparticles can be present at about 0.5 mg / kg to about 8 mg / kg, such as about 1 mg / kg, 2 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, or a range ending at any combination of the foregoing values.

[0040] The spherical metal nanoparticles may have an average particle size (i.e., diameter) in the range of about 1 nm to about 20 nm, such as about 3 nm to about 14 nm, or about 4 nm to about 13 nm, or about 5 nm to about 12 nm, or about 6 nm to about 10 nm. In some embodiments, the spherical metal nanoparticles may have a diameter of about 40 nm or less, about 35 nm or less, about 30 nm or less, about 25 nm or less, about 20 nm or less, about 15 nm or less, about 10 nm or less, about 7.5 nm or less, or about 5 nm or less. The composition may include nanoparticles within a concentration range having endpoints defined by any two of the foregoing values.

[0041] As used herein, unless otherwise specified, average size (i.e., average particle size) refers to the number average, which can be determined according to standard methods known in the art. As an example, the average size can be determined via microscopy (e.g., scanning transmission electron microscopy (STEM)) and analysis of the resulting images. Another suitable method for determining the average size of a set of metal nanoparticles is dynamic light scattering (DLS), which is typically reported on a volume basis.

[0042] The spherical metal nanoparticles may have a size distribution in which at least 99% of the metal nanoparticles have a size within 30% of the mean diameter, or within 20% of the mean diameter, or within 10% of the mean diameter, and / or a size distribution in which at least 99% of the spherical nanoparticles have a size within ±3 nm of the mean diameter, or within ±2 nm of the mean diameter, or within ±1 nm of the mean diameter. The spherical nanoparticles may have a ξ potential of at least about ±10 mV (absolute value), or at least about ±15 mV, or at least about ±20 mV, or at least about ±25 mV, or at least about ±30 mV.

[0043] In some embodiments, coral-shaped metal nanoparticles may be used in conjunction with spherical metal nanoparticles. In general, spherical metal nanoparticles may be smaller than coral-shaped metal nanoparticles, and in this way provide a much higher surface area for catalyzing a desired reaction or providing other desired benefits. On the other hand, the generally larger coral-shaped nanoparticles may exhibit a higher surface area per unit mass compared to spherical nanoparticles, since coral-shaped nanoparticles have internal spaces and surfaces, rather than just a solid core and an exterior surface.

[0044] In at least some cases, a synergistic effect may be obtained by providing a nanoparticle composition that includes both spherical nanoparticles and coral-shaped nanoparticles. In addition to providing their own unique benefits, the coral-shaped nanoparticles may also help to preserve and / or enhance the activity of the spherical nanoparticles. For example, smaller particles may provide better relative protection against UVB radiation, while larger particles may provide better protection against UVA radiation. In some embodiments, the combination of spherical nanoparticles and coral-shaped nanoparticles may provide synergistic broad-spectrum protection with a greater amount of protection (e.g., amount of reflected UV radiation) per unit amount of active ingredient compared to a single size and / or shape composition.

[0045] In some embodiments, the mass ratio of spherical nanoparticles to coral-shaped nanoparticles in the nanoparticle composition can be in the range of about 1:1 to about 50:1, or about 2.5:1 to about 25:1, or about 5:1 to about 20:1, or about 7.5:1 to about 15:1, or about 9:1 to about 11:1, or about 10:1. The particle number ratio of spherical nanoparticles to coral-shaped nanoparticles in the nanoparticle composition can be in the range of about 10:1 to about 500:1, or about 25:1 to about 250:1, or about 50:1 to about 200:1, or about 75:1 to about 150:1, or about 90:1 to about 110:1, or about 100:1.

[0046] In some embodiments, at least a portion of the metal nanoparticles are selected to selectively reflect, block, and / or scatter a particular range of solar radiation. For example, a first set of metal nanoparticles may be selected as spherical shaped metal nanoparticles having a smaller relative size and therefore more strongly reflecting, scattering, and / or blocking UVB radiation, while a second set of metal nanoparticles may be selected as coral shaped metal nanoparticles having a larger relative size and therefore more strongly reflecting, scattering, and / or blocking UVA radiation.

[0047] In some embodiments, the polymer composition comprises at least one spherical antimicrobial nanoparticle component and a larger coral-shaped nanoparticle component. III. Antibacterial function of nanoparticles 2A-2C are STEM images showing thermoplastics containing silver (Ag) nanoparticles resulting in antimicrobial and / or wavelength-shifting polymer compositions.

[0048] 3A-3B show schematic diagrams of a microorganism after absorbing spherical metal nanoparticles from a substrate and disulfide bonds that have been catalytically modified by the spherical nanoparticles. FIG. 3A shows schematic diagram of a microorganism 608 that has absorbed spherical nanoparticles 604 from a solid substrate 602, such as by active absorption or other transport mechanism. Alternatively, the spherical nanoparticles 604 may be provided in a composition (not shown), such as in a liquid or gel carrier. The nanoparticles 604 are free to move throughout the interior 606 of the microorganism 608 and can come into contact with one or more vital proteins or enzymes 610 that, when modified, will kill or incapacitate the microorganism.

[0049] One way that nanoparticles can kill or modify microorganisms is by catalyzing the cleavage of disulfide (SS) bonds in vital proteins or enzymes. Figure 3B shows a schematic of a microbial protein or enzyme 710 with disulfide bonds being catalytically modified by an adjacent spherical nanoparticle 704 to form a modified protein or enzyme 712. In the case of bacteria or fungi, microorganisms can be killed in this manner by cleavage of disulfide bonds and / or cleavage of other chemical bonds in vital proteins or enzymes occurring inside the cell. Such catalytic cleavage of disulfide (SS) bonds is facilitated by the generally simple protein structure of microorganisms, where many vital disulfide bonds are exposed and easily cleaved by catalysts.

[0050] Another possible mechanism by which metal (e.g., silver) nanoparticles can kill microorganisms is through the generation of reactive oxygen species, such as peroxides, which can oxidatively cleave protein bonds, including but not limited to amide bonds.

[0051] Despite their lethal nature to microorganisms, non-ionic metal nanoparticles have been shown to be harmless and non-toxic to humans, mammals, and animals because they have much more complex protein structures compared to simple microorganisms, with most or all of the vital disulfide bonds protected by other, more stable regions of the protein. In many cases, non-ionic nanoparticles do not interact or adhere to human cells, other mammalian cells, or other animal cells, and can be rapidly and safely excreted through the urine without damaging the kidneys or other cells, tissues, or organs.

[0052] In the case of spherical silver (Ag) nanoparticles, the interaction of silver (Ag) nanoparticles in microorganisms is not related to silver ions (Ag), as is typical with conventional colloidal silver compositions. + It has been shown that silver (Ag) nanoparticles are particularly lethal without the need to rely on the production of toxic silver ions (Ag + It is a substantial advance in the art to be able to provide effective microbial control without significant or actual release of ions into the patient or surrounding environment. Any amount or concentration of silver ions released from silver nanoparticles, if any, is well below known or inherent toxicity levels to animals, such as mammals, birds, reptiles, fish, and amphibians.

[0053] Figure 4 shows STEM images of silver (Ag) nanoparticles inside MRSA SA62 drug-resistant bacteria. STEM images coupled with electron diffraction spectroscopy confirmed disruption at disulfide bonds and ferredoxin sites.

[0054] The use of non-ionic silver nanoparticles created using laser ablation offers advantages over conventional silver nanoparticles, which are known to function primarily through the release of silver ions and have been shown to lead to antimicrobial silver nanoparticle resistance. As discussed above, conventional silver nanoparticles created using chemical reduction processes are known to lead to antimicrobial resistance, meaning that their effectiveness at killing microorganisms decreases over time. Some studies have demonstrated microbial resistance to ionic silver in as little as six generations.

[0055] In contrast, the spherical nanoparticles that may be included in the polymer compositions disclosed herein have been shown to have stable antibacterial activity, even after 28 passages / generations, with no decrease in antibacterial activity, including a significant deterioration in MIC (minimum inhibitory concentration).

[0056] IV. UV protection function of nanoparticles Metal nanomaterials of the type disclosed herein, having diameters or sizes within the range of about 10 nm to 40 nm, have a loose dielectric field. When large numbers of particles are present together, the dielectric effect on passing light waves may not attenuate, but may cause a frequency shift toward either the red or blue end of the electromagnetic spectrum. Polymer compositions having enough of such nanoparticles may affect UV radiation, shifting it toward the red end of the spectrum, reducing the penetration of light energy at a level that reduces overall damage.

[0057] In some embodiments, the polymeric composition may include metal nanoparticles having a high refractive index to reflect and / or scatter incident UV radiation. For example, the nanoparticles used in the polymeric compositions of the present disclosure may have a refractive index for UVA and / or UVB radiation of about 1.5 to about 4.6, or about 2.0 to about 4.0, or about 2.5 to about 3.5. In some embodiments, the refractive index of the nanoparticles is higher for UVB radiation compared to UVA radiation (e.g., the refractive index increases with decreasing wavelength). However, in other embodiments, the refractive index of the nanoparticles is lower for UVB radiation compared to UVA radiation (e.g., the refractive index increases with increasing wavelength).

[0058] In some embodiments, the polymeric composition can include nanoparticles that have photostability such that upon exposure to solar radiation (e.g., in an environment with a relatively high UV index of about 15), the nanoparticles do not decrease or lose their protective efficacy against UV radiation (e.g., maintain about 100% efficacy, or maintain about 95-100% efficacy, or maintain about 90-100% efficacy, or maintain about 80-100% efficacy) for at least a given time period (e.g., about 1 hour, or about 2-4 hours, or about 4-6 hours, about 6-12 hours or more, or even indefinitely).

[0059] In some embodiments, the polymer composition exhibits radiation protection properties. For example, some embodiments include a plurality of nanoparticles (e.g., beryllium and / or gold) configured to absorb harmful radiation (e.g., alpha particles, beta particles, and / or gamma rays), thereby reducing or eliminating the amount of radiation that passes through the nanoparticle-treated material.

[0060] In some embodiments, the gold nanoparticles dispersed throughout the polymer composition downconvert the incident UV radiation to less harmful UV radiation. In some embodiments, the gold nanoparticles may downshift the incident UV radiation by at least about 50 nm, or at least about 100 nm, or at least about 150 nm, such as approximately 200 nm. In some embodiments, the gold nanoparticles may downshift the incident UV radiation from UV light to visible light. In some embodiments, the gold nanoparticles may downshift the incident UV radiation from UV wavelengths toward red and / or green wavelengths.

[0061] In some embodiments, gold nanoparticles dispersed throughout the polymer composition can absorb incident UV radiation at high energy and emit lower energy wavelengths, thereby providing UV protection to the polymer composition and products made therefrom. Unexpectedly, the ability of gold nanoparticles to perform this downshift in wavelength / radiation energy permanently does not appear to degrade with use; that is, the gold nanoparticles retain their UV protection capabilities and do not undergo any obvious degradation from incident UV radiation. This beneficially prolongs the effectiveness of the polymer composition and products made therefrom. This also means that lower concentrations of gold nanoparticles, or other wavelength-shifting metal nanoparticles, can be used, resulting in products that are less expensive to manufacture while still maintaining their integrity.

[0062] V. Fiber-Spun Polymer Compositions Containing Nanoparticles a.Electrospinning The process of electrospinning is particularly suited to producing polymeric microfibers and nanofibers. These fibers can then be applied to or incorporated into a variety of devices and surfaces. Many medical devices can be made using electrospun fibers.

[0063] 8A is a schematic diagram of an example electrospinning system 100. Electrospun fibers are produced by applying a sufficiently high voltage between a tip 102 and a collector 104. Contained within the tip 102 is a polymer solution / melt 106. Upon application of a voltage, the polymer solution / melt 106 becomes charged. Electrostatic repulsion overcomes surface tension, elongating the droplet. At a critical point, a charged liquid jet is formed that propels toward the collector 104.

[0064] This charged liquid jet can be stretched by a whipping process caused by electrostatic repulsion initiated at small bends in the fibers. The fibers are eventually deposited and collected on a collector 104. The illustrated system 100 includes a rotating collector 104. Other embodiments can additionally or alternatively include other types of collectors, such as a flat surface collector.

[0065] Fiber stretching and thinning resulting from bending instability results in the formation of uniform fibers with diameters down to the nanometer scale. Various solution parameters such as viscosity, polymer concentration, molecular weight, conductivity, and / or surface tension affect the size and shape of the resulting fibers. Additional parameters may include voltage, tip-to-collector distance, feed rate, humidity, temperature, collector motion and size, and / or tip 102 thickness.

[0066] By mixing the metal nanoparticles with the polymer solution / melt 106, the resulting fibers incorporate the metal nanoparticles throughout the bulk and on the fiber surface. b. Wet (hydro) spinning Another manufacturing process for plastics, polymers, and fibers is wet spinning (also called hydrospinning). Like electrospinning, the process of wet spinning is particularly suited for producing polymeric microfibers and nanofibers. These fibers can then be applied or incorporated into a variety of devices and surfaces.

[0067] 8B is a schematic diagram of an example wet spinning system 200. Wet spun fibers are made by injecting a polymer solution / melt 206 from a vessel 202 into a coagulation bath 208, which is typically water. As the polymer solution / melt 206 is injected or extruded into the bath 208, the injected stream begins to precipitate to form a fiber. The fiber may be spun or wrapped around a collector 204, such as a rotary collector. The polymer solution / melt 206 may be injected (or extruded) into the bath 208 using a spinneret or other suitable device.

[0068] By mixing the metal nanoparticles with the polymer solution / melt 206, the resulting fibers incorporate the metal nanoparticles throughout the bulk and on the fiber surface. The nanoparticles can also be applied to the spun fibers via a coagulation bath 208.

[0069] c. Polymer solution / melt examples In the electrospinning or wet spinning process, various polymers may be used as the polymer solution / melt, including any of the polymer compositions disclosed elsewhere herein, mixtures thereof. The polymer selected may depend on the desired properties of the resulting fiber and the end use of the fiber. Industrial polymers, biodegradable polymers, specialty polymers, and natural polymers are all suitable starting materials. Polymer matrix nanofiber composites can be produced using electrospinning with electrospinnable polymers. The polymer solution / melt may include or use as starting materials resins and / or epoxies.

[0070] One or more fillers may be mixed with the polymer solution / melt prior to the fiber spinning process. Fillers may include, but are not limited to, metal oxide nanoparticles (e.g., in addition to the metal nanoparticles disclosed herein), therapeutic agents, or combinations thereof. Therapeutic agents may include, but are not limited to, nonsteroidal anti-inflammatory drugs (NSAIDs) and other anti-inflammatory drugs, antibiotics, pulmonary medications, antiallergic drugs, antihistamines, vasodilators, muscle relaxants, steroids, antifungals, bronchodilators, nitroglycerin, cough suppressants, and / or other suitable therapeutic agents. The therapeutic agents incorporated into the polymer solution / melt will depend on the end use of the resulting fiber (e.g., placement in an implantable medical device) and / or the particular medical condition to be treated (e.g., allergies, bacterial infections, etc.).

[0071] VI. Medical Devices The polymeric composition produced using one or more of the methods disclosed herein may include a medical device. The medical device thus formed is advantageously protected from UV radiation and microbial growth. The metal nanoparticles incorporated into the medical device can down-convert the incident UV radiation to lower energy radiation. This advantageously prevents the general degradation of the polymeric device or article from UV radiation. The polymeric device or article can be used for a longer period of time without cracking, discoloring, clouding, leaking, and / or complete failure.

[0072] Metal nanoparticles incorporated into medical devices can also inactivate or kill microorganisms, preventing their accumulation on or within the medical device. For example, the antimicrobial activity of embedded nanoparticles can act to inhibit microbial growth and biofilm formation on implanted medical devices, beneficially extending the life of the device in environments such as hospitals or clinics. This also benefits the sterility of the product, leading to reduced costs of storage and sterilization procedures.

[0073] Examples of medical devices that may be formed, at least in part, using the methods disclosed herein include, but are not limited to, gloves, catheters, wound dressings, syringes and other drug delivery components, and polymeric portions of implantable devices (e.g., pacemakers, artificial joints, drug pumps, intrauterine contraceptive devices (IUDs), cochlear implants, vascular access devices, polymeric portions of prosthetic heart valves), bone implants, bone pins, bone screws, tissue grafts, airway devices such as endotracheal tubes, catheters, arteriovenous grafts, bypass grafts, anastomosis clips, arterial hemostasis devices, patent foramen ovale closure devices, and drug delivery balloons.

[0074] The nanoparticle-impregnated fibers may be disposed on or form any part of the structure of such devices. The nanoparticle-impregnated fibers may be disposed on the exterior surface of such devices. Additionally or alternatively, the nanoparticle-impregnated fibers may be disposed on the exterior surface that contacts the tissue or tissue-air interface (if the device is implanted).

[0075] 9 is a rendering of nanoparticles embedded in the electrospun material. The embedded nanoparticles can be any of the nanoparticles discussed above, such as laser ablated spherical nanoparticles, laser ablated coral-shaped nanoparticles, metal oxide nanoparticles, and / or combinations thereof.

[0076] Working Example VII. Examples Example 1 Silver nanoparticles were suspended in 99.9% isopropyl alcohol. Nanoparticle concentration was confirmed using inductively coupled plasma optical emission spectroscopy (ICPOES). Nanoparticle diameter was confirmed using DLS and found to be approximately 6-10 nm. Surface composition and short bond lengths were confirmed by STEM imaging using electron loss spectroscopy (ELS).

[0077] Drug-resistant bacteria were found to be killed at nanoparticle concentrations ranging from 0.5 mg / L (0.5 ppm) to 2 mg / L (2 ppm). The highest concentration found to kill drug-resistant bacteria was 8 mg / L (8 ppm). STEM imaging using a dark-field camera with a 3 nm carbon coating without the use of stains allowed tracking of the nanoparticles in and around the bacteria. STEM imaging coupled with electron diffraction spectroscopy (EDS) confirmed cleavage at the disulfide bonds and ferredoxin sites.

[0078] Example 2 Polyethylene (PE) products embedded with silver nanoparticles were tested for antibacterial properties. Two polymers were provided, Tecoflex FG-93A-B20 (W filament) and Isoplast 2510 (D filament), each treated with silver nanoparticles. Figures 5A-C show STEM images of Tecoflex EG-93A-B20 thermoplastic with embedded nanoparticles. Figures 6A-C show STEM images of Isoplast 2510 thermoplastic with embedded nanoparticles. Figures 7A-B show silver nanoparticles embedded in thermoplastic.

[0079] Silver nanoparticles were prepared in isopropyl alcohol at a concentration of 38 mg / L (38 ppm). This alcohol mixture was applied to polymer beads or granules. The polymer beads or granules were melted to a final concentration of 6 mg / kg (6 ppm) in the resulting PE polymer. This concentration of 6 mg / kg has been previously shown to be successful in surface antibacterial testing. The extruded filaments were then embedded in a toming polymer, sectioned to a thickness of 80-100 nm, and mounted on 200 mesh Formvar Carbon B TEM grids for imaging.

[0080] Imaging was performed on a JEOL 2800 scanning transmission electron microscope (STEM) equipped with a dark-field camera, a bright-field camera, and a secondary surface camera. 2Elemental mapping up to 1000 nm resolution was performed and nanoparticles and microparticles were identified using dual EDS detectors for triangulation and net count accuracy.

[0081] Tecoflex FG-93A-B20 thermoplastic was light purple in color and required a clenching or cooling step after melt extrusion at 230° C. Large solid metal particles hundreds of nanometers in size were observed under STEM, as shown in Figures 5A-C. EDS mapping confirmed these to be barium sulfate.

[0082] It is believed that the silver nanoparticles directly interacted with the sulfur chemicals and that the overwhelming amount of barium sulfate (used as a filler and reinforcing agent in Tecoflex FG-93A-B20) sequestered the silver nanoparticles. No direct nanoparticles were found on any of the grids from STEM imaging. Background silver was detected in the barium sulfate particles. Thermal dissociation was observed on the filament surface, which is expected due to poor thermal control in the final filament formation.

[0083] The Isoplast 2510 thermoplastic was a darker purple color and had a more glass-like surface finish. The Isoplast 2510 thermoplastic was melted at 230°C and cooled at room temperature (22.5°C). This thermoplastic used phosphate as a filler and reinforcement instead of barium sulfate. As shown in Figures 6A-C, the phosphate did not interact with the Ag nanoparticles and it was easy to find and elementally map the silver nanoparticles present. Isoplast 2510 is a better candidate to distribute the silver nanoparticles evenly in the plastic. The surface did not undergo the same type of thermal dissociation.

[0084] Example 3 Surface antibacterial testing was performed using the standard penicylinder method. A conventional penicylinder has an outer diameter of 7.8 mm, an inner diameter of 5.8 mm, and is 9.9 mm long. The surface area can be calculated as follows:

[0085] A s =(Outer surface area)+(Inner surface area)+2(Edge surface area) A s =242.6mm 2 +180.4mm 2 +42mm 2 A s =465mm 2 Because both ends of the penicylinder have a 45° taper, the total surface area is a little less than calculated, but the difference is not significant.

[0086] A 20 mm long filament similar to a penicylinder was used for the antibacterial test. The filament diameter was 1.2 mm, with a 7.5 mm gap per mm of length. 2 The surface area of ​​each end is 2.3 mm 2 The total surface area of ​​a 20 mm long filament is A f = 152.3mm 2 The total number of 20 mm long filaments needed to replace the penicylinder is:

[0087] A s / A f =465 / 152.3=3.1 Three filaments were used in each test sample set to roughly equal the surface area of ​​one penicylinder, with metal nanoparticles suspended throughout each filament.

[0088] The filament was cut using a disposable straight blade razor that had been cleaned with at least 70% isopropyl alcohol. The filament was measured against a continuous surface with two marks spaced 20 mm apart and the filament was cut to that length. The cut filament was transferred to a 50 mL sample tube containing 25 mL of isopropyl alcohol and vortexed for 1 minute. The filament was then removed using flame / heat sterilized tweezers into a 50 mL sample holding container.

[0089] Antibacterial test is 10 5 , 10 6 , and 10 7 The study was performed with E. coli at the colony forming unit (CFU) level. Each set of three filaments was introduced into E. coli in tryptic soy broth and exposed to E. coli for 1 hour. Two sample sets (three filaments) were used for each concentration of E. coli.

[0090] The filament was removed from the tryptic soy broth containing the E. coli colony and allowed to drip until the filament was free of liquid. The filament was then introduced into purple Dey-Engley (DE) broth. If E. coli grew from the filament transferred to the DE broth, the color of the broth would turn yellow.

[0091] A sample of the DE broth was cultured on a tryptic soybean template for colony growth and the initial 10 5 , 10 6 , and 10 7 The CFUs were compared with the cultures. The colonies were then counted after 24 and 48 hours of growth. The CFUs of E. coli were confirmed by counting on agar as follows: 10 5 =23CFU;10 6 = 256 CFU; and 10 7 =1000CFU.

[0092] After 24 hours of testing, the CFU on the filament can plate was zero for all concentrations of E. coli prepared. After 48 hours of testing, the CFU on the filament can plate was zero for all concentrations of E. coli prepared. DE broth showed no color change after 24 and 48 hours for all concentrations of E. coli exposed to the filament. 5 , 10 6 , and 10 7 No viable bacteria were present on the surface of any of the filaments exposed to CFU E. coli concentrations for 1 hour. Duplicate samples from the test showed the same results.

[0093] Example 4 Spherical silver nanoparticles created by laser ablation, which have no external bond angles or edges, are non-ionic and do not release silver ions, were tested to determine whether they could induce silver nanoparticle-resistant bacteria. Even after 28 passages, no such resistance was detected.

[0094] Two different types of spherical silver nanoparticles were tested: Silver Lot No. Desktop Laser: Ag200917-104 (19 ppm) and Silver Lot No. Industrial Laser: 171229-101 (16.8 ppm). The spherical silver nanoparticles produced using the desktop laser had an average diameter of 8-10 nm, and the spherical silver nanoparticles produced using the industrial laser had an average diameter of 8-12 nm.

[0095] The experimental procedure is outlined below. Bacteria preparation: 1. Streak bacteria onto tryptic soy agar (TSA) plates and incubate overnight at 37°C. 2. The next day, inoculate 10 mL of AgMueller-Hinton Broth Mix with one colony. a.Desktop laser: i. E. coli - Make a 4.75 ppm silver nanoparticle mix in broth (2.5 mL of Ag + 7.5 mL of broth). ii. P. aeruginosa – Make a 4.75 ppm silver nanoparticle mix in broth (2.5 mL of Ag + 7.5 mL of broth). b. Industrial lasers: i. E. coli - Make a 2 ppm silver nanoparticle mix in broth (1.2 mL of Ag + 8.8 mL of broth). ii. P. aeruginosa – Make a 2 ppm silver nanoparticle mix in broth (1.2 mL of Ag + 8.8 mL of broth). 3.Incubate at 37°C and 250 RPM for 24-36 hours. 4. Monitor growth the next day. 5. Continue serial passaging in fresh silver broth mixture by placing an inoculating loop into the culture. 6. Every 5-7 days, streak the culture loop onto a TSA plate to preserve passage, then perform an MIC test on the colonies to measure whether the bacteria have developed resistance to the spherical silver nanoparticles.

[0096] The experimental results are as follows: MIC value: E. coli - Industrial Laser Sample: The MIC was maintained at 2 ppm for up to 28 serial passages. DT laser samples: Cultures stopped reproducing at passage 21. MICs were maintained at earlier passages. P. aeruginosa - industrial laser samples: MIC was maintained at 2 ppm for up to 28 serial passages. DT laser samples: Cultures stopped reproducing at passage 21. MICs were maintained at earlier passages. All negative and positive controls passed.

[0097] VIII. Additional Terms and Definitions Although certain embodiments of the present disclosure have been described in detail with reference to specific configurations, parameters, components, elements, etc., these descriptions are illustrative and should not be construed as limiting the scope of the invention as claimed.

[0098] Furthermore, for any given element of a component of a described embodiment, unless implicitly or explicitly stated otherwise, it is to be understood that any of the possible options listed for that element or component may be used generally, individually or in combination with each other.

[0099] In addition, numerical values ​​expressing amounts, components, distances, or other measurements used in the specification and claims are to be understood as being modified by the term "about" where appropriate. When terms such as "about," "approximately," and "substantially" are used in conjunction with a stated amount, value, or condition, it may be interpreted to mean that the amount, value, or condition deviates from the stated amount, value, or condition by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01%. Where appropriate, numerical values ​​may be modified by express use of the term "exactly" to clarify particular situations where the term "about" does not apply.

[0100] The headings and sub-headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the specification or the claims. It should also be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referring to a singular referent (e.g., a "medical device") may also include two or more such referents.

[0101] The embodiments disclosed herein should be understood as comprising / including the disclosed components, and therefore may include additional components not specifically described. If desired, the embodiments disclosed herein are essentially free or completely free of components not specifically described. That is, the components not disclosed may be completely or essentially omitted from the disclosed embodiments, if desired. For example, the nanoparticle conjugates not disclosed or the solvents not disclosed may be completely or essentially omitted from the polymeric compositions and / or finished medical products disclosed herein, if desired.

[0102] Embodiments that are "essentially omitted" or "essentially free" of an ingredient may include trace and / or non-functional amounts of the ingredient. For example, an "essentially omitted" ingredient may be present in an amount of 2.5% or less, 1% or less, 0.1% or less, or 0.01% or less by weight of the total composition. This is equally true for other negative modifiers, such as, but not limited to, "essentially omitted," "essentially free," "substantially," or similar phrases using other synonyms of "essentially."

[0103] A composition that "totally omits" or is "totally free" of a component does not contain a detectable amount of that component (i.e., does not contain an amount above the inherent background signal associated with the testing equipment) when analyzed using standard coating composition analytical techniques, such as, for example, chromatographic techniques (e.g., thin layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC)), or spectroscopic techniques (e.g., Fourier transform infrared (FTIR) spectroscopy).

[0104] It is also understood that the embodiments described herein may include properties and / or characteristics (e.g., ingredients, components, members, elements, parts, and / or portions) described in one or more separate embodiments, and are not necessarily limited to the precise features explicitly described for that particular embodiment. Thus, various features of a given embodiment may be combined with and / or incorporated into other embodiments of the present disclosure. Thus, the disclosure of a particular feature with respect to a particular embodiment of the present disclosure should not be construed as limiting the application or inclusion of said feature to that particular embodiment. Rather, it is understood that other embodiments may also include such features.

Claims

1. The process involves supplying or mixing metal nanoparticles, including nonionic metal nanoparticles formed by laser ablation, into a polymer solution or polymer melt. The process involves stretching the polymer solution or polymer melt into polymer fibers, thereby forming polymer fibers into which the metal nanoparticles are incorporated, and The polymer fibers are collected on the collector. A method for producing polymer fibers using a fiber spinning process, including the process described above.

2. The method according to claim 1, wherein stretching the polymer solution or polymer melt into fibers comprises an electrospinning process.

3. The method according to claim 1 or 2, wherein stretching the polymer solution or polymer melt into fibers comprises a wet spinning process.

4. The method according to claim 1 or 2, wherein the metal nanoparticles include silver nanoparticles.

5. The method according to claim 1 or 2, wherein the metal nanoparticles include gold nanoparticles.

6. The polymer fibers include silicone, polysiloxane, epoxy, polystyrene (PS), polyethylene (PE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), polycarbonate (PC), polyurethane (PU), polyether ether ketone (PEEK), polylactic acid (PLA), polyhydroxyalkanoate (PHA), polyester (PES), polyethylene terephthalate (PET), and polymethyl methacrylate. The method according to claim 1 or 2, comprising one or more polymers selected from the group consisting of tetrafluoroethylene (PMMA), polybutylene terephthalate (PBT), phenol-formaldehyde (PF), nylon / polyimide (PA), melamine-formaldehyde (MF), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinylpyrrolidone (PVP), acrylonitrile butadiene styrene (ABS), styrene block copolymer (SBC), rubber latex, nitrile, medical-grade thermoplastic elastomer (TPE), and aramid.

7. The method according to claim 1 or 2, wherein the metal nanoparticles include spherical nanoparticles.

8. The method according to claim 7, wherein the metal nanoparticles have an average diameter of 1 nm to 40 nm.

9. The method according to claim 1 or 2, wherein at least 99% of the metal nanoparticles have a particle size distribution having a particle size within 30% of the average diameter, and / or at least 99% of the spherical nanoparticles have a particle size distribution having a diameter within ±3 nm of the average diameter.

10. The method according to claim 1 or 2, wherein the nanoparticles have a ξ potential of at least about ±10 mV (absolute value).

11. The method according to claim 1 or 2, wherein the metal nanoparticles include coral-shaped nanoparticles.

12. The method according to claim 1 or 2, wherein the polymer solution or polymer melt after mixing contains the metal nanoparticles at a concentration of about 50 ppb to about 100 ppm.

13. The method according to claim 1 or 2, further comprising manufacturing a medical device containing the polymer fibers.

14. A polymer fiber product formed by the method described in claim 1 or 2.

15. The polymer fiber product according to claim 14, wherein the polymer fiber contains 0.5 mg / kg to about 8 mg / kg of the metal nanoparticles.

16. A method of supplying or mixing metal nanoparticles, including nonionic silver nanoparticles formed by laser ablation, into a polymer solution or polymer melt, wherein the silver nanoparticles are spherical in shape and have an average diameter of 1 nm to 40 nm, and the polymer solution or polymer melt after mixing contains the metal nanoparticles at a concentration of about 50 ppb to about 100 ppm. The process involves stretching the polymer solution or polymer melt into polymer fibers, thereby forming polymer fibers into which the metal nanoparticles are incorporated, and The polymer fibers are collected on the collector. A method for producing polymer fibers using a fiber spinning process, including the process described above.

17. The method according to claim 16, wherein stretching the polymer solution or polymer melt into fibers includes an electrospinning process.

18. The method according to claim 16 or 17, wherein stretching the polymer solution or polymer melt into fibers comprises a wet spinning process.

19. A polymer fiber product formed by the method described in claim 16 or 17.

20. The polymer fiber product according to claim 19, wherein the polymer fiber contains the silver nanoparticles in a concentration of about 0.5 mg / kg to about 8 mg / kg.

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