WO2015041695A1

WO2015041695A1 - Prosthetic device and coating

Info

Publication number: WO2015041695A1
Application number: PCT/US2013/061158
Authority: WO
Inventors: Christian Schwartz; Alvin G. WEE; Gerald GRANT; Mark BEATTY; Scott R. Schricker
Original assignee: Creighton University
Priority date: 2013-09-23
Filing date: 2013-09-23
Publication date: 2015-03-26

Abstract

In one or more implementations, an exterior prosthetic coating that employs example techniques in accordance with the present disclosure includes a siloxane resin, metal oxide nano- particles dispersed in the siloxane resin, and a colorant. A prosthesis device includes a prosthesis and an exterior prosthetic coating, which includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. A process for fabricating a prosthesis device with the exterior prosthetic coating includes receiving a prosthesis device and applying a prosthetic coating to the prosthesis device, where the prosthetic coating includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant.

Description

PROSTHETIC DEVICE AND COATING

BACKGROUND

[0001] Artificial replacements of diseased or damaged body parts are frequently needed. When surgical reconstruction is not ideal, craniofacial and other prosthetics are often utilized when they can restore the form and function of the absent feature. A facial silicone prosthesis for replacing missing structure and blending with surrounding facial features is often used in restoration of the diseased or damaged body part. Prostheses are designed to be similar to the natural anatomy and build of each individual. Their purpose can include covering, protecting, and disguising facial disfigurements or underdevelopments.

SUMMARY

[0002] Techniques are described to fabricate an exterior prosthetic coating, a corresponding prosthesis device, and a method for fabricating the exterior prosthetic coating. In one or more implementations, an exterior prosthetic coating that employs example techniques in accordance with the present disclosure includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. A prosthesis device includes a silicone prosthesis and an exterior prosthetic coating, which includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. A process for fabricating a prosthesis device with the exterior prosthetic coating includes receiving a prosthesis device and applying a prosthetic coating to the prosthesis device, where the prosthetic coating includes a siloxane resin, metal oxide nano- particles dispersed in the siloxane resin, and a colorant.

[0003] 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 aid in determining the scope of the claimed subject matter. DRAWINGS

[0005] The detailed description is described with reference to the accompanying figures. The use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items.

[0006] FIG. 1 is a cross-sectional view illustrating an exterior prosthetic coating in accordance with an example implementation of the present disclosure.

[0007] FIG. 2 is a partial isometric view illustrating a prosthesis device utilizing the exterior prosthetic coating in FIG. 1, in accordance with an example implementation of the present disclosure.

[0008] FIG. 3 is a flow diagram illustrating a process in an example implementation for utilizing and fabricating an exterior prosthetic coating and prosthesis device, such as the device shown in FIGS. 1 and 2.

DETAILED DESCRIPTION

[0009] Craniomaxillofacial (CMF) injuries suffered in military conflicts constitute approximately 30% of all battlefield injuries, with explosive devices being responsible for approximately 84% of CMF injuries. Soldiers with CMF injuries return from combat missing highly visible facial features, lacking oral and pharyngeal tissues needed for eating and speaking, and possibly suffering from traumatic brain injury. Reconstructive surgery is challenging due to difficulty in reconstructing cartilaginous structures (e.g. ear or nose), and often it cannot correct a defect suffered during combat. Consequently, a facial silicone prosthesis that replaces missing structure and esthetically blends with surrounding facial features is critical to restoring facial or body structure, self-esteem, and/or successful return to duty or re-integration into civilian life. An esthetically appropriate and durable prosthesis thus represents the difference between mere survival and meaningful quality of life after injury. [0010] Widely recognized shortcomings of current facial silicone materials include difficulty in color matching with adjacent facial tissues plus a rapid material deterioration including color fading, reduced flexibility, and surface hardening/peeling, which can occur in as little as six months. Added to this picture is confusion regarding what constitutes perceptible/acceptable color difference during color matching and/or color change caused by handling and weather exposure. Additionally, fungal infections (e.g., C. Albicans) are common on tissue-bearing surfaces, particularly where tissue fluid is produced within CMF defects located beneath a prosthesis. A comprehensive systems approach to these problems is required, where material improvements can produce more life-like prostheses that are durable, require minimal maintenance, and prevent microbial infection. Nanofilled coatings can address these issues because they can be incorporated into processing methods for prostheses, they require small quantities of nanofillers and/or modifying agents, their chemistries can be tailored without changing chemistry of the entire prosthesis, and they can be customized for different applications, such as for different challenges present on exterior and interior surfaces of a prosthesis.

[0011] Accordingly, techniques are described to fabricate an exterior prosthetic coating, a corresponding prosthesis device, and a method for fabricating the exterior prosthetic coating. In one or more implementations, an exterior prosthetic coating that employs example techniques in accordance with the present disclosure includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. A prosthesis device includes a silicone prosthesis and an exterior prosthetic coating, which includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. A process for fabricating a prosthesis device with the exterior prosthetic coating includes receiving a prosthesis device and applying a prosthetic coating to the prosthesis device, where the prosthetic coating includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. Example Implementations

[0012] FIG. 1 illustrates a prosthesis device 100 in accordance with example implementations of the present disclosure. As shown, the prosthesis device 100 (e.g., silicone based) includes a prosthesis 102 and an exterior prosthetic coating 104, where the exterior prosthetic coating 104 includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant.

[0013] As illustrated in FIG. 1, the prosthesis device 100 includes a prosthesis 102 and an exterior prosthetic coating 104. The prosthesis 102 can include an artificial device that replaces a missing body part lost through trauma, disease, or congenital conditions, etc. In some embodiments, the prosthesis 102 can include a facial prosthesis, a hand prosthesis, or other body prosthesis where coloration retention and longevity (e.g., retaining the replicated skin color) as well as antimicrobial properties are a priority. A maxillofacial prosthesis, such as the prosthesis 102 in this specific embodiment, may serve to provide a prosthesis with preserved skin color replication (e.g., coloration of the prosthesis matched with skin color of a prosthesis recipient) while simultaneously providing a prosthesis surface that inhibits fungal growth, such as C. Albicans. In other embodiments, a prosthesis 102 may include other types of prostheses configured for other areas of the body (e.g., a hand prosthesis, a leg prosthesis, a foot prosthesis, a breast prosthesis, etc.).

[0014] The exterior prosthetic coating 104 can be disposed on an outer and/or exterior surface (e.g., a surface configured to be substantially exposed outside the body) of the prosthesis device 100. In embodiments, the exterior prosthetic coating 104 includes a siloxane resin, metal oxide nano-particles dispersed in the siloxane resin, and a colorant. In implementations, a siloxane resin can include an inert, synthetic compound with a variety of forms and properties, including being heat-resistant and rubber-like. In one implementation, the siloxane resin includes acetoxy siloxane, a silicone-like material. In another embodiment, a siloxane resin includes polydimethylsiloxane (PDMS). PDMS includes a silicon-based organic polymer that is generally optically clear, inert, non-toxic, and non-flammable. In some embodiments, the exterior prosthetic coating 104 can include more than one layer of coating (e.g., the exterior prosthetic coating 104 can include a first coating of a first material and a second coating of a second material, and or a first layer including nanoparticles with a second coating, etc.). It is contemplated that other materials may be used in place of the siloxane resin such that dependability, utility, and comfort of the prosthesis device is retained. Using a siloxane resin serves to provide a comfortable and pliable material for use in a prosthetic device. In one specific implementation, a prosthesis device 100 includes PDMS as a base portion of the exterior prosthetic coating 104, where the PDMS provides a material that can include dispersed metal oxide nano-particles, colorants, and other materials and is easily molded as an exterior portion of a prosthesis device 100. In some implementations, the siloxane resin includes layered PDMS that may be formulated from uncured prosthetic resins and/or from a thermoplastic elastomer coating that includes a polysiloxane. These chemistries may allow for a stable interface with an already cured prosthetic 102. Additional nanofillers and/or other materials may be included in the siloxane resin for improving dispersion of metal oxide nano-particles, colorants, and/or other materials. The siloxane resin can be about 75% to about 95% total weight of the exterior prosthetic coating 104. For example, the siloxane resin can be from about 75%, 80%, 85%, 90%, 95% to about 75%, 80%, 85%, 90%, 95% by total weight of the exterior prosthetic coating 104.

[0015] The exterior prosthetic coating 104 includes metal oxide nano-particles dispersed in the siloxane resin. Metal oxide nano-particles may function as ultraviolet light (UV) absorbants, which serve to at least partially retain skin replicated color of the colorants. In some implementations, the metal oxide nano-particles may include ZnO, Ti0₂, Zr0₂, silver oxides, and/or Si0₂. It is contemplated that other metal oxides may be used. In some embodiments, the metal oxide nano-particles have a size between 20-30 nanometers. In yet other embodiments, the metal oxide nano-particles have a size between 2-5 nanometers. In one specific embodiment, the exterior prosthetic coating 104 includes Ti02 with a size of approximately 5 nanometers (nm) dispersed in a siloxane resin, where the siloxane resin has a molecular weight between 2,000 and 500,000. The metal oxide nano-particles may be mixed and/or dispersed into the siloxane resin in different amounts, for example 1%, 2.5%, 5%, 10%, 15%, 20%, 25%, and/or 30% by weight. In another embodiment, the exterior prosthetic coating 104 includes silver (Ag) as a nanoparticle, which may serve to inhibit growth of C. Albicans. It is further contemplated that a variety of different metal oxide nano-particles and a variety of sizes may be used in the exterior prosthetic coating 104. The metal oxide nano-particles can be about 0.05% to about 15% total weight of the exterior prosthetic coating 104. For example, the metal oxide nano-particles can be from about 0.05%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%, 0.60%, 0.70%, 0.80%, 0.90%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, to about 0.05%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%, 0.60%, 0.70%, 0.80%, 0.90%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, by total weight of the exterior prosthetic coating 104.

[0016] The exterior prosthetic coating 104 may include a colorant. In implementations, the colorant may be substantially matched with the skin color of a prosthesis device 100 recipient. In some examples, the colorant may be dispersed in the siloxane resin. In other examples, the colorant may be applied to the outer surface of the prosthesis device 100. The colorant may include materials and/or pigments that are added to the siloxane resin in order to replicate a skin color. Some examples of colorant materials may include pigments (e.g., a yellow pigment configured to substantially maintain replicated skin color during exterior prosthetic coating 104 placement and weathering). It is contemplated that a wide range of colorant colors or types may be used. The colorant can be about 0.01% to about 5% total weight of the exterior prosthetic coating 104. For example, the colorant can be from about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%, 0.60%, 0.70%, 0.80%, 0.90%, 1%, 2%, 3%, 4%, 5%, to about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%, 0.60%, 0.70%, 0.80%, 0.90%, 1%, 2%, 3%), 4%), 5%, by total weight of the exterior prosthetic coating 104.

[0017] In some implementations, the exterior prosthetic coating 104 may include a nano-fiber based mat, which may be incorporated with metal oxide nano-particles within a siloxane resin. Surface and bulk mechanical failure, along with color change, lead to short service lifetimes of facial prosthetic devices. In order to prolong the lifetime of a prosthetic device, a mat of nonofiber particles can be produced using, for example, an electrospinning process, further discussed below. Using an electrospinning process produces nanofibers within the exterior prosthetic coating 104 with substantial alignment of the polymer chains, thus yielding strong reinforcing fiber mats. A nano-fiber based mat formed from electrospinning or another process can function to provide ultraviolet radiation protection and mechanical reinforcement. In some implementations, the fibers formed within the nano-fiber based mat may be functionalized chemically or mechanically by manipulating the electrospinning process to impart non-circular cross sections or entrained beads. In some embodiments, the mats may include polyurethane, polyester, and/or PDMS-based mats. Fiber thickness, geometry, morphology, and density of a nano-fiber based mat can be varied to determine optimal protection against mechanical and tribological damage while exerting minimal color change on, for example, acetoxy-coated PDMS substrates. Different fiber types may be produced, including smooth fibers, fibers with entrained polymer beads, and/or fibers with distinct adhered beads. In some embodiments, the mats of spun fibers may be gold sputter coated.

[0018] Additionally, the nano-fiber based mat within the exterior prosthetic coating 104 may include varying fiber density and mat patterning. The nano-fiber based mat can be formed by the fibers impacting a collection target (e.g., a target in the form of the body part to be replicated by the prosthesis device), which is at ground potential. Thus, an electrospun mat can have a shape that mimics that of the collection target. In implementations, the shape of the nano-fiber based mat may be varied by using different target shapes (e.g., flat mats or three-dimensional shapes that substantially conform to the geometry of the prosthesis device, such as an ear or a nose, etc.). In one specific embodiment, the collection target may be machined from a copper alloy, for example, using a computer numerical controlled machining station and a three-dimensional model of the desired feature (e.g., replicated body part). In embodiments, fiber density may be increased by increasing the amount of time before the electrospinning process is stopped. In this embodiment, more fibers can be deposited on the target because of increased process time, which can lead to increased fiber density.

[0019] In one embodiment, the nano-fiber based mat may be integrated into the siloxane resin by laying down the mat as a mesh scaffold over the substrate (e.g. collection target) and infusing the coating over and through the mat. The process utilized in this embodiment may avoid edge effects due to voids in the mat and may not require precise scaffold placement by a clinician. In a second embodiment, ribbons and/or patches (e.g., a piece or portion) of an electrospun nano- fiber based mat can be selectively placed on the substrate in regions where the highest stress is anticipated. These ribbons and/or patches can be prepared by precise cutting of full sized mats and/or through using a specially patterned electrospinning target to produce the desired geometries.

[0020] In an implementation, the exterior prosthetic coating 104 may be configured to be painted on a prosthesis device 100. Painting a coating may include applying the exterior prosthetic coating 104, for example, using a brush, an airbrush, a paint sprayer, an aerosol spray, etc. In one embodiment, the exterior prosthetic coating 104 can be a painted coating on the prosthesis device 100 surface, where the exterior prosthetic coating 104 is sprayed using a sprayer. In another embodiment, the exterior prosthetic coating 104 is a painted coating and applied using a brush. A painted exterior prosthetic coating 104 may enable rapid drying of the coating. Additionally, a painted exterior prosthetic coating 104 may be advantageous because of ease of use and the potential for removal, which allows the painted layer to function as a sacrificial layer. In some embodiments, the exterior prosthetic coating 104 may be solvent-delivered. When the exterior prosthetic coating 104 is applied with a solvent such as xylene, the exterior prosthetic coating 104 can be removed with solvent (e.g., xylene or another solvent) and replaced on a regular basis due to the absence of cross-linking. The exterior prosthetic coating 104 can act as a sacrificial layer that can be replaced upon discoloration or damage and not require the complete remaking of the prosthetic device 100.

[0021] Additionally, the exterior prosthetic coating 104 may be configured to be thermally cured onto the prosthesis device 100. Some advantages of a cured coating include robustness and stability, however in some embodiments it may be more difficult to remove. In a specific implementation, an exterior prosthetic coating 104 can include metal oxide nano-particles functionalized with PDMS or other siloxane based polymers or hydrocarbon based polymers of varying and/or mixed molecular weights and incorporated into an unpolymerized facial silicone resin. A thin layer of the resulting coating can then coat a cope (e.g., a prosthesis form) and be thermally cured. The resulting exterior prosthetic coating 104 may include a thin layer of nano filled resin at the surface that can protect a prosthesis device 100 from UV radiation and/or mechanical stress. Because a thin layer of coating is used, a relatively small amount of nanofiller is needed and cost can be reduced. Further, a thermally cured exterior prosthetic coating 104 may be easily customized to match end-use requirements. For example, a thermally cured prosthesis device 100 used in a sunny climate can be tailored to maximize UV light resistance and weathering. In some embodiments, an adhesive may be used to secure the exterior prosthetic coating 104 to a prosthesis device 100.

[0022] In some implementations, the exterior prosthetic coating 104 may function as a sacrificial layer that can be applied with and removed using a solvent (e.g., xylene) and replaced as needed. In one embodiment, an exterior prosthetic coating 104 includes a siloxane polymer that can be grafted with a more rigid block or material. Within the exterior prosthetic coating 104 the rigid blocks can self-assemble and form crosslinks in the siloxane elastomer. Because the polymers are linear, crosslinking can be reversed by a combination of heat and/or solvent application, thus creating a removable coating.

[0023] In another implementation, the exterior prosthetic coating 104 can include a synthesized silver (Ag)-based coating. In one embodiment, nanoparticles can be synthesized utilizing block copolymers to template the synthesis and provide a polymer compatibilizing layer. In this embodiment, silver (e.g., silver nitrate) can be added to the polymer compatibilizing layer to form a silver nanoparticle. Often, a reducing agent may be added to control particle size. In one specific implementation, silver nitrate can be added to a polymer to form silver particles approximately 2-3 nm in size. Silver particles may serve to inhibit and/or reduce certain biofilms, such as C. Albicans.

[0024] In one specific example of an exterior prosthetic coating 104, a polymerized coating includes a vinyl-terminated polydimethyl siloxane (V2K)-based coating. In this example, a silicone thickener (e.g., fumed silica, 13 wt%) and a pigment (e.g., Fl-202 Yellow, 0.5 wt %) is added to V2K. A catalyst (e.g., platinum, 10 ppm) is added to the V2K, which is then reacted equimolar with a cross-linker (e.g., polymethylhydrogen siloxane (VXL)). This mixture is vacuumed at 5mTorr for approximately 20 minutes and poured into a mold. The mixture is then heated in the mold for approximately 75 minutes at 85°C to achieve polymerization. Following polymerization of the mixture, a nano-particle coating (e.g., acetoxy-terminated siloxane) is applied and air dried, subsequent to which another layer of material including the nano-particle coating and Ti0₂ (e.g.,10000(lwt%) ppm to 50000 ppm(5wt%)) is applied. An additional coat is applied as a top coat (e.g., acetoxy siloxane and silica mixed 5: 1 with cyclohexane and silica, as a diluent) and dried.

[0025] In another specific example of an exterior prosthetic coating 104, 1 wt% ZrO is rotary mixed into V2K for approximately 5 min at 5000 rpm. Any resulting agglomerates can be broken apart with an ultrasonic mixer by mixing the V2K mixture for between 5 and 15 minutes at 105 W/cm. The nanoparticles are then redistributed with a rotary mixer at 5000 rpm for approximately 2 minutes. For material control, 13 wt% 200-300 nm silica is rotary mixed into the V2K mixture at 1000 rpm until incorporated and then dispersed at 5000 rpm for approximately 15 minutes. A 0.2 wt% FI-202 pigment is added and rotary mixed at 5000 rpm for approximately 5 min. The V2K mixture is then reacted equimolar with VXL and 10 ppm of a platinum (Pt) catalyst. The resulting mixture is subjected to a 5 mTorr vacuum for between 5 and 10 minutes. The mixture can then be poured into molds and heated at approximately 84° C for 60 min. The exterior prosthetic coating 104 disclosed in these specific examples provide both discoloration prevention and inhibition of fungal growth in the resulting prosthesis devices utilizing the exterior prosthetic coating 104.

Example Fabrication Processes

[0026] FIG. 3 illustrates an example process 300 that employs techniques to fabricate prosthesis devices, such as the prosthesis device 100 shown in FIGS. 1 and 2. The prosthesis device 100 includes a prosthesis 102 and an exterior prosthetic coating 104. An exterior prosthetic coating 104, as shown in FIGS. 1 and 2, includes a siloxane resin, metal oxide nano-particles, and a colorant. The prosthesis 102 can include, for example, a facial prosthesis, an ear prosthesis, a nose prosthesis, etc.

[0027] As illustrated in FIG. 3, a prosthesis device is received (Block 302). In implementations, receiving a prosthesis device 100 includes receiving an artificial body part replacement (e.g., a facial prosthesis, an ear prosthesis, a nose prosthesis, a hand prosthesis, etc.). In these implementations, the prosthesis device 100 may include a prosthesis 102 prior to application of an exterior prosthetic coating 104. In one specific embodiment, a prosthesis 102 configured as an ear prosthesis and prepared to receive an exterior prosthetic coating 104 is received. The prosthesis 102 may include a durable material (e.g., a siloxane resin) configured to adhere to a subsequently applied exterior prosthetic coating 104.

[0028] Subsequent to receiving the prosthesis device, an exterior prosthetic coating is applied to the prosthesis device (Block 304). In some implementations, applying an exterior prosthetic coating 104 includes painting the exterior prosthetic coating 104 on prosthesis 102. Painting the exterior prosthetic coating 104 may include applying a coating, for example, using a brush or other applicator or spraying the coating on the prosthesis 102. Additionally, applying the exterior prosthetic coating 104 to a prosthesis 102 may include repainting the coating, which may include reapplying the coating to a previously applied coating or applying a coating to a prosthesis 102 that has previously had an exterior prosthetic coating 104. In a specific embodiment, an exterior prosthetic coating 104 can be applied to a prosthesis 102 using a spraying painting process, where the spraying painting process functions to evenly disperse the exterior prosthetic coating over the surface of the prosthesis 102.

[0029] In other embodiments, the exterior prosthetic coating 104 may be applied using a nanofiber based mat. In these embodiments, a fiber-based mat may be formed using an electrospinning process. Electrospinning may include selecting a polymer to dissolve in solution. This mixture may be drawn from a source to a target (e.g., a prosthesis mold or cope) through electrostatic attraction caused by application of very high voltage potentials. As a jet of solution is drawn from the source to the target, the solvent evaporates, thereby leaving a mat of fibers of substantially only the original polymer. These nanofiber mats can be incorporated with appropriate nano-oxides and/or nanoparticles (e.g., Ti0₂, silver, etc.) within the acetoxy and/or siloxane-based exterior prosthetic coating 104. In one embodiment, a nanofiber mat can be integrated into the exterior prosthetic coating 104 by laying the nanofiber mat as a mesh scaffold or support over the substrate (e.g., a prosthesis, a mold, etc.) and infusing the exterior prosthesis coating 104 over and through the nanofiber mat. Infusing the exterior prosthesis coating 104 over and through the mat may include spraying and/or painting the coating and/or submersing the mat in the exterior prosthesis coating 104. Utilization of this technique may avoid edge defects due to voids in the mat. In another embodiment, portions of the nanofiber based mat may be selectively placed on the substrate in regions where the highest stresses are anticipated. The portions of the nanofiber-based mat may be prepared by precisely cutting a full sized mat and/or by utilizing a specially patterned electrospinning target. The siloxane-based coating may then be infused over and through the nanofiber mat portions and over the substrate. Nanofiber mats produced using an electrospinning process may function as UV protection and/or mechanical reinforcement of the exterior prosthetic coating 104.

[0030] In another embodiment, applying an exterior prosthetic coating 104 can include applying an exterior prosthetic coating 104 having metal-oxide nanoparticles, where the nanoparticles are precipitated from a solution. In an example embodiment, the exterior prosthetic coating 104 includes a solution with silver, for example silver nitrate. The silver may be precipitated from solution using a reducing agent. In one specific embodiment, silver that precipitates into solution in an exterior prosthetic coating 104 is approximately 2-3 nm. It is contemplated that other sizes of silver and/or nanoparticles may be precipitated from solution for use in the exterior prosthetic coating 104.

[0031] In one specific embodiment, applying an exterior prosthetic coating 104 can include applying a first coating having metal oxide nanoparticles with a second and/or additional coating, which can include additional nanoparticles and result in a multilayer exterior prosthetic coating 104. In an embodiment, an exterior prosthetic coating 104 includes a first coating having metal oxide nanoparticles with a second polymer coating, which includes additional precipitated silver nanoparticles.

[0032] In other implementations, applying an exterior prosthetic coating 104 can include applying a coating having metal oxide nanoparticles and then exposing the exterior prosthetic coating 104 to heat and/or UV light. Exposing the coating to heat and/or light can function to cure the coating. In one specific embodiment, applying an exterior prosthetic coating 104 includes applying a silanol-terminated polymer coating that is heated in the presence of a metal oxide nanoparticle, which results in a grafting reaction. Thus, a stable exterior prosthetic coating 104 capable of inhibiting fungal growth, retaining coloration, and/or preventing weathering.

[0033] The exterior prosthetic coating may be removed (Block 306) and a second exterior prosthetic coating reapplied (Block 308). In an embodiment, an exterior prosthetic coating 104 can be removed, for example, with a solvent. In this embodiment, a second exterior coating (e.g., the same material used for the original exterior prosthetic coating and/or a second and different material than the original exterior prosthetic coating) may then be reapplied. The second exterior prosthetic coating may serve to replace a coating that has been weathered and/or worn out and is nonfunctional.

Conclusion

[0034] Although the subject matter has been described in language specific to structural features and/or process operations, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

CLAIMS What is claimed is:

1. An exterior prosthetic coating, comprising:

a siloxane resin;

metal oxide nano-particles dispersed in the siloxane resin, where the metal oxide nano-particles are configured to provide antifungal properties and prevent discoloration; and a colorant.

2. The exterior prosthetic coating as recited in claim 1, wherein the siloxane resin comprises acetoxy siloxane.

3. The exterior prosthetic coating as recited in claim 1, wherein the siloxane resin comprises polydimethyl siloxane.

4. The exterior prosthetic coating as recited in claim 1, wherein the metal oxide nano-particles comprise at least one of zinc oxide, titanium dioxide, zirconium dioxide, Ag, or silicon dioxide.

5. The exterior prosthetic coating as recited in claim 1, wherein the metal oxide nano-particles are between approximately 2-5 nm.

6. The exterior prosthetic coating as recited in claim 1, wherein the metal oxide nano-particles are between approximately 20-30 nm.

7. The exterior prosthetic coating as recited in claim 1, wherein the metal oxide nano-particles are between approximately 200-300 nm.

8. The exterior prosthetic coating as recited in claim 1, wherein the metal oxide nano-particles include a precipitated nano-particle.

9. The exterior prosthetic coating as recited in claim 1, wherein the siloxane resin is between 75% and 95% by total weight, the metal oxide nano-particles are between

approximately 0.05%> and 15% by total weight, and the colorant is between about 0.01% and 5% by total weight of the exterior prosthetic coating.

10. The exterior prosthetic coating as recited in claim 1, further comprising:

a fiber mat.

11. A prosthesis device, comprising:

a prosthesis; and

an exterior prosthetic coating, including

a siloxane resin;

metal oxide nano-particles dispersed in the siloxane resin, where the metal oxide nano- particles are configured to provide antifungal properties and prevent discoloration; and

a colorant.

12. The prosthesis device as recited in claim 11, wherein the prosthesis includes a facial prosthesis.

13. The prosthesis device as recited in claim 11, wherein the exterior prosthetic coating includes a removable coating.

14. A process comprising:

receiving a prosthesis;

applying an external prosthetic coating to the prosthesis, where the external prosthetic coating includes

a siloxane resin;

a colorant.

15. The process as recited in claim 14, wherein applying the prosthetic coating to the prosthesis device comprises:

curing the prosthetic coating.

16. The process as recited in claim 15, wherein curing the prosthetic coating comprises:

exposing the prosthetic coating to ultraviolet light.

17. The process as recited in claim 14, wherein applying the prosthetic coating to the prosthesis device comprises:

precipitating the metal oxide nano-particles.

18. The process as recited in claim 14, wherein applying the prosthetic coating to the prosthesis device comprises:

applying a removable prosthetic coating, where the removable prosthetic coating is solvent removable.

19. The process as recited in claim 14, wherein applying the prosthetic coating to the prosthesis device comprises:

applying a prosthetic coating that includes textile fibers in a nanofibermat configuration, where forming the nanofibermat includes electrospinning.

20. The process as recited in claim 14, further comprising: removing the external prosthetic coating; and

reapplying a second external prosthetic coating.