Polymers and Composites in the Medical Device Industry
December 2018
Thermoplastic and thermoset polymers and their composites are widely used in medical devices where they are increasingly replacing metals and glass.
The main reason for this trend is the amazing versatility of polymers, which enables the design and manufacture of a vast range of products to meet very different application requirements.
The abilities to prepare blends of polymers, to incorporate many types of performance-enhancing additives, and to prepare polymer matrix composites by incorporating reinforcing agents (such as fibers, platy fillers, and particulate fillers) all enhance the versatility of polymers far beyond the versatility provided by individual polymers on their own.
At Bicerano & Associates, our expertise in polymers and composites helps our clients to develop polymers and composites for any application they may require.
Benefits Provided by Polymers and Composites
Polymers and polymer matrix composites have helped improve the quality of healthcare delivery as well as saving many lives by providing the following benefits:
- Making it easier to maintain sterility.
- Polymers enable the production of cheap, disposable tools and devices, such as syringes, catheters, and surgical gloves.
- For example, before disposable plastic syringes became available, syringes had to be sterilized carefully after each use, creating the risk of infecting the next patient if a syringe was not sterilized properly after use.
- Enhancing safety by enabling the manufacturing of safety devices such as tamper-proof caps on medical packaging.
- Increasing comfort, since contact with polymeric surfaces generally feels more comfortable to people than contact with metallic surfaces.
- Increasing ease of handling as a result of being of lighter weight than metals and glass.
- Reducing the risk of allergic reactions by replacing metals that some patients may be allergic to with hypoallergenic plastics.
- Greater biocompatibility, which is crucial in applications such as implants.
- Enabling innovative customization since even articles with the most intricate shapes can be molded by using polymers.
- The development of additive manufacturing (also known as 3D printing) has recently further enhanced the ability to provide innovative customization.
- Additive manufacturing makes it easier to manufacture parts from many materials that are difficult to process by using other fabrication techniques.
- Providing cost-effective solutions to many medical device needs.
Polymer and Composite Material Selection Criteria
The following factors must be considered in selecting or developing a polymer or polymer matrix composite for use in a medical device application:
- Are its physical properties adequate for meeting the performance needs of the medical device?
- Are its responses to the chemicals and/or biologicals (fluids and/or tissues) that it may come in contact with acceptable?
- If it is expected to come into intimate contact with the patient’s tissues, such as in an implant or an endoscope, does it have the required level of biocompatibility?
- Has it been cleared by the U.S. Food and Drug Administration (FDA) and/or similar regulatory agencies in foreign countries for use in medical devices?
- The regulatory approval process requires time and effort. If all other factors are equal, a material which has already been approved will be preferred.
- If a material which has not been approved yet is clearly the best choice, it will be worthwhile to go through the regulatory approval process.
- The cost of the material is extremely important for disposable devices. It can also be a factor, but of significantly less importance, for reusable devices and implant materials.
Examples of Applications
The following industry and application highlights provide a sampling of the vast range of applications of polymers and composites in the medical device industry. Some of these applications are for composites of an identified polymer.
|
Materials |
Applications |
|
Poly(vinyl chloride) (PVC) |
Tubing, blood bags, pre-sterilized disposable devices |
|
Polypropylene |
Surgical trays, suture materials, surgical meshes, oxygenator membranes, caddies, wheels, instrument components, extruded film applications such as medical pouches and monoblister packaging containers |
|
Ultrahigh-molecular-weight polyethylene |
Knee and hip replacement parts |
|
High-density polyethylene |
Packaging, inner lining of catheters, graft for craniofacial contour augmentation |
|
Low-density polyethylene |
Packaging |
|
Poly(4-methyl-1-pentene) |
Oxygenator membranes without plasma leakage |
|
Cyclic olefin copolymers |
Vials, prefilled syringes, needleless injectors, media containers, diagnostic devices, pharmaceutical containers and packaging |
|
Polystyrene |
Trays |
|
Thermoplastic elastomers (styrenic, olefinic, urethane, ether-ester, ether-amide) |
“Soft touch” surfaces, tubing, catheters, grips (toothbrushes, razors, surgical tools), seals, vial closures, drug delivery or monitoring patches, connectors, coating of drug eluting stents, ultrasound training models |
|
Poly(vinyl pyrrolidone) |
Antifouling coating, dialysis membrane |
|
Polyacrylonitrile |
Dialysis membranes |
|
Poly(vinyl alcohol) |
Antifouling coating, hydrogel formation nucleus pulposus, vitreous body replacement |
|
Ethylene-vinyl alcohol copolymers |
Hemodialysis membrane components |
|
Poly(methyl methacrylate) |
Bone cements, intraocular lenses, dialysis membranes |
|
Poly(2-hydroxyethyl methacrylate), copolymers of with methyl methacrylate |
Antifouling coating, hydrogel for intraocular lenses |
|
Tartaric acid based polymers |
Plastic pill casings that break down gradually and release enclosed medication slowly |
|
Aliphatic polyamides (nylons) |
Suture material, ligament and tendon repair, balloon of catheters, dialysis membranes |
|
Polyphthalamide |
Trays able to bear load of medical instruments |
|
Poly(ethylene terephthalate) |
Intelligent dosing systems that require reliable parts in a confined space, bottles and other pharmaceutical containers, membranes, vascular grafts, surgical meshes, ligament and tendon repair |
|
Flexible polyesters |
Replacement for flexible PVC |
|
Polyurethanes |
Catheter tubing, feeding tubes, other tubing, hospital bedding, surgical drapes, wound dressings, injection-molded devices, short-term implants, artificial hearts, surgical drains, intra-aortic balloon pumps, dialysis devices, non-allergenic gloves, medical garments, hospital bedding, wound dressings, adhesives, sealants, wheels and bumpers on carts |
|
Polycarbonate |
Reservoirs, high-pressure syringes, artery cannulas, stopcocks, Luer-Lok™ fittings, centrifugal force separators, blood filter housings, dialyzer housings |
|
Polyoxymethylene (acetal) |
Intelligent dosing systems that require reliable parts in a confined space, equipment handles, trays |
|
Poly(ethylene oxide) |
Antifouling coating on catheters, hydrogel or pore former in dialysis membranes |
|
Liquid crystalline polymers |
Minimally invasive surgical instruments, biomedical packaging |
|
Poly(ether ether ketone) and related copolymers |
Long-term orthopedic implant applications (such as bone screws, plates and pins, tissue anchors, and suture screws), replacement for metals as a hip stem component, inner lining of load bearing catheters |
|
Polyimide |
Inner lining of load bearing catheters, tubing |
|
Poly(phenylene sulfide) |
Surgical instruments and other injection-molded parts |
|
Polyetherimide |
Instrument components |
|
Poly(phenylene sulfone) |
Long-term implant applications |
|
Poly(ether sulfone) |
Hemodialysis membranes |
|
Polysulfone |
Component of hemodialysis membranes |
|
Cyanoacrylate thermosets |
Adhesives |
|
Epoxy thermosets |
Adhesives |
|
Natural rubber, synthetic rubbers and elastomers |
Gloves |
|
Polytetrafluoroethylene (PTFE, Teflon) |
In-body applications (due to inertness in blood or tissue); porous membranes, rods, and tapes |
|
Expanded PTFE (Gore-Tex®) |
Vascular grafts, surgical meshes, ligament and tendon repair |
|
Poly(vinylidene fluoride) |
Suture materials, surgical meshes |
|
Perfluoroether synthetic oils and greases |
Lubricants that provide exceptional wear resistance and friction reduction in medical devices that need outstanding lubrication |
|
Specialty fluoropolymer additives |
Incorporated into polymers used to create non-stick and anti-adhering surfaces in bottles and other containers for high-value pharmaceuticals, medical devices that may benefit from having non-stick and anti-adhering surfaces |
|
Poly(dimethyl siloxane) |
Catheters, nucleus pulposus substitute, plastic surgery, intraocular lenses, glaucoma drainage devices, dialysis membranes |
|
Poly(p-xylylene) (Parylene) coatings |
Biocompatible coatings providing exceptional protection to all medical devices (including implants) from moisture, electrical charges, bodily fluids, and contamination |
|
Polymer matrix nanocomposites |
|
|
Biosorbables, such as poly(lactic acid), poly(glycolic acid), poly(ε-caprolactone), and related copolymers |
Suture materials, bone screws, small orthopedic plates or rods tissue anchors, vascular stents or internal meshes that allow cell seeding and reconstruction of an organ as in repairing a perforated heart, tissue and organ scaffolding, drug delivery |