Biocompatible Liquid Silicone Rubber
Designed for the fabrication of radiation-sterilized biocompatible valves used in medical devices, Silpuran 6610/40 liquid silicone rubber has been engineered to prevent valve slits from closing up when subjected to radiation and thus impairing delivery of the correct dose of liquid medication. Supplied by Wacker Chemical Corp., this silicone material allows such valves to be manufactured without the use of auxiliary liquid or particulate-release coatings to prevent the so-called healing of valve slits under high radiation dosages. Eliminating the need for incorporating a release agent into the production process makes it possible to manufacture silicone valves more quickly and cleanly while lowering the risk of contamination associated with release agents, according to the company. Packaged in cleanrooms, the white, two-component silicone rubber is free of organic plasticizers and has been proven biocompatible through ISO 10993 and USP Class VI testing.
Wacker Chemical Corp.
Silicone Swelling Agent
Offering designers flexibility in creating product specifications, Swellex from MicroCare Medical addresses the challenge of joining or assembling molded silicone components with rigid parts and barbed fittings. Used to swell silicone, this agent is absorbed into the material to expand it to a dimension that facilitates assembly to the fitting or rigid part. Then, it evaporates quickly, returning the component to its original size to create a secure connection without the use of adhesives. This swelling technique is quicker and less messy than methods that involve lubricating oils or alcohol, according to the manufacturer. The swelling agent employs proprietary solvent technology designed to swell silicone more effectively than hexane solvents. Featuring an ozone depletion potential of zero, it meets strict EPA regulations controlling volatile organic compounds.
NEW BRITAIN, CT
TPUs for Implantable Devices
The Quadrathane family of biomaterials from Biomerics LLC consists of polycarbonate-based thermoplastic polyurethanes (TPUs) that are specifically developed for long-term-implantable medical device applications. Available in aliphatic and aromatic formulations, these materials offer biocompatibility, mechanical properties, chemical resistance, and oxidative stability that compare favorably with the characteristics of other TPUs. They have passed ISO 10993 and USP Class VI biological tests for hemocompatibility, cytotoxicity, irritation, and sensitization. Typically used in catheter applications, the eight body-softening and eight high-resiliency standard aliphatic grades are nonyellowing. Featuring chemical resistance and toughness, the aromatic-polycarbonate grades are useful in applications requiring tolerance of solvents, resiliency, and biodurability. All grades are naturally clear, accommodate extrusion and injection molding processes, and can be customized with radiopacifiers, colors, antimicrobials, and other additives.
SALT LAKE CITY
Rigid and Flexible Vinyls
The Geon HC family of flexible and rigid vinyl materials from PolyOne Corp. is available to OEMs for use in medical devices and device housings. The portfolio of flexible vinyl grades includes nonphthalate hemocompatible formulations used in critical healthcare applications involving contact with human blood. The supplier also offers an expanded line of USP Class VI–certified options, including medical device materials that meet the ISO 10993-5 standard for in vitro cytotoxicity. Rigid vinyl formulations for medical device housings and enclosures exhibit good flame resistance and withstand the chemicals used in hospital cleaning agents and disinfectants. Because they are available in a range of colors and metallic effects, these formulations support design flexibility and aesthetic considerations. The supplier can assist customers with part and mold design, processing, and agency approvals.
Online Bone Database
Offered by Granta Design, the Human Biological Materials data module is an online information resource that covers the properties of human bone. The database is part of an expanded materials information system for orthopedic device designers and manufacturers that helps them to make informed decisions regarding the selection, substitution, qualification, regulation, and biocompatibility of materials. An authoritative collation of data on the mechanical properties of primary load-bearing bones gathered from various publications, the module can serve as a reference for a designer working on an implantable device that must mimic or complement human body performance. In its first release, the searchable resource presents the tensile, compressive, flexural, and general properties of the femur, tibia, vertebrae, and acetabulum, providing age- and direction-dependence information.