TECHNOLOGY NEWS: MATERIALS
A polymeric biomaterial with permanently bonded antimicrobial surface properties has been developed by DSM PTG, part of DSM Biomedical (Berkeley, CA, USA; www.dsmptg.com). “The device industry has been challenged to produce polymeric biomaterials with built-in antimicrobial surface properties for reducing device-centered infection,” says Bob Ward, CEO of the company. “But most approaches to date have used drug-eluting compounds or coatings that are eventually consumed,” he adds. “It is much more desirable to have easily processed biomaterials with good wet-strength and long-term efficacy without leachable additives, drugs or biocides.” Ward reports that the new polymer has these characteristics.
At the World Biomaterials Congress in Amsterdam in May, company researcher Shanger Wang reported that the polymer had proven its antimicrobial action against gram-positive bacteria in a variety of laboratory tests. According to the company, the polymer, which is a polyurethane with surface-active alkylammonium chloride end groups, offers low water absorption, excellent strength and processability, and high molecular weight. During his presentation at the World Biomaterials Congress, Wang also announced that modified thermoplastic polycarbonate urethanes and polymers with other antimicrobial self-assembling monomers and groups are also being investigated for use in various medical applications.
Very small amounts of biologically active end groups can be permanently incorporated into a polymeric biomaterial during its synthesis, Ward explains. “The novelty here is that after extrusion or moulding, the device modifies its own surface,” he says. This capability results from the polymer’s surface activity and the self assembly of its novel end groups. Antimicrobial groups concentrate on the surface where they are needed, according to Ward. For this reason, the polymer does not require secondary coating processes or treatments. “This can reduce the cost of goods and manufacturing times while increasing yield,” he says.
Earlier this year, the developer of the polymer was acquired by Royal DSM N.V. (Heerlen, Netherlands)—a company that also specializes in developing polymers for medical applications.