Foster Corporation (Putnam, Connecticut / USA; www.fostercomp.com), manufacturer of custom polymers for healthcare markets, said it is launching its "Combat" antimicrobial masterbatches for blending with medical device polymers. Components made with these antimicrobial polymer blends kill harmful bacteria that lead to infections, including methicillin-resistant staphylococcus aureus (MRSA) and carbapenem-resistant enterobacteriaceae (CRE), the company said.

According to a survey by the U.S. Center for Disease Control, 4% of inpatients in US acute care hospitals contract at least one healthcare associated infection – with device-associated infections accounting for one out of four infections. In-dwelling devices, such as central venous catheters, are particularly susceptible to bacteria colonisation which can enter the blood stream.

Increasingly, medical device companies are evaluating antimicrobial additives for plastics to kill harmful bacteria on the surface of device components. Ionic silver is highly successful at killing bacteria and preventing colonisation. Additives based on this chemistry are commonly melt blended directly into medical plastics for the manufacture of antimicrobial device components.

However, evaluation of multiple custom compound formulations can be costly. Combat masterbatches, made from Sciessent’s (Wakefield, Massachusetts / USA; www.sciessent.com) "Agion" ionic silver technology, provide an economical way for customers to evaluate several antimicrobial filler loadings in their device components by dry blending different ratios. “Combat masterbatches are available in quantities as low as two pounds to minimise costs for initial evaluations,” said executive vice president Larry Johnson. “With letdown percentages of 2-10%, depending on the polymer and applications, these small order quantities allow engineers to test several antimicrobial formulations from a single order quantity.”