For some time, news media outlets have been reporting on hospital- and device-acquired infections.

But even though the news stories have died down, giving way to a contentious Democratic primary and a sagging economy, the problem still exists prompting med-tech companies to come up with an answer to the spread of deadly bacteria, which has become resistant to the common antibiotics.

Polymer Technology Group (PTG; Berkeley, California), a company that specializes in the development of biomaterials, said that it thinks that it has a much better solution than current coatings and drug-eluting compounds presently on the market.

The company touted its Thermoplastic Polycarbonate-Urethane biomaterial application as being a much stronger solution than other applications, during the 8th World Biomaterials Congress in Amsterdam, the Netherlands, this week.

The announcement coincides with PTG being acquired for an unspecified amount by Royal DSM (Heerlen, the Netherlands), which makes synthetic fibers. The companies said the DSM and PTG organizations will be "closely linked" to best service the global market. To secure a smooth integration, CEO Bob Ward will stay on as president of DSM PTG.

"The device industry has been challenged to produce polymeric biomaterials with built-in antimicrobial surface properties for reducing device-centered infection," said Ward. "But most approaches to date have used drug-eluting compounds or coatings that are eventually consumed. It is much more desirable to have easily processed biomaterials with good wet-strength and long-term efficacy without leachable additives, drugs or biocides. We believe we have an answer to this problem."

Shanger Wang, PhD, gave a characterization at the conference of PTG's polymeric biomaterial with permanently-bonded antimicrobial surface properties designed to reduce medical device-centered infection.

Wang's report detailed that polyurethanes with surface-active alkylammonium chloride end-groups were successfully synthesized and their physical properties, surface chemistry and biocidal activities evaluated. The presence and self-assembly of end-groups in the surface was confirmed by SFG (sum frequency generation spectroscopy).

The polymers exhibit low water absorption, excellent strength and processability, high molecular weight, and effective contact-killing of Gram-positive bacteria relative to controls. Wang also discussed how these modified TPCUs (thermoplastic polycarbonate urethanes) and polymers with other antimicrobial "self-assembling monomer end groups" are being optimized by PTG for use in various biomedical applications.

Part of the appeal, according to a report published by the company, is that a device doesn't need a secondary coating process once the biomaterial is placed on its surface — a fact that is a cost-saving measure, according to the company.

"The results being presented by Dr. Wang demonstrate that very small amounts of biologically active end-groups can be permanently incorporated into a polymeric biomaterial during its synthesis," said Ward. "The novelty here is that after extrusion or molding, the device modifies its own surface' because of the surface activity and self assembly of the novel end-groups. Antimicrobial groups concentrate in the surface where they are needed. For this reason secondary coating processes or treatments are not needed. This can reduce the cost of goods and manufacturing times while increasing yield."

In the past, Medical Device Daily has reported on a plethora of alternatives and the emergence of a new sector formed to stop the spread of bacterial infection.

Most applications use some type of silver coating.

Acrymed (Portland, Oregon) has Silvagard, which are nanoparticles that are formed chemically in a solution, that are uniform in size (10 nm) and do not agglomerate to form large particles, but stay in suspension pending application to materials.

Pure Bioscience (San Diego) has its silver dihydrogen citrate, which is an electrolytically generated source of stabilized ionic silver. The bacteria views the molecule as a food source and once the organism consumes it, SDC destroys the bacteria by disabling proteins and halting its metabolic and reproductive functions.

C.R. Bard (Murray Hill, New Jersey) recently received FDA clearance for the Agento endotracheal tube, which is coated with a thin layer of silver (Medical Device Daily, Dec. 20, 2007).

Angiotech Pharmaceuticals' (Vancouver, British Columbia) 5-FU is different than the previous offerings and is a well-known and approved compound that principally acts as a thymidylate synthase inhibitor, meaning that it interrupts the action of this enzyme which is a critical factor in the synthesis of the pyrimidine thymine — important in DNA replication.

Some of its principal uses are in combating colorectal cancer and pancreatic cancer, in which it has been the established form of chemotherapy for decades.

It is estimated that one out of every 20 hospital patients in the U.S. acquires an infection, totaling some 20 million a year, with about two-thirds of those infections being drug-resistant. Of those 20 million, there are as many as 100,000 die each year (MDD, Dec. 3, 2007).

PTG specializes in the development of specialty chemicals, polymers and medical devices. The company has about 100 employees. It said it expects to exceed $40 million in net sales in 2008, with above-average operating profit margin. It also said it expects more than 20% annual sales growth in the next three to five years, based on existing business and a pipeline of new products.