Fiber Scientist Invents a Nontoxic Sterilization Process for Biomaterials

Article excerpt

A researcher in the Department of Textiles and Apparel has made two breakthroughs to help the health care industry and medical patients: a nontoxic method for sterilizing biodegradable medical materials and devices and an innovative chemical process that could make implants "biologically active" to help promote healing and fight off disease. Both have been recently approved by the U.S. Patent Office.

The first invention involves modifying the currently used gamma irradiation sterilization process with extremely low temperatures (-192 degrees C) and a very strong vacuum. This method could replace the current ethylene oxide gas method of sterilizing biodegradable materials and devices, which is tedious, time-consuming, and toxic to workers.

The second invention is a new chemical process to attach nitric oxide and its derivatives - molecules that play important roles in blood clotting, blood pressure, and neurotransmission and that have antitumor functions, among others - onto biomaterials. Such bonding could transform implants from having "passive" roles to becoming "biologically active" in helping repair tissue and resist disease.

These inventions are the work of C. C. Chu, professor of fiber science and an expert in polymer science and biomaterials.

Currently, biodegradable biomaterials such as surgical thread, staples, clips, and meshes must be sterilized by ethylene oxide gas, a highly toxic substance that poses serious risk to workers. Other methods of sterilization destroy the properties of these biodegradable-sensitive biomaterials.

By modifying the existing convenient and efficient gamma irradiation process, however, Chu has successfully sterilized biodegradable biomaterials without any deterioration of the materials' mechanical properties.

"Extremely low temperatures - those used for liquid nitrogen - in a strong vacuum somehow retard the breakdown of the biomaterials' properties by gamma rays," says Chu.

Adapting existing gamma sterilization equipment would be relatively inexpensive, Chu says, and easy for the industry to accept. …