Friday, 30 November 2012

Silicone breast implants with spider silk-based coating show reduced side-effects in preclinical studies

AMSilk is developing a novel spider silk-based coating, called BioShield-S1, for silicone breast implants designed to reduce commonly known side effects that are initiated when the immune system reacts to the implants.

Preclinical tests conducted jointly with the University of Bayreuth, Germany and the Department of Trauma, Hand, Plastic and Reconstructive Surgery of the University of Wuerzburg, Germany, showed the efficacy of the implant coating. A first test in rats showed that coated silicone implants were accepted much better than implants without silk coating. In particular, capsular fibrosis and inflammation at the tissue border to the coated implants were significantly reduced.

A follow-up one-year study, completed in 2012, confirmed the results and the findings are currently being prepared for publication. In this second study it was shown that the capsule formation around the implant differs significantly from controls, resulting in a thinner, more flexible and translucent capsule accompanied by a significant reduction in inflammation markers. Some inflammation markers, as well as fibroblast infiltration, were found to be at lower levels even twelve months after surgery. “This new technology offers a real option for further improving current implants and can be used for nearly all silicone-based products,” says Dr. Philip Zeplin, a surgeon who conducted the study. 

Silicone implants are primarily in use for reconstructive and aesthetic breast surgery. The BioShield-S1 coating consists of a thin layer of recombinant spider silk proteins manufactured at AMSilk. It modifies the implant, presenting a more biocompatible surface to the immune system. This new technology addresses a number of problems associated with silicone implants. More than 10% of all women who undergo reconstructive breast surgery, for example after breast cancer, experience pain, inflammation or deformation of the breast due to the contraction of the capsule which forms around the silicone implants. Between 2.4% and 4.6% of women who receive such implants for purely aesthetic reasons face the same problem within six years. Complication rates are even higher over the lifetime of an implant. 

The coating can be applied to any silicone implant after the final production step, just prior to packaging and sterilization; it does not alter the mechanical performance of the implant. Other surgical applications will be tested in the future.