All too often, when a breast cancer survivor gets implants to replace surgically removed breasts, she finds herself back in the operating room in a matter of years due to complications with the implants. Around 46% of women with silicone implants undergo re-operation within three years; 25% have their implants removed due to irritation, or the body “rejecting” the implant. The human body is extremely adept at recognizing foreign objects and non-natural materials; because silicone is highly synthetic, it often fails to cooperate with the surrounding natural tissues, leading to irritation and infection.
For years, scientists have attempted to develop a solution to this issue in the form of a coating that would support the implant’s incorporation into the body. The German biotech company AMSilk thinks it has finally succeeded. Known for developing synthetic silk polymers from proteins that mimic natural substances–Adidas has used its biofabricated spider-silk fibers to create a line of biodegradable shoes–AMSilk bioengineered silk coating specifically for medical and cosmetic implants that scientists believe will lead to better outcomes from implant surgeries.
AMSilk’s product starts as a powder, which the company grows from genetically modified E. coli bacteria that, once fermented, becomes a protein that mimics the properties of silk, and can be molded into various forms, like fibers or the liquid silk coating. But because it’s a protein, the body recognizes it as a natural substance, says AMSilk co-founder Lin Roemer. “Nothing else is out there that is a protein except for animal tissue, which no one wants in their body,” Roemer says. AMSilk’s biofabricated material produces the same effect as would a product actually derived from animals. “Our body sees the silk protein and says, ‘Okay, I’m a protein, this is another protein, I like proteins,’ and therefore the body is much less likely to react negatively to this coating than other substances like silica or polypropylene,” Roemer adds.
Beginning this year, AMSilk is partnering with Polytech Health & Aesthetics, the leading manufacturer of silicone implants, to begin a clinical trial of silk-coated implants on a handful of patients in Austria; the trial will expand throughout Europe after the first phase wraps. According to Polytech, demand for implants is on the rise; in 2016, the company sold over 200,000 implants. As such, they felt a particular need to increase the safety and comfort of their products. Preclinical trials demonstrated that the AMSilk coating certainly helped–and because so little of the silk is required to coat an implant, Roemer says, there’s little additional cost attached to the development.
Eventually, AMSilk aims to scale up the use of this silk coating beyond breast implants to all other medical and cosmetic implants, like sensors and birth control implants (they chose the silicone molds because of their relative ubiquity and simple shape). Their strategy, Roemer says, will be to distribute the coating to their medical partners, who will apply it to their devices and sterilize them before inserting them into human bodies. The silk protein, Roemer adds, is strong enough to withstand the sterilization process, which often breaks down weaker proteins.
It’s the first few weeks after implantation, Roemer says, that are most critical from the patient perspective: that’s when people are most susceptible to infection and inflammation. Sometimes, negative reactions to a foreign object can prompt the body to form a protective cystic capsule around the implant. In the case of breast implants, that causes irritation, but in the case of more advanced implants–like birth control, or the payment and communication microchips we’ll all eventually have–that capsule prevents them from working effectively. The AMSilk coating, Roemer says, allows the body enough time to adjust to the foreign objects, and then will dissolve in a matter of few months, leaving the implant comfortably in place, reducing the need for subsequent surgeries to correct or remove it.