Preventing capsular contracture by coating of silicone implants with bioglass
At a glance
Due to its inertness, low toxicity and anti-adhesive properties, silicone is one of the most frequently used materials for medical implants. Amongst silicone materials typically transplanted to patients one finds silicone implants used for breast augmentations in plastic surgery. According to the “International Society of Aesthetic Plastic Surgery (ISAP)”, 1.5 million women received silicone breast implants world-wide in 2017, either for the purpose of breast reconstruction after mastectomy in breast cancer or for cosmetic reasons. Given the increasing incidence of breast cancer and growing awareness of reconstruction surgery, the demand for breast implants is expected to grow rapidly. Although silicone implants have been optimized and improved over the years, breast augmentations are still associated with significant complications. Every patient shows capsular fibrosis, i.e. the formation of a thin connective tissue capsule around implants, as a natural response to a foreign body. However, up to 50% of patients develop a capsular contracture (CC), a contractile, connective tissue capsule of increased thickness, formed around the implants due to an excessive inflammatory/fibrotic response. Typically, this leads to distortion of the implant, causes severe pain, a systemic inflammatory response and ultimately requires implant removal. Despite major research efforts undertaken to elucidate the mechanisms underlying CC, its aetiology remains poorly understood. It has been hypothesized that a bacterial biofilm of bacteria colonizing the implant surfaces during or directly after surgery may trigger a local inflammatory response, which transitions into excessive fibrosis causing CC. In line with this idea, bacterial strains physiologically populating the human skin as well as bacteria normally occurring in mammary glands, have been detected on patient implants. Accordingly, therapeutic strategies preventing the colonization of implants by bacteria, e.g. by surface-coating of silicone implants with antibiotics, have been put forward – yet with limited success so far. In light of rising antibiotic resistance we will in this project look into an alternative way for the prevention of capsular fibrosis: through the implementation of an implant coating of bioglass, which has been shown to have antibiotic properties, we aim to prevent the formation of a bacterial biofilm and excessive tissue fibrosis. In a first step, we will establish the bioglass coating. Subsequently, the coating will be examined with regard to antibacterial properties as well as inhibition of capsular fibrosis.