Zwitterionic polymer on silicone implants inhibits the bacteria-driven pathogenic mechanism and progress of breast implant-associated anaplastic large cell lymphoma.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) occurs in the capsule surrounding breast implants. Malignant transformation of T cells by bacteria-driven chronic inflammation may be underlying BIA-ALCL mechanism. Here, we covalently grafted 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymers on a silicone surface and examined its effects against BIA-ALCL pathogenesis. MPC grafting strongly inhibited the adhesion of bacteria and bacteria-causing inflammation. Additionally, cancer T cell proliferation and capsule-derived fibroblast-cancer cell communication were effectively inhibited by MPC grafting. We further demonstrated the effect of MPC against the immune responses causing BIA-ALCL around human silicone implants in micro-pigs. Finally, we generated a xenograft anaplastic T cell lymphoma mouse model around the silicone implants and demonstrated that MPC grafting could effectively inhibit the lymphoma progression. This study is the first to show that bacteria-driven induction and progression of BIA-ALCL can be effectively inhibited by surface modification of implants. STATEMENT OF SIGNIFICANCE: Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a major concern in the field of plastic and reconstructive surgery. In this study, we demonstrate strong inhibitory effect of zwitterionic polymer grafting on BIA-ALCL pathogenesis and progression, induced by bacterial infection and inflammation, both in vitro and in vivo. This study provides a molecular basis for the development of novel breast implants that can prevent various potential complications such as excessive capsular contracture, breast implant illness, and BIA-ALCL incidence, as well as for expanding the biomedical applications of zwitterionic polymers.

Novel Chitosan Dermal Filler with Enhanced Moldability and Elasticity.

Currently, dermal fillers are largely based on commercialized cross-linked hyaluronic acid (HA) injections, which require a large injection force. Additionally, HA can be easily decomposed by enzymes, and HA-treated tissues present a risk of developing granuloma. In this study, a chitosan-based dermal filler is presented that operates on a liquid-to-gel transition and allows the injection force to be kept ≈4.7 times lower than that required for HA injections. Evaluation of the physical properties of the chitosan filler indicates high viscoelasticity and recovery rate after gelation at 37 °C. Furthermore, in an in vivo evaluation, the liquid injection-type chitosan filler transitions to a gel state within 5 min after injection into the body, and exhibits a compressive strength that is ≈2.4 times higher than that of cross-linked HA. The filler also exhibits higher moldability and maintains a constant volume in the skin for a longer time than the commercial HA filler. Therefore, it is expected that the chitosan filler will be clinically applicable as a novel material for dermal tissue restoration and supplementation.