Polydimethylsiloxane(PDMS) Surface Modification with Itaconic Acid for Developing Biocompatible Hydrophilic Materials

Silicone has been used widely in medicine for the last 70 years, with the first implant placed in humans in 1946 for duct repair during biliary surgery. However, silicone implants have been associated with a number of risks and complications, which has significantly limited their application. The PDMS surface is the possibility of bacterial attachment, leading to the formation of biofilms such as capsular contracture (CC) – an excessive foreign body reaction that forms a tight and hard fibrous capsule around the silicone implant, which is experienced by up to 50 percent of patients after breast augmentation and reconstruction. Furthermore, anaplastic large cell lymphoma (ALCL) is a very rare breast implant-associated T-cell lymphoma that is CD30+ and anaplastic lymphoma kinase (ALK) negative. This disease is now widely recognized and there is an increased public awareness of the association between breast implants and the development of ALCL, a rare form of non-Hodgkin’s lymphoma after warnings were released from the U.S. Food and Drug Administration on January 26, 2011. Therefore, the development of novel silicone implants with anti-inflammatory, anti-fibrosis and anti-protein functionality products is necessary to prevent adverse immune response on silicone implants. The present study provides an overview of the currently available techniques, including novel nano/microtechniques, to reduce silicone implant-induced contracture and associated foreign body responses. In addition to this, we present the novel method for improving its anti-inflammatory, anti-fibrosis and anti-protein functionality. We conjugated the PDMS surface with itaconic acid (IA), and IA conjugated gelatin polymer (IA-GTpoly) via a chemical method. The PDMS surfaces conjugated with IA and IA-GTpoly via a chemical method better-prevented protein adsorption than the bare PDMS. IA and IA-GTpoly conjugated PDMS surfaces did not show cytotoxicity. The IA (150 mmol)-conjugated PDMS and IA-GTpoly (0.25 & 0.50 wt%)-conjugated PDMS surfaces showed lower inflammation than the bare PDMS. The in vivo capsule thickness of IA (150 mmol)-conjugated PDMS and IA-GTpoly (0.25 & 50 wt%)-conjugated PDMS surfaces showed significantly lower than the bare PDMS. More importantly, after 8 weeks, the lowest capsule thickness was explicitly found for IA-GTpoly (0.50 wt%)-conjugated PDMS surface. The collagen density of IA (50 & 150 mmol)-conjugated PDMS and IA-GTpoly (0.25 & 50 wt%)-conjugated PDMS surfaces showed significantly lower than the bare PDMS. Importantly, after 8 weeks, the less collagen density found for IA-GTpoly (0.50 wt%)-conjugated PDMS surface. In the case of myofibroblast, a significant decrease was observed in the IA (150 mmol)-conjugated PDMS and IA-GTpoly (0.50 wt%)-conjugated PDMS surfaces compared to the bare PDMS. Notably, only a small amount of myofibroblast was observed in IA (150 mmol)-conjugated PDMS and IA-GTpoly (0.50 wt%) PDMS surfaces at 8 weeks. The hydrophilic polymer materials conjugations used on these silicone implants demonstrate significant potential for preventing capsular contracture and developing biocompatible hydrophilic materials for various biomedical applications.