Plasma-Enhanced Surface Modification of Biopolymers

Recent advances in polymer surface science have been largely due to the well-recognized need to control the surface properties of polymer materials and the development of sophisticated surface-specific characterization techniques. While the majority of the research and development efforts have been mostly focused on bulk properties, demands for low surface energy polymers exhibiting low adhesion (friction) and good biocompatibility have generated significant interest on physical and chemical properties of polymer surfaces. For instance, ultra-high molecular weight polyethylene (UHMWPE) and low-density polyethylene (LDPE) are the principal materials used to replace damaged cartilage in total joint arthroplasty and to fabricate catheters for balloon angioplasty, respectively. Therefore, surface treatments to improve adhesion and biocompatibility of these polymer surfaces are of paramount importance in the medical field. Radio frequency (rf) plasma-enhanced surface modification (PESM) provides an effective means for altering the biochemical properties of polymer surfaces without affecting the bulk behavior. The main process steps of PESM are discussed here and its effectiveness is demonstrated by representative friction coefficient, contact angle, and biocompatibility results for LDPE and UHMWPE surfaces treated with various plasma chemistries.