This Small Business Innovation Research Phase I project is designed to develop new zwitterionic click methodology for orthopedic surfaces with enhanced durability. As Americans live longer and more actives lives, total joint replacement is becoming more common. Current orthopedic joints have average life spans of approximately 20 years. By that point wear on the joint causes particulate formation, with subsequent pain and inflammation, requiring eventual revision. Revision surgeries to replace joint implants are more difficult, painful, and expensive than initial joint replacement. Academic work from Japan demonstrated a promising photochemical graft coating of phosphorylcholine zwitterion that reduced wear significantly while also decreasing pro-inflammatory cytokine release and macrophage recruitment in vivo. However, this method uses hazardous monomer and will not scale well for manufacturing use. This project focuses on """"""""Click To"""""""" coating methodology which consists of a pre-made phosphorylcholine or other zwitterionic copolymer that will undergo very fast non-photochemical reactions with the functionalized ultrahigh crosslinked polyethylene orthopedic implant to achieve an implant with increased wear resistance. The """"""""Click To"""""""" technology will allow commercialization of the zwitterionic coating technology by a manufacturing-friendly process.
Zwitterionic coatings on orthopedic implants have tremendous potential for decreasing implant wear and improved anti-fouling properties. Approximately 600,000 Americans receive knee and hip implants annually in the US, over 1 million worldwide. This market is large, over $5.4 billion in 2006, and more than a fivefold increase in the number of total joint replacements are expected in the next 20 years. Substantial savings in the United States, on the order of more than $100 million, can be achieved with even a one year improvement of in the average life of an implant. The cost savings is a minor point when the benefit of an improved quality of life for the many users is considered by the elimination of the need for painful revision surgeries.