Enhanced growth of animal and human endothelial cells on biodegradable polymers

Biodegradable polymers such as poly(L-lactic acid) (PLLA), poly(glycolic acid) (PGA) and PGA coated with PLLA are being employed for cell transplantation and for in vivo regeneration of vascular tissue. Ingrowth and organization of fibrovascular tissue inside polymer scaffolds lead to the occlusion of the regenerated blood vessel. In order to provide regulatory mechanisms to control the development of an inner capsule, endothelialization of these materials is necessary. To achieve this, we employed a novel ammonia plasma technique to surface modified PLLA substrates. Human endothelial cell (HUVEC) and rabbit microvascular endothelial cell (RbMVEC) growth was studied on modified PLLA and control PLLA. Our studies show that modified PLLA and fibronectin (Fn)-coated modified PLLA exhibited statistically significant improvement in HUVEC and RbMVEC growth (P<0.001) when compared to PLLA and Fn-coated PLLA. Therefore, ammonia plasma treatment gives us the unique capability of modifying prosthetic biomaterials of various constructs with the eventual transplantation of mammalian cells to be used in tissue engineering or as biological implants.