In vitro investigation of maleated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) for its biocompatibility to mouse fibroblast L929 and human microvascular endothelial cells.

Abstract

Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a polyester with strong mechanical properties and biocompatibility, is a member of microbial polyhydroxyalkanoates (PHA) family. Maleic anhydride was used to graft PHBHHx to form maleated PHBHHx (Ma-PHBHHx). Ma-PHBHHx with a graft degree of 0.59% was found to be more thermo-stable in comparison with PHBHHx. In vitro study demonstrated that the biocompatibility to mouse fibroblast L929 and human microvascular endothelial cells (HMEC) was improved in different degrees on Ma-PHBHHx films and scaffolds. Compared with their growth on PHBHHx, L929 and HMEC grown on Ma-PHBHHx films and scaffolds showed approximately 120% and 260% more in proliferation rates, respectively. Morphology study suggested that fine whorl-like surface structures with porosities on Ma-PHBHHx films attributed to MA grafting would be better for cell attachment and proliferation. Ma-PHBHHx scaffolds prepared by thermally induced phase separation (TIPS) with increased porosity, hydrophilicity, surface energy, and charges also were more favorable for cell growth. In addition, Ma-PHBHHx showed an accelerated degradation incubation in SBF at 37 degrees C, losing 21.4% of its original weight after 21 weeks while PHBHHx just lost 7.3%. Based on the improved biocompatibility, reasonable mechanical properties as well as accelerated biodegradation, Ma-PHBHHx has shown advantages over PHBHHx as a biomaterial for biomedical applications.