Nanofibrous polyhydroxyalkanoate matrices as cell growth supporting materials

Polyhydroxyalkanoates (PHAs) have been demonstrated to be a family of biopolymers with good biodegradability and biocompatibility. To mimic the real microenvironment of extracellular matrix (ECM) for cell growth, novel nanofiber matrices based on PHA polymers were prepared via a phase separation process. Three-dimensional interconnected fibrous networks were observed in these matrices with average fiber diameters of 50–500 nm, which are very similar to the major ECM component collagen. Compared with nanofiber matrix made of poly(l-lactide), the mechanical properties of PHA nanofiber matrices were significantly improved, especially those matrices of PHA blends PHB/PHBHHx containing polyhydroxybutyrate (PHB) and copolyesters PHBHHx consisting of 3-hydroxybutyrate and 3-hydroxyhexanoate, and PHB/P3HB4HB that are PHB blended with copolyesters of 3-hydroxybutyrate and 4-hydroxybutyrate, respectively. More importantly, cell attachment and growth of human keratinocyte cell line HaCat on the nanofiber PHA matrices showed a notable improvement over those on PHA matrices prepared via an ordinary solution casting method. It was therefore proposed that PHA nanofiber matrices combined the advantages of biodegradation, improved mechanical strengths and the nanostructure of a natural extracellular matrix, leading to a better cell compatibility, thus they can be used for future implant biomaterial development.