Nanofiber PHA Matrices Applications In Stem Cell-based Tissue Engineering

Polyhydroxyalkanoates (PHA) was demonstrated to be a family of biopolymers with good biodegradability and biocompatibility. To mimic the real microenvironment of extracellular matrix (ECM) for stem cell growth and differentiation, novel nano-fiber matrices based on PHA polymers were prepared via a sonication with freeze-drying process. Three-dimensional interconnected fibrous networks were observed in these PHA matrices with average fiber diamaters of 50 ~ 500 nm, which are very similar to the major ECM component collagen.It was revealed that cell attachment and viability of HaCat on the nano-fibrous PHA matrices showed a notably improvements over those on solid-walled PHA matrices prepared via an ordinary solution casting method. Moreover, the differentiation behavior of rat adipose-derived mesenchymal stem cell (RADSC) was also evaluated. The results showed that RADSC was tended to osteoblast differentiation on the nanofiber matrix made of 5.7% mol PHBV, and inclined neuron-like differentiation on the nanofiber matrix made of 5.0% mol P3HB4HB, respectively.Compared with self-assembling oligopeptide nanofiber and nano-fibrous polylactic acid (PLA) matrix, the mechanical properities of PHA nano-fibers were significantly improved, and can be properly adjusted. It was therefore proposed that PHA nano-fiber matrices combined the advantages of biodegradation, improved mechanical strengths and the nanostructure of a natural extracellular matrix, are leading to a better cell compatibility. They can be very favorable to biomaterial development in the stem cell-based tissue engineering.