Scaffolds from electrospun polyhydroxyalkanoate copolymers: fabrication, characterization, bioabsorption and tissue response.

Polyhydroxyalkanoate (PHA) copolymers of poly[(R)-3-hydroxybutyrate-co-5mol%-(R)-3-hydroxyhexanoate], poly[(R)-3-hydroxybutyrate-co-7mol%-4-hydroxybutyrate] and poly[(R)-3-hydroxybutyrate-co-97mol%-4-hydroxybutyrate] were electrospun to fabricate scaffolds with enhanced biocompatibility and bioabsorption. Subcutaneous implantation of the fibers in rats was performed to investigate their bioabsorption behavior and tissue response. The fibers before and after the in vivo experiments were characterized using gel permeation chromatography, scanning electron microscopy, X-ray diffraction and tensile test. Histological evaluation was also performed to determine the tissue response. The structures and properties of the electrospun PHA copolymers were compared with those of the electrospun poly[(R)-3-hydroxybutyrate]. The content and type of the second monomer and the diameter of fiber significantly influence the bioabsorption. The tissue response was found to improve with the high content of 4-hydroxybutyrate.