Drug release from electrospun fibers of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) grafted with poly(N‐vinylpyrrolidone)

Poly(N‐vinylpyrrolidone) (PVP) groups were grafted onto poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) backbone to modify the properties of PHBV and synthesize a new novel biocompatible graft copolymer. Based on these graft copolymers, electrospun fiber mats and commonly cast films were explored as drug delivery vehicles using tetracycline hydrochloride as a model drug. Toward that end, the fibers were electrospun and the films were cast from chloroform solutions containing a small amount of methanol to solubilize the drug. The Brookfield viscosities of the solution were determined to achieve the optimal electrospinning conditions. The vitro release of the tetracycline hydrochloride from these new drug delivery systems was followed by UV–vis spectroscopy. To probe into the factors affected on the release behavior of these drug delivery systems, their water absorbing abilities in phosphate buffer solution were investigated, together with their surface hydrophilicity, porosity and crystallization properties were characterized by water contact angles, capillary flow porometer, DSC, and WAXD, respectively. The morphological changes of these drug delivery vehicles before and after release were also observed with SEM. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012