Biodegradable PHBH/PVA blend nanofibers: Fabrication, characterization, in vitro degradation, and in vitro biocompatibility

Abstract

Electrospinning was used to fabricate the different ratio of poly [(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBH)/Poly (vinyl alcohol) (PVA) blend nanofibers. These nanofibers of ratio PHBH/PVA 100/0, 90/10, 70/30, and 50/50 were prepared by using HFIP as solvent. Mixed solvent of HFIP/water was used to prepare for PHBH/PVA 30/70, 10/90 and water was used for pure PVA. The characteristic of morphology, thermal properties, miscibility, wettability, water absorption, and enzymatic biodegradable behaviour of these blend nanofibers have been investigated. The result indicated that PHBH/PVA blend nanofibers are immiscibility in the crystalline phase from DSC analysis with two peaks appear in 137 °C and 230 °C in the blend nanofibers. WAXD pattern of the blend nanofiber also exhibited the decrease of PHBH crystalline intensity with the increase of PVA content. However, FTIR spectra of blend nanofiber displayed the shift of hydroxyl and carbonyl stretching band which indicates the intermolecular interaction in amorphous phase. The water contact angle values increased with the increase of PVA content more than 30%. These showed the surface of blend nanofibers were hydrophobic since WCA value was more than 90°. The increase of WCA value is due to surface morphological change that is the decrease of fiber diameter. Nevertheless, blend nanofibers of PHBH/PVA of 70/30 exhibited the high water absorption more than 350% from initial weight. SEM-photograph of samples after immersing in the water showed that structure of nanofiber did not change in blend ratio of more over 50% PHBH content. These nanofibers of pure PHBH and ratio PHBH/PVA of 90/10, 70/30, and 50/50 will expect to be useful material to have the biocompatibility with cell attachment. In vitro enzymatic biodegradable resulted that degradation rate of blend nanofiber can be greatly improved by ratio of PVA polymer. NIH3T3 cells attached and proliferated well on pure PHBH nanofiber. However, blend nanofibers with PVA-rich content inhibited growth of the NIH3T3 cells.