Nanofibrous-structured biopolymer scaffolds obtained by a phase separation with camphene and initial cellular events

A simple and novel methodology to create a biopolymer PHBV (polyhydroxybutyrate-co-hydroxyvalerate) with a nanofibrous morphology is introduced in this paper. PHBV solution was mixed with hydrocarbon camphene (C10H16) at various concentrations (camphene : PHBV 1 : 1 similar to 12 : 1) to create an interpenetrating network. During the solvent evaporation, camphene was easily solidified due to its low freezing point (similar to 40 degrees C), and the sublimation of camphene at ambient condition generated pores, resulting in the production of a highly porous PHBV membrane. As the camphene concentration increased, the pore part increased and the resultant PHBV network became nanofibrous. The nanofibrous morphology was uniformly observed throughout the PHBV membrane. Additionally, the nanofibrous surface could be easily implemented onto a 3D macro-porous scaffold by applying standard scaffolding techniques, such as salt impregnation-and-leaching and robotic dispensing. The initial cell adhesion events assessed up to 24 h were significantly enhanced on the PHBV with nanofibrous surfaces when compared to those with dense surfaces, as confirmed by the adherent cell number, morphological traits, and the expression of adhesion proteins including focal adhesion kinase and paxillin. Overall, this study conveys a novel and simple methodology of producing a biopolymer with nanofibrous morphology that may be an alternative to electrospinning, with which the production of 3D macroporous scaffolds with complex shapes has been a challenge.