OBJECTIVETo fabricate polyvinyl alcohol (PVA)/chitosan hybrid nanofibrous scaffolds owning the similar physiological structure of ECM, and to observe its biodegradation behavior in vivo and in vitro.

METHODS(1) The PVA nanofibrous scaffold and PVA/chitosan hybrid nanofibrous scaffold were fabricated by electrospinning technique, and then they were crosslinked by glutaraldehyde vapor method. The morphology of both scaffolds was observed by scanning electron microscope (SEM). (2) Biodegradation experiment in vitro: the samples of two scaffolds with size of 2 cm x 2 cm were placed into phosphate-buffer saline (PBS) fluid under 37.0 degrees C water for incubation, and then they were dried to observe morphologic changes under SEM on post incubation day (PID) 3, 7, and 14. (3) Biodegradation experiment in vivo: 48 Wistar rats were divided into PVA group and PVA/chitosan group according to the random number table, with 24 rats in each group. PVA or PVA/chitosan nanofibrous scaffold was implanted into subcutaneous tissue on both sides of back in rats of both groups, with 4 scaffolds in each rat. The scaffold samples were harvested to observe morphologic changes with HE staining on post operation day (POD) 3, 7, 14, and 28.

RESULTS(1) After crosslinking, the surface of fibers in PVA and PVA/chitosan hybrid nanofibrous scaffolds were smooth, and the diameters of fibers were similar, ranging from 200 to 300 nm, with high porosity. (2) Biodegradation experiment in vitro showed that the morphologic changes in fiber was respectively swelling, dissolution, fusion in PVA nanofibrous scaffold on PID 3, 7, 14, and that in PVA/chitosan hybrid nanofibrous scaffold was respectively swelling, dissolution and fragmentation, and disappearance. (3) Biodegradation experiment in vivo showed that the morphologic changes in scaffold structure was respectively loosening, fuzziness of edges, degradation, and disappearance in PVA group and PVA/chitosan group on POD 3, 7, 14, 28.

CONCLUSIONSPVA/chitosan hybrid nanofibrous scaffolds can be prepared with electrospinning technique, and it has an appropriate biodegradation rate compatible with tissue reconstruction after crosslinking.