Study On Multilayering Electrospinning Of PLA/Silk Fibroin-Gelatin Composite Fibers Film

The electrospinning technique is one of the most important methods of producing continous nanofibers with diameter range from several micrometers to tens of nanometers. With small diameter, high surface area to volume ratio and high porosity, nanofiber can be used in tissue engineering and biomedical engineering.In this paper, the multilayer nanofibers composed of PLA nanofibers and SF-Gelatin nanofibers were prepared by electrospinning PLA solution and SF-Gelatin solution separately.The Technical parameters,structure and capability of PLA/SF-Gelatin composite fibers were studied. Firstly, the effect of the different spinning solvents, concentration, voltage, distance, flow rate and needle diameter on the morphology and structure of the PLA nanofibers were studied in order to decide the best parameters of electrospinning PLA fibers. Secondly, PLA/SF-Gelatin composite fibers were prepared by multilayering elctrospinning. we combined the PLA nanofibers and SF-Gelatin nanofibers with electrospinning and investigated the multilayer nanofibers'morphology(including pore diameter and porosity),microstructure, dimension stability, dissolving stability and mechanical property with and without methanol or ethanol post-treatment. Finally, cells were cultured on the PLA compotise fibers film and examined by scanning electron microscopy(SEM) and MTT .The results showed that with the decreasing of the spinning solution concentration and the increasing of the voltage, the nanofibers diameter were smaller. The spinning distance, flow rate, needle diameter played an important pole in the fibers morphology. The higher solution concentration and spinning voltage, the better mechanic property of the PLA nanofibers film. The PLA-SF-Gelatin nanofibers was porosity reticulation structure. Compared with the silk-gelatin nanofibers film, more content ofβ-sheet of SF was found in the PLA-SF-Gelatin nanofibers film, the pore diameter was bigger, the porosity and the water-dissolved rate declined, the dimension stability and the mechanics property was better. After methanol or ethanol post-treatment, the diameter of silk-gelatin nanofibers become bigger, the structure of silk was mainlyβ-sheet structure, and the mechanics property become better. The human umbilic vein cells growed very well on the PLA/silk composite fibers film by MTT, PLA played a mechanics scaffold effect on cell growth; PLA-SF-Gelatin nanofibers was proved to be capable to promote mouse fibroblasts attachment and proliferation by MTT, the cell nearly reached confluence by SEM micrographs, so they were considered to be a candidate scaffold for tissue engineering and biomedical engineering.