Study On Nanofibers Made Of Fish Gelatin By Electrospinning

Abstracts: The fabrication of cell scaffolds for guided tissue regeneration (GTR) is one of the core technologies in tissue engineering field. Cells have better adhesion properties on the fibers whose diameter are less than theirs (in nanometer). The three-dimensional electrospun(ES) fibers with high porosity can mimic the structure of native extracellular matrices (ECMs), which would enhance the adhesion and growth capabilities of cells. So, they are expected to be ideal candidates as tissue engineering scaffolds. In our study, channel catfish skin-extracted gelatin was electrospun into gelatin nanofibers and blended with poly-L-lactic acid (PLLA) to fabricate composite nanofibers. After analysis of structural and biological properties, the composite nanofibrous membrane was considered to be very promising in tissue engineering field with good biological compatibility and mechanical properties.Firstly, the optimization principles of electrospinning applied in scaffold fabrication were systematically discussed through the study on important ES parameters, such as concentration of aqueous acid and fish gelatin solutions, electric field intensity and polar distance. Their effects on the morphologies and distributions of diameters of the gelatin nanofibers were examined by scanning electron microscopy (SEM) and the optimum process parameters of gelatin electrospinning were determined. The results showed fish gelatin nanofibers with good morphology could be obtained under the experimental condition of formic acid concentration from 70% to 85%, fish gelatin concentration of 12% to 23%, voltage from13 kV to 24kV, polar distance from 8cm to16cm.Secondly, fish gelatin/PLLA composite nanofibers were electrospun from the blends by mixing fish gelatin and PLLA solutions at the volume ratios of 1:3, 1:1 and 3:1 (fish gelatin/PLLA, v/v). Morphologies of the composite nanofibers with different ratios were observed by SEM. Infrared spectroscopy (IR) analysis was investigated to study the interaction between fish gelatin and PLLA in composite nanofibers.The results suggested that there was a weak hydrogen bond between fish gelatin and PLLA, which improved the stability of composite nanofibers membrane, and saved the identifiable signal factors in the gelatin.Thirdly, the analysises of mechanical properties, degradation properties, porosity and pore size were carried out on the nanofibrous membranes made of fish gelatin and fish gelatin/PLLA to lay a foundation for the cells culture experiment. The results indicated that fish gelatin/PLLA composite nanofibrous membrane has good mechanical properties, degradation and appropriate porosity and pore size, which can meet the requirements for the structure of tissue engineering scaffold.Finally, the comparisons of biological properties between cross-linked fish gelatin nanofibrous membrane, fish gelatin/PLLA composite nanofibrous membrane and ordinary membrane were carried out by culturing fibroblast cells of L929 on these different membranes. Cells'adhesion, growth and proliferation on different mats were analyzed by MTT colorimetric test and their growth states were observed by SEM. These can lay a good theory basis for the application of composite nanofibrous membrane as a new medical material. Cell culture test showed that fish gelatin/PLLA composite nanofibrous membrane had a better capacity to support cells'growth, division and proliferation than the cross-linked fish gelatin nanofibrous membrane and ordinary film.In this investigation, fish gelatin/PLLA composite nanofibrous membrane was firstly prepared and proved to be an alternative medical material due to its good application prospect as tissue engineering scaffold.