Research On The Silk Gel Induced By Biosurfactants

Silk fibroin(SF) hydrogels have mass potential as biological materials based on their excellent biocompatibility. In this paper, three types of surfactants were used to induce SF to gel. The hydrogels were charactered of their structure and properties to explore the gelation mechanism. They are betaine surfactants, peptide surfactants and amino acids surfactant.Betaine surfactants can accelerate SF gelation, the gelation time was independent on the carbon chain length in active agent, but dependent on its surface tension. The active agent appears shorter gel time with the lowest point in surface tension, wherein lauryl betaine was with the shortest gel time, in about 20 min. Internal structural changes in gel process were characterized by fluorescence test. Hydrophobic and hydrophilic interaction induced molecular chain stretch open and restructuring, fibroin conformation turned toβ-sheet to form a uniform structure. The three-dimensional network structure formed at last.With some antibacterial effect, the hydrogels can be used as a hydrogel dressing to solve the inconvenience by traditional wound paste.Peptide surfactants, surfactin induce the formation of silk fibroin hydrogels. A low surfactin concentration required, 1 g/L of surfactin can induce SF to gel in 2 h under 37℃.The hydrogels have a certain biocompatibility.Amino acid-based surfactants, sodium N-lauroyl sarcosine(SNS) can accelerate the formation of SF hydrogels. The gel time can be changed for the required time by adjusting temperature, SNS concentration and SF concentration. Infrared spectroscopy, X-ray diffraction, scanning electron microscopy, circular dichroism and fluorescence spectra were used to explore the structure, properties and gel mechanism of hydrogels.Hydrophobic and hydrophilic interaction induced molecular chain stretch open and restructuring. With electrostatic interaction, more crystalline structures were formed to hydrogel. SNS/SF gel has a relatively high strength and excellent elasticity. With good biocompatibility, SNS/SF hydrogels have great potential in tissue repair.