Study On Preparation And Properties Of Tissue Repair Materials Based On Tannic Acid/silk Fibroin Composite

Tissue repair materials used to replace damaged tissues or induce tissue regeneration and functional reconstruction have always been a research focus in materials science and life sciences.Inspired by mussel byssus,more and more polyphenols are used in the development of adhesive tissue repair materials.The main idea of this work is to systematically study preparation and properties of TA/SF-based tissue repair materials at different scales?macro,micro,and nano levels?by utilizing the interaction between polyphenol and protein and based on natural plant polyphenol tannic acid?TA?and silk fibroin?SF?.The main contents and results of this work are as follows:1.The macro-scale bulk TA/SF composite gel?TASK?applied in wound closure was prepared by direct mixing method.Infrared spectroscopy,DSC,¹³C solid-state NMR and other methods demonstrated the physical interaction mechanism between tannic acid and silk fibroin molecules and the main random coil structure of silk fibroin in TASK gel.Compared with silk fibroin solution at room temperature,TASK freeze-dried powder has better stability for storage.Rheological test,self-healing property test,tensile test and adhesion test have demonstrated that TASK gel has excellent deformability,temperature sensitivity,self-healing property,stretchability and wet-resistant adhesion.Animal experiments have further proved that TASK gel can quickly and effectively close the wounds of the liver and the beating heart in vivo with reduced blood outflow.2.Calcium alginate-tannic acid/silk fibroin?Ca A-TA/SF?composite hydrogel microfiber that can promote the adhesion of neural stem cells was prepared by microfluidic method and immersion method.By comparing the adhesion of hydrogel microfibers treated with ethanol and enzymes to neural stem cells?NE-4C?and bone marrow mesenchymal stem cells?BMSC?,the combination of tannic acid and silk fibroin has been proved that it can significantly increase the adhesion and uniform dispersion of NE-4C and BMSC on microfibers.Differentiation culture experiment of NE-4C have proved that ordered Ca A-TA/SF composite hydrogel microfibers can effectively support and guide the axon extension and connection of NE-4C,showing the potential application of this composite hydrogel microfiber in nerve tissue repair.3.The polycaprolactone?PCL?-tannic acid/silk fibroin-Copper nanofibers(PTSCu^II)with promoting adhesion to bone marrow derived mesenchymal stem cells?BMSC?was prepared by the"one-pot method".The contact angle test proves that the introduction of TA/SF composite can effectively improve the hydrophilicity of PCL electrospinning nanofibers,and the introduction of Cu^II does not affect the hydrophilicity of PTSCu^II.Cell culture has proved that PTSCu^II is more beneficial than PCL nanofibers to the spreading of BMSC.Mechanical test demonstrates that the introduction of Cu^II can increase the elastic modulus of the nanofiber material to a certain extent.The strong mechanical properties of PCL and Cu^IIwith the function of simulating the microenvironment of bone tissue and promote the differentiation of stem cells into osteoblasts,make PTSCu^II have application potential in bone tissue repair such as skulls.