Preparation Of Carboxymethyl Chitosan /Silk Fibroin Blend Porous Scaffold And Biocompatibility Analysis

Carboxymethyl chitosan(CMCS) and silk fibroin(SF) are wonderful natural polymer materials with excellent biological compatibility, great biodegradation, and non-toxicity, which have already shown great application prospect in many fields such as bone, skin, cartilage, etc.In the past few decades, large number of studies have demonstrated that the binary-blending of polymers is a cost-effective way for preparing new materials with the desired mechanical, thermal, biological properties, etc. The structure of collagen and SF are similar. For another, Chitosan and its derivatives are structurally similar to various glycosaminoglycans(GAGs). Therefore, Scaffold established by SF and CMCS maybe a kind of promising biomaterial which mimic extracellular matrix(ECM). Compared with pure silk fibroin scaffold, the silk scaffold blend with some chitosan or its derivatives has shown more excellent biocompatibility. The three-dimensional structure of scaffolds serves as a necessary template or matrix for attachment, spreading, proliferation of cells and it is good for cells to exchange nutrients and metabolites with microenvironment.Different quantity of CMCS were added into the mixture solution of SF/NF with weight ratio of SF/NF being 15/1, then the blend solution was freeze-dried for 48 hours to obtain the scaffold. But the prepared lyophilized SF/CMCS scaffolds were dissolved easily in deionized water, which can not provide a satisfied cell adhesion biotemplate, so it must be crossed with EDC-NHS-methanol compound. The corresponding properties of blended scaffolds were characterized below. The morphology of SF/CMCS scaffolds was revealed by SEM photographs, which displays the porous structure with 3-dimensional interconnection throughout the scaffolds. Different with the smooth porosity walls of pure SF scaffolds, many elliptic patch appear on the prepared blend scaffolds porosity walls. FTIR spectra technology was used to analyze the secondary structure of scaffold,CMCS did not affect SF transition from silk-Ⅰto silk-Ⅱ With the quantity of CMCS in scaffold increasing, swelling rate and thermostability also increased, but the compressive modules decreased. The proliferation and cell viability, as a function of time on a scaffold, are indicative of the cellular compatibility and appropriateness for tissue engineering applications. The mice’s bone marrow mesenchymal stem cells were seeded on those scaffolds and cultured for a period of time. It was found these stem cells on all kind of scaffolds grew well, especially on the blended scaffold with CMCS more than 20%(CMCS/SF).In summary, the above study proves that SF/CMCS blend scaffolds would be a promising biomaterial for soft tissue regeneration physical and chemical properites.