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Introduction: In this study, the silk fibroin blended constructs were produced, scaffold performances of different kinds of scaffold were analyzed, and the better type for tissue engineering was optimized. Methods: The silk fibroin/collagen (SF/C) and silk fibroin/chitosan (SF/CS) were made using a freeze-drying technique, porosity, water absorption expansion rate, mechanical properties and pore size of different scaffold was detected. Bone marrow mesenchymal stem cells (BMSCs) of 4-week-old male Wistar rats were separated by density gradient centrifugation, third generation BMSCs were seeded onto scaffolds, cultured 14 days, proliferation and metabolize of cells were detected in different time using the thiazolyl blue tetrazolium bromide (MTT) assay method, and cell morphology and distribution were observed by histological analysis and scanning electron microscopy (SEM). Results: Porosity, water absorption expansion rate and Young's modulus of SF/C were significantly higher than SF/CS ( p < 0.05); pore size of SF/C and SF/CS was 103 ± 12 and 76 ± 11 μm and had no significant differences between two types ( p > 0.05); MTT results showed that the metabolism of cells in the SF/C was better than SF/CS; after cultivation for 14 days, in the inner zone of scaffolds, cells staining were little or absent from SF/CS, lots of cells staining were existing in SF/C; pore size was consistent, holes communicated with each other better, stem cells grew well inside the scaffolds, extended fully and secreted much extracellular matrix under SEM in SF/C scaffold; internal structure of SF/CS was disorder, holes size were not consistent, and did not communicated with each other and cells were partly dead. Conclusion: Compared with SF/CS, SF/C scaffold showed better porosity, water absorption expansion rate, elasticity modulus and pore size, cells grow well inside the scaffolds, and was more suitable for tissue engineering. [ABSTRACT FROM AUTHOR]

As a promising alternative to autologous nerve grafts, tissue-engineered nerve grafts have been extensively studied as a way to bridge peripheral nerve defects and guide nerve regeneration. The main difference between autogenous nerve grafts and tissue-engineered nerve grafts is the regenerative microenvironment formed by the grafts. If an appropriate regenerative microenvironment is provided, the repair of a peripheral nerve is feasible. In this study, to mimic the body’s natural regenerative microenvironment closely, we co-cultured Schwann cells (SCs) and adipose-derived stem cells (ADSCs) as seed cells and introduced them into a silk fibroin (SF)/collagen scaffold to construct a tissue-engineered nerve conduit (TENC). Twelve weeks after the three different grafts (plain SF/collagen scaffold, TENC, and autograft) were transplanted to bridge 1-cm long sciatic nerve defects in rats, a series of electrophysiological examinations and morphological analyses were performed to evaluate the effect of the tissue-engineered nerve grafts on peripheral nerve regeneration. The regenerative outcomes showed that the effect of treatment with TENCs was similar to that with autologous nerve grafts but superior to that with plain SF/collagen scaffolds. Meanwhile, no experimental animals had inflammation around the grafts. Based on this evidence, our findings suggest that the TENC we developed could improve the regenerative microenvironment and accelerate nerve regeneration compared to plain SF/collagen and may serve as a promising strategy for peripheral nerve repair. [ABSTRACT FROM AUTHOR]