title: Silk fibroin/collagen and silk fibroin/chitosan blended three-dimensional scaffolds for tissue engineering.
abstract: BACKGROUND
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Tianjin Medical University, Qi Xiangtai Road No. 22, Heping District, Tianjin, 300070, China, lilinsunkai521@sina.cn.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Ruixin
authors.initials: R
authors.lastname: Li
authors.forename: Zhenghao
authors.initials: Z
authors.lastname: Nian
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Cheng
authors.initials: C
authors.lastname: Xu
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D048271:Chitosan; D003094:Collagen; D055119:Elastic Modulus; D005349:Fibroins; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D003094:Collagen; D005349:Fibroins; D048271:Chitosan