title: Development and potential of a biomimetic chitosan/type II collagen scaffold for cartilage tissue engineering.
abstract: BACKGROUND
  Damaged articular cartilage has very limited capacity for spontaneous healing. Tissue engineering provides a new hope for functional cartilage repair. Creation of an appropriate cell carrier is one of the critical steps for successful tissue engineering. With the supposition that a biomimetic construct might promise to generate better effects, we developed a novel composite scaffold and investigated its potential for cartilage tissue engineering.
  
  
  METHODS
  Chitosan of 88% deacetylation was prepared via a modified base reaction procedure. A freeze-drying process was employed to fabricate a three-dimensional composite scaffold consisting of chitosan and type II collagen. The scaffold was treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Ultrastructure and tensile strength of the matrix were carried out to assess its physico-chemical properties. After subcutaneous implantation in rabbits, its in vivo biocompatibility and degradability of the scaffold were determined. Its capacity to sustain chondrocyte growth and biosynthesis was evaluated through cell-scaffold co-culture in vitro.
  
  
  RESULTS
  The fabricated composite matrix was porous and sponge-like with interconnected pores measuring from 100-250 microm in diameter. After cross-linking, the scaffold displayed enhanced tensile strength. Subcutaneous implantation results indicated the composite matrix was biocompatible and biodegradable. In intro cell-scaffold culture showed the scaffold sustained chondrocyte proliferation and differentiation, and maintained the spheric chondrocytic phenotype. As indicated by immunohistochemical staining, the chondrocytes synthesized type II collagen.
  
  
  CONCLUSIONS
  Chitosan and type II collagen can be well blended and developed into a porous 3-D biomimetic matrix. Results of physico-chemical and biological tests suggest the composite matrix satisfies the constraints specified for a tissue-engineered construct and may be used as a chondrocyte carrier for cartilage tissue engineering.
authors.affiliation: Department of Orthopedic Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China.
authors.forename: De-hai
authors.initials: DH
authors.lastname: Shi
authors.forename: Dao-zhang
authors.initials: DZ
authors.lastname: Cai
authors.forename: Chang-ren
authors.initials: CR
authors.lastname: Zhou
authors.forename: Li-min
authors.initials: LM
authors.lastname: Rong
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Yi-chun
authors.initials: YC
authors.lastname: Xu
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D002356:Cartilage / Q000166:cytology*; D048271:Chitosan / Q000737:chemistry*; D018920:Coculture Techniques; D024043:Collagen Type II / Q000737:chemistry*; D007150:Immunohistochemistry; D011817:Rabbits; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D024043:Collagen Type II; D048271:Chitosan