title: [Experimental study on chitosan mediated insulin-like growth factor gene transfection repairing injured articular cartilage in rabbits].
abstract: OBJECTIVE
  To study the effect of chitosan (CS) mediated insulin-like growth factor 1 gene (igf-1) transfection on the repair of articular cartilage defect.
  
  
  METHODS
  Twelve 3-month-old healthy male rabbits weighting 2.0-2.5 kg were randomly divided into 2 primary groups, control and intervention groups (n = 6 per group). Control group was further divided into normal control (left knee) and normal saline (NS) control (right knee) groups. While, intervention group was divided into CS (left knee) and CS/igf-1 intervention (right knee) groups. Cartilage defects were created in the knee joints except normal control. Intra-articular injections of CS/igf-1 complex was administrated 2 times a week for 4 weeks in CS/igf-1 intervention group, 0.5 mL CS in CS intervention group, and 0.5 mL saline solution in normal control and saline control groups. At 28 days after treatments, the cartilage samples were collected for histological observation and collagen type II and aggrecan mRNA evaluation.
  
  
  RESULTS
  HE staining and toluidine blue staining revealed that CS/igf-1 and CS intervention could significantly stimulated cartilage regeneration accompanied with fibrosis and inflammatory cell infiltration, however, CS/igf-1 treatment resulted in the best repair of cartilage defect. In contrast, saline control group only showed fibrous tissue proliferation and inflammatory cell infiltration without significant cartilage repairing. In terms of collagen type II and aggrecan gene expression, significant differences were observed in each pairwised comparison among 4 groups in the order of CS/igf-1 > CS > NS > normal control (P < 0.05).
  
  
  CONCLUSIONS
  In situ CS/ifg-1 complex transfection can enhance the formation of mesochondrium by upregulating collagen type II or aggrecan expression, which might enhance the repair of articular cartilage defect.
authors.affiliation: Institute of Endocrinology, Metabolic Disease Hospital, Tianjin Medical University, Key Laboratory of Hormones and Development, Ministry of Health, Tianjin 300070, PR China.
authors.forename: Ronglan
authors.initials: R
authors.lastname: Zhao
authors.forename: Yuping
authors.initials: Y
authors.lastname: Ren
authors.forename: Bei
authors.initials: B
authors.lastname: Sun
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Dongchun
authors.initials: D
authors.lastname: Liang
mesh_terms: D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects* / Q000293:injuries*; D048271:Chitosan / Q000627:therapeutic use*; D024043:Collagen Type II / Q000378:metabolism; D015316:Genetic Therapy; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000627:therapeutic use*; D008297:Male; D011817:Rabbits; D014162:Transfection
chemical_list: D053674:Aggrecans; D024043:Collagen Type II; D007334:Insulin-Like Growth Factor I; D048271:Chitosan