title: Collagen crosslinking of porcine sclera using genipin.
abstract: OBJECTIVE
  To evaluate the effect of collagen cross-linking induced by genipin in porcine sclera.
  
  
  METHODS
  Porcine cadaver eyes were treated with genipin at concentrations (by w/v) of 0.01%, 0.03%, 0.1%, 0.3%, 1.0% for 15 and 30 min. Riboflavin/ultraviolet A(UVA)-treated and untreated samples were used as controls. After treatment, scleral strips of 4.0 × 10.0 mm were cut. Twenty-four hours later, the stress-strain parameters of the strips were measured using a biomaterial microtester. The stress and Young's modulus at 8% strain were evaluated.
  
  
  RESULTS
  Compared with untreated groups, after treatment with genipin for 15 min, the stress was increased by 66-246%, depending on the concentration of genipin. As for the 30-min groups, the stress was 171-444% higher than that of the control. The difference of the Young's modulus between genipin 15-min groups, except the 0.01% groups (p = 0.095), also had statistical significance (p < 0.05). The Young's modulus had significant difference between the untreated group and the genipin 30-min groups (all p < 0.05). Of 0.3% genipin for 15 min or 0.01% genipin for 30 min had a similar stress-strain curve with those of eyes treated with the riboflavin/UVA group. The sclera exhibited a bluish colour which became deeper with increase concentration and cross-linking time.
  
  
  CONCLUSIONS
  Collagen cross-linking induced by genipin could increase the biomechanical strength in porcine sclera. The effect depends on the concentration and treatment time of genipin.
authors.affiliation: Zhongshan Ophthalmic Center at Sun Yat-sen University, The State Key Laboratory of Ophthalmology, Guangzhou, China.
authors.forename: Tai-Xiang
authors.initials: TX
authors.lastname: Liu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000269:Adhesives; D000818:Animals; D003094:Collagen / Q000187:drug effects / Q000378:metabolism*; D003432:Cross-Linking Reagents; D004195:Disease Models, Animal; D004548:Elasticity; D039823:Iridoids / Q000494:pharmacology*; D009216:Myopia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D012590:Sclera / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D013552:Swine
chemical_list: D000269:Adhesives; D003432:Cross-Linking Reagents; D039823:Iridoids; D003094:Collagen; C007834:genipin