Construction of tissue engineering cartilage for the damaged load bearing section of pig knee-joint by CD44 monoclonal antibody-biotin-avidin binding technique

Abstract

Objective To evaluate the effect of repairing cartilage defect using tissue engineering cartilage with CD44 monoclonal antibody-biotin-avidin (CBA) binding technique in vitro and in vivo.Methods The tissue engineering cartilages were designed and divided into 3 groups:general group,chitosan scaffold + chondrocyte group; biotin-avidin (BA) group,chitosan scaffold bound with BA + chondrocyte; CBA group,chitosan scaffold bound with CD44 monoclonal antibody-BA + chondrocyte.The levelthrough cartilage damages of load bearing sections were divided into four groups:group A,transplanted with the tissue engineering cartilage in the general group; group B,transplanted with the tissue engineering cartilage in the BA group; group C,transplanted with the tissue engineering cartilage in the CBA group;group D,transplanted with the autologous cartilage.Samples were taken after transplantation for 12 weeks,and estimated by Moran estimate system.The modulus of elasticity and rigidity of the samples were estimated by biomechanics method.The contents of collagen Ⅱ (col Ⅱ) and aggrecan were tested by Western blotting.The samples were stained with hematoxylin and eosin (HE),and TB dye,and the Wakitani scores were recorded.Results In the Moran estimate system,the score in group D was 4.48 ± 0.23,which showed no statistically significant difference from group C (P ＞ 0.05),but higher than in groups A and B,P ＜ 0.05.The modulus of elasticity in group D was (20.61 ± 2.02) mPa and the rigidity was (72.28 ±6.16) N/mm.The expression of col Ⅱ and aggrecan in group D was 1.59 ±0.14 and 1.44 ± 0.13 respectively,significantly higher than other groups,P ＜ 0.05.The histologic staining and Wakitani score revealed the more satisfactory repair effectiveness in group D.Conclusion The repair effect of tissue engineering cartilage constructed by the BA technique for the damaged load bearing section of pig knee-joint is more satisfactory than the general method.The effect,however,is much better when the tissue engineering cartilage is prepared by CD44 monoclonal antibody-BA binding technique.Though it cannot be equal to the autologous repair totally,the CD44 monoclonal antibody-BA binding technique can achieve nearly the same repair effect. Key words: CD44 monoclonal antibody; Biotin ; Adivin ; Tissue engineering; Cartilage damage