ABSTRACT
Objective To explore a new way to improve the repairing effect of tendon allograft by pretreatment with ethyldimethylaminopropyl carbodiimide (EDC) cross-linking. Methods Rabbits' tendon allografts were obtained by lyopyilization.The allografts were then cross-linked and heparinized by EDC and N-hydroxy-succinimide (NHS) respectively.The degradation rate,cytotoxicity and histocompatibility of the cross-linked allografts were detected and compared with those of untreated at different time points.The injured anterior cruciate ligaments (ACL) were repaired by tendon allografts with and without cross-linking pretreatment in rabbits.The tendon-bone healing was observed and compared by light microscopy and scanning electron microscopy (SEM) at 1,3,6 months. Results The degradation rate of the pretreated tendon allografts [(6.26 ± 3.16)％] was significantly lower than that of the unpretreated [(30.70 ± 10.24)％]( t = 14.200,P = 0.025 ).The pretreated tendon allografts were atoxigenic and produced significantly lower inflammatory reaction ( P ＜ 0.05 ).The pretreated tendon allografts also showed more powerful capability of repairing ACL injury and shorter time of tendon-bone healing. Conclusion Tendon allografts cross-linked and heparinized by EDC/NHS may promote tendon-bone healing with improved stability,degradation and biocompatibility.
ABSTRACT
Under low temperature conditions, the hapten carboxyl-norketamine was synthesized by reacting norketamine and succinaldehyde acid.Identification result using electrospray ionization mass showed the hap ten was successfully synthesized.The artificial antigen confirmed by infrared spectroscopy was developed by conjugating hapten to carrier proteins with carbodiimide(EDC) method.Matrix-assisted laser desorption ioni zation time of flight mass spectrometry(MALDI-TOF-MS) showed that the ratio of hapten to BSA was 11:1.The antibody with high titer(5.12 × 10~4) was produced after immuning to rabbits.