Objective To study the immunological rejection occurred in different period after the in vivo implantation of vitreous-cryopreservation tissue engineered tendons for the repair of tendon defect and investigate its influences on the hepatic, renal, and cardiovascular function of rats. Methods Tenocytes obtained from tail tendon of one-weekold SD rats were cultured in vitro. The tenocytes at passage 2-4 (5 × 106 cells/mL) were co-cultured with 1.5 cm bio-derived tendon material to reconstruct tissue engineered tendon. The 21% DMSO was used as cryopreservation protection solution andthe Eurocoll ins solution served as basic solution for pre-frozen solution (4 ) and eluent. The cell-scaffold composites were vitreous-cryopreserved by self-designed method. Seventy-two healthy SD rats (male and/or female) weighing 210-230 g were randomly divided into three groups: group A (n=32), group B (n=32), and group C (n=8). The 0.5 cm tendon defect model was establ ished in the middle part of Achilles tendon in groups A and B. The defect in group A and B was repaired by the transplantation of tissue engineered tendon with and without vitreous-cryopreservation, respectively. At 2, 4, 6, and 8 weeks after transplantation, the general observation and the detection of hepatic function, renal function, and cardiovascular function were conducted. At 2, 4, and 6 weeks after transplantation, serum immunology test was conducted. Results There were no tissue necrosis, hydrops, and suppurative infection in groups A and B. The adhesion was evident in groups A and B 2 weeks after transplantation, improved gradually during 4-6 weeks, and disappeared at 8 weeks. The neonatal tissue had full integration and continuity, and the bridging region of the tendon healed and was similar to the normal tendon. For serum IgG and IgM content, there was no significant difference when group A or B was compared with group C, and between group A and group B 2, 4, and 6 weeks after transplantation (P gt; 0.05). Hepatic function: aspartate aminotransferase (AST) content of group A was less than that of group C 4 weeks after transplantation (P lt; 0.05); AST content of group B was less than that of group C 4 and 6 weeks after transplantation (P lt; 0.05); but there was no significant difference when group A or B was compared with group C in terms of other indexes 8 weeks after transplantation (P gt; 0.05). Renal function: serum albumin and creatinine in groups A and B were decreased obviously, and significant difference was evident when compared with group C (P lt; 0.05). Cardiovascular function: there was no significant difference between group A and group C in terms of blood glucose, triglyceride, and cholesterol (P gt; 0.05);there was a significant difference between group B and group C in terms of triglyceride 8 weeks after transplantation (P lt; 0.05). Conclusion Repairing tendon defect with the implantation of vitreous-cryopreservation tissue engineered tendons results in no obvious immunological rejection and exerts no obvious influences on hepatic, renal, and cardiovascular function.
Objective To investigate the osteogenic potential of four kinds of new bioactive ceramics combined with bovine bone morphogenetic proteins (BMP) and to explore the feasibility of using compounds as bone substitute material.Methods Ninety-six rats were divided into 4 groups(24 in each group). BMP was combined with hydroxyapatite(HA), tricalcium phosphate(TCP), fluoridated-HA(FHA), and collagen-HA(CHA) respectively. The left thighs of the rats implanted with HA/BMP, TCP/BMP, FHA/BMP,and CHA/BMP were usedas experimental groups. The right thighs of the rats implanted with HA, TCP, CHA, and decalcified dentin matrix(DDM) were used as control groups. The rats weresacrificed 1, 3, 5 and 7 weeks after implantation and bone induction was estimated by alkaline phosphatase(ALP),phosphorus(P), and total protein(TP)measurement. The histological observation and electronic microscope scanning ofthe implants were also made. Results The cartilage growth in the 4 experimental groups and the control group implanted with DDM was observed1 week after operation and fibrous connective tissues were observed in the other 3 control groups. 3 weeks after implantation, lamellar bone with bone marrow and positive reaction in ALP stain were observed in the 4 experimental groups. No bone formation or positive reaction in ALP stain were observed in the control groups. The amount of ALP activity, P value, and new bone formation in the experimental groups were higher than those in the control group(Plt;0.05). The amount of ALP activity, P value, and new bone formation in TCP/BMP group were higher than those in HA/BMP, CHA/BMP and FHA/BMP groups(Plt;0.05). There was no significant difference in TP between the BMP treatment group and the control groups. From 5th to 7th week, new bone formation, histochemistry evaluation, and the level of ALP、P、TP value were as high as those in the 3rd week. Conclusion New composite artificial bone of TCP/BMP, HA/BMP, CHA/BMP, and FHA/BMP all prove to be effective, but TCP/BMP is the most effective so that it is the most suitable biomaterial replacement of tissue.