Objective To investigate the effect of two kinds of injected biomaterial combined with bone morphological protein (BMP) on tendon-to-bone healing after anterior cruciate ligament reconstruction (ACL) in rabbits. Methods ACL reconstruction was performed bilaterally in 50 skeletally mature rabbits using long digital extensor tendon grafts. Injected fibrin glue (FG) or injected calcium phosphate cements (CPC) combined with BMP were implanted into the treated knee of each rabbit,with the contralateral knees as controls. Every three rabbits were killed at 2,6 and 12 weeks postoperatively for routine histological studies. The samples were processed through Micro CT and subsequent HE and toludine blue staining. The remaining 16 rabbits were sacrificed at 6 and 12 weeks. Their femur-tendon graft-tibia complexes were harvested for subsequent mechanical testing. Results Imageological results showed that 6 weeks after operation,bone mineral density (BMD) values in FG-bBMP group were higher than those in CPC-bBMP group. However,12 weeks after operation,BMD values in CPC-bBMP group were the highest in the three groups. Histological findings of the interface between the tendon and bone differed in the three groups. Two weeks after operation,more chondrocyte-like cells that were fairly disorganized were noted between the tendon and bone in FG-bBMP group. Six weeks after operation,mature bone formation around the tendon was observed in FG-bBMP group while more immature bone ingrew toward implanted tendon in CPC-bBMP group; at 12 weeks,more chondrocyte cells and new bone formation were seen in CPC-bBMP group while a small quantity of mature bone was around tendon in FG-bBMP group. In biomechanical evaluation,the maximum pull-out load of the tendon from the bone tunnel was significantly higher in the two treatment groups than in the control group 6 and 12 weeks after operation (P

BACKGROUND:Local administration of anti-tuberculosis drugs is a commonly used therapy. Due to the rapid absorption, the drugs cannot have the durable therapy effect; therefore, it is necessary to seek an optimal carrier material for the agents. OBJECTIVE:To review the new development for the carrier materials of anti-tuberculosis drugs. METHODS:A computer-based search of PubMed and VIP databases was performed by the first author to search articles related to sustained-released anti-tuberculosis drugs published from January 1990 to December 2014. The key words were osteoarticular tuberculosis; anti-tuberculosis; sustained-released drugs in English and Chinese, respectively. RESULTS AND CONCLUSION:Inorganic materials (calcium phosphate, calcium sulfate), polymer materials (polylactic acid, polyglycolic acid, polylactic-co-glycolic acid) and biomaterials (protein, glutin, alginates, chitin, demineralized bone matrix) are the main three kinds of carrier materials for anti-tuberculosis drugs. These carrier materials have their own advantages and disadvantages, which cannot be the optimal carrier materials. However, the complex of these materials is a promising technology for the optimal carrier materials in the future.

Objective A new type of bone graft material was constructed by combining calcium phosphate cement(CPC) with bone morphogenetic protein(BMP). In order to evaluate the feasibility to use this material to repair the segmental bone defect in clinic, the ability of CPC was compared with CPC/BMP in bone defects reconstruction by animal experiments. Methods The model of 15 mm bone defect was established in the middle shaft of the radius in 60 rabbits, of which 30 defects were implanted with CPC/BMP composites, 22 implanted with CPC, and the other 8 rabbits served as control group. The specimens were harvested separately at the end of 2, 4, 8, 16 and 24 weeks after operation. In order to observe the formation of new bone and the degradation process of the material, a series of examinations were carried out including of radiography, histomorphology, serum detection, energy dispersion analysis X-ray(EDAX), scanning electron microscope(SEM),bone density detection, mechanical measurement and inorganic substance detection. The results of CPC group and CPC/BMP group were compared on the same condition. Results All the animals survived after operation, and no reactions of toxicity were found. New bone formation was observed to be increasing significantly in CPC/BMP group with the time of implantation. Only little new bone formed in CPC group and no healing was found in the control group. By the end of 24 weeks, new bone had bridged the gap between the proximal and distal fragments in CPC/BMP group. In histomorphological detection, chondrocytes were found at the 2nd week, and woven bone at 4th week in CPC/BMP group. Remodeling of new lamellar bone and absorption of the composite material were observed at the 16th week, and the mechanical strength of the composite material reached almost to normal level at the 24th week. Calcification was significantly higher in CPC/BMP group than that in CPC group examined by EDAX, new bone density detection and measurement of inorganic substance in specimens. During the repairing process of bone defect, the material degraded while new bone formed, the speed of degradation of CPC/BMP was evidently higher than that of CPC group. Moreover, in the process of CPC degradation, the concentration of calcium in serum increased, and the concentration of phosphate in serum kept unchanged. Conclusion The CPC/BMP composite has great potential in bone defects repairing and could be used as a material for bone graft substitute in clinical patients.

[Objective]To study the differentiation of adipose-derived adult stem cells(ADASCs)into chondrocytes induced by TGF-?1 in the presence of different concentrations of serum in vitro.[Method]Adipose tissue-derived adult stem cells were isolated from rabbits subcutaneous adipose tissue using enzymatic digestion.The adipose tissue was minced and digested with collagenase type I,and the released cells were collected by density centrifugation and then placed in culture.After being passaged three times,ADASCs were induced to differentiate into chondrocytes by chondrogenic culture media containing 1% or 10% of FBS for 2 weeks.MTT,alkaline phosphatase toluidine blue staining and type Ⅱ collagen immunohistochemistry staining were then tested in both groups.Gray value was analyzed by Leica patho-image analysis system to observe if there was any difference in differentiative status between the two groups.[Result]MTT showed that the cells of 10% FBS group had higher proliferation activity than those of 1% FBS group(P

Objective To observe histomorphology of neo-cartilage obtained with tissue-engineering by combining calcium alginate gel and in vitro cultrue of chondrocytes. Methods Articular chondrocytes from the knee joints of 2-week-old New Zealand white rabbits were harvested, expanded in cell culture, and following the second generation of the culture, the chondrocyte suspension was mixed with calcium alginate gel resulting in a cell density of 5? 10 6/ml. Finally the mixture, which contained 1％ sodium alginate, 40 mmol/L calcium gluconate, 0.135 mol/L NaCl, 0.1 mol/L K 2HPO 4 and 5? 10 6 chondrocytes per milliliter, were injected into the dorsal subcutaneous tissue in rabbits of experimental groups (A and B). Animals of the control groups (C and D) were injected with calcium alginate without chondrocytes or chondrocytes without calcium alginate. Specimens were harvested at the 2nd and 4th week after injection, and stained with HE and toluidine blue. Results In the HE stained specimens in the experimental groups, proliferation of chondrocytes was demonstrated at the 2nd week and the formation of neo-cartilage at the 4th week after injection of calcium alginate chondrocyte-composite. Toluidine blue stained specimens showed positive staining of chondrocytes and cartilage matrix of neo-cartilage. In some animals injected with chondrocytes without calcium alginate, relative small amount of neo-cartilage was also formed and no neo-cartilage was observed in animals injected with calcium alginate without chondrocytes. Conclusion Injectable calcium alginate-chondrocyte-composite can induce tissue engineered neo-cartilage in allogenic animal.

[Objective]To explicate whether the telomerase activity is regulated by human telomerase reverse transcriptase (hTERT) in human bone marrow mesenchyme stem cells(hBMSC).[Method]hBMSC were cultured and transfected with eukaryotic expressing plasmid pCIneo-hTERT encoding hTERT. After selection with G418 to stabilize the transfection,expression of hTERT mRNA was detected with TR-PCR, detecting the expression of hTERT protein was detected with Western Bolt, and the telomerase activity in untransfected and transfected cells were detected by RT-PCR.[Result]The hMSCs grew well after transfecting plasmid pCIneo-hTERT.The cells began to suspend and die after the day of the G418 selection. At the tenth day,all the untransfected cells were dead, but the transfected cells began to clone proliferation. So the density of G418 subdued to 100 ?g/ml for maintaining selecting, at the twentieth day,there were obvious anti-G418 cell clones. After stable transfection, hTERT was expressed at mRNA and protein level in these anti-418 cell clones, and meanwhile telomerase activity was positive and obviously raise up in these transfected cells.[Conclusion]In human' bone marrow mesenchyme cells,telomerase could be activated by exogenous hTERT. This is a foundation to establish immortalized human bone marrow mesenchyme stem cell line.

[Objective]To explore the potential of a novel collagen I /chitosan /Nano?-tricalcium phosphate(?-TCP)bilayered scaffold for being used in tissue engineering(TE)of osteochondral repair.[Method]Bilayered scaffolds were produced with collagen Ⅰ,chitosan and?-TCP,using a special cross-linking and freeze drying method.The pore size,porosity and interpores of the scaffold were observed by scanning electron microscopy(SEM).Rabbit bone mesenchymal stem cells(BMSC)were isolated and amplified,then inoculated onto the scaffold.By SEM scanning,the condition of the cells adhering onto the scaffold was observed.The proliferation of the cells on the scaffolds was examined using MTT method,and the growth curve was drawn.The cell-scaffold composite were then induced to differentiate towards cartilage by 3-D culturing,and then implanted into muscle pouches 2 weeks later.The result was observed 6 weeks later by HE staining,toluidine blue staining and type Ⅱ collagen immunohistochemistry.[Result]The scaffold possessed high porosity and proper pore size,the porosity was above 95%.BMSC could adhere onto the scaffold well,and the proliferation rate of the cells on the scaffolds was perfectly good.After in vitro induction,BMSC-scaffold composite can differentiate toward cartilage ectopicly.[Conclusion]The novel collagen I /chitosan /?-TCP bilayered scaffold possesses good pore structure and biocompatibility,and will possibly become a new biomaterial of TE used for osteochondral repair.

[Objective]To compare the purity and extraction rate of four purecollagen type I products prepared from various biomaterials by a limited enzyme digestion method for the use in tissue engineering.[Method]Bovine cortical bone, bovine achilles tendon, porcine achilles tendon and porcine skin were splitted into pieces of 0.2-0.5 mm. After being immersed in glacial acetic acid, they were extracted with pepsin. Then the crude products were dissolved, centrifuged, dialyzed and freeze drying to prepare pure collagen type I. The final products were confirmed by absorbance, amino acid analysis and'SDS-PAGE electrophoresis comparing them with the products of Sigma Company.[Result]The wave length of maximum absorbance of the final products was 230 nm, and the amino acid analysis and SDS-PAGE electrophoresis confirmed that the final products were collagen type I. The purity of product extracted from bovine cortical bone was the highest (96.12%) and higher than that from Sigma Company. The extraction rate of bovine achilles tendon collagen was the highest (75.34%).[Conclusion]Collagen type I of higher purity and higher extraction rate can be prepared using a limited enzyme digestion method.And the product from bovine cortical bone is better than the others,which has a promising prospect.

[Objective] To study the effect of anti-infective reconstituted bone xenograft(ARBX)on treating chronic hematogenous osteomyelitis as one-stage grafting.[Method]ARBX was used to treat 24 cases of chronic hematogenous osteomyelitis as one-stage grafting after debridement since September of 2001,17 cases of which were followed up for an average period of 34 months(range,12 to 79 months).[Result]Except 1 case failed to cure,and 1 resulted in recurrence of infection,and 1 with large segmental bone defect nonunion post-operatively,other 14 cases were cured,the cure rate was 82.4% which was better than traditional therapy.[Conclusion]ARBX has high osteoinductive activity and enhanced anti-infective capability,which enables it to be used as primary grafting to treat chronic hematogenous osteomyelitis.

[Objective]To investigate the changes of pore sizes,crosslinking index,swelling ration,degradation rate,cytotoxicity and biocompatibility of genipin crosslinked collagen/chitosan scaffolds affected by the different crosslinking temperature points.[Method]The freeze-dried collgaen/chitosan scaffolds crosslinked with 0.5% genipin within 24 h were divided into 3 groups by crosslinking temperature:4℃ group,20℃ group and 36℃ group.The characteristics of pore sizes,crosslinking index,swelling ratio,degradation rate,cytotoxicity and biocompatibility were evaluated.Collagen/chitosan scaffolds without crosslinking were chosen as control group.[Result]With the increase of temperature,crosslinking index was increased,but swelling ratio and degradation rate were decreased.In 4℃ group,the crosslinking index was 47.88%?6.4%,the swelling ratio was 721%?46%,and the degradation rate was decreased by 3.95%?6.4% at 4 weeks.In 20℃ group,the crosslinking index was 67.69%?3.6%,the swelling ration was 662%?72%,and the degradation rate was 0.91%?5.9% in 4 weeks.In 36℃ group,the crosslinking index was 70.32%?5.7%,the swelling ration was 635%?27%,and the degradation rate was 0.66%?7.3% at 4 weeks.The above indexes of the three groups were much better than those of control group(P