In order to investigate the effect of motion on repairing articular cartilage defect following autogenous periosteal graft, sixty adult rabbits were divided randomly into three groups: out-cage motion (OCM), in-cage motion (ICM) and immobilization (IMM). A defect of the articular cartilage, 1 cm x 0.5 cm in size, was made in the patellar-groove of femur of each hind limb. Free autogenous periosteal graft from the proximal tibia was sutured on the base of the left defect, while the right limb was served as control. The animals were sacrificed at 4, 8 and 12 weeks, respectively, after operation. The regeneration of the cartilage implanted was observed through gross, histology, histochemical assay and electronic microscope. The influence of different amount of motion on the chondrogenesis from the periosteal implant was also compared. The result showed that the hyaline cartilage produced from periosteal implant could be capable to repair full-thickness of articular cartilage. From statistical study, there was significant difference between OCM and ICM groups (P lt; 0.05), ICM and IMM (P lt; 0.05) as well as OCM and IMM (P lt; 0.01). It was suggested that the periosteal graft was effective in repair of defect of articular cartilage and the amount of motion was important for chondrogenesis.
To investigate the feasibility of using the pedicled patella for repaire of the superior articular surface of the medial tibial condyle, 37 lower limbs were studied by perfusion. In this series, there were 34 obsolete specimens and 3 fresh specimens of lower legs. Firstly, the vessels which supply to patella were observed by the methods of anatomy, section and casting mould. Then, the form and area of the patellar and tibial medial conylar articular surface were measured in 30 cases. The results showed: (1) the arteries supplied to patella formed a prepatellar arterial ring around patella, and the ring gave branches to patella; (2) medial inferior genicular artery and inferior patellar branches of the descending genicular arterial articular branch merge and acceed++ to prepatellar ring at inferior medial part of patella; (3) the articular surface of patella is similar to the superior articular surface of the tibial medial condyle on shape and area. It was concluded that the pedicled patella can be transposed to medial tibial condyle for repaire of the defect of the superior articular surface. The function of the knee can be reserved by this method.
Objective To construct recombinant lentiviral expression vectors of porcine transforming growth factor β1 (TGF-β1) gene and transfect bone marrow mesenchymal stem cells (BMSCs) so as to provide TGF-β1 gene-modified BMSCs for bone and cartilage tissue engineering. Methods The TGF-β1 cDNA was extracted and packed into lentiviral vector, and positive clones were identified by PCR and gene sequencing, then the virus titer was determined. BMSCs were isolated frombone marrow of the 2-month-old Bama miniature pigs (weighing 15 kg), and the 2nd and 3rd generations of BMSCs wereharvested for experiments. BMSCs were then transfected by TGF-β1 recombinant lentiviral vectors (TGF-β1 vector group)respectively at multi pl icity of infection (MOI) of 10, 50, 70, 100, and 150; then the effects of transfection were detected bylaser confocal microscope and Western blot was used to determine the optimal value of MOI. BMSCs transfected by empty vector (empty vector group) and non-transfected BMSCs (non-transfection group) were used as control group. RT-PCR, immunocytochemistry, and ELISA were performed to detect the expressions of TGF-β1 mRNA, TGF-β1 protein, and collagen type II. Results Successful construction of recombinant lentiviral vectors of porcine TGF-β1 gene was identified by PCR and gene sequencing, and BMSCs were successfully transfected by TGF-β1 recombinant lentiviral vectors. Green fluorescence was observed by laser confocal microscope. Western blot showed the optimal value of MOI was 70. The expression of TGF-β1 mRNA was significantly higher in TGF-β1 vector group than in empty vector group and non-transfection group (P lt; 0.05). Immunocytochemistry results revealed positive expression of TGF-β1 protein and collagen type II in BMSCs of TGF-β1 vector group, but negative expression in empty vector group and non-transfection group. At 21 days after transfection, high expression of TGF-β1 protein still could be detected by ELISA in TGF-β1 vector group. Conclusion TGF-β1 gene can be successfully transfected into BMSCs via lentiviral vectors, and long-term stable expression of TGF-β1 protein can be observed, prompting BMSCs differentiation into chondrocytes.
Objective To observe the long-term clinical results of repairing large articular cartilage defects of the hip and the knee with free autogeneous periosteum. Methods Based on the results of experimental studies, the authors used free autogeneous periosteum transplantation and postoperative continuous passive motion (CPM) to repair large articular cartilaginous defects in 52 patientsfrom February 1987 to August 1995. Of 37 patients with complete follow-up data, 16 had congenital dislocation of the hip, 6traumatic arthritis of hip, 1 femoral head destruction following mild infection, 2 ankylosing spondylitis, 6 intra-articular fracture of the knee, 4 arthritisof the knee and 2 stiff knee following joint infection. The patients with dislocation of hip were given relieving traction before operation. The cartilages of pathological changes were excised to bleeding bone. The defects were repairedwith periosteum removing from tibia. CPM were immediately applied for 4-6 weeksand no bearing was allowed 6 months after discharge. The silicon membrane was taken out in the 6th month. Results Thirty-seven patients (17 males, 20 females) were followed up 7-15 years with an average of 10.5 years. The functional evaluation referred to joint pain degree，joint mobile range，daily activity and X-ray findings. The results were excellence in 11 patients , good in 18 patients , poor in 8 patients. Conclusion The method to repair articular cartilage defect with free autogeneous -periosteum is effective and may be applied clinically.
ObjectiveTo evaluate the effect of bone cement filling on articular cartilage injury after curettage of giant cell tumor around the knee. MethodsFifty-three patients with giant cell tumor who accorded with the inclusion criteria were treated between January 2000 and December 2011, and the cl inical data were retrospectively analyzed. There were 30 males and 23 females, aged 16-69 years (mean, 34.2 years). The lesion located at the distal femur in 28 cases and at the proximal tibia in 25 cases. According to Campanacci grade, there were 6 patients at grade I, 38 at grade Ⅱ, and 9 at grade Ⅲ. Of 53 patients, 42 underwent curettage followed by bone cement fill ing, and 11 received curettage followed by bone grafts in the subchondral bony area and bone cement fill ing. Two groups were divided according to whether secondary osteoarthritis occurred or not during postoperative follow-up. The gender, age, lesion site, the subchondral residual bone thickness, tumor cross section, preoperative Campanacci grade, subchondral bone graft, and Enneking function score were compared between 2 groups, and multivariate logistic regression analysis was done. ResultsAll incisions healed by first intention. The average follow-up time was 65 months (range, 23-158 months). Of 53 cases, 37 (69.8%) had no osteoarthritis, and 16 (30.2%) had secondary osteoarthritis. Three cases (5.7%) recurred during the follow-up period. Univariate logistic regression analysis showed no significant difference in gender, age, lesion site, and Campanacci grade between 2 groups (P>0.1); difference was significant in the subchondral residual bone thickness, tumor cross section, Enneking function score, and subchondral bone graft (P<0.1). The multivariate logistic regression analysis showed that the decreased subchondral residual bone thickness, the increased tumor cross section, and no subchondral bone graft are the risk factors of postoperative secondary osteoarthritis (P<0.05). ConclusionCurettage of giant cell tumor around the knee followed by bone cement filling can increase the damage of cartilage, and subchondral bone graft can delay or reduce cartilage injury.
ObjectiveTo review the research progress of different cell seeding densities and cell ratios in cartilage tissue engineering. MethodsThe literature about tissue engineered cartilage constructed with three-dimensional scaffold was extensively reviewed, and the seeding densities and ratios of most commonly used seed cells were summarized. ResultsArticular chondrocytes (ACHs) and bone marrow mesenchymal stem cells (BMSCs) are the most commonly used seed cells, and they can induce hyaline cartilage formation in vitro and in vivo. Cell seeding density and cell ratio both play important roles in cartilage formation. Tissue engineered cartilage with good quality can be produced when the cell seeding density of ACHs or BMSCs reaches or exceeds that in normal articular cartilage. Under the same culture conditions, the ability of pure BMSCs to build hyaline cartilage is weeker than that of pure ACHs or co-culture of both. ConclusionDue to the effect of scaffold materials, growth factors, and cell passages, optimal cell seeding density and cell ratio need further study.
In order to observe the histological changes of the autogenous perichondrium graft from rib in the repair of injured articular cartilage of the condylar process of mandible, 50 rabbits were used, in which 15 were served as control. The articular cartilage with its subchondral bone were resected and an autogenous graft of costal perichondrium was sutured onto the raw surface of the condylar process, and in the controls, only the articular portion of the condylar process was resected without the application of autogenous costal perichondrium graft. The morphological changes of the newly formed cartilage during the process of its development were investigated by hiostological and autoradiog aphic techniques. The result revealed that 10 days after operation, the graft had increased in thickness and was richly populated form the proliferation of mesenchyme-like cells. Twenty to thirty days later, the chondrocytes were matured and the newly formed cartilage had covered the bony surface of mandibular condyle. At 60 days, the newly formed cartilagenous joint surface became glossy, and the morphology and arrangement of cells tended to be regular simulating the morphology of normal articular cartilage. From the experiment, it could be concluded that (1) The autogenous perichondrium graft placed on the condylar surface of mandible could form new articular cartilage which was similar in tissue morphology to the normal condylar cartilage. (2) The process of development of newly formed cartilage was similar to that of the normal cartilage. (3) The motion and loading on the joint could promote the formation of new cartilage and undergo biological reformation, gradually resulting in normal joint morphology. On this basis, the clinical application of autogenous perichondrium graft to repair injured cartilage of the condylar process of the mandible was feasible.
Cartilage surface fibrosis is an early sign of osteoarthritis and cartilage surface damage is closely related to load. The purpose of this study was to study the relationship between cartilage surface roughness and load. By applying impact, compression and fatigue loads on fresh porcine articular cartilage, the rough value of cartilage surface was measured at an interval of 10 min each time and the change rule of roughness before and after loading was obtained. It was found that the load increased the roughness of cartilage surface and the increased value was related to the load size. The time of roughness returning to the initial condition was related to the load type and the load size. The impact load had the greatest influence on the roughness of cartilage surface, followed by the severe fatigue load, compression load and mild fatigue load. This article provides reference data for revealing the pathogenesis of early osteoarthritis and preventing and treating articular cartilage diseases.
OBJECTIVE To investigate the feasibility of repairing the whole layer defects of tibial plateau by implanting tissue-engineering cartilage. METHODS: The chondrocytes of 2-week-old rabbits were cultured and transferred to the 3rd generation, and mixed with human placenta collagen-sponge. The whole layer defects of tibial plateau in adult rabbits were repaired by the tissue-engineering cartilage in the experimental group; the defects were left un-repaired in control group. The repair results of defects were observed after 4, 12 and 24 weeks. RESULTS: In experimental group, no obvious new cartilage formation was seen 4 weeks after operation; some new cartilage formation was found after 12 weeks. Histological observation showed that chondrocytes had irregular edge, honeycombing structure and that cartilage cavities formed around the chondrocytes. After 24 weeks, obvious new cartilage formation was found with smooth surface, and linked with the tissues around it, but the defect was not repaired completely; histological results showed that cartilage cavities formed and that cartilage matrix was stained positively for toluidine blue. In control group, the defect was not repaired. CONCLUSION: The tissue-engineering cartilage can repair the defects of the whole layer cartilage of tibial plateau in rabbits, it is feasible to repair the whole layer cartilage defects of tibial plateau by this method.
Objective To construct a new type of self-assembling peptide nanofiber scaffolds—RGDmx, and to study the cell compatibility of the new scaffolds and the proliferation and chondrogenic differentiation of precartilaginous stem cells(PSCs) in scaffolds. Methods PSCs were separated and purified from newborn Sprague Dawley rats by magnetic activated cell sorting and indentified by immunohistochemistry and immunofluorescent staining. The RGDmx were constructed by mixing KLD-12 and KLD-12-PRG at volume ratio of 1 ∶ 1. PSCs at passage 3 were seeded into the KLD-12 scaffold (control group) and RGDmx scaffold (experimental group). The proliferation of PSCs in 2 groups were observed with the method of cell counting kit (CCK) -8 after 1, 3, 7, and 14 days after culture. The RGDmx were constructed by mixing KLD-12-PRG and KLD-12 at different volume ratios of 0, 20%, 40%, 60%, 80%, and 100% and the prol iferation of PSCs was also observed. The complete chondrogenic medium (CCM) was used to induce chondrogenic differentiation of PSCs in different scaffolds. The differentiation of PSCs was observed by toluidine blue staining and RT-PCR assay. Results PSCs were separated and purified successfully, which were identified by immunohistochemistry and immunofluorescent staining methods. The results of CCK-8 showed that the absorbance (A) value in the experimental group increased gradually and reached the highest at 7 days; the A value in the experimental group was significantly higher than that in the control group at 7 days and 14 days (P lt; 0.05). Meanwhile, the A value in the RGDmx scaffold with a volume ratio of 40% was significantly higher than those in others (P lt; 0.05). After 14 days of induction culture with CCM, the toluidine blue staining results were positive in 2 groups; the results of RT-PCR showedthat the expression levels of collagen type II and the aggrecan in the experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion The self-assembling peptide nanofiber scaffold—RGDmx is an ideal scaffold for tissue engineer because it has good cell compatibility and more effective properties of promoting the differentiation of PSCs to chondrocytes.