Objective To summarize the recent development on chondroprotective effect of alendronate (ALN) on articular cartilage in osteoarthritis (OA). Methods The related literature was reviewed and the main achievements in vitro/vivo studies in the fields were summarized. Results ALN can improve the metabolic microenvironment of the articular cartilage in OA, inhibit subchondral bone remodeling, so it has potential protective effect on articular cartilage. Conclusion ALN is expected to become a disease-modifying OA drug in future, but OA treatment still lack a uniform basic and clinical evaluation criteria, so it has guiding significance in development and application of ALN to develope a uniform standard and obtain the clinical data.
Objective To explore the relationship of the limited resource of the autologous bone marrow mesenchymal stem cells (MSCs) in articularcavity to the treatment results of full-thickness articular cartilage defect, and to investigate whether the extrogenous sodium hyaluronate(SH) promotes the migration of MSCs cultured in vitro tothe articular defect in vivo. Methods Sixty-six Japan rabbits were made the model of the full-thickness articular cartilage defect (5 mm width and 4 mm depth).The autologous MSCs were extracted from the rabbit femur, cultured in vitro, labeledby Brdu, and injected into the injured articular cavity with or without SH. Theexperiment was divided into 4 groups; group A (MSCs and SH, n=15); group B (MSCs, n=15); group C (SH, n=18); and group D (non-treatment, n=18). The morphologic observation was made by HE staining, Mallory staining and immunohistochemical staining after 5 weeks, 8 weeks and 12 weeks of operation. Results There were significant differences in the thickness of repairing tissue between group A and group B(Plt;0.01); but there were no significant differences between group A and group C, and between group B and group D(P＞0.05). Thehistological observation showed that the main repairing tissue was fibrocartilage in group A and fiber tissue in group B. Conclusion MSCs cultured in vitro and injected into the articular cavity can not improve the treatment results of the articular cartilage defect. Extrogenous SH has effect on repairing cartilage defect. The extrogenous SH has no effect on the chemotaxis of the MSCs, and on the collection of MSCs into the joint defect.
OBJECTIVE: To study the feasibility of the formation of allogeneic tissue-engineered cartilage of certain shape in immunocompetent animal using the injectable biomaterial. METHODS: Fresh newborn rabbits’ articular cartilages were obtained under sterile condition (lt; 6 hours after death) and incubated in the sterile 0.3% type II collagenase solution. After digestion of 8 to 12 hours, the solution was filtered through a 150 micron nylon mesh and centrifuged, then the chondrocytes were washed twice with phosphate buffered saline (PBS) and mixed with the biomaterial to create a final cell density of 5 x 107/ml. The cell-biomaterial admixture was injected into rabbits subcutaneously 0.3 ml each point while we drew the needle back in order to form the neocartilage in the shape of cudgel, and the control groups were injected with only the biomaterial or the suspension of chondrocytes with the density of 5 x 10(7)/ml. After 4, 6, 8 and 12 weeks, the neocartilages were harvested to analyze. RESULTS: The new nodes could be touched subcutaneously after 2 weeks. In the sections of the samples harvested after 4 weeks, it was found that the matrix secreted and the collagen formed. After 6 weeks and later than that, the neocartilages were mature and the biomaterial was almost completely degraded. The cudgel-shaped samples of neocartilage could be formed by injection. In the experiment group, there was no obvious immune rejection response. On the contrary, there were no neocartilage formed in the control group. CONCLUSION: The injectable biomaterial is a relatively ideal biomaterial for tissue engineering, and it is feasible to form allogeneic tissue engineered cartilage of certain shape by injection in an immunocompetent animal.
Objective To investigate the effect of homograft of marrow mesenchymal stem cells (MSCs) seeded onto poly-L-lactic acid (PLLA)/gelatin on repair of articular cartilage defects. Methods The MSCs derived from36 Qingzilan rabbits, aging 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitroand seeded onto PLLA/gelatin. The MSCs/ PLLA/gelatin composite was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty-six healthy Qingzilan rabbits were made models of cartilage defects in the intercondylar fossa. These rabbits were divided into 3 groups according to the repair materials with 12 in each group: group A, MSCs and PLLA/gelatin complex(MSCs/ PLLA/gelatin); group B, only PLLA/gelatin; and group C, nothing. At 4,8 and 12 weeks after operation, the gross, histological and immunohistochemical observations were made, and grading scales were evaluated. Results At 12 weeks after transplantation, defect was repaired and the structures of the cartilage surface and normal cartilage was in integrity. The defects in group A were repaired by the hylinelike tissue and defects in groups B and C were repaired by the fibrous tissues. Immunohistochemical staining showed that cells in the zones of repaired tissues were larger in size, arranged columnedly, riched in collagen Ⅱ matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in group A at 12 weeks postoperatively. In gross score, group A(2.75±0.89) was significantly better than group B (4.88±1.25) and group C (7.38±1.18) 12 weeks afteroperation, showing significant differences (P＜0.05); in histological score, group A (3.88±1.36) was better than group B (8.38±1.06) and group C (13.13±1.96), and group B was better than group C, showing significant differences (P＜0.05). Conclusion Transplantation of mesenchymal stem cells seeded onto PLLA/gelatin is a promising way for the treatment of cartilage defects.
Objective To study the biological characteristic and potential of chondrocytes grafting cultured on fascia in repairing large defect of articular cartilage in rabbits. Methods Chondrocytes of young rabbits were isolated and subcultured on fascia. The large defect of articular cartilage was repaired by grafts of freeze-preserved and fresh chondrocytes cultured on fascia, and free chondrocytes respectively; the biological characteristic and metabolism were evaluated bymacroscopic, histological and immunohistochemical observations, autoradiography method and the measurement of nitric oxide content 6, 12, 24 weeks after grafting. Results The chondrocytes cultured on fascia maintained normal growth feature and metabolism, and there was no damage to chondrocytes after cryopreservation; the repaired cartilage was similar to the normal cartilage in cellular morphology and biological characteristics. Conclusion Chondrocytes could be cultured normally on fascia, which could be used as an ideal carrier of chondrocytes.
OBJECTIVE This paper aims to investigate the suitable cell density and the best formation time of tissue engineered autologous cartilage and to provide theoretical basis and parameters for clinical application. METHODS The chondrocytes isolated from mini swines’ ears were mixed with injectable biocompatible matrix (Pluronic), and the density of cell suspensions were 10, 20, 30, 40, 50, 60, 70 x 10(4)/ml. The chondrocyte-polymer constructs were subcutaneously injected into the abdomen of autologous swine. The specimens were observed grossly and histologically after 6 weeks, and investigated the suitable cell density. Then the chondrocyte-polymer constructs with suitable cell density were transplanted into the abdomen of autologous swine and evaluated grossly and histologically in 1, 3, 6, 9, 15 weeks after transplantation to investigate the best formation time of tissue engineered cartilage. RESULTS The experiments demonstrated that the tissue engineered autologous cartilage was similar to the natural cartilage on animals with normal immune system in histological characteristics. The optimal chondrocyte density is 50 x 10(6)/ml, and the proper harvest time is the sixth week. CONCLUSION With tissue engineering skills, we have identified the optimal chondrocyte density and the proper harvest time.
Objective To evaluate the immunological reaction and the outcome of allogeneic chondrocyte transplantation in repairing articular cartilage defects in porcins. Methods Full articular cartilage from the knee of two Shanghai white porcins about one-month-old was removed and cut mechanically, digested by 0.25% trypsin and 0.2% type Ⅱ collagenase and cultured in 10％ DMEM medium. Defects of 0.5 cm×0.5 cm involving the subchodral bone were created in both the left and right femur condyloid in 8 two-month-old Yunnai bama porcins. Allogeneic chondrocyte transplantation were implanted in defects at a density of (1.0-2.0)×106,0.2 ml. The lymphocytes from the receivers’ blood were collected before transplantation and after 3, 5, 7 and 12 weeks of transplantation, then mixed with allogeneic chondrocytes to determin the lymphocyte stimulation index(SI) in vitro. The histological observation in vivo was made after 5, 7 and 24 weeks of transplantation. Results Lymphocyte SI at 3, 5, 7 and 12 weeks(1.457±0.062,1.739±0.142,1.548±0.047，1.216±0.028) after transplantation was higher than that before transplantation(1.102±0.034，Plt;0.05). SI began to increase in the 3rd week and reached the peak value in the 5th week, then gradually declined at the 7th and 12th weeks, showing significant differences when compared with in the 5th week (Plt;0.05). Inflammation and lymphocytes infiltration could be seen in subchondral bone and the intergration area between repair tissue and normal cartilage in the 5th week, and then decreased and limited in subchondral bone in the 7th week. Defects were filled with cartilage tissue, which had good intergration with subchondral bone at 24 weeks after transplantation. Conclusion Immunological reactions can be found at early stage of allogeneic chondrocyte transplantation and then decreased with the time, the fullthickness articular cartilage defects could be repaired mainlywith hyaline cartilage by the allogeneic chondrocyte transplantation. This may provide a new method to repair articular cartilage defects clinically.
OBJECTIVE To present a simple and reliable method for the reconstruction of metacarpophalangeal joint by the cartilage transplantation of metatarsophalangeal joint. METHODS From 1990, nine cases (11 sides) with traumatic metacarpophalangeal joint defect were treated by the autogenous cartilage transplantation of metatarsophalangeal joint followed by modified treatment. Appropriate biological mechanics was provided by internal fixation and collateral ligament repair. RESULTS Followed up 6 months to 7 years, the range of joint motion was increased 35.1 degrees. The fusion of donor phalanges was fine, and the range of joint motion was decreased, even ankylosis after plastic operation, but no pain and no effect on walk. CONCLUSION The key to successful operation is better matching of cartilage, reliable internal fixation, ligament reconstruction, thin cartilage and little bone of the donor, appropriate biological mechanical surroundings.
ObjectiveTo summarize the research progress of microRNA (miRNA) in the osteoarthritis (OA) cartilage matrix degradation. MethodsThe domestic and foreign related literature about the miRNA in the OA cartilage matrix degradation was reviewed, summarized, and analyzed. ResultsOA is a common chronic joint disease characterized by cartilage degeneration, its etiology and pathogenesis are still not completely clear. miRNA, a kind of small single stranded non-coding RNA molecule, is closely correlated with inflammatory mediators and various cytokines during the cartilage matrix degradation, suggesting that miRNAs have important regulatory functions at the molecule and cellular levels. ConclusionmiRNA can serve as potential biomarkers and will give new insight into diagnosis and therapeutic strategies in OA.
【Abstract】 Objective To compare the effect of PLGA and collagen sponge combined with rhBMP-2 on repairing ofarticular cartilage defect in rabbits respectively. Methods PLGA and collagen sponge were made into cyl inders which were 4 mm in diameter and 3 mm in thickness, and compounded with rhBMP-2 (0.5 mg). Defect 4 mm in diameter were made in both of femoral condyles of 24 two-month-old New Zealand white rabbits. The defects in right 18 knees were treated with PLGA/rhBMP-2 composites (experimental group 1), and the left 18 knees were treated with collagen sponge/rhBMP-2 composites (experimental group 2), the other 12 knees were left untreated as control group. At 4, 12 and 24 weeks after operation, the animals were sacrificed and the newly formed tissues were observed macroscopically and microscopically, graded histologically and analyzed statistically. Results From the results of macroscopical and microscopical observation, in the experimental group 1, the defects were filled with smooth and translucent cartilage; while in the experimental group 2, the white translucent tissues did notfill the defects completely; and in the two experimental groups, the new cartilage tissues demarcated from the surrounding cartilage,chondrocytes distributed uniformly but without direction; a l ittle fibrous tissue formed in the control group 4 weeks postoperatively. In the experimental group 1, the defects were filled completely with white, smooth and translucent cartilage tissue without clear l imit with normal cartilage; while in the experimental group 2, white translucent tissues formed, the boundary still could be recognized; in the two experimental groups, the thickness was similar to that of the normal cartilage; the cells paralleled to articular surface in the surface layer, but in the deep layer, the cells distributed confusedly, the staining of matrix was positive but a l ittle weak; subchondral bone and tide mark recovered and the new tissue finely incorporated with normal cartilage;however, in the control group, there was a l ittle of discontinuous fibrous tissue, chondrocytes maldistributed in the border andthe bottom of the defects 12 weeks postoperatively. In the experimental group 1, white translucent cartilage tissues formed, the boundary disappeared; in the experimental group 2, the color and the qual ity of new cartilage were similar to those of 12 weeks; in the two experimental groups, the thickness of the new cartilage, which appeared smooth, was similar to that of the normal cartilage, the chondrocytes arranged uniformly but confusedly; the staining of matrix was positive and subchondral bone and tide mark recovered, the new tissue finely incorporated with normal cartilage; in the control group, a layer of discontinuous fibrous tissue formed in the bottom of the defects 24 weeks postoperatively. Results of histological grade showed that there were significantdifference between experimental group (1 and 2) and control group at any time point (P lt; 0.01); the scores of 12 weeks and 24 weeks in experimental group 1 and 2 had a significant difference compared with that of 4 weeks (P lt; 0.01), there was no significant difference between 12 weeks and 24 weeks (P gt; 0.05), and there were no significant difference between the two experimental groups at the same time point (P gt; 0.05). Conclusion Both PLGA and collagen sponge as a carrier compounded with rhBMP-2 can repair articular cartilage defects.