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 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 explore the methods of repairing cartilagedefects and to introduce the clinical experience with the autologous osteochondral transplantation. Methods Twenty-five patients with chondral and osteochondral defects of the weight-bearing surfaces were treated by the autologous osteochondral transplantation for the repair of the chondral and osteochondral defects of the unweightbearing surfaces under arthroscope. According to the shape of the defects, the different dimensions of the osteochondral autograft were selected. All the patients began the training of the continuous passive motion after operation. Six weeks after operation, the patients began to walk in the weightbearing habitus. However, in the control group, another 25 patients were retrospectively analyzed, who had chondral and osteochondral defects of the weight-bearing surfaces but were treated only by the cleaning and drilling procedures. The scores evaluated bythe Brittberg-Peterson scoring scale of the 2 group were 98.65±9.87 and 96.98±8.94 respectively. Results The follow-upfor 3-24 months after operation revealed that the treated knee joint had a goodmotion extent. The pain was obviously alleviated. Based on the longitudinal study with the three-dimensional spoiled magnetic resonance imaging (MRI), the signal intensity of the repaired tissues approached to the normal condition. The scores evaluated by the Brittberg-Peterson scoring scale were almost zero 3 monthsafter operation in the experimental group, and the scores were 58.48±6.98 inthe control group. There were significant differences between the experimental group and the control group(P＜0.01). Conclusion Autologous osteochondral transplanation under arthroscope is a good curative method for the cartilage defects, with advantages of minimal invasiveness and avoidanceofrejections resulting from allografts. However, its long-term effect needs to befurther studied. The conventional therapies including cleaning and drilling are useful in alleviating the symptoms.
Objective To investigate the curative effects of homograft of the mesenchymal stem cells(MSCs) compbined with the medical collagen membrane of the guided tissue regeneration(MCMG) on the full thickness defects of the articular cartilage. Methods MSCs derived from New Zealand rabbits aged 3-4 months weighing 2.1-3.4 kg were cultured in vitro with a density of 5.5×108/ml and seeded onto MCMG. The MSC/MCMG complex was cultured for 48 h and transplanted into the fullthickness defects on the inboardcondyle and trochlea. Twenty-seven healthy New Zealand rabbits were randomly divided into 3 groups of 9rabbits in each. The cartilage defects in the inboard condyle and trochlea werefilled with the auto bone marrow MSCs and MCMG complex (MSCs/ MCMG) in Group A (Management A), with only MCMG in Group B (Management B)and with nothing in Group C (Management C). Three rabbits were killed at 4, 8 and 12 weeks after operation in each group, and the reparative tissue samples evaluated grossly,histologically and immunohistochemically were graded according tothe gross and histological scale. Results Four weeks after transplantation, the cartilage and subchondralbone were regenerated in Group A;for 12 weeks, the regenerated cartilage gradually thicked; 12 week after transplantation, the defect was repaired and the structures of the carticular surface and subchondral bone was in integrity.The defects in Group A were repaired by the hylinelike tissue and the defects in Groups B and C were repaired by the fibrous tissues. Glycosaminoglycan and type Ⅱcollagen in Groups A,B and C were reduced gradually.The statistical analysis on the gross at 12 weeks and the histologicalgradings at 4 weeks,8 weeks and 12 weeks showed that the inboardcondylar repairhad no significant difference compared with the rochlearepair(Pgt;0.05).Management A was significantly better than Managements B and C (Plt;0.05), and Management B was better than Management C(Plt;0.05). Conclusion Transplantation of the MSCs combined with MCMG on the full thickness defects of the articular cartilage is a promising approach to the the treatment of cartilage defects. MCMG can satisfy the demands of the scaffold for the tissue-engineered cartilage.
Objective To investigate the clinical application of periosteal autograft in repair of cartilage defect caused by osteoarthritis of knee. Methods From 1996 to 1999, 36 knees of cartilage defect of knee joint in 28 cases were treated. In the operation, the cracked degenerative cartilage was removed before free periosteum from tibia was transplanted to repair the defect, and the meniscuses in 8 knees of the 36 knees were reconstructed. After operation, early continuous passive movement was adopted for 4 weeks, and 8 knees with reconstruction ofthe meniscus were immobilized by plaster splint for 7 days after operation and before passive movement. All of the cases were followed up for 1 to 4 years before clinical evaluation in symptoms, signs and radiological findings. Results The general satisfactory rate was 86.1%, in which the function was excellent in 22 knees and good in 9 knees. Conclusion The periosteal autograft is a good choice for repairing cartilage defect due to osteoarthritis, with a satisfactory outcomein the short term.
Objective To explore the effect of tissue engineered cartilage reconstructed by using sodium alginate hydrogel and SIS complex as scaffold material and chondrocyte as seed cell on the repair of full-thickness articular cartilage defects. Methods SIS was prepared by custom-made machine and detergent-enzyme treatment. Full-thickness articularcartilage of loading surface of the humeral head and the femoral condyle obtained from 8 New Zealand white rabbits (2-3weeks old) was used to culture chondrocytes in vitro. Rabbit chondrocytes at passage 4 cultured by conventional multipl ication method were diluted by sodium alginate to (5-7) × 107 cells/mL, and then were coated on SIS to prepare chondrocyte-sodium alginate hydrogel-SIS complex. Forty 6-month-old clean grade New Zealand white rabbits weighing 3.0-3.5 kg were randomized into two groups according to different operative methods (n=20 rabbits per group), and full-thickness cartilage defect model of the unilateral knee joint (right or left) was establ ished in every rabbit. In experimental group, the complex was implanted into the defect layer by layer to construct tissue engineered cartilage, and SIS membrane was coated on the surface to fill the defect completely. While in control group, the cartilage defect was filled by sodium alginate hydrogel and was sutured after being coated with SIS membrane without seeding of chondrocyte. General condition of the rabbits after operation was observed. The rabbits in two groups were killed 1, 3, 5, 7, and 9 months after operation, and underwent gross and histology observation. Results Eight rabbits were excluded due to anesthesia death, wound infection and diarrhea death. Sixteen rabbits per group were included in the experiment, and 3, 3, 3, 3, and 4 rabbits from each group were randomly selected and killed 1, 3, 5, 7, and 9 months after operation, respectively. Gross observation and histology Masson trichrome staining: in the experimental group, SIS on the surface of the implant was fused with the host tissue, and the inferface between them disappeared 1 month after operation; part of the implant was chondrified and the interface between the implant and the host tissue was fused 3 months after operation; the implant turned into fibrocartilage 5 months after operation; fiber arrangement of the cartilage in theimplant was close to that of the host tissue 7 months after operation; cartilage fiber in the implant arranged disorderly andactive cell metabol ism and prol iferation were evident 9 months after operation. While in the control group, no repair of thedefect was observed 9 months after operation. No obvious repair was evident in the defects of the control group within 9months after operation. Histomorphometric evaluation demonstrated that the staining intensity per unit area of the reparative tissue in the defect of the experimental group was significant higher than that of the control group at each time point (P lt; 0.05), the chondrification in the experimental group was increased gradually within 3, 5, and 7 months after operation (P lt; 0.05), and it was decreased 9 months after operation comparing with the value at 7 months after operation (P lt; 0.05). Conclusion Constructed by chondrocyte-sodium alginate hydrogel-SIS in complex with surficial suturing of SIS membrane, the tissue engineered cartilage can in-situ repair cartilage defect, promote the regeneration of cartilage tissue, and is in l ine with physiological repair process of articular cartilage.
ObjectiveTo study the effect and feasibility of poly-lactide-co-glycolide (PLGA) loaded with recombinant human bone morphogenetic protein 2 (rhBMP-2) on repairing articular cartilage defect in rabbits. Methods PLGA was made into cylinders which were 4 mm in diameter and 3 mm in thickness. rhBMP-2 was fully homogenated before used. PLGA combined with 0.5 mg rhBMP-2 under the condition of vacuum(700 mmHg),and then lyophilized, packed ,sterilized with ethylene oxide and reserved. Defects of 4 mm in diameter and reaching medullary cavity were made in femoral condyles of 72 two-month-old New Zealand white rabbits. The 36 right defects were repaired with PLGA-rhBMP-2 composites as the experimental group, the 36 left defects with PLGA only as PLGA group, the other 36 left defects were left untreated as control group, and the other 36 right defects with PLGA-MSCs composites as cell group. At 4, 8, 12, 24, 36 and 48 weeks after operation, macroscopical and microscopical observations were made, and the histological grade wasdone.Results After 4 weeks of operation: In the experimental group and cell group, defects were filled with white translucent tissue which appeared smooth and soft; the matrix around chondrocytes was weakly metachromatic, the newly formed cartilage tissue was thicker than normal cartilage tissue; there was no formed tissue in the PLGA group and the blank control group. After 8 weeks of operation: In the experimental group and cell group, the new tissue was white, translucent, tenacious and smooth. The boundary with normal cartilage became vague. New cartilage cells distributed evenly. The cells of the surface layerparalleled, but the deeper layer lost directivity. The matrix dyed weakly. The new cartilage gradually became thinner, but it still thicker than the normal cartilage ones. The PLGA degraded besides some drops.In the blank control group and PLGA group, a little white membrane formed at the bottom of the defect. After 1224 weeks of operation: In the experimental group and cell group, defects were filled with new tissues which were white, translucent, tenacious and smooth. The boundary disappeared.The thickness of the new cartilage was similar to that of the normal ones. The cells of the surface layer paralleled to each other,but the cells of the deeper layer tended to arrange vertically. The matrix around chondrocytes was metachromatic,but the color was lighter than that of the normal cartilage. Bone under the cartilage and the tide mark recovered. The new cartilage linked with nomal cartilage finely.In the blank control group and PLGA group, there was a little fibrous tissue at the bottom of the defect withe obvious boundary. After 36 weeks and 48 weeks of operation：in the experimental group and the cell group, the new cartilage was slightly white，continuous and less smooth. The boundary disappeared. There was no proliferated synovial membrane.The thickenss of the new cartilage was thinner than that of the normal ones. The matrix around chondrocytes was weakly metachromatic. In the blank control group and PLGA group, the defect still existed, but became smaller.At the bottom of the defect, fibrous tissues formed. Some cartilage denudated and became less smooth.Some bone under cartilage exposed,and the synovial membrane became thick. The histologic grade of the repair tissue at 12 weeks and 24 weeks of operation in experimental group and cell group was significantly different from that at 4, 8 and 48 weeks of operation(Plt;0.01). There was also significant difference in the experimental group and cell group compared with the blank control group and PLGA group at each time after operation(Plt;0.01). But there was no significant difference between the experimental group and the cell group. Conclusion In the course of degradation。。。。。。.
OBJECTIVE To evaluate the results of free auto-periosteal graft in primary repair of cartilage defect accompanying severe comminuted fractured of patella. METHODS From January 1992 to August 1998, seventeen cases with extensive cartilage defect due to severe comminuted fracture of patella were primarily repaired with free auto-periosteal graft. In these cases, there were whole patellar fracture in 9 patients, upper two third patellar fracture in 3 patients and lower two third patellar fracture in 5 patients. During operation, "S"-shaped incision along medial side of knee through intra-cavity pathway were used. After fixation of the patellar fracture and clearance of the residual cartilage in the fracture area, the cancellous bone was exposed and trimmed. The free periosteum was incised from the anterior medial side of upper tibia and then transplanted to the region of cartilage defect. The size of grafted periosteum ranged from 3 cm x 4 cm 5 cm 6 x cm. The knee joint was received passive motion at 7 days after operation. RESULTS All cases were followed up 8 to 74 months. There were excellent recovery in 12 patients and the function of knee joint was normal, better recovery in 4 patients and the function of knee joint was nearly normal, and moderate recovery in 1 patient and the function of knee joint was limited mildly. CONCLUSION Free auto-periosteal graft is a simple and effective treatment in primary repair of cartilage defect accompanying patellar fracture. It is valuable to apply in clinical practice.
Objective To evaluate the effect of implantation of the complex of high viscous chitosan/glycerol phosphate with demineral ized bone matrix (HV-C/GP-DBM) in repairing cartilage defects of rabbits. Methods HV-C/ GPDBM was prepared by compounding HV-C/GP and DBM by 2:1 (W/W). Twenty-four 34-week-old New Zealand white adult rabbits, weighing 3.5-4.5 kg, were included. A bit with the diameter of 3.5 mm was used to drill 3-cm-deep holes in both sides of femoral condyle to make cartilage defects. The complex of HV-C/GP-DBM was then injected into the right holes as the experimental group and the left ones serve as the control group. The rabbits were killed at 4, 8 and 16 weeks after theoperation, respectively. The obtained specimens were observed macroscopically, microscopically and histologically. According to the International Cartilage Repair Society Histological Scoring (ICRS), the effect of cartilage repair was assessed at 16 weeks postoperatively. Results At 4-8 weeks postoperatively, in the experimental group, the defects were filled with hyal ine cartilage-l ike tissues; the majority of chitosan degradated; and the DBM particles were partly absorbed. However, in the control group, there were small quantities of discontinuous fibrous tissues and maldistributed chondrocytes at the border and the bottom of the defects. At 16 weeks postoperatively, 6 joints in the experimental group had smooth surface, and the defects were basically repaired by hyal ine cartilage-l ike tissues. The newly-formed tissues integrated well with the surrounding area. Under the cartilage, the new bone formation was still active and some DBM particles could be seen. However, the defects in the control group were repaired by fibrous tissues. The result of histological scoring of the specimens at 16 weeks showed that a total of 6 aspects including formation of chondrocytes and integration with the surrounding cartilages were superior in the experimental group to those in the control group, and there were significant differences between the two groups (P lt; 0.05). Conclusion The biodegradable and injectable complex of HV-C/GP-DBM with good histocompatibil ity and non-toxic side effects can repair cartilage defects and is a promising biomaterial for cartilage defect repair.
Objective To investigate the effect of allogeneic chondrocytes-calcium alginate gel composite under the intervention of low intensive pulsed ultrasound (LIPUS) for repairing rabbit articular cartilage defects. Methods Bilateral knee articular cartilage were harvested from 8 2-week-old New Zealand white rabbits to separate the chondrocytes by mechanical-collagen type II enzyme digestion. The 3rd passage chondrocytes were diluted by 1.2% sodium alginate to 5 × 106 cells/mL, then mixed with CaCl2 solution to prepare chondrocytes-calcium alginate gel composite, which was treated with LIPUS for 3 days (F0: 1 MHz; PRF: 1 kHz; Amp: 60 mW/cm2; Cycle: 50; Time: 20 minutes). An articular cartilage defect of 3 mm in diameter and 3 mm in thickness was established in both knees of 18 New Zealand white rabbits (aged 28-35 weeks; weighing, 2.1-2.8 kg), and divided into 3 groups randomly, 6 rabbits in each group: LIPUS group, common group, and model group. Defect was repaired with LIPUS-intervention gel composite, non LIPUS-intervention gel composite in LIPUS group and common group, respectively; defect was not treated in the model group. The general condition of rabbits was observed after operation. The repair effect was evaluated by gross and histological observations, immunohistochemical staining, and Wakitani score at 8 and 12 weeks after operation. Results Defect was filled with hyaline chondroid tissue and white chondroid tissue in LIPUS and common groups, respectively. LIPUS group was better than common group in the surface smooth degree and the degree of integration with surrounding tissue. Defect was repaired slowly, and the new tissue had poor elasticity in model group. Histological observation and Wakitani score showed that LIPUS group had better repair than common group at 8 and 12 weeks after operation; the repair effect of the 2 groups was significantly better than that of model group (P lt; 0.05); and significant differences in repair effect were found between at 8 and 12 weeks in LIPUS and common groups (P lt; 0.05). The collagen type II positive expression area and absorbance (A) value of LIPUS and common groups were significantly higher than those of model group (P lt; 0.05) at 8 and 12 weeks after operation, and the expression of LIPUS group was superior to that of common group at 12 weeks (P lt; 0.05); and significant differences were found between at 8 and 12 weeks in LIPUS group (P lt; 0.05), but no significant difference between 2 time points in common and model groups (P gt; 0.05). Conclusion Allogeneic chondrocytes-calcium alginate gel composite can effectively repair articular cartilage defect. The effect of LIPUS optimized allogeneic chondrocytes-calcium alginate gel composite is better.