ObjectiveTo summarize the application status and progress of platelet-rich plasma (PRP) in clinical orthopedics. MethodsThe recent related literature concerning the application of PRP in clinical orthopedics was extensively reviewed and analyzed. ResultsRecently, a large number of clinical studies on PRP have been carried out, which are applied in bone defects or nonunion, spinal fusion, osteoarthritis and cartilage injuries, ligament reconstruction, muscle strain, tendon terminal diseases, and a variety of acute and chronic soft tissue injuries. Some results show certain effectiveness, while others demonstrate invalid. ConclusionEasily drawing, achieving autologous transplantation, and the biological repair potential of the musculoskeletal tissues make PRP to be widely used in clinical orthopedics. However, there are still no uniform standards accepted and reliable clinical guidelines about the application of PRP. Furthermore, a variety of PRP products and their respective indications are also different. The clinical evidences with the greater sample size and higher quality are still needed to further support the safety and effectiveness of PRP in clinical orthopedics.
ObjectiveTo investigate whether subchondral bone microstructural parameters are related to cartilage repair during large osteochondral defect repairing based on three-dimensional (3-D) printing technique. MethodsBiomimetic biphasic osteochondral composite scaffolds were fabricated by using 3-D printing technique. The right trochlea critical sized defects (4.8 mm in diameter, 7.5 mm in depth) were created in 40 New Zealand white rabbits (aged 6 months, weighing 2.5-3.5 kg). Biomimetic biphasic osteochondral composite scaffolds were implanted into the defects in the experimental group (n=35), and no composite scaffolds implantation served as control group (n=5); the left side had no defect as sham-operation group. Animals of experimental and sham-operation groups were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after operation, while animals of control group were sampled at 24 weeks. Subchondral bone microstructural parameters and cartilage repair were quantitatively analyzed using Micro-CT and Wayne scoring system. Correlation analysis and regression analysis were applied to reveal the relationship between subchondral bone parameters and cartilage repair. The subchondral bone parameters included bone volume fraction (BV/TV), bone surface area fraction (BSA/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular spacing (Tb.Sp). ResultsIn the experimental group, articular cartilage repair was significantly improved at 52 weeks postoperatively, which was dominated by hyaline cartilage tissue, and tidal line formed. Wayne scores at 24 and 52 weeks were significantly higher than that at 16 weeks in the experimental group (P<0.05), but no significant difference was found between at 24 and 52 weeks (P>0.05); the scores of experimental group were significantly lower than those of sham-operation group at all time points (P<0.05). In the experimental group, new subchondral bone migrated from the surrounding defect to the centre, and subchondral bony plate formed at 24 and 52 weeks. The microstructural parameters of repaired subchondral bone followed a "twin peaks" like discipline to which BV/TV, BSA/BV, and Tb.N increased at 2 and 16 weeks, and then they returned to normal level. The Tb.Sp showed reversed discipline compared to the former 3 parameters, no significant change was found for Tb.Th during the repair process. Correlation analysis showed that BV/TV, BSA/BV, Tb.Th, Tb.N, and Tb.Sp were all related with gross appearance score and histology score of repaired cartilage. ConclusionSubchondral bone parameters are related with cartilage repair in critical size osteochondral repair in vivo. Microstructural parameters of repaired subchondral bone follow a "twin peaks" like discipline (osteoplasia-remodeling-osteoplasia-remodeling) to achieve reconstruction, 2nd week and 16th week are critical time points for subchondral bone functional restoration.
ObjectiveTo summarize the tissue engineering techniques for cartilage repair on the combination fields of the three elements of tissue engineering:cells, scaffolds and signals. MethodsThe literature on cell-scaffold-based cartilage repair techniques, cell-free scaffolds, and scaffold-free approaches was reviewed and summarized. ResultsThe cell-scaffold-based cartilage repair techniques such as matrix-induced autologous chondrocyte implantation (chondrocytes are seeded on the scaffold) are able to enhance the survival of the cells; cell-free scaffolds can promote cell recruitment with chemoatractants; and scaffold-free approaches have better hyaline-like properties and can avoid the toxic effect of scaffold degradation products. ConclusionCombination fields of the three elements of tissue engineering provide a more biomimetic environment for cartilage repair and have broad prospects.
ObjectiveTo summarize the recent progress of the controlled releasing delivery of biological factors for cartilage repair. MethodsThe recently published 1iterature at home and abroad on the controlled releasing delivery of biological factors for cartilage repair was reviewed and summarized. ResultsVarious biological factors have been applied for repairing cartilage. For better cartilage repair effects, controlled releasing delivery of biological factors can be applied by means of combining biological factors with degradable biomaterials, or by micro- and nano-particles. Meanwhile, multiple biologic delivery and temporally controlled delivery are also inevitable choices. ConclusionAlthough lots of unsolved problems exist, the controlled releasing delivery of biological factors has been a research focus for cartilage repair because of the controllability and delicacy.
ObjectiveTo isolate and identify the cartilage progenitor cells (CPCs) from normal cartilage, and to explore the influence of interleukin 1β (IL-1β) in different concentrations on its chondrogenesis. MethodsCPCs were isolated from normal cartilage of adult New Zealand white rabbit with the fibronectin adhesion assay;the cell phenotype was identified;and the cloning and differentiation of CPCs were observed. CPCs were incubated with H-DMEM in group A, with chondrogenic induced medium in group B, with chondrogenic induced medium+0.1 ng/mL IL-1β in group C and chondrogenic induced medium+1.0 ng/mL IL-1β in group D for 3 weeks. The histology, biochemistry, and real-time fluorescence quantitative PCR were performed to observe the effect of IL-1β on the chondrgenic differentiation. ResultsThe CPCs from normal cartilage expressed positively stem cell phenotype, which have similar ability of cloning and differentiation to stem cells. The cell pellets in groups C and D were significantly smaller than those in group B, and cell showed hypertrophic morphology change. There were more expressions of collagen type Ⅱ and collagen type X in group B than in group A, in group B than in groups C and D, and in group C than group D with Safranin O staining. The biochemistry results showed that collagen type Ⅱ content, glycosaminoglycan (GAG) content, and the ratio of GAG/DNA were significantly lower in groups C and D than in group B (P<0.05), and in group D than in group C (P<0.05);but the DNA content was significantly higher in groups C and D than in group B (P<0.05), and no significant difference between groups C and D (P>0.05). The real-time fluorescence quantitative PCR results showed that the relative mRNA expressions of collagen type Ⅱ, collagen type X, and Sox-9 were significantly lower in groups C and D than in group B (P<0.05), and in group D than in group C (P<0.05), but the relative mRNA expressions of Runx-2 and matrix metalloproteinase 13 were significantly higher in groups C and D than in group B (P<0.05), and in group D than in group C (P<0.05). ConclusionThere are CPCs having the character of stem cells in normal cartilage, and they have the capability of cloning and potential differentiation. IL-1β can inhibit the chondrogenesis of CPCs, and possibly promote the osteogenic differentiation.
ObjectiveTo discuss the effect of glucosamine-hydrochloride (Glu/Ch) in protecting and repairing the cartilage in blood-induced joint damage (BJD) in vivo. MethodsThirty-two adult New Zealand rabbits were randomly divided into 4 groups (n=8):high-dose Glu/Ch treated group (group A), low-dose Glu/Ch treated group (group B), positive control group (group C), and negative control group (group D). A joint bleeding model was established by blood injection into articular cavity in groups A, B, and C. Glu/Ch was given by gavage in groups A (250 mg/kg) and B (21.5 mg/kg) once a day for 8 weeks, and the same dosage of saline was given in groups C and D. The serum cartilage oligomeric matrix protein (COMP), serum chondroitin sulfate 846(CS846), and urinary C-terminal telopepide of type II collagen (CTX-II) were measured at 3 days, 7 days, 2 weeks, and 8 weeks after modeling. The expressions of cytokines such as interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) in synovial fluid were analyzed by ELISA at 8 weeks after modeling. The expression of matrix metalloproteinase 13(MMP-13) was detected by immunohistochemistry. Alcian blue staining and Safranin-O staining were performed to calculate the percentage of the positive staining areas. The proteoglycan content was detected by semi-quantitative analysis in the articular cartilage. ResultsThe COMP concentration was significantly higher in groups A, B, and C than group D, and in groups B and C than group A at 3 days after modeling (P<0.05); no significant difference was found among groups A, B, and D at 7 days (P>0.05), and it was significantly lower in groups A, B, and D than group C (P<0.05); there was no significant difference among 4 groups after 2 and 8 weeks (P>0.05). Difference in CS846 concentration had no significance among 4 groups at each time point (P>0.05). The CTX-II concentration of groups A, B, and C was significantly higher than that of group D at each time point (P<0.05); it was significantly lower in group A than groups B and C at 7 days, 2 weeks, and 8 weeks (P<0.05). The TNF-α concentration of groups A and B was significantly higher than group D, and was significantly lower than group C at 8 weeks (P<0.05), but no significant difference was observed between groups A and B (P>0.05). The IL-1β concentration was significantly higher in group C than the other groups (P<0.05), and in group B than groups A and D (P<0.05), but there was no significant difference between groups A and D (P>0.05). The MMP-13 expression was significantly higher in group C than groups A, B, and D (P<0.05), in groups A and B than group D (P<0.05). A significant decrease in the area stained with Alcian blue and Safranin-O was observed in group C. There were significant differences in the percentage of the positive stained areas of Alcian blue and Safranin-O among 4 groups (P<0.05). The relative quantities of proteoglycan from small to large in order was groups C, B, A, and D, respectively, showing significant differences (P<0.05). ConclusionThe metabolism disorder of cartilage matrix and synovium inflammatory reaction can be observed in rat joint bleeding model. Glu/Ch has certain protective effect on the cartilage after BJD by down-regulating IL-1β, TNF-α, and MMP-13, as well as increasing proteoglycan content in the cartilage.