The role of mitochondrial quality control mechanisms in chondrocyte senescence.

Chondrocytes are the exclusive cellular constituents of articular cartilage, and their functional status governs the health of the cartilage. The primary factor contributing to the deterioration of cartilage structure and function is chondrocyte senescence. In hypoxia and hypodextrose environment, chondrocytes heavily rely on glycolysis for energy metabolism. Mitochondria, acting as the regulatory hub for chondrocyte energy metabolism, exhibit dysfunction before chondrocyte senescence, indicating their crucial involvement in the process. Previous research has suggested that molecules associated with mitochondrial quality control mechanisms can effectively restore mitochondrial function and alleviate chondrocyte senescence. However, there remains to be clarity regarding the relationship between mitochondrial quality control mechanisms and differences in efficacy among various target molecules, which pose challenges when evaluating them in chondrocytes. By conducting a comprehensive review of the existing literature on mitochondrial quality control mechanisms and chondrocyte senescence, we gain further insights into this intricate relationship while identifying promising targets that could potentially open up novel avenues for the treatment of chondrocyte senescence.

Tissue adhesive, ROS scavenging and injectable PRP-based 'plasticine' for promoting cartilage repair.

Platelet-rich plasma (PRP) that has various growth factors has been used clinically in cartilage repair. However, the short residence time and release time at the injury site limit its therapeutic effect. The present study fabricated a granular hydrogel that was assembled from gelatin microspheres and tannic acid through their abundant hydrogen bonding. Gelatin microspheres with the gelatin concentration of 10 wt% and the diameter distribution of 1-10 µm were used to assemble by tannic acid to form the granular hydrogel, which exhibited elasticity under low shear strain, but flowability under higher shear strain. The viscosity decreased with the increase in shear rate. Meanwhile, the granular hydrogel exhibited self-healing feature during rheology test. Thus, granular hydrogel carrying PRP not only exhibited well-performed injectability but also performed like a 'plasticine' that possessed good plasticity. The granular hydrogel showed tissue adhesion ability and reactive oxygen species scavenging ability. Granular hydrogel carrying PRP transplanted to full-thickness articular cartilage defects could integrate well with native cartilage, resulting in newly formed cartilage articular fully filled in defects and well-integrated with the native cartilage and subchondral bone. The unique features of the present granular hydrogel, including injectability, plasticity, porous structure, tissue adhesion and reactive oxygen species scavenging provided an ideal PRP carrier toward cartilage tissue engineering.

Treatment of Calcific Insertional Achilles Tendinopathy: Knotless Internal Brace versus Knot-Tying Suture Bridge.

BACKGROUND: This study aimed to compare the knotless internal brace technique and the knot-tying suture bridge technique via the medial approach in the treatment of calcific Achilles tendinopathy. METHODS: The clinical data of 25 cases of calcific Achilles tendinopathy in which nonoperative treatments had failed were retrospectively collected. All the patients received Achilles tendon debridement and Haglund deformity excision through a medial approach, followed by repair using the knotless internal brace technique or the knot-tying suture bridge technique. Pain was evaluated by using the visual analog scale (VAS). The American Orthopedic Foot and Ankle Score (AOFAS) questionnaire was administered preoperatively and postoperatively. RESULTS: The mean follow-up time was 2.6 (range 2-3.5) years. There were no wound complications and no Achilles tendon ruptures. At 1 year postoperatively, the internal brace group was superior to the suture bridge group in terms of the VAS scores (p = 0.003). However, no differences were noticed between the two groups in either the VAS or the AOFAS scores at 2 years postoperatively. CONCLUSIONS: The medial approach in combination with the suture bridge technique was effective in treating calcific Achilles tendinopathy. The knotless internal brace technique involved less pain compared to the knot-tying suture bridge technique only at the early postoperative stage.

Comparison of Femoral Triangle Block in Combination with IPACK to Local Periarticular Injection in Total Knee Arthroplasty.

OBJECTIVE: This article studied the efficacy of two different analgesic methods after unilateral primary total knee arthroplasty (TKA) to find an effective analgesic method. METHODS: A randomized, double-blind, placebo, parallel, and controlled study was performed to evaluate the benefits of combining the femoral triangle block (FTB) and the interspace between the popliteal artery and the capsule of the posterior knee (IPACK). Forty patients diagnosed with knee osteoarthritis and underwent unilateral primary TKA with FTB and IPACK were divided grouped into the experimental group, and 40 patients undergoing TKA with intra-articular cocktail analgesic mixture local injection were grouped into the control group. All patients received the patient-controlled anesthesia pump for analgesia at postoperative 48 hours. The main indexes were postoperative knee joint rest and activity pain (visual analog scale) and muscle strength of the affected limb; secondary indexes were anesthetic consumption, total morphine consumption, range of motion, and complications (such as postoperative nausea and vomiting [PONV]). RESULTS: There was no significant difference in the general data of each treatment group. Compared with the conventional group, the quadriceps muscle strength of the combined FTB and IPACK group was higher with significant statistical differences after surgery (p < 0.05). At postoperative 2, 6, 12, 24, 48, and 72 hours, active pain was better than in the conventional group (p < 0.05). Resting pain was significantly smaller than the traditional group only at postoperative 2, 6, 12, and 48 hours (p < 0.05). Morphine consumption, anesthetics consumption, and hospitalization time were lower than the conventional group, the difference being statistically significant. There were no significant differences between the two groups in postoperative wound healing, infection incidence, blood pressure, heart rate, rash, respiratory depression, deep vein thrombosis, and urinary retention. There were also no significant differences in PONV (p > 0.05). CONCLUSION: Combining FTB and IPACK significantly increased the quadriceps muscle in patients, together with relieving early pain and reducing the amount of anesthetic consumption at different postoperative intervals.

Corrigendum: Disulfiram suppressed peritendinous fibrosis through inhibiting macrophage accumulation and its pro-inflammatory properties in tendon bone healing.

[This corrects the article DOI: 10.3389/fbioe.2022.823933.].

Disulfiram Suppressed Peritendinous Fibrosis Through Inhibiting Macrophage Accumulation and Its Pro-inflammatory Properties in Tendon Bone Healing.

The communication between macrophages and tendon cells plays a critical role in regulating the tendon-healing process. However, the potential mechanisms through which macrophages can control peritendinous fibrosis are unknown. Our data showed a strong pro-inflammatory phenotype of macrophages after a mouse tendon-bone injury. Moreover, by using a small-molecule compound library, we identified an aldehyde dehydrogenase inhibitor, disulfiram (DSF), which can significantly promote the transition of macrophage from M1 to M2 phenotype and decrease macrophage pro-inflammatory phenotype. Mechanistically, DSF targets gasdermin D (GSDMD) to attenuate macrophage cell pyroptosis, interleukin-1ß, and high mobility group box 1 protein release. These pro-inflammatory cytokines and damage-associated molecular patterns are essential for regulating tenocyte and fibroblast proliferation, migration, and fibrotic activity. Deficiency or inhibition of GSDMD significantly suppressed peritendinous fibrosis formation around the injured tendon and was accompanied by increased regenerated bone and fibrocartilage compared with the wild-type littermates. Collectively, these findings reveal a novel pathway of GSDMD-dependent macrophage cell pyroptosis in remodeling fibrogenesis in tendon-bone injury. Thus, GSDMD may represent a potential therapeutic target in tendon-bone healing.

Ubiquitin-specific protease 3 attenuates interleukin-1ß-mediated chondrocyte senescence by deacetylating forkhead box O-3 via sirtuin-3.

Osteoarthritis (OA) affects approximately 12% of the aging Western population. The sirtuin/forkhead box O (SIRT/FOXO) signaling pathway plays essential roles in various biological processes. Despite it has been demonstrated that ubiquitin-specific protease 3 (USP3) inhibits chondrocyte apoptosis induced by interleukin (IL)-1ß, the role of USP3/SIRT3/FOXO3 in the senescence of chondrocytes in OA is unclear. This study initially isolated articular chondrocytes and investigated the role of USP3 in IL-1ß-induced senescence of chondrocytes. After USP3 was overexpressed or silenced by lentivirus, expressions of genes and proteins were detected using quantitative polymerase chain reaction and immunoblotting, respectively. Cell cycle analysis was performed using flow cytometry. Reactive oxygen species (ROS) levels and senescence were analyzed. Then, SIRT3 was inhibited or overexpressed to explore the underlying mechanism. We found that overexpression of USP3 hindered IL-1ß-mediated cell cycle arrest, ROS generation, and chondrocyte senescence. The inhibition of SIRT3 blocked the protective effect of USP3 on cell senescence, whereas the overexpression of SIRT3 abolished USP3-silencing-induced cell senescence. Furthermore, SIRT3 attenuated cell senescence, probably by deacetylating FOXO3. USP3 upregulated SIRT3 to deacetylate FOXO3 and attenuated IL-1ß-induced chondrocyte senescence. This study demonstrated that USP3 probably attenuated IL-1ß-mediated chondrocyte senescence by deacetylating FOXO3 via SIRT3.

Early Efficacy of Type I Collagen-Based Matrix-Assisted Autologous Chondrocyte Transplantation for the Treatment of Articular Cartilage Lesions.

Background: Articular cartilage is a complex structure that allows for low frictional gliding and effective shock absorption. Various sports injuries and inflammatory conditions can lead to lesions in the articular cartilage, which has limited regenerative potential. Type I collagen combined with autologous chondrocytes in a three-dimensional culture were used to induce the regeneration of single-layer autologous expanded chondrocytes without chondrogenic differentiation. Purpose: To assess the clinical, radiological, and histological changes following collagen-based autologous chondrocyte transplantation (MACT) for chondral knee lesions. Methods: The study prospectively enrolled 20 patients with symptomatic knee chondral lesions (mean size lesion was 2.41 ± 0.43 cm2, range: 2.0-3.4 cm2) in the lateral femoral condyle and femoral groove who underwent type I collagen-based MACT between July 2017 and July 2019. knee injury and osteoarthritis outcome score (KOOS) was assessed before the procedure, and periodic clinical follow-up was conducted every 3 months for a maximum of 12 months following the procedure and at 1-year intervals thereafter. Magnetic resonance imaging (MRI) T2 mapping of repaired cartilage was also used for the quantitative analysis of regeneration. In one patient, second-look arthroscopy was performed to assess cartilage regeneration characteristics, and a portion of regenerated cartilage was harvested for histological evaluation 12 months after implantation. Results: At pre-operation and at three, six, 12, and 24 months after the operation, KOOS pain, symptoms, daily life activities, sports and recreation, as well as the quality of life were significantly improved between every two time points. Hematoxylin and eosin (HE) staining indicated that the newly formed cartilage was comprised of naive chondrocytes. Safranin O-fast (S-O) green staining of the regenerated tissue revealed fibroblast-like cells surrounded by glycosaminoglycans. Immunohistochemistry (IHC) analysis indicated that collagen type II was uniformly distributed at the deep zone of articular cartilage and type I collagen mainly depositing in the superficial cartilage layer. The T2 values for repaired tissue gradually decreased, eventually approaching near-average values. Conclusion: The present study demonstrated that type I collagen-based MACT is a clinically effective treatment for improving functionality and pain levels. Histological evidence confirmed hyaline cartilage induction and showed that repaired cartilage tended to emerge from the deep to the superficial layer. The quantitative MRI T2 mapping test indicated that there still was a difference between the transplanted cartilage and the surrounding hyaline cartilage. Taken together, the current method represents an efficient approach for the restoration of knee cartilage lesions.

Exosomes from human umbilical cord mesenchymal stem cells inhibit ROS production and cell apoptosis in human articular chondrocytes via the miR-100-5p/NOX4 axis.

Cyclic strain-induced chondrocyte damage is actively involved in the pathogenesis of osteoarthritis and arthritis. MicroRNAs (miRNAs) carried by exosomes have been implicated in various diseases. However, the role of miR-100-5p in cyclic strain-induced chondrocyte damage remains to be elucidated. miR-100-5p and NADPH oxidase 4 (NOX4) were silenced or overexpressed in human primary articular chondrocytes. PKH-67 Dye was used to trace exosome endocytosis. Reactive oxygen species (ROS) production was monitored using DCFH-DA. Cell apoptosis was measured using a flow cytometer. Quantitative RT-PCR and Western blots were used to evaluate gene expression. Cyclic strain promoted ROS production and apoptosis in primary articular chondrocytes in a time-dependent manner. HucMSCs-derived exosomal miR-100-5p inhibited cyclic strain-induced ROS production and apoptosis in primary articular chondrocytes. miR-100-5p directly targeted NOX4. Overexpressing NOX4 attenuated hucMSCs-derived exosomes-mediated protective effects in primary articular chondrocytes. Cyclic strain promotes ROS production and apoptosis in primary articular chondrocytes, which was abolished by hucMSCs-derived exosomal miR-100-5p through its target NOX4. The findings highlight the importance of miR-100-5p/NOX4 axis in primary articular chondrocytes injury and provide new insights into therapeutic strategies for articular chondrocytes injury and osteoarthritis.

miR-107 affects cartilage matrix degradation in the pathogenesis of knee osteoarthritis by regulating caspase-1.

BACKGROUND: Knee osteoarthritis (KOA) seriously affects the quality of life of KOA patients. This study aimed to investigate whether miR-107 could regulate KOA through pyroptosis to affect collagen protein secreted by chondrocytes through IL-1ß. METHODS: The proliferation of chondrocytes was detected by CCK-8 assay. RT-qPCR analysis was used to identify miR-107 expression and transfection effects. The expression of Col II, IL-1ß, IL-18, and MMP13 in supernatant of chondrocytes or chondrocytes was detected by ELISA assay and western blot analysis. The pyroptosis of chondrocytes was analyzed by TUNEL assay and the expression of pyroptosis-related proteins was analyzed by western blot. Luciferase reporter assay confirmed the relation of miR-107 to caspase-1. RESULTS: The proliferation of chondrocytes was decreased after LPS induction and further decreased by treatment of ATP. Single LPS treatment for chondrocytes downregulated the Col II expression while upregulated the expression of IL-1ß, IL-18, and MMP-13, which was further changed by ATP treatment. miR-107 expression was decreased in chondrocytes induced by LPS and further decreased in chondrocytes induced by LPS and ATP. In addition, miR-107 overexpression increased the proliferation and decreased the pyroptosis of chondrocytes induced by LPS and ATP. miR-107 overexpression upregulated the Col II expression while down-regulated the expression of IL-1ß, IL-18, and MMP-13 in supernatant of chondrocytes or chondrocytes induced by LPS and ATP. miR-107 overexpression down-regulated the expression of caspase-1, c-caspase-1, GSDMD-N, and TLR4 in chondrocytes induced by LPS and ATP. Furthermore, miR-107 directly targeted caspase-1. CONCLUSIONS: miR-107 can protect against KOA by downregulating caspase-1 to decrease pyroptosis, thereby promoting collagen protein secreted by chondrocytes by down-regulating IL-1ß.

Ubiquitin-specific protease 3 targets TRAF6 for deubiquitination and suppresses IL-1ß induced chondrocyte apoptosis.

Traditionally, the development of osteoarthritis (OA) is associated with factors such as aging and injure, but more and more epidemiological and biological evidence suggests that the disease is closely related to metabolic syndrome and metabolic components. Ubiquitin-specific protease 3(USP3), a member of the USPs family, is a specific protease capable of cleavage of ubiquitin chains linked by proline residues. In our presented study, we firstly found that USP3 expression level was decreased in OA. USP3 overexpression inhibited IL-1ß induced chondrocytes apoptosis and nuclear factor κB (NF-κB) activation. USP3 knockdown induced chondrocytes apoptosis and activated NF-κB pathway. USP3 interacts with TRAF6 (tumor necrosis factor-receptor-associated factor 6), which is an essential adaptor protein for the NF-κB (nuclear factor κB) signaling pathway and plays important roles in inflammation and immune response. IL-1ß treatment up-regulated the polyubiquitination of TRAF6 in chondrocytes, which was attenuated when USP3 was forced expression. Our study mechanistically links USP3 to TRAF6 in osteoarthritis development. Moreover, these data support the pursuit of USP3 and TRAF6 as potential targets for osteoarthritis therapies.

MicroRNA-218 promotes early chondrogenesis of mesenchymal stem cells and inhibits later chondrocyte maturation.

BACKGROUND: MicroRNAs (miRNAs) reportedly participate in the mesenchymal stem cell (MSC) chondrogenic differentiation regulation. We objected to examine how miR-218 regulate chondrogenic differentiation of synovium-derived MSCs (SDSCs) and the maturation of RCJ3.1C5.1 chondrocytes. SDSCs were sourced from the knee joint synovium of New Zealand white rabbits, and their multilineage differentiation potentials were examined. The level of miR-218 was measured during SDSC chondrogenic differentiation, together with determination of SDSCs chondrogenic markers and RCJ3.1C5.1 chondrocytes maturation markers expression level after transfection of miR-218 mimics/inhibitor. RESULTS: miR-218 expression was notably upregulated in early chondrogenesis but mostly ceased during the maturation phases of chondrogenic differentiation in SDSCs. The transfection of miR-218 mimics notably enhanced SDSCs chondrocytes differentiation, as evidenced by augmented expressions of chondrogenic markers (SOX9, COL2A1, ACAN, GAG, and COMP) in terms of mRNA and protein level, and the inhibition of miR-218 yielded opposite resutls. Additionally, miR-218 overexpression substantially suppressed the expression of osteogenic markers (ALP, BSP, COL1A1, OCN and OPN) during the early stage of chondrogenesis while increasing that of chondrogenic markers (SOX9, COL2A1, ACAN, GAG and COMP). However, miR-218 mimics notably suppressed maturation markers (CMP, COL10A1, MMP-13 and VEGF) expression in RCJ3.1C5.18 chondrocytes, and the miR-218 inhibitor promoted the expression of these maturation markers. We proposed miR-218 plays a regulatory role on 15-hydroxyprostaglandin dehydrogenase (HPGD), which plays a key role in chondrogenic differentiation, and this finding indicates that miR-218 directly regulates HPGD expression in SDSCs. CONCLUSION: Our study suggests that miR-218 contributes to early chondrogenesis while suppressing later chondrocyte maturation. The miR-218-HPGD pathway offers us a perspective into how SDSCs differentiate into chondrogenic cells.

Downregulation of miR-223 and miR-19a induces differentiation and promotes recruitment of osteoclast cells in giant-cell tumor of the bone via the Runx2/TWIST-RANK/RANKL pathway.

Giant-cell tumor (GCT) of the bone is an invasiveness and high recurrent bone tumor that is considered borderline or potentially malignant. To explore the molecular mechanism leading to bone destruction and identify novel targets for treatment, we conducted silencing of miR-223 and miR-19a in stromal giant cells and identified TWIST and Runx2 as their target genes. We investigated the impact of these microRNAs and their target genes on stromal giant cells that promote the differentiation of monocyte/macrophages into osteoclast cells and recruitment to the bone microenvironment, which in turn enhances the bone destruction capacity of GCT. MiR-223 and miR-19a were found to regulate the expression of TWIST and Runx2, influence the RANKL-RANK pathway and the expression of MCP-1, and finally regulate the pathophysiological process of osteolytic bone destruction. Our results indicate that re-expression of miR-223 and miR-19a induces an inhibitory effect on the bone destruction capacity of GCT, suggesting that re-expression of miR-223 and miR-19a can be a novel strategy for the treatment of GCT.

MicroRNA­218 promotes prostaglandin E2 to inhibit osteogenic differentiation in synovial mesenchymal stem cells by targeting 15­hydroxyprostaglandin dehydrogenase [NAD(+)].

The chondrogenic differentiation of synovial mesenchymal stem cells (SMSCs) is regulated by essential transcription factors and signaling cascades. However, the precise mechanisms involved in this process remain unclear. MicroRNAs (miRs/miRNAs) are undersized non­coding RNAs responsible for the post­transcriptional regulation of gene expression, by binding to the 3'­untranslated regions (3'­UTRs) of their target mRNAs. miRNAs may constitute a promising tool to regulate SMSC differentiation and to advance the controlled differentiation of SMSCs in therapeutic applications. The aim of the present study was to examine the role of miR­218 in SMSC differentiation towards chondrocytes. The present study comparatively analyzed the expression profile of known miRNAs and specific target genes in SMSCs between early and late differentiation stages. Western blotting and reverse transcription­quantitative polymerase chain reaction analysis of gene expression demonstrated the upregulation of 15­hydroxyprostaglandin dehydrogenase [NAD(+)] (15­HPGD), prostaglandin E2 (PGE2) and rate limiting enzymes responsible for the synthesis of PGE2 precursors throughout chondrogenesis. Through correlation analysis, it was observed that there was a significant association between miR­128, 15­HPGD gene expression, 15­HPGD protein expression and microsomal prostaglandin E synthase 1. Further experiments demonstrated that miR­218 decreased PGE2 concentration by binding to the 3'­UTR of 15­HPGD. Using an immunofluorescence reporting system, it was observed that miR­218 regulated the expression of 15­HPGD during the differentiation of SMSCs into cartilage, and subsequently inhibited osteogenesis during chondrogenesis by acting on the 3'UTR of 15­HPGD. Therefore, miR­218 may be an important regulator targeting osteogenic factors and modulating cartilage formation and differentiation. The results of the present study provided a novel insight beneficial to cellular manipulation methods during cartilage regeneration, and in cartilage tissue engineering research.

Arthroscopic lateral retinacular release, medial retinacular plication and partial medial tibial tubercle transfer for recurrent patellar dislocation.

OBJECTIVE: To assess the efficacy of a therapeutic protocol composed of arthroscopic lateral retinacular release, medial retinacular plication, and partial medial tibial tuberosity transfer for patients with recurrent patellar dislocation. METHOD: 71 patients, 11 males and 60 females and a total of 77 knees, with recurrent dislocation of the patella were enrolled between 1998 and 2012. The average age of the patients was 19.5 years and 67 of them had previous knee trauma history. Tibial tubercle avulsion fractures were all surgically treated without complications like dysplasia in the femoral trochlear groove or valgus deformity. The Q angle, sulcus angle, patella-femoral trochlear congruence angle and lateral patellofemoral angle were measured on X-ray, while tibial tubercle-trochlear groove (TT-TG) distance was measure on CT scans, before the arthroscopic operation. RESULT: 69 patients were followed-up for 2-16 years (average of 7.2 years), while 2 patients were lost during follow-up. Among the patients with follow-up, one patient had recurrent patella dislocation two months after the operation. Q angle decreased from 13.2° to 9.2° in male patients (P < 0.05) and from 21.0° to 15.4° in female patients (P < 0.05). On average, the patella-femoral trochlear congruence angle decreased from 24.2 ± 6.8° to -2.1 ± 5.8° (P < 0.05) and the lateral patellofemoral angle increased from -2.0 ± 5.2° to 10.9 ± 4.0° (P < 0.05). TT-TG distance decreased from 19.8 ± 2.1 mm to 13.6 ± 1.8 mm (P < 0.01). Mean Lysholm score increased from 45.6 ± 4.8 to 92.3 ± 10.8 (P < 0.05) and, IKDC score increased from 48.3 ± 6.8 to 94.3 ± 8.4 (P < 0.05). CONCLUSION: As evidenced by minimal trauma and markedly improved knee joint function, the proposed therapeutic protocol demonstrated clear benefits for patients with recurrent patella dislocation.

Meniscus, articular cartilage and nucleus pulposus: a comparative review of cartilage-like tissues in anatomy, development and function.

The degradation of cartilage in the human body is impacted by aging, disease, genetic predisposition and continued insults resulting from daily activity. The burden of cartilage defects (osteoarthritis, rheumatoid arthritis, intervertebral disc damage, knee replacement surgeries, etc.) is daunting in light of substantial economic and social stresses. This review strives to broaden the scope of regenerative medicine and tissue engineering approaches used for cartilage repair by comparing and contrasting the anatomical and functional nature of the meniscus, articular cartilage (AC) and nucleus pulposus (NP). Many review papers have provided detailed evaluations of these cartilages and cartilage-like tissues individually but none have comprehensively examined the parallels and inconsistencies in signaling, genetic expression and extracellular matrix composition between tissues. For the first time, this review outlines the importance of understanding these three tissues as unique entities, providing a comparative analysis of anatomy, ultrastructure, biochemistry and function for each tissue. This novel approach highlights the similarities and differences between tissues, progressing research toward an understanding of what defines each tissue as distinctive. The goal of this paper is to provide researchers with the fundamental knowledge to correctly engineer the meniscus, AC and NP without inadvertently developing the wrong tissue function or biochemistry.

[CONDITIONS OF SYNOVIAL MESENCHYMAL STEM CELLS DIFFERENTIATING INTO FIBROCARTILAGE CELLS].

OBJECTIVE: To explore the conditions of synovial derived mesenchymal stem cells (SMSCs) differentiating into the fibrocartilage cells by using the orthogonal experiment. METHODS: The synovium was harvested from 5 adult New Zealand white rabbits, and SMSCs were separated by adherence method. The flow cytometry and multi-directional differentiation method were used to identify the SMSCs. The conditions were found from the preliminary experiment and literature review. The missing test was carried out to screen the conditions and then 12 conditions were used for the orthogonal experiment, including transforming growth factor ß1 (TGF-ß1), bone morphogenic protein 2 (BMP-2), dexamethasone (DEX), proline, ascorbic acid (ASA), pyruvic acid, insulin + transferrin + selenious acid pre-mixed solution (ITS), bovin serum albumin (BSA), basic fibroblast growth factor (bFGF), intermittent hydraulic pressure (IHP), bone morphogenic protein 7 (BMP-7), and insulin-like growth factor (IGF). The L60 (212) orthogonal experiment was designed using the SPSS 18.0 with 2 level conditions and the cells were induced to differentiate on the small intestinal submucosa (SIS)-3D scaffold. The CD151+/CD44+ cells were detected with the flow cytometry and then the differentiation rate was recorded. The immumohistochemical staining, cellular morphology, toluidine blue staining, and semi-quantitative RT-PCR examination for the gene expressions of sex determining region Y (SRY)-box 9 gene (Sox9), aggrecan gene (AGN), collagen type I gene (Col I), collagen type II gene (Col II), collagen type IX gene (Col IX) were used for result confirmation. The differentiation rate was calculated as the product of CD151/CD44+ cells and cells with Col I high expression. The grow curve was detected with the DNA abundance using the PicoGreen Assay. The visual observation and the variances analysis among the variable were used to evaluate the result of the orthogonal experiment, 1 level interaction was considered. The q-test and the least significant difference (LDS) were used for the variance analysis with a type III calibration model. The test criteria (a) was 0.05. RESULTS: The cells were certified as SMSCs, the double-time of the cells was 28 hours. During the differentiation into the fibrocartilage, the volume of the SIS-3D scaffold enlarged double every 5 days. The scaffolds were positively stained by toluidine blue at 14 days. The visual observation showed that high levels of TGF-ß1 and BMP-7 were optimum for the differentiation, and BMP-7 showed the interaction with BMP-2. The conditions of DEX, ASA, ITS, transferrin, bFGF showed decreasing promotional function by degrees, and the model showed the perfect relevance. P value was 0.000 according to the variance analysis. The intercept analysis showed different independent variables brought about variant contribution; the TGF-ß1, ASA, bFGF, IGF, and BMP-7 were more remarkable, which were similar to the visual observation. CONCLUSION: In the process of the SMSCs differentiation into the fibrocartilage, the concentrations of TGF-ß1, ASA, bFGF, and IGF reasonably can improve the conversion rate of the fibrocartilage cells. The accurate conditions of the reaulatory factor should be explored further.

[PERIOPERATIVE BLOOD MANAGEMENT STRATEGIES FOR JOINT ARTHROPLASTY].

OBJECTIVE: To summarize the perioperative blood management strategies for joint arthroplasty. METHODS: The literature concerning preoperative, intraoperative, and postoperative blood management was reviewed and summarized. RESULTS: At present, a variety of blood management and conservation strategies are available. Preoperative strategies include iron supplementation, erythropoietin (EPO), and preoperative autologous donation (PAD). Intraoperative options include acute normovolemic hemodilution (ANH), antifibrinolytics, and the use of a tourniquet. Postoperative strategies include the use of reinfusion systems and guided transfusion protocols. Preoperatively, administration of either simple EPO or a combination of EPO and PAD can be efficacious in anemic patients. Intraoperatively, tourniquet use and tranexamic acid can effectively control bleeding. Postoperatively, appropriate transfusion indications can avoid unnecessary blood transfusions. CONCLUSION: Perioperative blood management strategies for joint arthroplasty should be integrated for the individual patient using a variety of ways to reduce perioperative blood loss and blood transfusion, and promote the rehabilitation of patients.

Strategies to minimize hypertrophy in cartilage engineering and regeneration.

Due to a blood supply shortage, articular cartilage has a limited capacity for self-healing once damaged. Articular chondrocytes, cartilage progenitor cells, embryonic stem cells, and mesenchymal stem cells are candidate cells for cartilage regeneration. Significant current attention is paid to improving chondrogenic differentiation capacity; unfortunately, the potential chondrogenic hypertrophy of differentiated cells is largely overlooked. Consequently, the engineered tissue is actually a transient cartilage rather than a permanent one. The development of hypertrophic cartilage ends with the onset of endochondral bone formation which has inferior mechanical properties. In this review, current strategies for inhibition of chondrogenic hypertrophy are comprehensively summarized; the impact of cell source options is discussed; and potential mechanisms underlying these strategies are also categorized. This paper aims to provide guidelines for the prevention of hypertrophy in the regeneration of cartilage tissue. This knowledge may also facilitate the retardation of osteophytes in the treatment of osteoarthritis.

Changes of hemoglobin and hematocrit in elderly patients receiving lower joint arthroplasty without allogeneic blood transfusion.

BACKGROUND: It has rarely been reported about the changes of hemoglobin (Hb) and hematocrit (Hct) in elderly patients receiving total knee arthroplasty (TKA) or total hip arthroplasty (THA). This study aimed to evaluate the changes of Hb and Hct after TKA or THA in elderly patients, and analyze its relationship with sex and type of arthroplasty. METHODS: This is a prospective cohort study, including 107 patients receiving TKA or THA without allogeneic blood transfusion. There were 54 males and 53 females, with a mean age of 69.42 years. Levels of Hb and Hct were examined preoperatively and during the 6 months follow-up after operation. RESULTS: Levels of Hb and Hct decreased postoperatively and reached their minimum points on postoperative day 4. Thereafter, Hb and Hct recovered to their preoperative levels within 6-12 weeks. No significant differences in the levels of Hb and Hct were noticed between different sexes. THA patients showed significantly greater drop in Hb and Hct than TKA patients in the first 4 days postoperatively (P < 0.05). CONCLUSIONS: Levels of Hb and Hct decreased during the first 4 days after arthroplasty and gradually returned to their normal levels within 6-12 weeks postoperatively. THA may be associated with higher postoperative blood loss than TKA.