Objective To produce a decellularized cartilage matrix (DCM) and investigate its possibil ity to be used as a scaffold for tissue engineering. Methods Fresh bovine articular cartilage from knee joints was sl iced, freeze-dried and freeze-ground into fine powder, and then was treated sequentially with Trypsin, Triton X-100 and hypotonic solution for decellularization. The decellularized matrix was freeze-dried for shaping and cross-l inked by UV radiation. Histological, immunohistological, SEM, porosity assays and biomechanical assays were used to characterize the DCM. BMSCs were isolated from rabbit bone marrow aspirate and cultured in DCM extraction medium of different concentration (100%, 10% and 1%) for 0, 24, 48 and 72 hours, respectively, to detect the release rate of the lactate dehydrogenase (LDH). The DMEM medium (5% FBS) served as the control. Biocompatibil ity was evaluated using BMSCs (1 × 107/mL) cultured with DCM. Results The DCM showed white spongy appearances, and histological analysis showed that the material was constructed by cartilage particles without any cells or cell fragments left in the matrix. Immunohistology staining and alcian blue staining showed that DCM retained the collagen and glycosaminoglycan components of cartilaginous matrix. SEM scanning showed that DCM had a porous spongy-l ike structure with the aperture ranging 30-150 μm .The porosity assay showed that the average porosity was 89.37% and the average aperture was 90.8 μm. The mechanical assay showed that there was no difference for the compress module before and after the decellularization process, which was (17.91 ± 0.98) MPa and (15.12 ± 0.77) MPa, respectively (P gt; 0.05), but were both statistical different from normal articular cartilage [(26.30 ± 1.98) MPa, P lt; 0.05]. The LDH release rate in the DCM extraction medium of different concentration was not significantly different from that in the normal DMEM medium (P gt; 0.05). The cell adhesion test showed BMSCs grew well on DCM without any signs of growth inhibition. Conclusion Articular cartilage can be decellularized and fabricated into a scaffold which retains the major components of cartilaginous matrix. DCM has goodbiochemical, biophysical characteristics and good biocompatibil ity with cultured BMSCs and may be used as a novel scaffold for tissue engineering studies.
ObjectivesTo systematically review the prevalence and disease burden of knee osteoarthritis (KOA) in China.MethodsPubMed, EMbase, CNKI, WanFang Data and VIP databases were searched to collect cross-sectional studies about the prevalence and disease burden of KOA in China from January 1st 1995 to August 31st 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then meta-analysis was performed by using R statistical software.ResultsA total of thirty-three studies were included. The results of meta-analysis showed the prevalance rate of KOA was 18% (95%CI 14% to 22%), and it was higher in women (19%, 95%CI 16% to 23%) than in men (11%, 95%CI 9% to 13%) (P<0.05). The prevalence rates of KOA in different regions were as follows: 11% (95%CI 8% to 14%) in north, 17% (95%CI 15% to 20%) in north-east, 21% (95%CI 13% to 32%) in east, 21% (95%CI 13% to 33%) in north-west, 22% (95%CI 6% to 57%) in south-west, and 18% (95%CI 13% to 23%) in south-central, respectively.ConclusionsThe prevalence of KOA in China is high, and the disease burden is heavy. Due to the quantity and quality of included studies, more high-quality studies are required to verify the above conclusions in future.
Mechanical signal transduction are crucial for chondrocyte in response to mechanical cues during the growth, development and osteoarthritis (OA) of articular cartilage. Extracellular matrix (ECM) turnover regulates the matrix mechanical microenvironment of chondrocytes. Thus, understanding the mechanotransduction mechanisms during chondrocyte sensing the matrix mechanical microenvironment can develop effective targeted therapy for OA. In recent decades, growing evidences are rapidly advancing our understanding of the mechanical force-dependent cartilage remodeling and injury responses mediated by TRPV4 and PIEZOs. In this review, we highlighted the mechanosensing mechanism mediated by TRPV4 and PIEZOs during chondrocytes sensing mechanical microenvironment of the ECM. Additionally, the latest progress in the regulation of OA by inflammatory signals mediated by TRPV4 and PIEZOs was also introduced. These recent insights provide the potential mechanotheraputic strategies to target these channels and prevent cartilage degeneration associated with OA. This review will shed light on the pathogenesis of articular cartilage, searching clinical targeted therapies, and designing cell-induced biomaterials.