Hydrogel-hydroxyapatite-monomeric collagen type-I scaffold with low-frequency electromagnetic field treatment enhances osteochondral repair in rabbits.

BACKGROUND: Cartilage damage is a common medical issue in clinical practice. Complete cartilage repair remains a significant challenge owing to the inferior quality of regenerative tissue. Safe and non-invasive magnetic therapy combined with tissue engineering to repair cartilage may be a promising breakthrough. METHODS: In this study, a composite scaffold made of Hydroxyapatite-Collagen type-I (HAC) and PLGA-PEG-PLGA thermogel was produced to match the cartilage and subchondral layers in osteochondral defects, respectively. Bone marrow mesenchymal stem cells (BMSC) encapsulated in the thermogel were stimulated by an electromagnetic field (EMF). Effect of EMF on the proliferation and chondrogenic differentiation potential was evaluated in vitro. 4 mm femoral condyle defect was constructed in rabbits. The scaffolds loaded with BMSCs were implanted into the defects with or without EMF treatment. Effects of the combination treatment of the EMF and composite scaffold on rabbit osteochondral defect was detected in vivo. RESULTS: In vitro experiments showed that EMF could promote proliferation and chondrogenic differentiation of BMSCs partly by activating the PI3K/AKT/mTOR and Wnt1/LRP6/ß-catenin signaling pathway. In vivo results further confirmed that the scaffold with EMF enhances the repair of osteochondral defects in rabbits, and, in particular, cartilage repair. CONCLUSION: Hydrogel-Hydroxyapatite-Monomeric Collagen type-I scaffold with low-frequency EMF treatment has the potential to enhance osteochondral repair.

Selonsertib Alleviates the Progression of Rat Osteoarthritis: An in vitro and in vivo Study.

Osteoarthritis (OA) is a prevalent degenerative joint disease. Its development is highly associated with inflammatory response and apoptosis in chondrocytes. Selonsertib (Ser), the inhibitor of Apoptosis Signal-regulated kinase-1 (ASK1), has exhibited multiple therapeutic effects in several diseases. However, the exact role of Ser in OA remains unclear. Herein, we investigated the anti-arthritic effects as well as the potential mechanism of Ser on rat OA. Our results showed that Ser could markedly prevent the IL-1ß-induced inflammatory reaction, cartilage degradation and cell apoptosis in rat chondrocytes. Meanwhile, the ASK1/P38/JNK and NFκB pathways were involved in the protective roles of Ser. Furthermore, intra-articular injection of Ser could significantly alleviate the surgery induced cartilage damage in rat OA model. In conclusion, our work provided insights into the therapeutic potential of Ser in OA, indicating that Ser might serve as a new avenue in OA treatment.

Rhoifolin Ameliorates Osteoarthritis via Regulating Autophagy.

Osteoarthritis (OA) is a common age-related joint disease. Its development has been generally thought to be associated with inflammation and autophagy. Rhoifolin (ROF), a flavanone extracted from Rhus succedanea, has exhibited prominent anti-oxidative and anti-inflammatory properties in several diseases. However the exact role of ROF in OA remains unclear. Here, we investigated the therapeutic effects as well as the underlying mechanism of ROF on rat OA. Our results indicated that ROF could significantly alleviate the IL-1ß-induced inflammatory responses, cartilage degradation, and autophagy downregulation in rat chondrocytes. Moreover, administration of autophagy inhibitor 3-methyladenine (3-MA) could reverse the anti-inflammatory and anti-cartilage degradation effects of ROF. Furthermore, P38/JNK and PI3K/AKT/mTOR signal pathways were involved in the protective effects of ROF. In vivo, intra-articular injection of ROF could notably ameliorate the cartilage damage in rat OA model. In conclusion, our work elucidated that ROF ameliorated rat OA via regulating autophagy, indicating the potential role of ROF in OA therapy.

Effects of electromagnetic fields treatment on rat critical-sized calvarial defects with a 3D-printed composite scaffold.

BACKGROUND: Current strategies for craniofacial defect are faced with unmet outcome. Combining 3D-printing with safe, noninvasive magnetic therapy could be a promising breakthrough. METHODS: In this study, polylactic acid/hydroxyapatite (PLA/HA) composite scaffold was fabricated. After seeding rat bone marrow mesenchymal stem cells (BMSCs) on scaffolds, the effects of electromagnetic fields (EMF) on the proliferation and osteogenic differentiation capacity of BMSCs were investigated. Additionally, 6-mm critical-sized calvarial defect was created in rats. BMSC-laden scaffolds were implanted into the defects with or without EMF treatment. RESULTS: Our results showed that PLA/HA composite scaffolds exhibited uniform porous structure, high porosity (~ 70%), suitable compression strength (31.18 ± 4.86 MPa), modulus of elasticity (10.12 ± 1.24 GPa), and excellent cyto-compatibility. The proliferation and osteogenic differentiation capacity of BMSCs cultured on the scaffolds were enhanced with EMF treatment. Mechanistically, EMF exposure functioned partly by activating mitogen-activated protein kinase (MAPK) or MAPK-associated ERK and JNK pathways. In vivo, significantly higher new bone formation and vascularization were observed in groups involving scaffold, BMSCs, and EMF treatment, compared to scaffold alone. Furthermore, after 12 weeks of implanting, craniums in groups including scaffold, BMSCs, and EMF exposure showed the greatest biomechanical properties. CONCLUSION: In conclusion, EMF treatment combined with 3D-printed scaffold has great potential applications in craniofacial regeneration.

Performing ICSI within 4 hours after denudation optimizes clinical outcomes in ICSI cycles.

BACKGROUND: The study aimed to investigate whether and how general and partial time intervals between processes, from human chorionic gonadotrophin (HCG) trigger to intracytoplasmic sperm injection (ICSI), affected the laboratory and reproductive outcomes in ICSI cycles. METHODS: This was a retrospective data analysis of 3602 women who underwent ICSI treatment cycles using partner or donor sperms, performed at Reproduction Medicine Center of Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology (Wuhan, China) between October 2016 and September 2018. The clinical pregnancy rate was the major outcome in the study. The fertilization and available embryo rates were secondary outcomes. RESULTS: Data from 3602 consecutive fresh ICSI cycles was analysed. Multivariate linear regression and logistic regression analysis of factors related to fertilization and clinical pregnancy rates showed that fertilization rate (P = 0.001) and clinical pregnancy rate (P = 0.037) were significantly associated with denudation (DN)-ICSI interval. Long DN-ICSI interval was associated with higher rate of fertilization than short DN-ICSI interval but significantly decreased clinical pregnancy rate when the interval is over 4 h (P < 0.05). CONCLUSIONS: DN-ICSI time interval can act as an independent predictor for clinical outcomes in ICSI cycles. The optimal time for ICSI is within 4 h after oocyte denudation for excellent laboratory and reproductive outcomes in ICSI cycles.

The combinatory effect of sinusoidal electromagnetic field and VEGF promotes osteogenesis and angiogenesis of mesenchymal stem cell-laden PCL/HA implants in a rat subcritical cranial defect.

BACKGROUND: Restoration of massive bone defects remains a huge challenge for orthopedic surgeons. Insufficient vascularization and slow bone regeneration limited the application of tissue engineering in bone defect. The effect of electromagnetic field (EMF) on bone defect has been reported for many years. However, sinusoidal EMF (SEMF) combined with tissue engineering in bone regeneration remains poorly investigated. METHODS: In the present study, we investigated the effect of SEMF and vascular endothelial growth factor (VEGF) on osteogenic and vasculogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Furthermore, pretreated rBMSC- laden polycaprolactone-hydroxyapatite (PCL/HA) scaffold was constructed and implanted into the subcritical cranial defect of rats. The bone formation and vascularization were evaluated 4 and 12 weeks after implantation. RESULTS: It was shown that SEMF and VEGF could enhance the protein and mRNA expression levels of osteoblast- and endothelial cell-related markers, respectively. The combinatory effect of SEMF and VEGF slightly promoted the angiogenic differentiation of rBMSCs. The proteins of Wnt1, low-density lipoprotein receptor-related protein 6 (LRP-6), and ß-catenin increased in all inducted groups, especially in SEMF + VEGF group. The results indicated that Wnt/ß-catenin pathway might participate in the osteogenic and angiogenic differentiation of rBMSCs. Histological evaluation and reconstructed 3D graphs revealed that tissue-engineered constructs significantly promoted the new bone formation and angiogenesis compared to other groups. CONCLUSION: The combinatory effect of SEMF and VEGF raised an efficient approach to enhance the osteogenesis and vascularization of tissue-engineered constructs, which provided a useful guide for regeneration of bone defects.

Isorhapontigenin Suppresses Interleukin-1ß-Induced Inflammation and Cartilage Matrix Damage in Rat Chondrocytes.

Osteoarthritis (OA) is a common cause of joint pain and physical disability in the elderly. It is highly associated with local inflammatory reactions and cartilage degradation. Isorhapontigenin (ISO), a natural compound existing in various plants, has shown prominent anti-inflammatory and anti-oxidative properties in several inflammatory diseases. However, the effects of ISO on OA remain to be elucidated. Here, we investigated the effects of ISO on interleukin-1ß (IL-1ß)-treated rat chondrocytes and cartilage explants. Our results revealed that ISO could suppress the IL-1ß-induced elevated levels of nitric oxide (NO), inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX2). Besides, ISO could also inhibit the IL-1ß-induced up-regulation of cartilage matrix catabolic enzymes such as matrix metalloproteinases (MMPs) and aggrecanase-2 (ADAMTS5). Moreover, the IL-1ß-induced downregulation of collagen II and aggrecan could be reversed by ISO. Furthermore, ISO prevented rat cartilage explant damage induced by IL-1ß. Mechanistically, ISO worked partly by suppressing mitogen-activated protein kinase (MAPK)-associated ERK and p38 pathways. Taken together, our study indicated the anti-inflammatory potential of ISO on IL-1ß-treated rat chondrocytes, providing a new idea for OA treatment.

Liquiritigenin inhibits IL-1ß-induced inflammation and cartilage matrix degradation in rat chondrocytes.

Osteoarthritis (OA) is an age-related arthropathy which has been considered to be associated with inflammatory damage and cartilage degradation. Liquiritigenin (LG), the main bioactive component of the rhizomes of Glycyrrhiza uralensis, has exhibited promising anti-inflammatory and anti-oxidative potential in numerous inflammatory diseases. However, the effects of LG on OA remain unclear. In this study, the therapeutic effects as well as the underlying mechanisms of LG on interleukin-1ß (IL-1ß)-treated rat chondrocytes had been investigated. Our results showed that LG could inhibit the IL-1ß-induced expression of nitic oxide (NO) and prostaglandin E2 (PGE2). In consist with these findings, the IL-1ß-induced production of inducible nitic oxide synthase (iNOS) and cyclooxygenase-2 (COX2) could also be decreased by LG. Meanwhile, LG could suppress the IL-1ß-induced upregulation of cartilage matrix catabolic enzymes including aggrecanase-2 (ADAMTS5) and matrix metalloproteinases (MMPs). Besides, the IL-1ß-induced degradation of collagen II and aggrecan could be alleviated by LG. Moreover, LG prevented cartilage damage in IL-1ß-treated rat cartilage explants. Mechanistically, LG functioned by inhibiting mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways activation. In general, this study reveals the anti-inflammatory properties of LG on IL-1ß-treated rat chondrocytes and the possible mechanisms behind it, which may provide new ideas for OA therapy.

Schisandrin A Inhibits the IL-1ß-Induced Inflammation and Cartilage Degradation via Suppression of MAPK and NF-κB Signal Pathways in Rat Chondrocytes.

Osteoarthritis (OA) is a common joint disease in the elderly population. Its development has been reported to be associated with cartilage degradation and inflammatory responses. Schisandrin A, a bioactive lignin in Schisandra sphenanthera, has shown its anti-inflammatory potential in various inflammation diseases. However, the effects of Schisandrin A on OA remain to explore. In this study, rat chondrocytes were treated with IL-1ß (10 ng/ml) with or without different concentrations of Schisandrin A for 24 h. Cell viability was evaluated by CCK-8 assay. Production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Griess reaction and ELISA. The MAPK/NF-κB-related signaling molecules expression and the protein production of inducible nitric oxide synthase (iNOS), cyclooxygenase (Cox)-2, MMPs (MMP1, MMP3, MMP13), ADAMTS5, Collagen II, aggrecan, and Sox9 were detected by Western blot. Protein expression of Collagen II, aggrecan, and p65 nuclear translocation was evaluated by immunofluorescence. In vivo, intra-articular injection of 50 µM Schisandrin A or equal volume of vehicle was performed on rat OA models. Severity of cartilage damage was evaluated by HE and Safranin-O-Fast green staining. Our results revealed that Schisandrin A could suppress the IL-1ß-induced production of NO and PGE2 in rat chondrocytes. Consistent with these findings, the upregulation of iNOS and Cox2 could also been decreased by Schisandrin A. Additionally, Schisandrin A could inhibit IL-1ß-induced cartilage matrix catabolic enzymes including MMPs and ADAMTS5. Moreover, the IL-1ß-induced downregulation of Collagen II, aggrecan, and Sox9 could be ameliorated by Schisandrin A. Mechanistically, Schisandrin A functioned by suppressing MAPK and NF-κB signal pathways. In vivo, Schisandrin A prevented cartilage damage in rat OA model. In conclusion, this study elucidates that Schisandrin A inhibits the IL-1ß-induced inflammation and cartilage degradation via suppression of MAPK and NF-κB signal pathways, indicating its potential role in OA therapy.

The legacy effects of electromagnetic fields on bone marrow mesenchymal stem cell self-renewal and multiple differentiation potential.

BACKGROUND: The effects of electromagnetic fields (EMF) on bone nonunion have been reported for many years. Many studies and randomized controlled trials have demonstrated that EMF exhibited benefits in curing delayed union and nonunion of long bone fractures. Most of them focused on the immediate effects, while the legacy effects of EMF remain poorly investigated. METHODS: In this study, rat bone marrow mesenchymal stem cells (BMSCs) were treated with EMF, and after a period of time the BMSC proliferation and differentiation were detected. Additionally, BMSC sheets with or without EMF treatment were transplanted into the rat tibia fracture nonunion models. The bone formation was evaluated after 2, 4, and 6 weeks. RESULTS: Our results showed that the proliferation capacity of BMSCs was heightened after EMF pretreatment. Over a period of time of EMF pretreatment, the capacities of osteogenic and chondrogenic differentiation were enhanced, while adipogenic differentiation was weakened. BMSC sheets pretreated with EMF could better promote the healing of tibia fracture in rats, compared to BMSC sheets alone. Furthermore, significantly higher values of radiographic grading scores were observed in the EMF group. CONCLUSIONS: EMF has lasting effects on the proliferation and differentiation of BMSCs, and together with cell sheet technology can provide a new method for the treatment of fracture nonunion.