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BACKGROUND:Cartilage degeneration and subchondral bone damage are the main pathological features of osteoarthritis,and treatment based on this pathological feature will be a promising improvement for osteoarthritis. OBJECTIVE:To design and study an annotated strontium ranelate-loaded drug delivery system and to observe its therapeutic effect on promoting cartilage repair and improving subchondral bone structure in osteoarthritis. METHODS:(1)In vitro experiment:Strontium ranelate was loaded into sodium alginate/collagen hydrogel matrix to construct in situ drug delivery system,and the in vitro slow release performance of the system was characterized.Strontium ranelate-loaded sodium alginate/collagen hydrogel(experimental group)and alginate sodium/collagen hydrogel(control group)were co-cultured with bone marrow mesenchymal stem cells,respectively,and cultured cells were used as a blank control group to detect cell proliferative activity.After chondroblast-induced differentiation,saffron O staining,Alcian blue staining and RT-qPCR were performed respectively.The two hydrogels were co-cultured with osteoblasts,and the cultured cells were used as a blank control group for immunofluorescence staining and RT-qPCR.(2)In vivo experiment:A total of 18 adult SD rats were selected and the model of right posterior knee osteoarthritis was established by the method of medial meniscectomy.After 1 week,the rats were divided into three groups by the random number table method:The blank group did not receive any treatment.The control group was injected with sodium alginate/collagen hydrogel in the knee,and the experimental group was injected with strontium ranelate-loaded sodium alginate/collagen hydrogel,with 6 rats in each group.After 6 weeks,the samples were subjected to Micro-CT scanning,hematoxylin-eosin staining,saffron O-solid green staining and immunofluorescence staining. RESULTS AND CONCLUSION:(1)In vitro experiment:Strontium ranelate-loaded sodium alginate/collagen hydrogel had porous microstructure and sustainable release of strontium ranelate.At 21 days,the cumulative release reached(60.89±0.58)%.Bone marrow mesenchymal stem cell staining showed that both hydrogels had good cytocompatibility.The results of the CCK-8 assay demonstrated that strontium ranelate-loaded sodium alginate/collagen hydrogel could promote the proliferation of bone marrow mesenchymal stem cells.The results of Safranin O staining,Alcian blue staining,immunofluorescence staining and RT-qPCR exhibited that strontium ranelate-loaded sodium alginate/collagen hydrogel could promote chondrogenic differentiation of bone marrow mesenchymal stem cells.Immunofluorescence staining and RT-qPCR revealed that strontium ranelate-loaded sodium alginate/collagen hydrogel could decrease bone resorptivity by increasing the ratio of osteophosphorin/nuclear factor κB receptor activator ligand.(2)In vivo experiment:Micro-CT scan verified that compared with the blank group and control group,the subchondral bone volume fraction and bone mineral density of the knee of rats were increased in the experimental group(P<0.05,P<0.01).Histological staining displayed that compared with the blank group and control group,the knee cartilage injury was significantly reduced;the expression of type II collagen was promoted,and the expression of matrix metalloproteinase 2 protein was inhibited in the experimental group(P<0.05,P<0.01).(3)These results confirm that the strontium ranelate-loaded sodium alginate/collagen hydrogel can promote the repair of cartilage defects in osteoarthritis and reconstruct the complex interface between cartilage and subchondral bone.
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BACKGROUND: Dermis-derived extracellular matrix, as a cartilage repair scaffold, provides a space for the growth of cartilage tissue, and promotes cell adhesion and proliferation. Bone marrow mesenchymal stem cells have the potential to differentiate into chondrocytes. Both of them used alone have disadvantages. OBJECTIVE: To evaluate the feasibility of bone marrow mesenchymal stem cells combined with calf acellular dermal matrix to repair beagle dog articular cartilage defects. METHODS: Beagle dog bone marrow blood was extracted from Beagle dogs. Bone marrow mesenchymal stem cells were obtained by density gradient centrifugation and passaged. Acellular dermal matrix was prepared from the dorsal dermis of neonatal calves by ultrasonic oscillation, freeze-drying and pepsin. 0. 2 mL of cell suspension was added to the surface of acellular dermal matrix until covered, then which was placed in a 5% CO2 incubator at 37 °C for 48 hours. Twelve adult beagle dogs were used to establish knee joint cartilage defect models, and then randomized into three groups: In the acellular dermal matrix combined with bone marrow mesenchymal stem cells group (combination group), cartilage defects were repaired with acellular dermal matrix combined with bone marrow mesenchymal stem cells. In the single acellular dermal matrix group, cartilage defects were repaired with acellular dermal matrix. The model control group received no treatment. At 12 weeks after surgery, the right knee joints were observed by stereomicroscope, hematoxylin-eosin staining and type II collagen immunohistochemical staining. RESULTS AND CONCLUSION: (1) Scanning electron microscopy showed that bone marrow mesenchymal stem cells adhered to and grew well in the acellular dermal matrix. (2) Hematoxylin-eosin staining revealed that the repaired surface in the combination group was slightly lower than that of the surrounding normal tissues, and the repaired tissues integrated well with the surrounding cartilages. The defects in the single acellular dermal matrix group were filled with fibrous tissues. Few surrounding tissues of defect were repaired in the model control group. (3) Type II collagen immunohistochemical staining showed that in the combination group, articular cartilage defects were filled with chondrocyte-like tissues. In the single acellular dermal matrix group, the defect was filled with fibrous tissues. No tissue was found in the model control group. (4) These results indicate that the new calf acellular dermal matrix has good biocompatibility and can promote the proliferation of bone marrow mesenchymal stem cells. Autologous bone marrow mesenchymal stem cells combined with acellular dermal matrix can effectively repair beagle dog knee joint cartilage defects.
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@# Objective To explore the effect of Botulinum toxin type A (BTX-A) injection combined with rehabilitation training and medicated bath on spasm for children with cerebral palsy. Methods 80 children with spastic and mixed cerebral palsy were randomly divided into two groups with 40 cases in each group. The control group received physical therapy, and the observation group received BTX-A injection and rehabilitation training and medicated bath. They were assessed with modified Ashworth scale (MAS) and Gross Motor Function Measure (GMFM-88) before and 3 months after treatment. Results The scores of MAS and GMFM were better in 2 groups after treatment (P<0.05) and the observation group was better than that of the control group (P<0.05). Conclusion BTX-A injection combined with medicated bath can reduce muscle tension, improve gross motor function of children with spastic and mixed cerebral palsy.