BACKGROUND:Smal intestinal submucosa is characterized as antimicrobial activity, good biocompatibility, bio-mechanical properties, and rapid degradation in vivo, similar to the extracellular matrix of meniscal
fibrochondrocytes.
OBJECTIVE:To observe whether there exists a good histocompatibility between smal intestinal submucosa and synovial mesenchymal stem cells.
METHODS:Smal intestinal submucosa was treated with physical and chemical treatment. And hematoxylin-eosin staining and scanning electron microscopy observation were performed. Then, smal intestinal submucosa extracts were prepared for the fol owing experiments. (1) Pyrogenic test:smal intestinal submucosa extracts were injected into the ear vein of New Zealand white rabbits. (2) Skin sensitization test:smal intestinal submucosa extracts, paraformaldehyde solution and normal saline were respectively injected intradermal y into New Zealand white rabbits. (3) General toxicity test:smal intestinal submucosa extracts and normal saline were respectively injected into the ear vein of New Zealand white rabbits. Smal intestinal submucosa was co-cultured with osteogenic rabbit synovial mesenchymal stem cells, and smal intestinal submucosa cultured alone served as control. RESULTS AND CONCLUSION:There were some intestinal mucosal epithelial cells, fat cells and other cells adhered onto the surface of smal intestinal submucosa after physical treatment. While, the amount of residual cells decreased sharply after chemical treatment. But the main structure and the component had not been changed. The surface of smal intestinal submucosa was smooth and no cells remained, and there was a three-dimension network spatial structure. The porosity was 80%. Smal intestinal submucosa is a non-toxic, nonirritating, non-immunogenic biomaterial with very good biocompatibility, which has a good histocompatibility with rabbit synovial mesenchymal stem cells.

BACKGROUND:A large amount of studies have confirmed that synovial mesenchymal stem cells have the similarity in cellmorphology, immune phenotype, colony forming ability and differentiation potential with bone marrow mesenchymal stem cells. But bone marrow mesenchymal stem cells are better than synovial mesenchymal stem cells in the ability to differentiate into cartilages. OBJECTIVE:To discuss the possibility of using synovial mesenchymal stem cells as seed cells for meniscal tissue engineering. METHODS:The synovial mesenchymal stem cells were isolated from rabbit synovial tissues with limiting dilution monoclonal culture method, and then the cells were purified. The morphology, ultrastructure, molecular phenotype, proliferation kinetics, karyotype and tumorigenicity of the in vitro cultured cells were analyzed. RESULTS AND CONCLUSION:The synovial mesenchymal stem cells isolated from the rabbit synovial cells had high proliferation capacity during in vitro monolayer culture. The synovial mesenchymal stem cells grew to peak at 6 days, and the doubling time was (30.2±2.4) hours. Flow cytometry results showed the synovial mesenchymal stem cells could express some molecular makers of mesenchymal stem cells, such as CD44 and CD90. DNA contents check, karyotype test and oncogenicity test confirmed isolated and purified synovial mesenchymal stem cells were the normal diploid cells without tumorigenicity, so the cells can be used as seed cells for meniscal tissue engineering.

BACKGROUND:Postoperative acute mental disorders refer to patients without mental disorders suffer from neurological dysfunction after surgery. OBJECTIVE:To analyze the association between psychological resilience and postoperative acute mental disorders after total knee arthroplasty (TKA). METHODS:Convenience sampling, the Chinese Version of Connor and Davidson's resilience scale (CD-RISC), was used to measure the levels of psychological resilience in 832 patients undergoing TKA. The questionnaire covered three dimensions:tenacity, self-improvement and optimism. The incidence of postoperative acute mental disorders was observed after operation. RESULTS AND CONCLUSION:(1) The CD-RISC scores of the patients with TKA surgery were (57.64±10.07), lower than the average scores of the elderly community in China. 20 (2.4%) patients had postoperative acute mental disorders. (2) Pearson correlation analysis demonstrated the negative correlation between the levels ofresilience and the incidence of postoperative acute mental disorders (r=-2.43, P<0.05). (3) Patients with lower psychological resilience levels had a higher incidence of postoperative acute mental disorders. Developing psychological resilience may become an important strategy to reduce the occurrence of postoperative acute mental disorders.

Objective This article is aim to test the safety and the in vitro antibacterial activity of the Lentiviral-nedicated humanβ-defensin 3 (hβD-3) transfecion synovium-derived mesenchymal stem cells (SMSCs).Methods Tissues with SMSCs were obtained by surgical operations.Cells were explant cultured and purified by magnetic cell separation system.Cells were identified by microscopic observation, immunofluorescence and cell surface markers.Through inducing the cells into fat, osteoblasts and chondroblasts to respectively determine the multi-directional differentiation potential.Construct a hβD-3 contained lentivirus and transfected into SMSCs.Got the cell growth curve and determine the DNA content by using flow cytometry.The NOD/SCID mice were applied to verify the tumorigenicity of SMSCs.Agar diffusion test was applied to doing antibacterial activity test of posttransfecton SMSCs.The rabbit model of knee joint in staphylococcus aureus infections verify its bacteriostatic action in vivo.Results: Purified SMSCs had the structure and surface signatures of MSCs.It had the potential of multi-differentiation.Immunofluorescence had verified that SMSCs transfected by lentivirus could stably express hβD-3.Cell proliferation kinetics, karyotype analysis and Tumorigenic type analysis verified the safety of SMSCs after transfection.The in vivo and vitro antibacterial activity test of the recombinant SMSCs showed that after cell passages, the subcultured SMSCs (P5 cells were used in this article) could express hβD-3 stably and had antibacterial activity.The result of the antibacterial circle showed that low concentration group inhibit bacterial activity while the medium and high group could enlarge compared with the negative and positive control group.Conclusion Lentiviral-medicated hβD-3 gene express SMSCs could successfully subcultured and stably express hβD-3, meanwhile it had apparent in vitro antibacterial activity.

Objective To investigate the biosecurity and biocompatibility of small intestinal submucosa (SIS) as scaffold for tissue engineering and to explore the possibility to induce synovial mesenchymal stem cells (SMSCs) differentiate into cartilage with SIS as the scaffold and SMSCs as the seed cells. Methods The SMSCs were isolated and cultured from the synovial mem-brane of knee joints of rabbits by a conventional method. The SIS was harvested from pigs according to the physical method and Abraham's method. 4 rabbits are divided into the experimental group and control group. The biosecurity of SIS as scaf-folds were investigated in pyrogen test, skin sensitization test and systemic toxicity test. The SMSCs and SIS were co-cultured in vitro and induced to differentiate into cartilage to explore the biocompatibility of SMSCs and SIS, the proliferation and differ-entiation ability of SMSCs on the scaffold of SIS. The varietyies were identified by the microscope. Results The SIS isolated with the physical method and Abraham's method is a milky and translucent membrane with a smooth surface. Under the electron microscope, SIS presented a porous Stereoscopic three-dimensional network structure, which is formed by fibrous tissues' intertex-ture. Its' porosity was about 80%and its aperture was 100-200μm. Meanwhile, the biosecurity and biocompatibility of SIS were also fine. In the trial that the SMSCs and SIS were co-cultured in vitro, the SMSCs can grow, adhere to and differentiate on the sur-face of SIS and into the hollows very well. It can also secrete extracellular matrix. Through scanning microscope observation, cells contact with each other by their neuritis, or adhered to the wall of hole by cellular protrution. On the surface of SIS, the SMSCs maintain the property that it can easily differentiate into the chondrogenic lineage in the chondrogenic medium. Immunochemistry staining showed positive expression of type II collagen post 21 days of co-cultrue. Conclusion SIS can be used as the scaffold to construct tissue engineering meniscus as it has good biosecurity and biocompatibility with SMSCs without disturbing the cell form or inhibiting the growth and function of SMSCs.