This article is aim to test the safety and the in vitro antibacterial activity of the Lentiviral-medicated humanβ-defensin 3(hβD-3) transfecion synovium-derived mesenchymal stem cells(SMSCs).

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.

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.

Lentiviral-medicated hβD-3 gene express SMSCs could successfully subcultured and stably express hβD-3, meanwhile it had apparent in vitro antibacterial activity.

Defensins; Synovial membrane; Mesenchymal stem cells; Lentivirus