BACKGROUND:The absence of blood vessels in tendon tissue makes tendon repair challenging.Therefore,improving tendon healing and raising the efficacy of stem cell and other therapeutic cell transplantation after tendon damage have become hotspots for research in both clinical and scientific contexts. OBJECTIVE:The stem cells and gelatin microcarrier scaffold were joined to form tissue engineered stem cells.Human umbilical cord mesenchymal stem cells cultured in gelatin microcarriers were used to investigate the therapeutic impact and mode of action on tendinopathy healing in rats in vitro and In vivo. METHODS:(1)In vitro cell experiments:After seeding human umbilical cord mesenchymal stem cells with three-dimensional gelatin microcarriers,the cell vitality and survival were assessed.Human umbilical cord mesenchymal stem cells conventionally cultured were cultured as controls.(2)In vivo experiment:Adult SD rats were randomly assigned to normal group,tendinopathy group,2D group(tendinopathy+conventional culture of human umbilical cord mesenchymal stem cells),and 3D group(tendinopathy+gelatin microcarrier three-dimensional culture of human umbilical cord mesenchymal stem cells),with 6 rats in each group.Four weeks after therapy,animal behavior tests and histopathologic morphology of the Achilles tendon was examined. RESULTS AND CONCLUSION:(1)In vitro cell experiments:the seeded human umbilical cord mesenchymal stem cells on gelatin microcarriers showed high viability and as time went on,the stem cell proliferation level grew.Compared with the control group,3D stem cell culture preserved cell viability.(2)In vivo experiment:Following a 4-week treatment,the 3D stem cell culture group showed a significant improvement in both functional recovery of the lower limbs and histopathological scores when compared to the tendinopathy group.The 2D stem cell culture group also showed improvement in tendinopathy injury,but its effect is not as much as the 3D stem cell culture group.(3)The outcomes demonstrate that human umbilical cord mesenchymal stem cells cultured with three-dimensional gelatin microcarrier can promote the repair and regeneration of tendon injury tissue,and the repair effect is better than that of conventional human umbilical cord mesenchymal stem cells.