Transplantation of adipocyte-derived stem cells in a hydrogel scaffold for the repair of cortical contusion injury in rats.

Adipocyte-derived stem cells have emerged as a novel source of stem cell therapy for their autologous and readily accessible and pluripotent potential to differentiate into different lineages such as neural stem cells (NSCs) and endothelial progenitor cells (EPCs). Transplantation of NSCs and EPCs has been promising for the repair of brain injury. We explored using co-transplanted hydrogel scaffold to improve the survival of the transplanted cells and recovery of neurological function. Adult Wistar rats were transplanted with EPC-hydrogel, NSC-hydrogel, NSC-EPC-hydrogel, EPC only, or NSC only 7 days after cortical contusion injury. Behavioral tests were performed to evaluate neurological function before, and 1, 2, 3, and 4 weeks after transplantation. Size of injury, extent of vascularization, as well as the survival and differentiation of the transplanted EPCs and NSCs, were evaluated at week 5. All transplantation groups displayed significantly better neurological function compared with the control groups. Improved neurological function correlated with significantly smaller injury volumes than that of the saline group. Using immunostaining, we have shown that while transplanted NSCs differentiated into both neurons and astrocytes, the EPCs were incorporated into vessel epithelia. The extent of reactive gliosis (based on glial fibrillary acidic protein immunostaining) was significantly reduced in all treatment groups (NSC-EPC-hydrogel, NSC-hydrogel, and EPC-hydrogel) when compared with the saline group, with the highest reduction in the NSC-EPC-hydrogel transplantation group. Thus, co-transplantation of hydrogel scaffold provides a more conducive environment for the survival and differentiation of NSCs and EPCs at the site of brain injury, leading to improved vascularization and better recovery of neurological function.

[Biocompatibility of a novel cavernous nickel-titanium alloy with rat bone marrow stromal cells in vitro].

OBJECTIVE: To investigate the biocompatibility of a novel cavernous nickel-titanium alloy with rat bone marrow stromal cells (BMSCs) in vitro. METHODS: Rat BMSCs were cultured on the surface of compact, microporous and macroporous nickel-titanium alloys, and the cell proliferation on day 3 during the culture was assessed using MTT assay. On day 7 of the cell culture, the cells were labeled with Hoechst33342 for cell counting under a fluorescence microscope. Scanning electron microscopy (SEM) was performed on day 7 of cell culture to observe the morphological changes of the cells. RESULTS: The cell proliferation rate and cell numbers differed significantly between the cavernous alloy groups and the compact alloy group (P<0.05), but similar between the former two groups (P>0.05). SEM showed that compared with the compact alloy, microporous and macroporous nickel-titanium alloys had better biocompatibility with the BMSCs, and the cells on the surface of the cavernous alloys had normal cell morphology. CONCLUSION: Cavernous nickel-titanium alloy has good biocompatibility and can promote the adhesion, aggregation and proliferation of rat BMSCs in vitro.