Thermosensitive bFGF-Modified Hydrogel with DentalPulp Stem Cells on Neuroinflammation of Spinal Cord Injury

Acute spinal cord injury (SCI) induces severe neuroinflammation, which increases intermediary filaments and neurodegeneration. Previous studies have shown that a basic fibroblast growth factor (bFGF) and dental pulp stem cells (DPSCs) contribute to a protective effect on injured neuronal cells, but the mechanism of SCI repair is still unclear. In this study, in situ heparin (HeP) hydrogel injection containing bFGF and DPSCs (HeP-bFGF-DPSCs), as well as in vitro studies of bFGF and DPSCs, proved an effective control over inflammation. The in vivo application of HeP-bFGF-DPSCs regulated inflammatory reactions and accelerated the nerve regeneration through microtubule stabilization and tissue vasculature. Our mechanistic investigation also showed that bFGF-DPSCs treatment inhibited microglia/macrophage proliferation and activation. Furthermore, HeP-bFGF-DPSCs prevented microglia/macrophage activation and reduced proinflammatory cytokine release. In this paper, we discovered that bFGF and DPSCs worked together to attenuate tissue inflammation of the injured spinal cord, resulting in a superior nerve repair. Our results indicated that a thermosensitive hydrogel delivering bFGF and DPSCs could serve as a promising treatment option for spinal cord injuries.