Strontium implantation improving cell proliferation and adhesion on titanium surfaces through CaSR/AKT signaling pathway

Surface physical and chemical modifications can effectively enhance implant biocompatibility and soft tissue adhesion. In this study, titanium (Ti) plates were modified by magnetron sputtering to incorporate strontium (Sr), and the effects of Sr-doped Ti materials on fibroblast proliferation and adhesion were systematically evaluated. The results demonstrated that Sr-doped Ti significantly improved L929 fibroblast proliferation, cellular morphology during adhesion, and adhesion strength. Surface characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and atomic force microscopy confirmed the successful incorporation of Sr and revealed changes in surface morphology and potential. RNA sequencing and Western blot analyses showed that Sr enhanced fibroblast adhesion by activating the calcium-sensing receptor (CaSR)/PKC/AKT signaling pathway. Moreover, pharmacological inhibition of CaSR effectively reversed the Sr-induced promotion of fibroblast adhesion and AKT activation. These findings suggest that Sr-functionalized Ti implants can promote fibroblast adhesion and early soft tissue integration, offering a promising strategy to improve implant success rates and prevent peri-implant diseases.