This study investigated the impact of simulated microgravity on titanium implant osseointegration and assessed the reparative efficacy of icariin (ICA) combined with treadmill exercise. Male Sprague–Dawley rats (n = 24) were divided into four groups: normal gravity control (CON), simulated microgravity (SMG), SMG + ICA, and SMG + ICA+treadmill exercise (SMG + ICA+EXER). SMG groups underwent tail suspension for four weeks, followed by ICA (25 mg/kg/day) and/or exercise interventions. Micro-CT, fluorochrome labeling, toluidine blue staining, and biomechanical tests were performed at week 8. Micro-CT analysis revealed that Groups SMG, SMG + ICA, and SMG + ICA+EXER exhibited a gradual increase in Tb.Th, Tb.BV/TV, DA, Tb.BMD, and Tb.BMC, and a gradual decrease in BS/BV, Tb.Sp, and SMI compared to Group CON, Mineral apposition rate (MAR) and bone-to-implant contact (BIC) were also significantly higher in ICA groups ( P 0.05 ). Biomechanical strength was enhanced in ICA groups, with superior performance in SMG + ICA+EXER. Simulated microgravity impairs osseointegration, but ICA mitigates these effects, with treadmill exercise further augmenting bone integration and biomechanical strength. This combined strategy may serve as a viable countermeasure for maintaining implant stability in space medicine.
Zhou et al. (Sat,) studied this question.