Reinforcement of osteogenic and mechanical properties of calcium phosphate cement with palm tocotrienol

Introduction Calcium phosphate cement (CPC) is a promising bone substitute but lacks osteogenicity and mechanical strength. This study investigated the effects of CPC doped with palm tocotrienol, a bone-protective agent, on bone regeneration in ovariectomised rats with tibial defects. Material and methods Female Sprague-Dawley rats were divided into sham-operated controls, ovariectomised rats (OVX), ovariectomised rats with bone defects implanted with CPC (OVX + CPC) and ovariectomised rats with bone defects implanted with palm tocotrienol-doped CPC (OVX + CPC/T3). A tibial bone defect was created 11 weeks after ovariectomy. Results Whole-body BMC was higher in OVX + CPC (10.89 ±0.07 g) and OVX + CPC/T3 (11.26 ±0.07 g) than OVX (10.24 ±0.14 g) (p < 0.05). Whole-body BMD of OVX + CPC/T3 (0.175 ±0.003 to 0.182 ±0.003 g/cm2), left tibia BMC of OVX + CPC (0.308 ±0.016 to 0.343 ±0.022 g) and OVX + CPC/T3 (0.313 ±0.020 to 0.343 ±0.016 g) increased from week 11 to 15 (p < 0.05). The OVX + CPC/T3 group had higher bone stiffness (23.31 ±1.07 vs. 8.35 ±3.84 N/mm), collagen (scoring: 3 ±0.75 vs. 2 ±0), trabecular bone formation (scoring: 3 ±0 vs. 2 ±0), and trabecular bone volume (36.30 ±3.58 vs. 20.86 ±1.03%) but lower osteoclast surface (1.65 ±0.49 vs. 6.60 ±1.36%) than OVX (p < 0.05). Tibial BMP-2 in OVX + CPC/T3 (78.96 ±8.30 pg/mg protein) was higher than OVX (30.65 ±3.69 pg/mg protein) and OVX + CPC (48.09.96 ±8.39 pg/mg protein) (p < 0.05). Tibial Runx-2 in OVX + CPC/T3 (2589.75 ±204.74 pg/mg protein) was higher than OVX (1652.97 ±156.85 pg/mg protein) and OVX + CPC (1845.77 ±158.17 pg/mg protein) (p < 0.05). Conclusions Palm tocotrienol enhanced the osteogenic properties of CPC, promoting collagen and trabecular bone formation in ovariectomised rats with bone defects. These findings suggest its potential to overcome the drawbacks of CPC and promote bone regeneration.