A Magnesium Phosphate-Based Platform Alleviates Bone-Fat Imbalance for the Repair of Age-Related Osteoporotic Bone Defects.

Background/

Objectives

Osteoporosis poses significant obstacles as it causes an imbalance between osteoblasts and adipocytes, which results in the disruption of bone homeostasis. Although various magnesium-based scaffolds have been deployed for the treatment of osteoporotic bone defects, whether this can be achieved by alleviating bone-fat imbalance still requires further elucidation.

Methods

We designed magnesium phosphate-based platforms (GMPCs), based on magnesium photopolymerized methacrylated gelatin (GelMA) and phosphate (K-struvite, MPC), and used them to deliver magnesium ions (Mg2+) for alleviating bone-fat imbalance locally.

Results

The in vivo results demonstrated that the GMPCs not only improved osteogenic behavior at the implanted site, but also reduced the proportion of adipose tissues in a femoral defect model in 18-month-old SD rats. Moreover, by promoting the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts in a concentration-dependent manner, GMPCs significantly reduced adipogenic differentiation in vitro. Also, 5GMPC demonstrated the best comprehensive biologic properties compared to other platforms.

Conclusions

GMPCs have great potential in the treatment of age-related osteoporosis via the effective delivery of Mg2+.