Periosteum-Derived Osteo-Like Cells and Their Lyophilized Conditioned Medium Improve Bone Microarchitecture and Mineralized Tissue in Ovariectomized Rats: A Proof-of-Concept Study

Periosteum-derived osteo-like cells (PDOCs) and their lyophilized conditioned medium are promising tools for bone regeneration, but their therapeutic potential for osteoporosis remains unknown. This study evaluated the effects of PDOCs and their lyophilized conditioned medium on bone mineralization and microarchitecture in ovariectomized rats. Eighteen ovariectomized rats (6 animals per group) received PBS (Negative Control Group–NCG); PDOCs (Periosteum Osteolike Cell Group - POCG), or PDOCs lyophilized conditioned medium (Periosteum Osteolike lyophilized conditioned medium Group - POCM). All animals were euthanized after 42 days, and the femurs submitted to microCT and histomorphometric analysis to determine: (1) thickness of the cortical bone; (2) number of trabeculae; (3) percentage of mineralized tissue; (4) percentage of collagen fibers; and (5) percentage of medullary spaces. The thickness of the cortical bone was statistically higher in POCG and POCM than in NCG animals (p<0.05). The trabecular number was higher in POCG and POCM than in NCG rats (p<0.05). The percentage of mineralized tissue was higher in POCG and POCM than in NCG animals (p<0.05), and no statistically significant difference was observed for collagen fibers and percentage of medullary spaces among groups. The use of PDOCs and their lyophilized conditioned medium improved cortical bone thickness, the number of trabeculae and the level of mineralized tissue, suggesting that tissue engineering approaches with PDOC and their lyophilized conditioned medium have potential use for the treatment of osteoporosis.