Efficacy of soluble lansoprazole-impregnated beta-tricalcium phosphate for bone regeneration

The proton pump inhibitor lansoprazole has been previously identified to upregulate the expression and transcriptional activity of runt-related transcription factor 2 (Runx2) that promotes lineage commitment and differentiation of osteoprogenitor cells. We could not elicit the expected efficacy of insoluble lansoprazole in enhancing osteogenesis when combined with beta-tricalcium phosphate (β-TCP) bone substitutes. This study aimed to evaluate the effects of soluble lansoprazole on in vitro osteoblastogenesis and new bone formation in vivo. Commercially available human mesenchymal stem cells or patient-derived bone marrow-derived stromal cells were treated with 20 µM of soluble lansoprazole at the beginning of osteogenic induction. Soluble lansoprazole-impregnated β-TCP materials were embedded in the cortical bone defect model of rabbits. Rabbits were sacrificed four weeks postoperatively and undecalcified bone specimens were prepared for evaluation of intra-material new bone formation. Only a 1-day treatment with soluble lansoprazole facilitated osteoblastic differentiation and matrix calcium deposition when added to undifferentiated human mesenchymal stromal cells at the beginning of the osteogenic differentiation. Soluble lansoprazole dose-dependently accelerated intra-material new bone formation when being impregnated with porous β-TCP artificial bones. Local use of soluble lansoprazole can be applicable for fracture and bone defect repair when combined with porous β-TCP scaffolds.