Objectives: The aim of this study was to test the applicability of multipotent maxillary cells (MMC) for cell therapy concepts and to evaluate their in vitro behaviour on two different bone substitutes.
Material and methods: Cells isolated from maxillary bone from 10 donors were expanded using media containing human platelet lysate (HPL) replacing foetal bovine serum and differentiated towards both the osteogenic and the adipogenic lineage. Surface markers were determined by fluorescence-activated cell sorting analysis. Calcium deposits, alkaline phosphatase (ALP) and osteocalcin (OC) were used as biomarkers of osteogenic differentiation. Oil Red O was used to verify adipogenic differentiation. The osteogenic lineage and undifferentiated controls were further cultured on natural bone mineral of bovine origin (BioOss) and beta-tricalcium phosphate (Vitoss) scaffolds. Scaffold efficacy and cell migration were evaluated with live cell imaging.
Results: Isolated cells presented characteristics of bone marrow (BM)-stromal cells and could easily be expanded to clinical scales. Cells expressed osteogenic and adipogenic markers when cultured with inductive media. There were no obvious differences in cell migration and growth behaviour between the two bone substitutes, but significantly higher OC expression was observed on BioOss scaffolds. Both osteogenically differentiated and undifferentiated cell lines expressed ALP activity on the scaffolds.
Conclusion: Isolated maxillary cells demonstrate multipotent in vitro characteristics comparable with those of BM-stromal cells. HPL can predictably be used for clinical-scale expansion of MMCs. Both grafting materials provide potential carrier characteristics when loaded with MMCs.