Analysis of Osteogenic Differentiation of Bone Marrow Stromal Cells on New Materials

Objectives: Studies conducted in the past clearly denote how different material surfaces alter the growth of cultured cells. The interaction of cells grown on material surfaces- especially calcium phosphate (CaP) and titanium (Ti) substances- is known to enhance bone formation and inhibit bone resorption. Therefore, we aim to study the osteogenic activity of murine and human derived bone marrow mesenchymal stromal cells (BMSCs) growing on different material surfaces.
Methods: These BMSCs will be cultured on Ti-6AL-4V and Zirconium Dioxide (ZrO₂) discs in four different conditions in vitro: polished, acid-etched, coated with, and infiltrated with biomimetic CaP. Ti-6AL-4V is a titanium alloy used in joint replacement surgeries, and ZrO₂ is a ceramic material applied in dental crowns, bridges, and implants. We hypothesize that the BMSCs will differentiate into osteoblasts and begin synthesizing bone matrix at an increased rate on CaP coated or infiltrated discs compared to the controls. Once the cells are grown in selected media for 14 days, we harvest the RNA and evaluate the expression of osteoblast marker genes with Real Time qPCR. An alkaline phosphatase assay will further analyse the levels of gene expression during differentiation. In addition, Von Kossa staining of the minerals synthesized on the discs will allow for definitive identification of osteogenic differentiation after 21 days. The structure of the BMSC attachment and morphology with the material surface will be investigated and analysed through Scanning Electronic Microscopy (SEM).
Results: The different surface preparation methods influence a specific material’s ability to support osteogenesis. Coating or infiltrating with CaP could stimulate the differentiation of BMSCs. Other types of surface preparation may affect the proliferation rate of osteoblast progenitor cells.
Conclusions: This study provides important information to guide the application and selection of medical materials to increase bone growth and vitality.
Supported by Dr. Li’s grants + NIH/NIDCR 2R01 DE017925, NIH/NIAMS 5R01 AR056208.