HUMAN MESENCHYMAL STEM CELLS AS A MODEL OF STUDY FOR NEW BIOMATERIALS IN BONE TISSUE REGENERATION

The reconstruction of large bone segments remains a critical clinical problem in the case of extensive bone loss due to traumatic or pathological events. Due to its ideal biocompatibility and osteogenic properties, autologous bone is still considered the gold standard for bone replacement applications, however its use has limitations such as supply amount and unpredictable healing kinetics. These limitations and recent progress in biotechnology have driven the development of materials/scaffolds for bone repair. Biocompatibility issues and materials/scaffolds features need to be investigated and the usefulness of human cell cultures for biocompatibility testing is confirmed by experimental studies. In-vitro models employing human cells to study the interactions between the cell system and the biomaterial/device allow for a reasonable prediction of its performance in vivo. To study coral derived Hydroxyl-Apatite (HA) osteo-conductivity and cyto-toxicity we employed an engineered osteoblast-like cellular model named Saos-eGFP. Although the efficacy of this cellular model, the need of an in-vitro tool resembling a more physiological-like cellular response, led to the development of an adult human mesenchymal stem cell (hMSCs) model. This model was employed to assay porous stoichiometric HA and non-stoichiometric Mg-HA bone substitutes. Our studies showed how human cells may be employed to analyze osteo- conductivity/inductivity and cyto-toxicity, and specifically how hMSCs allow a more insightful understanding of the earliest phase of cell-biomaterial interaction, addressing the question of which type of biomaterials could be better for bone regeneration applications.