Periosteal-derived cells for bone bioengineering: a promising candidate

Over the last years so many efforts have been made in order to indentify natural sources of osteogenic cells for the success of bone bioengineering. Among them, periosteum tissue has emerged as an interesting candidate. Thus, we decided to evaluate the osteogenic potential of periosteal-derived cells by describing a sequence of biological events since initial morphological changes to mineralization of extracellular matrix (ECM).

Periosteal-derived cells were obtained from calvarial of adult rats. After the primary culture and expansion, the adherent cells were cultured at 7, 14, 21 and 28 days under a classical osteogenic culture medium in order to evaluate the differentiation of those cells in mature osteoblast. It was monitored by evaluating a time-line of alkaline phosphatase (ALP) activity (biomarker of osteoblast differentiation) and afterwards nodules of mineralization (measured by von Kossa staining and calcium content).

Analysis from phase-contrast microscopy revealed mainly morphological changes ranging since fibroblast-shaped (7 days, semi-confluent culture at exponential growth) to polyhedral-shaped cells (14-28 days, confluent culture during differentiation process). ALP activity was linearly increased since 14-28 days while amount of protein remained unchanged. Interesting, our data from von Kossa staining reveled a highest incidence of mineralization nodules at 28 days.

Taken our results together, we can suggest that periosteal-derived cells present an interesting potential to differentiate in mature osteoblast able to promote mineralization in vitro by incorporating to ECM circulating calcium from extracellular compartment. From our point of view, this source of osteogenic cells can be explored by bioengineers in order to advance therapeutic protocols able to solve bone degenerative lesions.