Multi-functionalization of
calcium phosphates to get delivery systems of therapeutic agents is gaining increasing relevance for the development of functional
biomaterials aimed to solve problems related to disorders of the muscolo-skeletal system. In this regard, we functionalized
Strontium substituted
hydroxyapatite (SrHA) with some β-
lactam integrin agonists to develop materials with enhanced properties in promoting cell adhesion and activation of intracellular signaling as well as in counteracting abnormal
bone resorption. For this purpose, we selected two monocyclic β-
lactams on the basis of their activities towards specific
integrins on promoting cell adhesion and signalling. The amount of β-
lactams loaded on SrHA could be modulated on changing the polarity of the loading
solution, from 3.5-24 wt% for compound 1 and from 3.2-8.4 wt% for compound 2. Studies on the release of the β-
lactams from the functionalized SrHA in aqueous medium showed an initial burst followed by a steady-release that ensures a small but constant amount of the compounds over time. The new composites were fully characterized. Co-culture of human primary mesenchymal stem cells (hMSC) and human primary osteoclast (OC) demonstrated that the presence of β-
lactams on SrHA favors hMSC adhesion and viability, as well as differentiation towards osteoblastic lineage. Moreover, the β-
lactams were found to enhance the inhibitory role of
Strontium on osteoclast viability and differentiation.