Osteogenic Differentiation of Human Mesenchymal Stem Cells by the Single Action of Luminescent Polyurea Oxide Biodendrimers.

Polyurea oxide (PURO) biodendrimers are a class of dendrimers that can trigger osteogenic differentiation of human mesenchymal stem cells (hMSCs). PURO biodendrimers are prepared by simple, solventless oxidation of polyurea dendrimers using hydrogen peroxide as the oxidant in quantitative yield, retaining both biocompatibility (up to 10 mg/mL for higher generations) and the non-traditional intrinsic luminescence. The effect of PURO biodendrimers in the differentiation of hMSCs was found by the single addition to a standard growth medium for MSCs differentiation (without differentiation inducers). After 21 days of incubation, the formation of osteoblasts was confirmed by the alizarin red staining assay and alkaline phosphatase activity. This is the first report of in vitro osteodifferentiation fully regulated by synthetic soft polymers such as dendrimers. Current osteogenic differentiation protocols rely on an in vitro inducing formulation (including dexamethasone, ascorbic acid, and β-glycerophosphate), which lacks therapeutic potential in vivo. The outstanding role of dendrimers in nanomedicine, under clinic translation, combined with this feature is envisaged to foster PURO dendrimers as an important strategy in cell therapy and regenerative medicine.