Polymersome nanoparticles for delivery of Wnt-activating small molecules ☆ ☆☆

E Scarpa, AA Janeczek, A Hailes, MC de Andrés, A De Grazia, ROC Oreffo, TA Newman, ND Evans

Index: 10.1016/j.nano.2018.02.014

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Abstract

Spatiotemporal control of drug delivery is important for a number of medical applications which may be achieved using polymersome nanoparticles (PMs). Wnt signalling is a molecular pathway activated in various physiological processes, including bone repair, that requires precise control of activation. Here, we hypothesise that PMs can be stably loaded with a small molecule Wnt agonist, 6-bromoindirubin-3′-oxime (BIO), and activate Wnt signalling promoting the osteogenic differentiation in human primary bone marrow stromal cells (BMSCs). We showed that BIO-PMs induced a 40% increase in Wnt signaling activation in reporter cell lines without cytotoxicity induced by free BIO. BMSCs incubated with BIO-PMs showed a significant up-regulation of the Wnt target gene AXIN2 (14 ± 4 fold increase, p < 0.001) and a prolonged activation of the osteogenic gene RUNX2. We conclude that BIO-PMs could represent an innovative approach for the controlled activation of Wnt signaling for promoting bone regeneration after fracture.