Glycogen Synthase Kinase 3ß Inhibitor Delivered by Chitosan Nanocapsules Promotes Safe, Fast, and Efficient Activation of Wnt Signaling In Vivo.

The Wnt-ß-catenin signaling is an evolutionarily conserved pathway with a prominent role in different biological processes such as stem cell renewal, cell proliferation, and differentiation. Wnt signaling dysfunctions have been associated with developmental and neurological diseases as well as formation and progression of tumors. Nanomedicine may provide safe and efficient drug delivery systems offering breakthrough innovation in targeting Wnt signaling. The natural polymer chitosan represents an excellent candidate for delivery platforms, showing interesting biophysical properties such as high biocompatibility and mucoadhesive properties. In this study, oily core chitosan nanocapsules were designed with the aim to deliver the Wnt signaling agonist alsterpaullone in the model organism Hydra vulgaris. Chitosan nanocapsules show negligible impact on animal morphology, without affecting the viability. Nile red-loaded nanocapsules reveal fast and efficient intracellular delivery of the fluorescent cargo. Short incubations with alsterpaullone-loaded nanocapsules ensure a more effective activation of Wnt signaling with respect to the same concentrations of the free drug. Altogether, these data provide evidence that chitosan nanocapsules may represent a very promising strategy for future therapies targeting the diseases associated with canonical Wnt signaling.

Inhibition of p38 MAPK in the brain through nasal administration of p38 inhibitor loaded in chitosan nanocapsules.

Aim: To determine whether a p38 MAPK inhibitor incorporated into nanoemulsion-based chitosan nanocapsules can reduce the activity of this kinase in the brain through their nasal administration in mice. Materials & methods: We selected the p38 MAPK inhibitor PH797804, an ATP-competitive inhibitor of p38α encapsulated in nanoemulsion-based chitosan nanocapsules. Biological effect was evaluated in microglial and neuronal cells in vitro and in ex vivo and in vivo systems, in a mouse model of Alzheimer's disease. Results: Encapsulated inhibitor retains enzymatic inhibitory activity and tissue penetration capacity in vitro, ex vivo and in vivo. Conclusion: Nasal administration of chitosan nanocapsules can be an effective approach for brain-restricted reduction of p38 MAPK activity, thus reducing the side effects of systemic administration.