Triggered-release nanocapsules for drug delivery to the lungs.

This study demonstrated the feasibility of trigger-responsive inhaled delivery of medicines using soft solid shelled nanocapsules. The delivery system was a 50nm sized lipid rich capsule carrier that distended rapidly when mixed with an exogenous non-ionic surfactant trigger, Pluronic® L62D. Capsule distension was accompanied by solid shell permeabilisation which resulted in payload release from the carrier; 63.9±16.3% within 1h. In electrolyte rich aqueous fluids Pluronic® L62D was loosely aggregated, which we suggest to be the cause of its potency in lipid nanocapsule permeabilisation compared to other structurally similar molecules. The specificity of the interaction between L62D and the nanocapsule resulted in carrier payload delivery into human epithelial cells without any adverse effects on metabolic activity or barrier function. This effective, biocompatible, trigger-responsive delivery system provides a versatile platform technology for inhaled medicines.