Langmuir, Vol.27, No.17, 10501-10506, 2011
Nanoparticle-Stabilized Colloids in Compressible Hydrofluoroalkanes
In this work, we show that nanoparticles,(NPs) dispersed in compressible hydrofluoroalkanes (HFAs) small volume fractions are capable of stabilizing micrometer-sized particle colloids, which otherwise flocculate due to strong van der Waals forces. Water-soluble, biodegradable NPs with a chitosan (CS) core, grafted with hilly HFA-philic moieties, can be readily dispersed in the low dielectric HFAs and are capable of imparting stability to a wide range of therapeutic particles having different chemistries (polar or hydrophobic; small and large molecular weight, including peptides and proteins) and morphologies (micronized crystals or amorphous). These NP systems thus serve as a broadly applicable platform for the noninvasive delivery of therapeutics to and through the lungs using propellant-based, portable inhalers, and are also of potential relevance in Other industries where HFAs are employed as solvents or propellants. This concept May also be applicable to other compressible solvents.