| dc.description.abstract | Drug delivery agents for chemotherapy drugs have gained significant interest over past few decades due to the need to localize the treatment to cancer cells. So far, polymeric micelles, liposomes, and carbon-based nanomaterials, among others, have shown great promise for this purpose. Starch nanoparticles have emerged as an avenue for drug delivery due to their low toxicity, biocompatibility and low cost. In this work, starch nanoparticles internally crosslinked by sodium trimetaphosphate (STMP) were prepared using a phase inversion emulsion process. From dynamic light scattering, transmission electron microscopy and environmental scanning electron microscopy, the particle size was determined to be 200-500 nm, regardless of STMP concentration used in the synthesis. 31P NMR determined that a wide variety of organic phosphates were present, apart from the desired phosphodiester crosslinking. These included triphosphates, monophosphates and diphosphates. In addition, like typical charged nanogels, these nanoparticles retained significant amounts of water when dispersed in solution. This was related to the electrostatic repulsion between the chains within the nanoparticle. The presence of salt decreased the amount of water retention by screening of this electrostatic repulsion. The prepared nanoparticles were, in general, non-toxic to HeLa cancer cells. In addition, all prepared nanoparticles displayed a high drug loading, with a maximum seen with 30 mol% STMP. This loading was higher at pH 7.6 compared to lower pH. Drug release occurred more readily at lower pH. Finally, it was seen that exposure to typical cell culture environments induced significant release of drug compared to simple buffer environments. | en |
