(617d) pH Induced Drug Release From Carbon Nanohorn Based Bionanoparticles

Nanoparticle mediated drug delivery plays an increasingly important role in the treatment of cancers and inflammatory diseases.  However, how to minimize basal drug release and thus the accompanying side effect is still a challenging problem.  In this study, we have synthesized carbon nanohorn (CNH) supported liposome particles.  A model drug, paclitaxel, was loaded into CNH, which displays a much higher loading capacity that that of liposomes.  Lipids with different pH sensitivity were assembled into the lipid bilayer.  Our initial study showed that under serum free condition, the drug release profiles of the assembled particles were highly pH dependent. At neutral pH, there was minimal release.  When the pH was reduced, the release increased significantly. However, the presence of serum clearly destabilized the lipid bilayer as the bionanoparticles and liposomes showed no distinctive drug release behavior. Efforts were taken to optimize the lipid formulation to reduce the basal drug release under physiological conditions.