It is possible to obtain intracellular drug delivery through some physical methods such as the microinjection/gene gun and hydrodynamics but there is concern that these techniques cause tissue damage. This is why most efforts focus on developing drug delivery vehicles that coat or encapsulate drugs and deliver them efficiently to the desired target. Surfactant free emulsion polymerization is used to synthesize the nanoparticles as this allows control over the size of nanoparticles. As no surfactant is used to stabilize the system, the formed nanoparticles are easily cleaned. This is an excellent process to make pure synthetic nanoparticles for biological applications. We have recently developed core (polymer)-shell (silica) nanoparticles that are promising candidates for the delivery of hydrophobic (e.g. antimitochondrial) drugs. A drug has been loaded in the polymeric cores during formation of the nanoparticles. An investigation into drug loading and release properties of the nanoparticles has been carried out. Thermally responsive polymers have been integrated into the cores of the nanoparticles in order to develop smart drug delivery vehicles that can be remotely triggered for releasing the drug at the tumor site. In vitro uptake of nanoparticle-mediated delivery using dye as model drug was also observed using prostate cancer cell lines. Also cytotoxicity studies using the drug loaded nanoparticles was done and showed promising cell death compared to the controls.