Treatment of cancer requires local medication at the tumor site to prevent side-effects of chemotherapy. Nanocarriers, such as micelles, can be used to transport drugs to the tumor site and limit side effects of cancer treatment. Micelles are easy to produce, have a high solubilization potential for hydrophobic drugs and therefore can have high loading capacity. Due to the increase in cell division and higher activity of cancer cells, elevated levels of reactive oxygen species (ROS) are often present at the tumor site. ROS have a highly oxidizing agent property by damaging DNA of cancer cells, it can be used to treat tumors. Beside ROS formation of the metabolic cycle, ROS can also be produced by ionizing radiation. With radiolysis of water, caused by radiation, the ROS concentrations at tumor sites can be increased. This research aimed to prepare micelles made from a block copolymer, that are sensitive to ROS and that are sensitive to ROS formed by radiolysis of water with gamma radiation for drug release purposes. 4-(methylthio)phenyl acrylate (MTPA) groups present in the block copolymer (PDMA-MTPA), are sensitive for oxidation reactions which will lead to decomposition of the polymer, and thus of the micelles. During this research, micelles with a hydrodynamic diameter between 30 and 50 nm were exposed to H2O2 levels between 2 wt% (0.6 M) and 0.007 wt% (2 mM) and a change in hydrodynamic diameter and light intensity scattering was observed, meaning that micelles decompose with elevated concentrations of H2O2. In addition, an increase in hydrodynamic diameter was observed for micelles exposed to a dose between 67 and 500 Gray by irradiating with gamma rays of 1.25 MeV originating from a 60Co source, indicating that micelles cluster after sufficient dose of gamma radiation. These characteristics can be useful for making PDMA-MTPA micelles, a suitable candidate for drug delivery applications.