A Trojan horse PRINT particle composition was developed that incorporates a reductively labile cross-linker to achieve activated release of doxorubicin in vitro. Particles of discrete size and shape (cube side length = 2 micron) containing 30 wt % of a disulfide-based cross-linker and 2 wt % doxorubicin were synthesized. This PRINT composition was shown to release doxorubicin in response to a reducing environment as measured by flow cytometry and was found to be highly proficient at killing HeLa cells in vitro.