In this work, nanostructured porous silicon (PSi) hosts, synthesized by electrochemical etching of Si, are designed to carry and release the anti cancer drug, mitoxantrone dihydrochloride (MTX). We study the effect of surface chemistry of the Si scaffold on its properties as a drug carrier. The freshly-etched PSi is modified by surface alkylation using thermal hydrosilylation with 1-dodecene. Fourier-transform infrared spectroscopy and nitrogen adsorption-desorption measurements are employed to characterize the PSi carriers after chemical modification. Both, drug loading efficiency and release kinetics are found to be significantly affected by surface chemistry of the PSi. In vitro cytotoxicity studies on human breast carcinoma (MDA-MB-231) cells show that the MTX released from the PSi hosts maintains its cytotoxic functionality.