Water soluble polyethyleneimine functionalized single wall carbon nanotubes (PEI-SWNTs) can be loaded with the therapeutic agents acetic acid and the gemcitabine analogue, deoxycytidine (dC). The amount of loading is based on initial sonication time and the solubility of the agent. The use of an endoscopic ultrasound (EUS) results in the controlled release of the agents from the PEI-SWNT conjugate. The release of acetic acid occurs by first-order kinetics, however, the release of the majority of the dC occurs by the more desired zero-order release.