Histamine (His) in humans is physiologically involved in neurotransmission and increases vascular permeability during the development of inflammatory response and immunity. It could be used to enhance
drug-loaded nanoparticles (NPs) distribution. However, it cannot be freely delivered due to the risk of His-dose-dependent deleterious effects. His can be attached to the polymeric backbone during polymerization to overcome this limitation. In this study, His was used as an initiator of
lactide polymerization, and the obtained macromolecules were subsequently used to prepare
doxorubicin (DOX)-loaded NPs by nanoprecipitation and microfluidics for examination of anti-
cancer properties. Notably, the in vitro activity towards
gastric cancer cells (AGS) of the NPs composed of
histamine-functionalized polylactides (PLAs) was greatly enhanced compared to control NPs built from hydroxy‑functionalized PLAs. Furthermore, Zonula occludens-1 (ZO-1)
tight junction protein production was significantly diminished after treating cells with DOX-loaded NPs assembled with PLAs with
histamine residues. These results demonstrate the synergistic effect in cytotoxicity towards
gastric cancer cells of DOX and the
histamine that are carried by NPs. It is believed that His-DOX NPs strategy may lead to effective, targeted, and low-toxic delivery of drugs into
cancer cells.