Cationic Polyelectrolyte‐Polyphenol Complex Derived Gold Nanoparticles for Efficacious Anticancer Drug Delivery

The straightforward production of gold nanoparticles (AuNPs) remains always desirable in contrast to traditional chemical based syntheses which often require separate components for reduction and stabilization as well as control over pH and temperature conditions. Herein, we report instantaneous synthesis of AuNPs using a polyelectrolytic complex of low molecular weight polyethylenimine (PEI) and plant based polyphenol, i.e., Gallic acid (GA) which served as both reducing and stabilizing agent. The presence of amine groups rich PEI induced GA mediated reduction of ionic gold and provided electrostatic stabilization as well as pH sensitivity to AuNPs in a single step. The method offered a monodisperse population of stable AuNPs which were thoroughly characterized by means of UV–vis spectrophotometry, field emission scanning electron microscopy (FE‐SEM), high resolution transmission electron microscopy (HR‐TEM), atomic force microscopy (AFM), X‐ray diffraction (XRD), dynamic light scattering (DLS), and zeta potential measurement studies. The confocal imaging, flow cytometry and MTT based cytotoxicity analysis revealed that the AuNPs mediated effective delivery of doxorubicin to drug sensitive (MDA‐MB‐231 and HeLa) and drug resistant (DR‐HeLa) cancer cell lines resulted in a significant cytotoxic response. The biocompatibility assessment in zebrafish model revealed that these AuNPs could be safe alternatives for practical drug delivery applications.