Paclitaxel-loaded chitosan oligosaccharide-stabilized gold nanoparticles as novel agents for drug delivery and photoacoustic imaging of cancer cells.

Polymer nanoparticles have gained significant attention as potential drug carriers for anticancer agents and molecular imaging. Biocompatible gold nanoparticles (AuNPs) were synthesized using chitosan oligosaccharide (COS) as a reducing and stabilizing agent and were subsequently loaded with paclitaxel (PTX) to demonstrate their use in drug delivery and photoacoustic imaging (PAI) of MDA-MB-231 cells. Paclitaxel-loaded chitosan oligosaccharide-stabilized gold nanoparticles (PTX-COS AuNPs) were spherical in shape with an average particle size of 61.86±3.01nm. PTX-COS AuNPs showed sustained and pH-dependent drug release profiles and exhibited strong cytotoxic effect against MDA-MB-231 cells through the induction of apoptosis with improved reactive oxygen species (ROS) generation and altered mitochondrial membrane potential (MMP) level. The cellular internalization of PTX-COS AuNPs was proven by fluorescence microscopy as well as flow cytometry. PTX-COS AuNPs were also evaluated as a new class of optical contrast agents for photoacoustic imaging (PAI). To the best of our knowledge, this is the first report that describes the use of PTX-COS AuNPs as novel agents for drug delivery and PAI of cancer cells. These results exposed the promising potential of PTX-COS AuNPs in the field of drug delivery, molecular imaging, and cancer therapy in the near future.