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.

Doxorubicin-loaded fucoidan capped gold nanoparticles for drug delivery and photoacoustic imaging.

Polymer nanoparticles are emerging as a useful tool for a wide variety of biomedical and therapeutic applications. The present study demonstrates the multifunctional doxorubicin-loaded fucoidan capped gold nanoparticles (DOX-Fu AuNPs) for drug delivery and photoacoustic imaging (PAI). Biocompatible AuNPs were synthesized using a naturally occurring fucoidan (Fu) as a capping and reducing agent. The Fu AuNPs synthesis was determined using UV-visible spectrum, and it was further characterized using high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. The release of DOX from DOX-Fu AuNPs was greater in acidic pH (4.5) than in neutral pH (7.4). The in vitro cytotoxic effect of fucoidan, Fu AuNPs, DOX, and DOX-Fu AuNPs inhibited the proliferation of human breast cancer cells with an inhibitory concentration of 35µg/mL, 30µg/mL, 15µg/mL, and 5µg/mL at 24h. DOX-Fu AuNPs induced both early and late apoptosis in a concentration-dependent manner compared with untreated control cells. The ability of DOX-Fu AuNPs as a contrast agent for in vitro breast cancer imaging with PAI has been evaluated. These results suggest that the multifunctional DOX-Fu AuNPs for drug delivery and PAI can soon provide considerable contribution to human health.

Cytotoxic Induction and Photoacoustic Imaging of Breast Cancer Cells Using Astaxanthin-Reduced Gold Nanoparticles.

Astaxanthin, a kind of photosynthetic pigment, was employed for gold nanoparticle formation. Nanoparticles were characterized using Ulteraviolet-Visible (UV-Vis) spectroscopy, transmission electron microscopy, and X-ray diffraction, and the possible presence of astaxanthin functional groups were analyzed by Fourier transform infrared spectroscopy (FTIR). The cytotoxic effect of synthesized nanoparticles was evaluated against MDA-MB-231 (human breast cancer cells) using a tetrazolium-based assay, and synthesized nanoparticles exhibited dose-dependent toxicity. The morphology upon cell death was differentiated through fluorescent microscopy using different stains that predicted apoptosis. The synthesized nanoparticles were applied in ultrasound-coupled photoacoustic imaging to obtain good images of treated cells. Astaxanthin-reduced gold nanoparticle has the potential to act as a promising agent in the field of photo-based diagnosis and therapy.