Specific photothermal therapy to the tumors with high EphB4 receptor expression. (November 2015) - Wang, Zuhua
Abstract: Photothermal therapy (PTT) employs photo-absorbing agents to generate heat from optical energy, leading to the 'burning' of tumor cells. Real-time imaging of in vivo distribution of photothermal agents and monitoring of post-treatment therapeutic outcomes are very important to design and optimize personalized PTT treatment. In this work, we used chitosan-stearic acid copolymer (CSO-SA) to encapsulate hollow gold nanospheres (HAuNS) and near-infrared (NIR) fluorescent tracer, DiR. Then, the surface of nanoparticles was further conjugated with a peptide (TNYL), which facilitates EphB4-positive tumor targeting delivery. Using a paired tumor mode in vivo and a double tumor-cell co-culture strategy in vitro, we demonstrated the feasibility of increasing the accumulation of our nanoparticles (DiR loaded and TNYL-CSO-SA coated HAuNS (DTCSH)) into EphB4-positive tumors through interaction between TNYL-peptide on the nanoparticles and EpHB4 receptors on tumor cells. When combined with NIR laser irradiation, our nanoparticles induced more EphB4-positive tumor cells death in vitro . We further developed optical imaging to temporally and spatially monitor the biodistribution of DTCSH. Under NIR laser irradiation, PTT exhibited dramatically stronger antitumor effect against EphB4-positive tumors than EphB4-negative tumors. This was attributed to enhanced accumulation of our nanoparticles in EphB4-positive tumors.