Fabrication of gold nanohybrids modified with antibody andfunctional dendrimers for targeted photothermaltheranostics

Targeted theranostics can improve benefits of therapeutics or imaging probes byminimizing the dose and by selective delivery to a target site. For this study, a goldnanorod (AuNR)-based nanohybrid was designed for efficient cancer treatmentand diagnosis. The AuNR was functionalized with polyamidoamine dendrimershaving poly(ethylene glycol) and Gd-DOTA residues to provide biocompatibilityand magnetic resonance (MR) imaging properties. Furthermore, trastuzumabwas conjugated to the obtained nanohybrids to enhance the delivery perfor-mance to HER-expressing tumor cells. Fabricated nanohybrids possessed uni-form hydrodynamic diameter and showed typical surface plasmon absorption,which is useful to convert light energy to heat for photothermal therapy. Nanohy-brids exhibited T-weighted relaxation and comparable MR imaging property tothat of commercially available MR contrast reagent. In vitro experiments demon-strated that photothermal effects of nanohybrid under near infrared (NIR) irra-diation were sufficient to kill %–% of cancer cells. The combination of thetargeted nanohybrid and NIR laser irradiation strongly suppressed tumor growthand extended the survival of HER-positive SKOV tumor-bearing nude mice.Therefore, fabricated nanohybrids are promising for targeted photothermal ther-apy and imaging.