| 초록 |
A simple and novel electrostatic coupling method is reported, which provides hyaluronic acid - quantum dot conjugate (HA-QD) that is colloidally stable and size-tunable from 50 to 120 nm. The HA-QDs show cancer targeting efficiency, which suggests diagnostic and imaging applications. The conjugates are also demonstrated for the fluorescence staining capability for lymphatic vessels in vitro and in vivo. Using the HA-QDs in small animal model, lymphatic vessels are visualized real-time in vivo for days. Comprehensive cytoxicity evaluations are made for the conjugates and the unconjugated counterpart. The HA-QDs showcase the potentials toward cancer imaging and real-time visualization of changes in lymphatic vessels such as lymphangiogenesis. On the other hand, photo-therapy agents have been in constant pursuit for longer wavelength absorption as it promises maximal tissue penetrations for better efficacy. Noble metal nanostructures can be ideal candidates for anticancer photothermal therapy, and the plasmon mode can be tuned to far-red or infrared-red by nanorods, nanoshells or nanocages. We use small and easy-to-make 10 nm spherical gold nanoparticles for ‘smart’ photothermal agent that is designed to aggregate in intercellular environment. The ‘smart’ gold nanoparticles are relatively small and can be efficiently internalized into cells. Inside cells, rapid pH-induced aggregations are triggered and the aggregates accumulate as their exocytosis is blocked by the increased size. Concurrently, their absorption shifts to longer wavelengths reaching near-infrared. This is exploited to demonstrate their potential for photothermal therapy. They show selective and efficient destruction of cancerous cells by turn-on mechanism, with the effective threshold illumination over an order of magnitude lower than other nanostructures. |
