Trimethylated chitosan-O-poly(-caprolactone) (TMC-PCL) micelles were used as nanocarriers for co-loading of two types of drugs with distinct hydrophilicity

including FDA-approved near-infrared (NIR) photosensitizer

indocyanine green (ICG) and a first-line anti-cancer drug

doxorubicin (DOX).Both two agents could be incorporated within the micelles with entrapment efficiency of more than 85% and loading content of up to 20%.The loading content could be adjusted by varying feed ratio of the agents to the micelles.A red-shift in absorption peak of ICG from 780 nm to 800 nm was observed upon incorporation in to the micelles.The competitive binding of the micelles to ICG molecules also increased the momoner/dimer ratio of ICG.TMC-PCL micelles showed an excellent ICG retention ability

and only 18.18% of ICG was leaked from micelles after 48 hours incubation in physiological media.In addition

the incorporation of ICG within the micelles enhanced its thermal and optical stability.ICG-loaded micelles (ICG-micelles) exhibited higher heating capacity than free ICG.DOX release behavior was affected by the temperature

while the presence of ICG within the micelles had little effect on DOX release.The cytotoxicity of the dual-agent-loaded micelles towards HepG2 cells was found to be higher than that of single-agent-loaded counterparts.