pH-responsive PEG-chitosan/iron oxide hybrid nanoassemblies for low-power assisted PDT/PTT combination therapy

To develop a hybrid nanoassembly platform using PEG-chitosan/iron oxide nanoparticles for effective low-power assisted photodynamic/photothermal combination therapy. The hybrid nanoassemblies (NAs) were firstly fabricated by self-assembling chitosan and iron oxide nanoparticles, following which their surfaces were modified with polyethylene glycolated triphenylphosphine and loaded with methylene blue (MB) photosensitizer. The physical characteristics and phototherapy effects of these NAs were evaluated. The formed MB-loaded NAs could produce both heat and singlet oxygen under low-power near-infrared irradiation, which would damage the cancer cells. Delivered by intravenous injection, the MB-loaded NAs showed high tendency to accumulate at the tumor sites, which would lead to effective cancer treatment under controlled photoexcitation without damaging the normal tissues. The proposed low-power assisted simultaneous photodynamic/photothermal approach effectively improves treatment efficiency and provides safe and precise treatment option.