IR 820 stabilized multifunctional polycaprolactone glycol chitosan composite nanoparticles for cancer therapy†

Photothermal therapy has gained worldwide attention for its less painful, non invasive/minimally invasive,<br>effective thermal ablation based therapy for cancer. It has been found to be effective in the treatment of<br>drug-resistant cancer. Currently available photothermal systems have several limitations such as a high<br>cost, incompatibility and clearance from the physiological system. To address these issues, we have<br>prepared multifunctional biocompatible and biodegradable cost effective IR 820 dye encapsulated glycol<br>chitosan coated polycaprolactone composite nanoparticles (PCLGC–IR) with improved performance.<br>Polycaprolactone (PCL) has been used as a cheap biodegradable polymer, glycol chitosan (GC) as an<br>immunoadjuvant for immune response generation followed by the cost-effective IR 820 dye for<br>photothermal therapy. IR 820 encapsulation increases the stability of the PCLGC–IR nanoparticles as<br>confirmed by DSC and XRD, while the glycol chitosan enhances the uptake of the composite<br>nanoparticles by MDA-MB-231 breast cancer cells. The PCLGC–IR composite nanoparticles with a size<br>of around 150–200 nm can be irradiated with a dual laser at 750 nm and 808 nm in photothermal<br>therapy (PTT). In addition to PTT, the PCLGC–IR composite nanoparticles can also be used for<br>sustainable controlled drug release as they retain their structural integrity even after laser treatment.<br>Further we analyzed the degraded product using liquid chromatography mass spectroscopy (LCMS)<br>upon photo irradiation. A cytotoxicity study of the PCLGC–IR composite nanoparticles was carried out<br>on NIH3T3 cells. Fluorescence microscope image analysis of MDA-MB-231 cells showed hyperthermic<br>cell death via apoptosis and necrosis due to an enhanced uptake of the PCLGC–IR composite<br>nanoparticles. Our results showed that this nanoformulation can be used for the effective treatment ofmultiple drug resistant cancer.