Preparation and investigations of PEG-AT-PEG organic nano-polymer photothermal material

Conjugated polymer (CPs) has good near infrared (NIR) absorption and high photothermal conversion effect, which is one of the most promising photothermal therapy (PTT) drugs for cancer therapy. Through the combination of hydrophobic conjugate component of aniline trimer (AT) and hydrophilic component of aldehyde polyethylene glycol (PEG-CHO), linear polymer (PEG-AT-PEG) is synthesized via Schiff base reaction. Self-assembly nanoparticles simply precipitated out by dropping the tetrahydrofuran solution of PEG-AT-PEG into deionized water under ultrasonic dispersion. Owing to the rigid hydrophobic conjugated structure in the middle and the hydrophilic long chain structure at both ends, the long chain material can undergo hydrophobic association and π-π stacking in deionized water to form spherical organic nanoparticle. Such self-assembly nanoparticles have strong NIR absorption at 700 ∼ 800 nm, and can significantly increase the temperature in a short time upon continuous 808 nm laser irradiation, showing good photothermal conversion efficiency. The nanoparticles of PEG-AT-PEG show good biocompatibility to Hela cells at low concentration, when exposed to laser light, the destruction of Hela tumor cells was very distinct in the concentration range of 200 to 800 ug ml⁻¹. Synthetic strategy based on CPs will be possible to develop more effective nanomaterials for treating cancer or tumors.