Modification of Tungsten Trioxide with Polyamidoamine Dendrimer: A Thermosensitive Nanocarrier for Near-Infrared Laser Triggered Delivery of Docetaxel

Abstract

The pH and thermo-sensitive nanocarrier was synthesized by the modification of tungsten trioxide (WO₃) through copolymerization reaction and branched polyamidoamine (PAMAM) dendrimer for use in near-infrared (NIR) triggered docetaxel (DTX) delivery. To do this, after grafting on the WO₃ nanoparticle surface with a thermo-sensitive poly [(vinyl methyl ether)]–co-[allylamine]s, three generations of PAMAM dendrimer using ethylenediamine and methyl methacrylate, were successfully grown formed. Nanostructures were characterized by using X-ray diffraction, FT-IR, SEM, TEM, GPC and TGA. Different parameters including temperature, pH, and contact times were considered to optimize the operating conditions and evaluate the potential of dendrimer nanocarrier for drug delivery. By analyzing the in vitro drug release after 6 h in fluids with different pH (5.6 and 7.4) and temperatures (37 and 50 °C), a good response was found at pH 5.6 and temperature 50 °C, which indicated controlled release of drug and the dual response (pH and thermo responsiveness) of the nanocarrier. Investigation of the effect of NIR irradiation showed that the release of DTX under NIR irradiation within 12 min was 99%, which was 10 times that without NIR. Photothermal effect of NIR induced the shrinkage of thermo-sensitive polymer which results in the control of drug. Besides, the adsorption kinetic was examined using Temkin, Dubinin, Freundlich, and Langmuir isotherm models. The sorption process of DTX by nanocarrier was best expressed by the Langmuir model with high coefficient of determination (R²) equal to 0.9985. Also, pseudo-second-order kinetic model confirmed the best correlation between experimental data with R² = 0.999. The results revealed that the pH/ thermo-sensitive nanocarrier is a promising candidate for drug delivery.