Modification of nanodiamond surface with hyper-branched dendrimer as a novel thermo-responsive nanocarrier for near-infrared light-mediated photothermal treatment of breast cancer cells

Abstract

In the current study, we reported the preparation of a nanodiamond surface modified with a thermo-responsive polymer and hyper-branched dendrimer as a drug delivery system for controlling the release of paclitaxel. To evaluate the features of the nanoadsorbent, X-ray diffraction and Fourier-transform infrared spectroscopy tests were performed, to discover the chemical bonding and physical interactions, respectively. Field emission scanning electron microscopy and thermogravimetric analyses were performed to investigate the morphology of the nanoparticles and the thermal behavior of the samples, respectively. The maximum sorption capacity of the drug at optimal conditions (pH = 6, temperature of 20 °C, and contact time of 15 min) was 16.01 mg g⁻¹. The pH_pzc value of 4 was also determined for the nanoadsorbent. The adsorption procedure was investigated based on the correlation coefficient values of the non-linear isotherm models (Langmuir (0.9977), Freundlich (0.9648), Temkin (0.9697), and Dubbini-Radushkevich (0.9254)). It is recommended that the sorption procedure fits best with the Langmuir model. The pseudo-2^nd-order kinetic model shows the most appropriate alignment with the sorption kinetics, exhibiting a correlation coefficient of unity. In vitro drug release after 6 h indicated a release rate of 61.55 % at pH = 7.4 (T = 45 °C) and a release rate of 21.90 % at pH = 7.4 (T = 37 °C), which means it has controlled temperature-responsive behavior. The relative release of the drug from the nanocarrier under near-infrared laser irradiation reached up to 100 % over 15 min, achieving on-demand drug release. The release of the drug occurs in a controlled manner through the non-Fickian diffusion mechanism and follows the Korsmeyer-Peppas kinetic model. The ‘n’ value given from the Korsmeyer-Peppas model was 0.6, showing the mechanism of drug diffusion. The maximum viability of MCF-7 cells observed for the nanocarrier in presense of the near-infrared laser irradiation was 55.30 % at the minimal concentration (100 μg mL⁻¹), whereas the viability of breast cancer cells for the nanocarrier approximated 42.52 % at a concentration of 5000 μg mL⁻¹, which shows good biocompatibility and high photo-thermal conversion efficiency. Accordingly, the developed drug-releasing platform is a promising candidate for photo-thermal chemotherapy and drug delivery for breast cancer treatment.