Near-infrared-laser-triggered drug release from two-dimensional tungsten trioxide nanosheets decorated by dual stimuli-responsive polymer and in vitro cytotoxicity studies
摘要
This study details the creation of a new pH- and temperature-responsive nanocarrier based on tungsten trioxide grafted with a copolymer of allyl alcohol and N-isopropylacrylamide designed for the controlled release of sorafenib. The successful synthesis was verified using various analytical techniques. To optimize the adsorption conditions, factors such as solution pH, initial drug concentration, contact time, and temperature were assessed using a central composite design with response surface methodology. A quadratic polynomial equation was derived to describe the drug adsorption efficiency of the nanoadsorbent. The highest adsorption rate of 81.39% was achieved at an initial drug concentration of 26.26 mg L−1, pH of 8.8, contact time of 18.83 min, and a temperature of 33.51 °C. The study of isotherm models indicated that the Langmuir isotherm model best matched the experimental data, suggesting monolayer adsorption on uniform surfaces. Additionally, the kinetic models showed that the pseudo-first-order model represented the drug adsorption data most accurately. Drug release experiments demonstrated that reducing the pH of the release medium from 7.4 to 5.6 significantly increased the release rate of the nanocarrier, especially at higher temperatures. The pH- and temperature-responsive system exhibited a sustained release profile over 6 h, reaching a maximum cumulative release of 98.51%. Furthermore, under near-infrared laser irradiation, the drug release efficiency reached 100% within 15 min, highlighting the potential for stimuli-responsive drug delivery. The Korsmeyer-Peppas kinetic model was the best fit for drug release from the nanocarrier in both fluids. Moreover, an MTT assay was conducted on A549 and HLF cell lines, representing lung cancer cells and normal fibroblasts, respectively, to assess the cytotoxicity of the samples. The results indicated that the drug-loaded nanocomposite exhibited greater cytotoxicity than pure drug. These data suggest that this nanocarrier could serve as a promising vehicle for delivering sorafenib with significantly enhanced bioavailability.