Aim: In this work, to improve the solubility and bioavailability of the rosuvastatin (RSV) drug, chitosan-coated mesoporous silica nanoparticles (CS-MSNs) as drug delivery systems were fabricated. Methods: To do this, first MSNs with a maximum specific surface area were synthesized from sodium silicate as silica source and different molar ratios of cethyl trimethylammonium bromide (CTAB) and pluronics (P123, PEO20PPO17PEO20) as surfactants via the sol-gel process. Then, the synthesized MSNs were coated by CS polymer with the help of (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) as a linker between MSNs and CS. Subsequently, the RSV drug was loaded into the synthesized CS-coated MSNs. The products were characterized by different techniques, including X-ray diffraction (XRD), the Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The in vitro drug release profile of the fabricated DDS was evaluated in a typical phosphate-buffered saline (PBS) solution at different pH values (i.e., 4, 6, and 7.4) for 48 h. To assess the cytotoxicity, the viability of the human fibroblast cells exposed to the fabricated DDS was also examined. Results: The results showed that at an optimal molar ratio of P123/CTAB, the amorphous MSNs with a specific surface area of about 1080 m2/g, a pore diameter of 4 nm, a pore volume of 1.1 cm3/g, and an average size of about 30 nm were synthesized. Also, the presence of all the components, including the CS coating and the RSV drug, was confirmed in the structure of the fabricated DDS by FTIR analysis. Due to the pH-responsive feature of the CS coating, the RSV drug release from the fabricated DDS showed a reasonable environmental response; as the pH value of the PBS solution decreased, the degree of drug release increased. Conclusion: The CS coating enhanced the cytotoxicity of the fabricated DDS and led to sustainable drug release behavior, which would provide a beneficial approach for drug delivery technology.

Nanoscale zinc oxide (ZnO) is one of the most important materials in semiconductor applications today. The ZnO nanoparticles (ZnO-NPs) have received the most interest among the various nanoparticles. The ZnO nanostructures are composed mainly of ZnO and have at least one dimension on the nanometer scale (1-100 nm). ZnO is a wide-bandgap semiconductor with an energy gap of 3.37 eV at room temperature. Different methods have been used to synthesize ZnO NPs, which has led to different physical and chemical properties. The high surface energy of the particles produced in most of these methods tends to accumulate them. Therefore, nanoparticles of ZnO are used in biosensors, gas sensors, solar cells, ceramics, nanogenerators, photodetectors, catalysts, and active fillers in rubber and plastic due to their unique properties. As a UV absorber, it can also be used in cosmetics, photocatalysis, electrical and optoelectronic systems, and as an additive in a wide variety of industrial products.