Synthesis, characterization, and cytotoxicity assessment of N-acetyl-l-cysteine capped ZnO nanoparticles as camptothecin delivery system

The chemical stability, good biocompatibility and high drug loading capacity of zinc oxide nanoparticles (ZnO NPs) and their biomedical potentials make them a promising candidate for drug delivery. The aim of this study was to develop and assess a simple procedure for surface functionalization of ZnO NPs by N-acetyl- l -cysteine (NAC) for anticancer camptothecin (CPT) delivery. NAC capped ZnO NPs were successfully made using ZnCl 2 and NaOH in the presence of NAC. CPT was covalently conjugated to the surface of as-synthesized ZnO-NAC NPs. To characterize the synthesized conjugate product (ZnO-NAC-CPT NPs), X-ray diffraction, Fourier Transform Infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering method were used. Our results indicated that the ZnO-NAC-CPT NPs exhibit near-spherical morphology and uniform dispersion with an average diameter of ∼70 nm. The hemolysis assay showed that ZnO-NAC-CPT NPs has almost no hemolytic activity. In addition, MTT cytotoxicity assessment on A549 lung cancer cells revealed a drop of IC 50 values from 1.17 μg/mL (free CPT) to 0.66 μg/mL (ZnO-NAC-CPT NPs). This result showed an augmented cancer-inhibitory effect of nanoconjugate complex. In conclusion, the novel ZnO-NAC-CPT NPs could be considered for new therapeutic endeavors.