RESUMO
The treatment of cancer often leads to a range of adverse effects. Encapsulating drugs can mitigate these effects and enhance drug efficacy by enabling a controlled release at the site of interest. This study details the successful synthesis of zinc oxide nanoparticles (ZnONPs) through the precipitation of Zn(NO3)2·6H2O with KOH. A Pd(II) complex drug was synthesized from a Schiff base ligand derived from 2-hydroxybenzohydrazide and (E)-1-(2-(p-tolyl)hydrazono)propan-2-one using potassium tetrachloropalladate(II). This complex was subsequently incorporated into ZnONPs. Characterization of the resulting compounds was performed using Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta Potential, Fourier Transform Infrared (FTIR) Spectroscopy, and UV-visible spectroscopy. TEM imaging revealed particle sizes of 160.69 ± 4.74 nm for ZnONPs and 185.28 ± 2.3 nm for the Pd(II) complex-encapsulated ZnONPs. The Zeta potential values were 6.53 mV for ZnONPs and 7.36 mV for Pd(II) complex-encapsulated ZnONPs. UV-visible spectroscopy showed an absorption peak at 360 nm for ZnONPs, while the Pd(II) complex-encapsulated ZnONPs exhibited a peak at 410 nm. FTIR analysis indicated the presence of the Pd(II) complex within the ZnONPs, as evidenced by a consistent Zn-O vibrational band at 832 cm-1 and a shift in another peak from 460 to 413 cm-1. Additionally, the detection of a C = N stretching vibration at 1548 cm-1 and a carbonyl stretch at 1626 cm-1 was observed. The Encapsulation Efficiency (E.E.) of the Pd(II) complex was 97.2%. A drug release experiment conducted at pH 7 showed a steady-state release pattern after 16 h, with a cumulative release of 44.3%. The cytotoxic effects of the Pd(II) complex and its encapsulated form in ZnONPs on the MCF-7 cell line were assessed via MTT test. The Pd(II) complex encapsulated within ZnONPs exhibited decreased toxicity relative to the unencapsulated drug, as evidenced by a higher IC50 value of 418.5 µg/ml. This suggests that the encapsulation facilitates a sustained release, which allows for targeted accumulation within cells. The elevated IC50 value indicates that the drug delivery system may be engineered to modulate the release of the drug in a more controlled manner, potentially resulting in a prolonged release profile rather than an immediate therapeutic impact.
RESUMO
BACKGROUND: Schiff base metal complexes are considered promising chemotherapeutic agents due to their potential application in cancer therapy. METHODS: The current work sought to synthesize a brand-new Schiff base ligand obtained from 2-hydroxybenzohydrazide and (E)- 1-(2-(p-tolyl)hydrazono)propan-2-one with metal ions which included Pd(II) and Zn(II) ions. Elemental analyses, FT-IR, mass spectra, 1H NMR, UV-Vis spectrometer, and computational analysis characterized the compound's structure. In vitro, the breast cancer cell line (MCF-7) was tested for its sensitivity to Schiff base (HL) and its Pd(II) and Zn(II) complexes. The half-maximal inhibitory concentration IC50 of the compounds was determined and used to perform the comet assay, which was carried out to reveal the photo-induced DNA damaging ability of the compounds of individual cells. Moreover, the compounds' effects on antioxidant defense systems of enzymes in cells: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities and oxidant Malondialdehyde (MDA) were examined in MCF-7 cells. RESULTS: The Pd(II) complex displayed approximately the same IC50 as Cisplatin, while Zn(II) complex had better activity than Cisplatin with very low IC50, 1.40 µg/ml. Significant alterations in SOD, CAT, GPx, and MDA production were discovered, inducing oxidative stress, enlarging ROS production, and reducing the antioxidant amount. This change was approximately similar in most compounds. Consequently, it promoted apoptosis, particularly the Zn(II) complex, which demonstrated an improved impact because of its ability to influence the antioxidant defense systems of enzymes, mostly SOD and GPx, besides increasing MDA levels. CONCLUSION: It can be concluded that Zn(II) complex is the most effective anticancer drug since it induced a very similar genotoxic effect as Cisplatin and has a very low IC50 value.
