In vitro spectroscopic investigation of groove binding interaction of Fe3O4@CaAl-LDH@L-Dopa with calf thymus DNA

Insight into the binding mechanism of macrolide antibiotic; erythromycin to calf thymus DNA by multispectroscopic and computational approaches

In the present study, the interactions between Erythromycin drug and calf thymus deoxyribonucleic acid (ct-DNA) were explored by multi spectroscopic techniques (UV-Visible, fluorescence, circular dichroism spectroscopies), viscosity, molecular docking simulation, and atomic force microscopy (AFM). In addition, the values of binding constant were calculated by the UV-Visible and fluorescence spectroscopy. Competitive fluorescence study with methylene blue (MB), acridine orange (AO), and Hoechst 33258 were indicated that the Erythromycin drug could displace the DNA-bound Hoechst, which displays the strong competition of Erythromycin with Hoechst to interact with the groove binding site of DNA. In addition, the observed complexes in AFM analysis comprise the chains of ct-DNA and Erythromycin with an average size of 314.05 nm. The results of thermodynamic parameter calculations (ΔS° = -332.103 ± 14 J mol^-1 K^-1 and ΔH° = -115.839 ± 0.02 kJ mol^-1) approved the critical role of van der Waals forces and hydrogen bonds in the complexation of Erythromycin-DNA. Fluorescence spectroscopy results demonstrate the existence of a static enhancement mechanism in the interaction of Erythromycin-DNA. According to the obtained results, Erythromycin drug interacts with the major groove of ct-DNA. These consequences were further supported by the molecular docking study, and it could be determined that DNA-Erythromycin docked model was in a rough correlation with our experimental results.Communicated by Ramaswamy H. Sarma.

Synthesis, characterization and in vitro cytotoxicity studies of novel Cu(II) complex containing zonisamide drug: DNA interaction by multi spectroscopic and molecular docking methods

In this study, the Cu(II) complex with Zonisamide (ZNS) and 1, 10-Phenanthroline (Phen) ligands as an anticancer metallodrug was synthesized and characterized successfully by FT-IR, mass spectrometry, TGA, XPS, AAS, CHNSO, magnetic susceptibility and electrical conductivity. The interaction of Cu(II) complex with DNA was explored through a multi-spectroscopic approach such as fluorescence, UV-vis spectrophotometry, CD spectroscopy, and viscosity measurements. Molecular docking simulation was carried out to gain a deeper insight into the target site of DNA which interacted with the mentioned complex. The competitive binding tests with Hoechst 33258 showed that [CuCl₂(ZNS)(Phen)EtOH].H₂O can bind to the groove site of DNA. The calculated thermodynamic parameters, ΔS° = +201.15 J mol^-1K^-1 and ΔH° = +41.32 kJ mol^-1 confirm that the hydrophobic forces and hydrogen bonding play an essential role in the binding process. The experimental and molecular modeling results demonstrate that the Cu(II) complex binds to DNA through major groove binding. Moreover, the in vitro cytotoxic effects of [CuCl₂(ZNS)(Phen)EtOH].H₂O against B92 cancer cell lines showed better activity in Cu(II) complex in comparison to free ZNS. Therefore, [CuCl₂(ZNS)(Phen)EtOH].H₂O can open a new horizon in the treatment of glioma cancer by ZNS metallodrugs.Communicated by Ramaswamy H. Sarma.

In vitro cytotoxicity studies of smart pH-sensitive lamivudine-loaded CaAl-LDH magnetic nanoparticles against Mel-Rm and A-549 cancer cells

In this study, an effective nano-drug delivery system was prepared by the co-precipitation method via two steps; the preparation of Fe₃O₄ magnetic nanoparticles and its surface modification with layered double hydroxide (LDH) and loading lamivudine on this nanocarrier (Fe₃O₄@CaAl-LDH@Lamivudine). The developed nanoparticles (NPs) were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis, Fourier-transformed infrared spectroscopy, vibrating-sample magnetometry, thermogravimetric analysis, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller. The prepared system demonstrated an average size of 130 nm. Also, the drug entrapment efficiency was estimated at ∼70%. In vitro, drug release investigations showed a controlled and pH-dependent lamivudine release over 300 min. The in vitro cytotoxic activity of Fe₃O₄@CaAl-LDH@Lamivudine NPs was explored against Mel-Rm and A-549 cancer cell lines in comparison with lamivudine and nanocarrier using lactate dehydrogenase colorimetric and MTT assay. The results of the MTT assay revealed that the Fe₃O₄@CaAl-LDH@Lamivudine NPs significantly inhibited the proliferation of Mel-Rm and A-549 cells in a dose-dependent manner. The influences of Fe₃O₄@CaAl-LDH@Lamivudine on the cancer cell lines by different therapeutic investigation illustrated the remarkable effect in comparison with free drug. Finally, the achieved consequences confirm the anticancer properties of Fe₃O₄@CaAl-LDH@Lamivudine and indicate that they may be a cost-effective substitute in the treatment of lung and skin cancer.Communicated by Ramaswamy H. Sarma.

Exploring the binding mechanisms of inorganic magnetic nanocarrier containing L-Dopa with HSA protein utilizing multi spectroscopic techniques

In this study, the interaction of Fe₃O₄@CaAl-LDH@L-Dopa nanoparticles (NPs) with human serum albumin (HSA) was investigated in simulated physiological conditions applying UV-visible, fluorescence, and circular dichroism (CD) spectroscopic techniques. The consequences of UV-vis and CD spectroscopy demonstrated that the interaction of HSA to Fe₃O₄@CaAl-LDH@L-Dopa NPs enforced some conformational alterations within HSA. The fluorescence spectroscopy analysis indicated that by enhancing temperature, the Stern-Volmer quenching constant (K_sv) was decreased, which is relevant to a static quenching mechanism. The binding constant (K_b) was 7.07 × 10⁴ M^-1 while the number of the binding site (n) was 0.94 which is in compromise with its binding constant. Also, thermodynamic parameters (ΔH° > 0, ΔG° < 0, and ΔS° > 0) have suggested that hydrophobic forces perform a key role in the interaction of HSA with Fe₃O₄@CaAl-LDH@L-Dopa NPs. Displacement studies successfully carried out using the Warfarin and Ibuprofen have predicted that the binding of Fe₃O₄@CaAl-LDH@L-Dopa NPs to HSA is situated at site II (subdomain IIIA).Communicated by Ramaswamy H. Sarma.