Synthesis, structural characterization, and biological studies of ATBS-M complexes (M(II) = Cu, Co, Ni, and Mn): Access for promising antibiotics and anticancer agents.

A new bidentate Schiff base ligand (ATBS [4-bromo-2-(thiazole-2-yliminomethyl)phenol]) was synthesized via the condensation reaction of 2-aminothiazole with 5-bromosalicylaldehyde in ethanol. The reaction of ATBS with transition metal salts of Cu(II), Co(II), Ni(II), and Mn(II) afforded the corresponding ATBS-M complexes. Results from physicochemical and spectral analyses, such as elemental analysis, infrared, UV-Vis spectroscopy, magnetic susceptibility, and molar conductance, revealed a nonelectrolytic nature with octahedral (Oh ) geometry and a metal/ligand ratio of 1:2 for Cu(II), Co(II), and Ni(II), but 1:1 for the Mn(II) complex. The density functional theory (DFT) calculations are correlated very well with the proposed structure and molecular geometry of the complexes as [M(ATBS)2 ] (M = Cu, Co, and Ni) and [Mn(ATBS)(H2 O)2 ]. Significantly, the prepared compounds showed strong inhibition activity for a wide spectrum of bacteria (Escherichia coli, Bacillus subtilis, and Staphylococcus aureus) and fungi (Candida albicans, Aspergillus flavus, and Trichophyton rubrum), with the ATBS-Ni complex being the most promising antibiotic agent. Molecular docking studies of the binding interaction between the title complexes with the bacterial protein receptor CYP51 revealed clear insights about the inhibition nature against the studied microorganisms, with the following order: ATBS-Cu > ATBS-Mn > ATBS-Ni > ATBS-Co for complex stability. Moreover, the cytotoxicity measurements of all prepared metal complexes against the colon carcinoma (HCT-116) and hepatocellular carcinoma (Hep-G2) cell lines showed exceptional anticancer efficacy of the complexes as compared with the free ATBS Schiff base ligand. Significantly, the results attested that ATBS-Cu is the most effective complex against HCT-116 cells, whereas ATBS-Mn has the highest cytotoxic efficiency against Hep-G2 cells. Furthermore, electronic spectra, viscosity measurements, and gel electrophoresis techniques were employed to probe the interaction of all prepared ATBS-metal complexes with calf thymus (CT)-DNA. Results confirmed that all complexes are strongly bound to CT-DNA via intercalation mode, with the ATBS-Co complex having the highest binding ability.

Incorporation of nanoparticles into transplantable decellularized matrices: Applications and challenges.

Decellularization of tissues can significantly improve regenerative medicine and tissue engineering by producing natural, less immunogenic, three-dimensional, acellular matrices with high biological activity for transplantation. Decellularized matrices retain specific critical components of native tissues such as stem cell niche, various growth factors, and the ability to regenerate in vivo. However, recellularization and functionalization of these matrices remain limited, highlighting the need to improve the characteristics of decellularized matrices. Incorporating nanoparticles into decellularized tissues can overcome these limitations because nanoparticles possess unique properties such as multifunctionality and can modify the surface of decellularized matrices with additional growth factors, which can be loaded onto the nanoparticles. Therefore, in this minireview, we highlight the various approaches used to improve decellularized matrices with incorporation of nanoparticles and the challenges present in these applications.