Antidepressant drug-protein interactions studied by spectroscopic methods based on fluorescent carbon quantum dots

Green Synthesis of Highly Fluorescent Carbon Dots from Bovine Serum Albumin for Linezolid Drug Delivery as Potential Wound Healing Biomaterial: Bio-Synergistic Approach, Antibacterial Activity, and In Vitro and Ex Vivo Evaluation

A simple and green approach was developed to produce novel highly fluorescent bovine serum albumin carbon dots (BCDs) via facile one-step hydrothermal treatment, using bovine serum albumin as a precursor carbon source. Inherent blue photoluminescence of the synthesized BCDs provided a maximum photostability of 90.5 ± 1.2% and was characterized via TEM, FT-IR, XPS, XRD, UV-visible, and zeta potential analyses. By virtue of their extremely small size, intrinsic optical and photoluminescence properties, superior photostability, and useful non-covalent interactions with the synthetic oxazolidinone antibiotic linezolid (LNZ), BCDs were investigated as fluorescent nano-biocarriers for LNZ drug delivery. The release profile of LNZ from the drug delivery system (LNZ-BCDs) revealed a distinct biphasic release, which is beneficial for mollifying the lethal incidents associated with wound infection. The effective wound healing performance of the developed LNZ-BCDs were evaluated through various in vitro and ex vivo assays such as MTT, ex vivo hemolysis, in vitro antibacterial activity, in vitro skin-related enzyme inhibition, and scratch wound healing assays. The examination of LNZ-BCDs as an efficient wound healing biomaterial illustrated excellent biocompatibility and low cytotoxicity against normal human skin fibroblast (HSF) cell line, indicating distinct antibacterial activity against the most common wound infectious pathogens including Staphylococcus aureus (ATCC^® 25922) and methicillin-resistant Staphylococcus aureus, robust anti-elastase, anti-collagenase, and anti-tyrosinase activities, and enhanced cell proliferation and migration effect. The obtained results confirmed the feasibility of using the newly designed fluorescent LNZ-BCDs nano-bioconjugate as a unique antibacterial biomaterial for effective wound healing and tissue regeneration. Besides, the greenly synthesized BCDs could be considered as a great potential substitute for toxic nanoparticles in biomedical applications due to their biocompatibility and intense fluorescence characteristics and in pharmaceutical industries as promising drug delivery nano-biocarriers for effective wound healing applications.

Transition Metal Chelation Augments the Half-life of Secnidazole: Molecular Docking and Fluorescence Spectroscopic Approaches

This current research aimed to establish the most required pharmacodynamics parameters of two transition metal complexes of an antimicrobial drug secnidazole. The spectroscopic fluorescence quenching strategy was outlined to evaluate the binding mechanism and binding affinity of nickel (II) and chromium (III) complexes of secnidazole with bovine serum albumin (BSA). The conformational modifications and the interacting patterns of the protein due to the interaction of the parent compound of the metal complexes have been investigated by molecular docking approach. The ligand-protein interactions were confirmed by the spectral quelling of the serum protein's intensity in the presence of metal chelate of secnidazole. The quenching mechanism was an endothermic dynamic process. The calculated thermodynamic factors delineated van der Waals interactions mainly influenced the spontaneous process. The UV-fluorescence curves were studied to establish the energy transformation profile according to the Förster resonance energy transfer (FRET) theory. The double-logarithm plot exhibited the binding number that ensured the drug-protein interaction was at a 1:1 ratio. The compared binding constants dictated that both metal chelates gained higher binding affinity, longer half-life, and achieved the capacity to show the pharmacological effects by a lower dose than the parent molecule.