Mechanochemical Preparation, Characterization and Biological Activity of Stable CuS Nanosuspension Capped by Bovine Serum Albumin

Impacts of neonicotinoid compounds on the structure and function of Apis mellifera OBP14: Insights from SPR, ITC, multispectroscopy, and molecular modeling

Honeybees are vital for biodiversity and agricultural productivity, yet their populations are declining globally, partly due to exposure to neonicotinoid pesticides. Odorant-binding protein 14 (OBP14) plays an important role in honeybee chemosensation, but its involvement in neonicotinoid toxicity remains underexplored due to limitations in traditional fluorescence spectroscopy techniques. This gap hampers our understanding of neonicotinoid risks to honeybee health. Here, we explored the molecular interactions between OBP14 from Apis mellifera and three widely used neonicotinoids (imidacloprid, thiamethoxam, and clothianidin) using molecular modeling, surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), and multispectroscopy. SPR and ITC characterized the binding affinity, specificity, and thermodynamic parameters of AmelOBP14 interacting with three neonicotinoid compounds, revealing that the binding process is spontaneous and primarily driven by hydrophobic and electrostatic interactions. Molecular modeling highlighted that phenylalanine residue Phe54, near the binding site, plays a critical role in these interactions. UV-vis absorption spectroscopy and synchronous fluorescence spectroscopy (SFS) support slight changes in the microenvironment around the aromatic amino acids of OBP14. Fourier Transform Infrared Spectroscopy (FTIR) and circular dichroism spectroscopy (CD) indicate a decrease in the α-helix content of OBP14, suggesting a change in its secondary structure, while three-dimensional (3D) fluorescence spectroscopy confirms the non-fluorescent nature of the OBP14 polypeptide backbone. The study results revealed its potential as a biomarker for pesticide risk assessment, providing important insights into the molecular mechanisms by which neonicotinoids may impair bee chemosensory function, and offering guidance for the design of safer pesticides to minimize harm to these important pollinators.

In vitro and ex vivo anti-myeloma effects of nanocomposite As4S4/ZnS/Fe3O4

Nanoparticles in medicine can integrate actively targeted imaging agents and drug delivery vehicles, and combining multiple types of therapeutics in a single particle has numerous advantages, especially in multiple myeloma. MM is an incurable hematological disorder characterized by clonal proliferation of plasma cells in the bone marrow. In this study, we evaluated the anti-myeloma activity of 3 nanocomposites (3NPs): As₄S₄/ZnS/Fe₃O₄ (1:4:1), As₄S₄/ZnS/Fe₃O₄ with folic acid (FA), and As₄S₄/ZnS/Fe₃O₄ with FA and albumin with reduced survival MM cell lines and primary MM samples by each of 3NP. Cytotoxic effects of 3NPs were associated with caspase- and mitochondria-dependent apoptosis induction and reduced c-Myc expression. Modulation of cell cycle regulators, such as p-ATM/ATM and p-ATR/ATR, and increases in p-Chk2, cyclin B1, and histones were accompanied by G₂/M arrest triggered by 3NPs. In addition, 3NPs activated several myeloma-related signaling, including JNK1/2/3, ERK1/2 and mTOR. To overcome BM microenvironment-mediated drug resistance, nanocomposites retained its anti-MM activity in the presence of stroma. 3NPs significantly decreased the stem cell-like side population in MM cells, even in the context of stroma. We observed strong synergistic effects of 3NPs combined with lenalidomide, pomalidomide, or melphalan, suggesting the potential of these combinations for future clinical studies.