Schiff bases represent a valuable class of organic compounds, synthesized via condensation of primary amines with ketones or aldehydes. They are renowned for possessing innumerable applications in agricultural chemistry, organic synthesis, chemical and biological sensing, coating, polymer and resin industries, catalysis, coordination chemistry, and drug designing. Schiff bases contain imine or azomethine (-C=N-) functional groups which are important pharmacophores for the design and synthesis of lead bioactive compounds. In medicinal chemistry, Schiff bases have attracted immense attention due to their diverse biological activities. This review aims to encompass the recent developments on the antimicrobial activities of Schiff bases. The article summarizes the antibacterial, antifungal, antiviral, antimalarial, and antileishmanial activities of Schiff bases reported since 2011.

This study describes the synthesis and characterization of chlorambucil (CLB)-functionalized mesoporous silica nanoparticles (MSNs) for potential application in cancer therapy. The nanoparticles were designed with a diameter between 20 and 50 nm to optimize cellular uptake and avoid rapid clearance from the bloodstream. The synthesis method involved modifying a previously reported technique to reduce particle size. Successful functionalization with CLB was confirmed through various techniques, including Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The cytotoxicity of the CLB-functionalized nanoparticles (MSN@NH₂-CLB) was evaluated against human lung adenocarcinoma cells (A549) and colon carcinoma cells (CT26WT). The results suggest significantly higher cytotoxicity of MSN@NH₂-CLB compared to unbound CLB, with improved selectivity towards cancer cells over normal cells. This suggests that MSN@NH₂-CLB holds promise as a drug delivery system for targeted cancer therapy.

This study reports the synthesis, characterization, DFT calculations and in vitro antimicrobial, cytotoxic and antiproliferative evaluation of La(III), Eu(III), and Gd(III) metal complexes with ampicillin. The compounds were characterized by Thermal Gravimetric Analysis (TGA), elemental analysis, ultraviolet–visible spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (¹H NMR), indicating a 2:1 metal-to-ligand ratio with ampicillin, and likely, a coordination through carbonyl, carboxylic and β-lactam groups, with the general formula [Ln₂(L)(Cl)₅(H₂O)_x] (Ln = La(III), Eu (III), Gd (III), and x = 2 for La(III), 5 for Eu(III) and Gd(III), L-ampicillin anion). Antimicrobial studies showed activity against ampicillin-resistant Staphylococcus aureus (MIC = 15.6 µg·mL⁻¹) but no activity against Escherichia coli. In cytotoxicity studies, all complexes inhibited B16-F10 (murine melanoma) proliferation, with GI₅₀ values around 140 µg·mL⁻¹. Against U251 (glioma) cell line, only [Eu₂(L)(Cl)₅(H₂O)₅] exhibited cytotoxicity activity, GI₅₀ = 104 µg·mL⁻¹, and notably, [Eu₂(L)(Cl)₅(H₂O)₅] was active against MCF7 (breast carcinoma) with a GI₅₀ = 8.1 µg·mL⁻¹. However, all complexes exhibited high cytotoxicity in NIH-3T3 cells (GI₅₀ = 0.030–2.90 µg·mL⁻¹), indicating limited selectivity between normal and cancer cells. Nevertheless, except for the La complex, most compounds were less cytotoxic than doxorubicin, highlighting the need for further optimization to improve selectivity.

The aim of this manuscript is to synthesize and characterize novel silylated Sm3+ and Eu3+ complexes and incorporate them into mesoporous silica nanoparticles (MSNs) and dense silica nanoparticles (DSNs). Sm3+ and Eu3+ ion complexes were chosen for their strong UV-visible emission, deep-red luminescence, and effective interaction with bidentate organic ligands, such as 2-thenoyltrifluoroacetone (tta) and 1,10-phenanthroline (phen). Silylated ligands were employed as coupling agents to form covalent bonds between the complexes and an oxide matrix via a conventional sol-gel process. This approach aims to enhance the thermal stability and photophysical properties of the resulting hybrid material compared to free complexes. The new silylated-bidentate ligand complexes, using tta and phen as organic ligands and 3-chloropropyltriethoxysilane as the silylating agent, were characterized by FTIR, luminescence spectroscopy, and luminescence decay. After incorporation into silica nanoparticles, the hybrid materials were characterized by SEM, TEM, DLS, zeta potential, SAXS, porosity, surface area measurements, luminescence spectroscopy, and MTT assay. The results confirm the successful synthesis of new luminescent silylated complexes with high luminescence intensity and their incorporation into silica nanoparticles.