Arylboronic acids are commonly used in modern organic chemistry to form new C–C and C–heteroatom bonds. These activated organic synthons show reactivity with heteroatoms in a range of substrates under ambient oxidative conditions. This broad reactivity has limited their use in protic, renewable solvents like water, ethanol, and methanol. Here, we report our efforts to study and optimize the activation of arylboronic acids by a copper(II) N-heterocyclic carbene (NHC) complex in aqueous solution and in a range of alcohols to generate phenol and aryl ethers, respectively. The optimized reactivity showcases the ability to make targeted C–O bonds, but also identifies conditions where water and alcohol activation could be limiting for C–C and C–heteroatom bond-forming reactions. This copper(II) complex shows strong reactivity toward arylboronic acid activation in aqueous medium at ambient temperature. The relationship between product formation and temperature and catalyst loading are described. Additionally, the effects of buffer, pH, base, and co-solvent are explored with respect to phenol and ether generation reactions. Characterization of the new copper(II) NCN-pincer complex by X-ray crystallography, HR-MS, cyclic voltammetry, FT-IR and UV-Vis spectral studies is reported.

Three new tridentate copper(II) N-heterocyclic carbene (NHC) complexes have been obtained and characterized with symmetrical C-4 substitutions on their pendent pyridine rings. Substitutions including methyl (Me), methoxy (OMe), and chloro (Cl) groups, which extend the library pincer Cu-NHC complexes under investigation, modify the impact of pyridinyl basicity on NCN pincer complexes. Both ligand precursors and copper(II) complexes are characterized using a range of techniques, including nuclear magnetic resonance (NMR) spectroscopy for ¹H, ¹³C, ³¹P, and ¹⁹F nuclei, electrospray ionization mass spectrometry (ESI-MS), X-ray crystallography, cyclic voltammetry, and UV-Vis spectroscopy. The pyridine substitutions lead to minimal changes to bond lengths and angles in the X-ray crystal structures of these related complexes; there is a pronounced impact on the electrochemical behavior of both the ligand precursors and copper complexes in the solution. The substitution in the pyridinyl units of these complexes show an impact on the catalytic reactivity of these complexes as applied to a model C–N bond-forming reaction (CEL cross-coupling) under well-established conditions; however, this observation does not correlate to the expected change in basicity in these ligands.

Sensorineural hearing loss (SNHL) remains a significant global health burden due to its irreversible nature and limited treatment options. Recent advances in nanotechnology have introduced new possibilities for targeted drug delivery to the inner ear, with poly(lactic-co-glycolic acid) (PLGA) nanoparticles emerging as a promising platform. Biodegradable and biocompatible, PLGA nanoparticles can encapsulate diverse therapeutic agents and enable sustained, site-specific delivery to cochlear and vestibular structures. This review highlights key physicochemical properties of PLGA nanoparticles relevant to inner ear therapy, including controlled release, tunable surface modifications, and ideal particle size. It explores advanced cochlear targeting techniques—such as round window membrane penetration, magnetic navigation, and ultrasound-assisted delivery—and their applications in otoprotection against ototoxic drugs and noise-induced hearing loss. Additionally, the potential of PLGA nanoparticles in inner ear regeneration, particularly through hair cell restoration and stem cell-based repair, is examined. Preclinical evidence, comparative advantages over other nanocarriers, and challenges in clinical translation are critically reviewed. Finally, emerging trends are discussed, including integration with gene editing, combination therapies, and personalized medicine. This review underscores the transformative potential of PLGA-based nanomedicine in protecting and restoring hearing function, paving the way for future clinical breakthroughs.

The persistence of per- and polyfluoroalkyl substances (PFAS) in the environment and their possible negative health impacts have attracted global attention. In Nigeria, there have been instances of PFAS contamination in many environmental areas, such as water sources. This paper raised concerns regarding limited research of PFAS in Nigeria, potential human exposure, and environmental consequences in Nigeria. This paper examines the present status of PFAS research in Nigeria, the sources from which contamination occurs, the environmental effects, and the implications for human health. This underscores the holes in understanding and areas of focus for study, underscoring the necessity for thorough evaluations of potential risks and regulatory actions to reduce exposure to PFAS and protect public health and the environment in Nigeria.