Erythromycin (ERY) is a macrolide compound with a broad antimicrobial spectrum which is currently being used to treat a large number of bacterial infections affecting the skin, respiratory tract, intestines, bones and other systems, proving great value from a clinical point of view. It became popular immediately after its discovery in 1952, due to its therapeutic effect against pathogens resistant to other drugs. Despite this major advantage, ERY exhibits several drawbacks, raising serious clinical challenges. Among them, the very low solubility in water and instability under acidic conditions cause a limited efficacy and bioavailability. Apart from this, higher doses promote drug resistance and undesirable effects. In order to overcome these disadvantages, during the past decades, a large variety of ERY formulations, including nanoparticles, have emerged. Despite the interest in ERY-(nano)formulations, a review on them is lacking. Therefore, this work was aimed at reviewing all efforts made to encapsulate ERY in formulations of various chemical compositions, sizes and morphologies. In addition, their preparation/synthesis, physico-chemical properties and performances were carefully analysed. Limitations of these studies, particularly the quantification of ERY, are discussed as well.

Copper-based nanoparticles, especially metallic copper (Cu NPs) and copper oxide (CuO NPs), have attracted increasing attention due to their redox activity, biological efficacy, and technological applications. However, conventional chemical synthesis often involves toxic reagents, limiting their biomedical applicability. In this context, plant-mediated green synthesis has evolved and has become a sustainable and cost-effective alternative. This review provides a comprehensive overview of recent advances in the biosynthesis of Cu and CuO nanoparticles using plant extracts. The main synthesis pathways are examined, with emphasis on the role of phytochemicals as reducing, stabilizing, and capping agents, as well as the influence of reaction parameters on nanoparticle yield. The review highlights the diversity of plant species and extract types used and clarifies their effects on nanoparticle size, morphology, oxidation state, and surface chemistry. Key physicochemical characterization techniques (ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), electron microscopy, and zeta potential analysis) are systematically discussed. Moreover, a summary of in vitro and in vivo biological activities is provided, including antimicrobial, antioxidant, cytotoxic, anticancer, wound-healing, and plant-growth-promoting effects. Overall, plant-mediated copper-based nanoparticles demonstrate significant potential as biofunctional nanomaterials. Nevertheless, challenges concerning reproducibility, mechanistic understanding, standardization and toxicological evaluation must be addressed to facilitate reliable translation into biomedical applications.

Gene delivery with cationic polymers requires balancing DNA compaction, colloidal stability, and intracellular release, yet for imine-linked low-molecular-weight polyethyleneimine (PEI) vectors, quantitative relationships connecting the N/P ratio with the full property–transfection cascade remain undefined. Here, two amphiphilic non-viral vectors were prepared by linking a hydrophobic benzene–siloxane core (TAS) to hyperbranched PEI (800 or 2000 Da) through reversible imine bonds and complexed with DNA across a broad N/P range (10–600). Polyplexes were characterized by atomic force microscopy (AFM), dynamic light scattering (DLS), ζ-potential, agarose gel electrophoresis, transfection via green fluorescent protein (GFP) imaging and luciferase assay in HeLa cells. Both vectors formed spherical nano-entities (AFM diameters ~30 nm for TAS-PEI800; ~100 nm for TAS-PEI2000). TAS-PEI2000 achieved complete DNA retardation at N/P ≈ 30 versus N/P ≈ 150 for TAS-PEI800, consistent with its higher charge density (ζ = +37.59 vs. +18.35 mV). Transfection efficiency was superior for TAS-PEI2000 across most N/P ratios; however, TAS-PEI2000 displayed an optimal transfection efficiency at N/P ≈ 100 (ζ ≈ 3.84 mV), beyond which efficiency declined, indicating a binding–release trade-off. Cell viability remained >77% across the N/P range for TAS-PEI800, but dropped below 25% at N/P ≥ 400 for TAS-PEI2000. A phenomenological logistic model identified characteristic transition thresholds (θ ≈ 60 for TAS-PEI800; θ ≈ 40 for TAS-PEI2000), capturing the onset of cooperative self-assembly; however, the post-optimum decline observed for TAS-PEI2000 requires additional inhibitory terms. These findings demonstrate that PEI molecular weight governs both the N/P threshold required for efficient transfection and the width of the therapeutic window, thereby providing structure–activity descriptors for the rational design of imine-linked polyplex systems.