Biology subjects

Ferreira, A. L.

Publications and source records attributed to Ferreira, A. L..

3 recordsLinked to original sources

bioRxiv2026

Organism-dependent ecotoxicological effects of transition metal-containing layered double hydroxides

Due to low environmental stability of certain molecule classes, such as phytohormones and RNA interference, layered double hydroxides (LDHs) have been investigated as nanocarriers capable of protecting and transporting molecules of interest in natural systems. Herein, the ecotoxicological effects of LDH nanoparticles composed by different transition metals (Al-Ni, Al-Co, and Al-Cu) were evaluated in maize (Zea mays), tomato (Lycopersicum esculentum), and the nematode Caenorhabditis elegans, two important crops and one soil organism found in agricultural systems. Plants were exposed to the nanoparticles through foliar spraying (5, 50, and 500 ug/mL), and physiological parameters were evaluated. In C. elegans, lethality, locomotion, larval development, and body length were analyzed. The nanoparticles exhibited high colloidal stability and characteristic lamellar morphology. The results demonstrated low phytotoxicity for all formulations, without significant changes in photochemical activity, effective quantum yield of photosystem II (psi-PSII), stomatal conductance (gs), and chlorophyll index (Chl a+b; ICF) in plants. In contrast, C. elegans exhibited greater sensitivity, showing reduced motility, developmental delay, and decreased body length, although mortality remained below 12% under all evaluated conditions. Toxicity was dependent on the metallic composition, following the order Al-Cu > Al-Ni > Al-Co. Collectively, the results indicate that LDHs exhibit high compatibility with those two crops but may cause sublethal effects in soil organisms. These findings highlight the importance of multispecies ecotoxicological assessments for the safe development of nanocarriers intended for agricultural applications.

pharmacology and toxicology↗

bioRxiv2026

Layered double hydroxide nanoparticles induce composition-dependent cytotoxic and phenotypic effects in mammalian cells

Layered double hydroxides (LDHs) are increasingly explored for agricultural, environmental, and biodelivery applications, but their composition-dependent effects on mammalian cells remain insufficiently defined. Here, we synthesized Al-Ni, Al-Co, and Al-Cu LDH nanoparticles and evaluated their physicochemical properties and biological responses across exposure-relevant mammalian cell models. The formulations showed hydrodynamic diameters of approximately 200-300 nm, moderate dispersity, strongly positive surface charge, and characteristic lamellar LDH features. Cytotoxicity was assessed using MTT, Calcein-AM, and Hoechst-PI assays in HaCaT, A549, and HT-29 cells, representing dermal, pulmonary, and intestinal exposure contexts, together with NIH/3T3 fibroblasts as a sensitive comparative model. LDH toxicity was strongly dependent on metal composition and cell type, with an overall trend of Al-Cu > Al-Co > Al-Ni and more pronounced cytotoxic effects in A549 and HT-29 cells. To detect cellular perturbations beyond overt viability loss, we applied high-content imaging using Live Cell Painting. Multiparametric single-cell profiling revealed composition- and dose-dependent alterations in acidic vesicle organization, nuclear texture, and cytoplasmic granularity. Notably, phenotypic deviations were detected at concentrations below those producing measurable effects in conventional viability assays, and linear discriminant analysis separated the phenotypic signatures induced by the three LDH formulations. Together, these findings show that LDH biological activity cannot be generalized across metal compositions and that high-content phenotypic profiling provides added sensitivity for detecting early cellular perturbations. This integrated approach supports composition-aware nanosafety evaluation and may inform the safer development of LDH-based technologies for agricultural and biotechnological applications.

cell biology↗

bioRxiv2019

Method to generate growth and degrowth models obtained from combinations of existing models applied to agrarian sciences

Mathematical models that describe gas production are widely used to estimate the rumen degradation digestibility and kinetics. The present study presents a method to generate models by combining existing models and to propose the von Bertalanffy-Gompertz two-compartment model based on this method. The proposed model was compared with the logistic two-compartment one to indicate which best describes the kinetic curve of gas production through the semi-automated in vitro technique from different pinto peanut cultivars. The data came from an experiment grown and harvested at the Far South Animal Sciences station (Essul) in Itabela, BA, Brazil and gas production was read at 2, 4, 6, 8, 10, 12, 14, 17, 20, 24, 28, 32, 48, 72, and 96 h after the start of the in vitro fermentation process. The parameters were estimated by the least squares method using the iterative Gauss-Newton process in the software R version 3.4.1. The best model to describe gas accumulation was based on the adjusted coefficient of determination, residual mean squares, mean absolute deviation, Akaike information criterion, and Bayesian information criterion. The von Bertalanffy-Gompertz two-compartment model had the best fit to describe the cumulative gas production over time according to the methodology and conditions of the present study.

developmental biology↗