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Poly(lactic-co-glycolic acid) is one of the most used polymers for drug delivery systems (DDSs). It shows excellent biocompatibility, biodegradability, and allows spatio-temporal control of the release of a drug by altering its chemistry. In spite of this, few formulations have reached the market. To characterize and optimize the drug release process, mathematical models offer a good alternative as they allow interpreting and predicting experimental findings, saving time and money. However, there is no general model that describes all types of drug release of polymeric DDSs. This study aims to perform a statistical comparison of several mathematical models commonly used in order to find which of them best describes the drug release profile from PLGA particles synthesized by nanoprecipitation method. For this purpose, 40 datasets extracted from scientific articles published since 2016 were collected. Each set was fitted by the models: order zero to fifth order polynomials, Korsmeyer-Peppas, Weibull and Hyperbolic Tangent Function. Some data sets had few observations that do not allow to apply statistic test, thus bootstrap resampling technique was performed. Statistic evidence showed that Hyperbolic Tangent Function model is the one that best fit most of the data.

A zeolitic sample, named MT-ZLSH, was synthesized using mining tailings (MT) as the precursor material, resulting in a structure comprising: Linde type A (LTA) and sodalite-hydroxysodalite (ZLSH). This naming convention reflects the material’s origin and its structural characteristics. The material was further modified by incorporating lithium, producing MT-ZLSH-Li+. Physicochemical characterizations were performed, and the material was evaluated for its potential to remove methylene blue (MB) from synthetic wastewater through adsorption and photocatalysis. Efficient adsorption was observed under typical wastewater pH conditions, with a maximum adsorption capacity of 23.4 mg·g−1, which fit well with the Langmuir isotherm model. The key mechanisms governing MB adsorption were identified as ion exchange, electrostatic attraction, and hydrogen bonding. The adsorption process was exothermic, with kinetic data fitting both the pseudo-second order and intraparticle diffusion models, achieving 82% removal and a maximum adsorption capacity of 40 mg·g−1 over 12 h. MB adsorption followed a two-step process, initially involving film diffusion, followed by intraparticle diffusion. Additionally, photocatalytic degradation of MB achieved 77% degradation within 180 min. However, a decrease in reusability was observed during a second cycle of MB adsorption and photodegradation, highlighting the need for further optimization to enhance the material’s long-term performance.

The family of mosquitoes (Diptera: Culicidae) contains several species of major public health relevance due to their role as vectors of human disease. One of these species, Aedes aegypti, is responsible for the transmission of some of the most important vector-borne viruses affecting humankind, including dengue fever, chikungunya and Zika. Traditionally, control of Ae. aegypti and other arthropod species has relied on the use of a relatively small diversity of chemical insecticides. However, widespread and intensive use of these substances has caused significant adverse environmental effects and has contributed to the appearance of pesticide-resistant populations in an increasing number of locations around the world, thereby dramatically reducing their efficiency. Therefore, it becomes urgent to develop novel alternative tools for vector control. In that context, our study aimed at evaluating the insecticidal activity against Ae. aegypti of aqueous extracts obtained from the fruits of Solanum mammosum L., as well as silver nanoparticles synthesized using aqueous extracts from this plant species (SmAgNPs). To perform the test, third instar Ae. aegypti larvae were exposed to increasing concentrations of plant extract and SmAgNPs for 24 h. Our results suggest that both the aqueous extract and SmAgNPs were toxic to the larvae, with SmAgNPs displaying a much higher level of toxicity than the extract alone, as reflected in their LC50 values (0.06 ppm vs 1631.27 ppm, respectively). These results suggest that both S. mammosum extracts and SmAgNPs exhibit noteworthy larvicidal activity, and should be further explored as potential source of alternative tools in the fight against insect vectors of human disease.

Water pollution caused by increasing industrial and human activity remains a serious environmental challenge, especially due to the persistence of organic contaminants in aquatic systems. Photocatalysis offers a promising and eco-friendly solution, but in the case of bismuth oxide (Bi2O3) there is still a limited understanding of how structural and morphological features influence photocatalytic performance. In this work, a straightforward hydrothermal synthesis method followed by controlled calcination was developed to produce phase-pure α- and β-Bi2O3 with tunable morphologies. By varying the hydrothermal temperature and reaction time, distinct structures were successfully obtained, including flower-like, broccoli-like, and fused morphologies. XRD analyses showed that the final crystal phase depends solely on the calcination temperature, with β-Bi2O3 forming at 350 °C and α-Bi2O3 at 500 °C. SEM and BET analyses confirmed that morphology and surface area are strongly influenced by the hydrothermal conditions, with the flower-like β-Bi2O3 exhibiting the highest surface area. UV–Vis spectroscopy revealed that β-Bi2O3 also has a lower bandgap than its α counterpart, making it more responsive to visible light. Photocatalytic tests using Rhodamine B showed that the flower-like β-Bi2O3 achieved the highest degradation efficiency (81% in 4 h). Kinetic analysis followed pseudo-first-order behavior, and radical scavenging experiments identified hydroxyl radicals, superoxide radicals, and holes as key active species. The catalyst also demonstrated excellent stability and reusability. Additionally, Methyl Orange (MO), a more stable and persistent azo dye, was selected as a second model pollutant. The flower-like β-Bi2O3 catalyst achieved 73% degradation of MO at pH = 7 and complete removal under acidic conditions (pH = 2) in less than 3 h. These findings underscore the importance of both phase and morphology in designing high-performance Bi2O3 photocatalysts for environmental remediation.

Silver nanoparticles (Ag-NPs) are known for their efficient bactericidal activity and are widely used in industry. This study aims to produce printable antibacterial devices by drop-on-demand (DoD) inkjet technology, using Ag-NPs as the active part in complex printable fluids. The synthesis of this active part is described using two methods to obtain monodisperse NPs: chemical and microwave irradiation. The synthesized NPs were characterized by UV-VIS, STEM, TEM, DLS and XRD. Two printable fluids were produced based: one with Ag-NPs and a second one, a polymeric nanocomposite, using silver nanoparticles and polyvinyl butyral (Ag-NPs/PVB). Cellulose acetate was used as a flexible substrate. The ecotoxicity analysis of fluids and substrate was performed with Artemia franciscana nauplii. Optimized electric pulse waveforms for drop formation of the functional fluids were obtained for the piezoelectric-based DoD printing. Activity of printed antibacterial devices was evaluated using the Kirby-Bauer method with Staphylococcus aureus and Escherichia coli. The results show that the printed device with Ag-NP fluids evidenced a bacterial inhibition. An important advantage in using the DoD process is the possibility of printing, layer by layer or side by side, more than one active principle, allowing an interleaved or simultaneous release of silver NP and other molecules of interest as for example with a second functional fluid to ensure effectiveness of Ag activity.

Zinc oxide nanoparticles (ZnO-NPs) are known to be one of the multifunctional inorganic compounds which are widely used in everyday applications. This study aims to fabricate ZnO-NPs using grapefruit (Citrus paradisi) peel extract with particle size ranging from 12 to 72 nm. Structural, morphological, and optical properties of the synthesized nanoparticles have been characterized by using UV-Vis spectrophotometer, TEM, DLS, and FTIR analysis. They show the significant photocatalytic degradation efficiency (>56%, 10 mg/L, 6 h) against methylene blue and antioxidant efficacy (≥80% for 1.2 mM) against 1,1-diphenyl-2-picrylhydrazyl. From the results obtained it is suggested that green ZnO-NPs could be used effectively in environmental safety applications and also can address future medical concerns.

Stingless bees are effective pollinators of native tropical flora. Their environmental service maintains flow of pollen through pollination, increase reproductive success and influence genetic structure in plants. The management of stingless bees “meliponiculture”, is an activity limited to the countryside in Ecuador. The lack of knowledge of their managers about pollen resources can affect the correct maintenance/production of nests. The objective is to identify botanical families and genera of pollen grains collected by stingless bees by morphological features and differentiate potential species using geometric morphometry. Thirty-six pot pollen samples were collected from three Ecuadorian provinces located in two climatically different zones. Pollen type identification was based on the Number, Position, Character system. Using morphological features, the families and genera were established. Morphometry landmarks were used to show variation for species differentiation. Abundance, diversity, similarity and dominance indices were established by counting pollen grains, as well as spatial distribution relationships by means of Poisson regression. Forty-six pollen types were determined in two study areas, classified into 27 families and 18 genera. In addition, it was possible to identify more than one species, classified within the same family and genus, thanks to morphometric analysis. 1148 ± 799 (max 4211; min 29) pollen grains were counting in average. The diversity showed a high richness, low dominance and similarity between pollen resources. Families Melastomataceae and Asteraceae, genera Miconia and Bidens , were found as the main pollen resources. The stingless bee of this study are mostly generalist as shown the interaction network. The results of the present survey showed that stingless bees do not collect pollen from a single species, although there is evidence of a predilection for certain plant families. The diversity indexes showed high richness but low uniformity in the abundance of each family identified. The results of the study are also meaningful to the meliponiculture sector as there is a need to improve management practices to preserve the biodiversity and the environment.

Excess phosphorus (P) and nitrogen (N) in wastewater contribute to eutrophication, driving the need for low–cost and sustainable recovery technologies. This study presents a novel adsorbent synthesized from spent coffee grounds biochar (CB) chemically modified with Mn2+/Zn2+/Fe3+ (oxy)hydroxide nanoparticles (CB–M) for simultaneous removal of phosphate and ammonium. Batch adsorption experiments using both synthetic solution and municipal wastewater were conducted to evaluate the material’s adsorption performance and practical applicability. Kinetic, isotherm, thermodynamic, and sequential extraction analyses revealed that CB–M achieved maximum phosphate adsorption capacities ranging from 42.6 to 72.0 mg PO43−·g−1 across temperatures of 20–33 °C, reducing effluent phosphate concentrations to below 0.01 mg·L−1. Ammonium removal was moderate, with capacities ranging between 2.8 and 2.95 mg NH4+·g−1. Thermodynamic analysis indicated that phosphate adsorption was spontaneous and endothermic, dominated by inner–sphere complexation, while ammonium uptake occurred primarily through weaker, reversible ion exchange mechanisms. Sequential extraction showed over 70% of adsorbed phosphate was associated with Fe-Mn-Zn phases, indicating the potential for use as a slow–release fertilizer. The CB–M retained structural integrity and exhibited partial desorption, supporting its reusability for nutrient recovery. Compared to other biochars, CB–M demonstrated superior phosphate selectivity at a neutral–pH, avoided the use of hazardous metals, and transformed coffee waste into a multifunctional material for wastewater treatment and soil amendment. These findings underscore the potential of CB–M as a circular economy solution for nutrient recovery without introducing secondary contamination.

In recent years, semiconductor hollow spheres have gained much attention due to their unique combination of morphological, chemical, and physico-chemical properties. In this work, we report for the first time the synthesis of BiFeO3 hollow spheres by a facile hydrothermal treatment method. The mechanism of formation of pure phase BiFeO3 hollow spheres is investigated systematically by variation of synthetic parameters such as temperature and time, ratio and amount of precursors, pressure, and calcination procedures. The samples were characterized by X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and UV-vis diffuse reflectance spectroscopy. We observe that the purity and morphology of the synthesized materials are very sensitive to synthesis parameters. In general, the chemically and morphologically very robust hollow spheres have diameters in the range of 200 nm to 2 μm and a wall thickness of 50–200 nm. The synthesized BiFeO3 hollow spheres were applied as catalysts in the photodegradation of the model pollutant Rhodamine B under visible-light irradiation. Notably, the photocatalyst demonstrated exceptionally high removal efficiencies leading to complete degradation of the dye in less than 150 min at neutral pH. The superior efficiencies of the synthesized material are attributed to the unique features of hollow spheres. The active species in the photocatalytic process have been identified by trapping experiments.

This work reports on the assessment of a non-hydrolytic electrochemical sensor for glucose sensing that is developed using functionalized carbon nanotubes (fCNTs)/Co(OH)2. The morphology of the nanocomposite was investigated by scanning electron microscopy, which revealed that the CNTs interacted with Co(OH)2. This content formed a nanocomposite that improved the electrochemical characterizations of the electrode, including the electrochemical active surface area and capacitance, thus improving sensitivity to glucose. In the electrochemical characterization by cyclic voltammetry and chronoamperometry, the increase in catalytic activity by Co(OH)2 improved the stability and reproducibility of the glucose sensor without the use of enzymes, and its concentration range was between 50 and 700 μmol L−1. The sensor exhibited good linearity towards glucose with LOD value of 43.200 µmol L−1, which proved that the Co(OH)2-fCNTs composite is judicious for constructing cost effective and feasible sensor for glucose detection.