Javier Roales

Metal–organic frameworks (MOFs) offer unique opportunities for drug delivery due to their high porosity and the possibility of hosting large drug molecules within well-defined pore systems. In this work, the zirconium-based MOF NU-1000 was investigated as a carrier for the antineoplastic drug mitoxantrone (MTX). NU-1000 particles were synthesized and characterized by PXRD, SEM, and DLS, confirming their crystallinity, morphology, and size distribution. MTX loading was achieved by aqueous incubation and quantified by UV-Vis spectroscopy and thermogravimetric analysis, yielding a high loading capacity of ~40–43 wt%, with most of the uptake occurring within the first three hours. Structural characterization demonstrated that the MOF preserves its crystallinity and morphology after drug incorporation, while the DLS results suggest that MTX is mainly accommodated within the internal pore system. To improve stability under physiological conditions, the composite was coated with NH₂-PEG-NH₂, resulting in PEG@MTX@NU-1000 particles with enhanced stability in phosphate-buffered saline. Cytotoxicity assays in HeLa cells showed that the PEGylated carrier is largely biocompatible, while PEG@MTX@NU-1000 exhibits a significantly enhanced antiproliferative effect compared to free MTX at short incubation times. These results demonstrate that NU-1000 is a promising platform for MTX delivery, combining high loading capacity, structural stability after PEGylation, and improved short-term therapeutic performance.

Metal–organic frameworks (MOFs) offer unique opportunities for drug delivery due to their high porosity and the possibility of hosting large drug molecules within well-defined pore systems. In this work, the zirconium-based MOF NU-1000 was investigated as a carrier for the antineoplastic drug mitoxantrone (MTX). NU-1000 particles were synthesized and characterized by PXRD, SEM, and DLS, confirming their crystallinity, morphology, and size distribution. MTX loading was achieved by aqueous incubation and quantified by UV–Vis spectroscopy and thermogravimetric analysis, yielding a high loading capacity of ~40-43 wt%, with most of the uptake occurring within the first three hours. Structural characterization demonstrated that the MOF preserves its crystallinity and morphology after drug incorporation, while DLS results suggest that MTX is mainly accommodated within the internal pore system. To improve stability under physiological conditions, the composite was coated with NH₂-PEG-NH₂, resulting in PEG@MTX@NU-1000 particles with enhanced stability in phosphate-buffered saline. Cytotoxicity assays in HeLa cells showed that the PEGylated carrier is largely biocompatible, while PEG@MTX@NU-1000 exhibits a significantly enhanced antiproliferative effect compared to free MTX at short incubation times. These results demonstrate that NU-1000 is a promising platform for MTX delivery, combining high loading capacity, structural stability after PEGylation, and improved short-term therapeutic performance.

Spectrophotometry and colorimetry are among the most-used techniques for chemical and biological analyses, but the required equipment is often expensive and restricted to laboratory use. We present here a low-cost and portable color measuring device that can provide similar results to laboratory spectrophotometers in color measuring applications. Our prototype was based on an RGB color sensor interfaced to a Raspberry Pi and mounted on custom sample holders with a dual illumination source for reflectance or transmittance measurements. To evaluate its capabilities for the detection of gases, we used two already-tested colorimetric molecular devices: Harrison’s reagent supported on porous TiO₂ films for the detection of phosgene, and mixed films of a porphyrinic metal–organic frameworks and polydimethylsiloxane for the detection of biogenic amines. The results showed that the prototype could accurately monitor the color change of the sensing devices when exposed to the analytes and that its versatility allowed for the measurement of samples with different characteristics. This inexpensive and portable prototype, able to run on a 5 V battery and work wirelessly, proved to be a valid alternative for color measuring when expensive spectrophotometers are not available, mobility is needed, or a full-spectral characterization is not necessary.

Lichens have long been considered as composite organisms composed of algae and/or cyanobacteria hosted by a fungus in a mutualistic relationship. Other organisms have been gradually discovered within the lichen thalli, such as multiple algal species, yeasts, or even viruses. Of pivotal relevance is the existence of the lichen microbiome, which is a community of microorganisms that can be found living together on the lichen surface. This community performs a growing number of functions. In this entry, we explore the journey of lichens being considered from a dual partnership to a multi-species symbiotic relationship.

Virgin olive oil (VOO) classification into quality categories determines its labeling and market price. This procedure involves performing a series of chemical–physical analyses and, ultimately, a sensory analysis through the panel test. This work explores the analysis of VOOs quality with an electronic olfactory system (EOS) and examines its abilities using the panel test as a reference. To do this, six commercial olive oils labelled as extra virgin were analyzed with an EOS and classified by three panels recognized by the International Olive Council. The organoleptic analysis of the oils by the panels indicated that most of the oils in the study were in fact not extra virgin. Besides this, the classifications showed inconsistencies between panels, needing statistical treatment to be used as a reference for the EOS training. The analysis of the same oils by the EOS and their subsequent statistical analysis by PCA revealed a good correlation between the first principal component and the olive oil quality from the panels using average scores. It also showed a more consistent classification than the panels. Overall, the EOS proved to be a cheaper, faster, and highly reliable method as a complement to the panel test for the olive oil classification.

Climate change and atmospheric nitrogen (N) deposition on drylands are greatly threatening these especially vulnerable areas. Soil biocrust-forming lichens in drylands can provide early indicators of these disturbances and play a pivotal role, as they contribute to key ecosystem services. In this study, we explored the effects of different long-term water availability regimes simulating climate changes and their interaction with N addition on the physiological response of the soil lichen Cladonia rangiferina. Three sets of this lichen were subjected to control, reduced watering, and reduced watering and N addition (40 kg NH₄NO₃ ha⁻¹ year⁻¹) treatments for 16 months. Finally, all samples were subjected to daily hydration cycles with N-enriched water at two levels (40 and 80 kg NH₄NO₃ ha⁻¹ year⁻¹) for 23 days. We found that reduced watering significantly decreased the vitality of this lichen, whereas N addition unexpectedly helped lichens subjected to reduced watering to cope with stress produced by high temperatures. We also found that long-term exposure to N addition contributed to the acclimation to higher N availability. Overall, our data suggest that the interactions between reduced watering and increased N supply and temperature have an important potential to reduce the physiological performance of this soil lichen.

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

A selective and inexpensive chemical paper-based sensor for the detection of gaseous H₂S is presented. The triggering of the sensing mechanism is based on an arene-derivative dye which undergoes specific reactions in the presence of H₂S, allowing for colorimetric analysis. The dye is embedded into a porous cellulose matrix. We passively exposed the paper strips to H₂S generated in situ, while the absorbance was monitored via an optic fiber connected to a spectrophotometer. The kinetics of the emerging absorbance at 534 nm constitute the sensor response and maintain a very stable calibration signal in both concentration and time dimensions for quantitative applications. The time and concentration dependence of the calibration function allows the extraction of unusual analytical information that expands the potential comparability with other sensors in the literature, as the limit of detection admissible within a given exposure time. The use of this specific reaction ensures a very high selectivity against saturated vapors of primary interferents and typical volatile compounds, including alkanethiols. The specific performance of the proposed sensor was explicitly compared with other colorimetric alternatives, including standard lead acetate strips. Additionally, the use of a smartphone camera to follow the color change in the sensing reaction was also tested. With this straightforward method, also affordable for miniature photodiode devices, a limit of detection below the ppm scale was reached in both colorimetric approaches.