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The valorization of wood industry residues is very desirable from a circular economy perspective. Pine needle extracts are known for their health-promoting properties and therefore can be used as herbal remedies and nutritional supplements. Since the withdrawal of antibiotics as growth promoters in the European Union, natural feed additives that improve poultry health and production are needed. It was proposed that pine needle extract could be a good alternative to antibiotic usage at sub-therapeutic concentrations. The results relevant to our assumption could be obtained by using domestic chickens as an in vivo model for the evaluation of gut microbiota-altering properties of pine needle extract as an herbal supplement. We tested the antimicrobial effects of Baltic pine (Pinus sylvestris) needle extract. Then, we used chicken (Gallus gallus) that received feed supplemented with two different concentrations of the extract for 40 days to evaluate the changes in gut microbiota using 16S rRNA gene sequencing. This preliminary study demonstrated trends toward dose-dependent desirable changes in broiler microbiome, such as a reduction in the relative abundance of Campylobacter.

Wastewater-based epidemiology (WBE) is a promising biomonitoring approach with the potential to provide direct information on human intake and exposure to food contaminants and environmental chemicals. The aim of this study was to apply WBE while employing the normalization method for exploring human exposure to selected mycotoxins according to population biomarker 5-hydroxyindoleacetic acid (5-HIAA). This type of normalization technique has been previously used to detect various other compounds. However, to the best of our knowledge, this is the first study tracking human exposure to mycotoxins. A sensitive analytical methodology was developed to achieve reliable quantification of deoxynivalenol, enniatins, and beauvericin in wastewater (WW) samples. The applicability of the method was evaluated by testing 29 WW samples collected at WW treatment plants in Latvia. With frequency of detection greater than 86%, enniatins B, B1, A, and A1 were revealed in WW samples. The estimated total daily intake for enniatins was in the range of 1.8–27.6 µg/day per person. Free deoxynivalenol (DON) was determined in all analysed WW samples. Based on the average 5-HIAA excretion level and the determined 5-HIAA content in the samples, the intake of DON by the human population of Riga was estimated at 325 ng/kg b.w. day.

Nanomaterials are highly attractive for use in many applications, primarily due to their greater contact surface area and enhanced effects compared to the corresponding bulk materials. However, nanomaterials present risks to human health, since they are able to penetrate deep into the respiratory tract. It is therefore important to know the particle sizes of these substances, although such measurements can present difficulties associated with the generation of this type of material. It is also important to investigate the mechanism of aerosol generation, considering the properties of the starting material. Here, evaluation was performed of the generation of an aerosol of silver nanoparticles from a suspension, using an environmentally friendly and simple synthesis method. A reduction reaction was used to produce the silver nanoparticles. The aerosol was generated using a modified nebulizer inhaler, and particles were counted using an SMPS system. The measurements showed that the predominant particle sizes were 45.63±2.49 nm (determined by SMPS) and 50.7±0.7 nm (determined by DLS analysis).

The occurrence and dietary exposure assessment of 16 mycotoxins, 6 biogenic amines (BAs), and 13 metallic elements in blue-veined cheeses (n = 46) is reported. Co-occurrence of mycophenolic acid (≤599 µg·kg−1) with roquefortine C (≤5454 µg·kg−1) was observed in 63% of the tested cheeses, while BAs were frequently present at concentrations between 0.2 and 717 mg kg−1. The concentrations of heavy metals in cheeses were very low. Chronic/acute exposure assessment based on consumption data from different European populations indicated that the levels of mycotoxins and heavy metals are safe to consumers, whereas, rather high hazard indexes (HI up to 0.77) were determined for BAs according to the worst-case scenario based on high consumption and 95th percentile occurrence. A more detailed acute dietary intake study indicated that histamine and tyramine were predominant among these BAs, reaching 27 and 41% of the acute oral intake reference doses.

This research was developed by considering that the solid waste produced in the process of pig iron production represents the loss of raw materials and the increase in environmental problem. The charcoal based mini blast-furnace off gases dust named CHARCOK was collected from SIDERPA fraction three-quarters Siderúrgica Paulino Ltda, located in Sete Lagoas, Minas Gerais. The Charcok was characterized and classified according to ABNT (Associação Brasileira de Normas Técnicas) standard. The results showed that the Charcok should be classified as Class I Wastes fraction three-quarters "Hazard Wastes" because of its high concentration of phenols (54.5mg C6H5OH/kg). The Charcok had high concentration of iron and charcoal which can be used as energy source.

In this work, an expedite synthesis was developed for a self-assembled micelle carrier for the antimicrobial peptide LL18. Covalent one-pot functionalization of dextrin with succinylated vitamin D3 and succinic anhydride produced an amphiphilic material that undergoes self-assembly into micelles in aqueous medium. Succinylated dextrin-vitamin D3 micelles were efficiently loaded with LL18 by electrostatic and hydrophobic interactions. Remarkably, the LL18-loaded micelle formulation dramatically improves the antibacterial activity of free LL18 against S. aureus , completely abrogates its severe hemolytic activity, redirects the internalization of LL18 from the perinuclear region of osteoblasts to the lysosomes and reduces cellular toxicity towards osteoblasts and macrophages. Overall, this work demonstrates that self-assembled micelle formulations based on dextrin, vitamin D3 and antimicrobial peptides, are promising platforms to develop multifunctional antibiotic-independent antimicrobial agents, not prone to the development of bacterial resistance, to treat bone infections.

Adipose tissue dysfunction influences the development of dyslipidemias associated with obesity, however, the mechanisms are still unclear. In this sense, the literature highlights the role of copper in cholesterol synthesis, contributing to the increase in concentrations of this lipid fraction and consequently to the manifestation of dyslipidemia. The objective of the study was to investigate the relationship between copper parameters and lipid profile markers in women with obesity. This is a cross-sectional study involving women aged 20 to 50 years divided into a case group (BMI ≥ 35 kg/m 2 ) and a control group (BMI between 18.5 and 24.9 kg/m 2 ). Copper concentrations in plasma and erythrocytes were determined by inductively coupled plasma optical emission spectrophotometry and ceruloplasmin activity by spectrophotometry. The lipid fractions were analyzed according to the enzymatic colorimetric method, using an automatic biochemical analyzer. Participants with obesity had elevated concentrations of copper in plasma and reduced concentrations in erythrocytes compared to the control group, but there was no significant difference in ceruloplasmin activity between the groups. The research does not identify a correlation between copper parameters and serum concentrations of lipid fractions, which does not allow inferring the role of copper in the manifestation of dyslipidemia in obesity., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Supramolecular hydrogels, particularly low-molecular-weight peptide hydrogels, are promising drug delivery systems due to their ability to change the solubility, targeting, metabolism and toxicity of drugs. Magneto-plasmonic liposomes, in addition to being remotely controllable with the application of an external magnetic field, also increase the efficiency of encapsulated drug release through thermal stimulation, for example, with magnetic and optical hyperthermia. Thus, the combination of those two materials-giving magneto-plasmonic lipogels-brings together several functionalities, among which are hyperthermia and spatiotemporally controlled drug delivery. In this work, a novel dehydrodipeptide hydrogelator was synthesised, and the respective hydrogel was functionalized with magneto-plasmonic liposomes. After individually characterising the components with regard to their rheological, spectroscopic and magnetic properties, the magneto-plasmonic lipogel was equally characterised and evaluated concerning its ability to deliver drugs in a controlled fashion. To this end, the response of the 5(6)-carboxyfluorescein-loaded magneto-plasmonic lipogel to near-infrared light was assessed. The results showed that the system is a proper carrier of hydrophilic drugs and allows to envisage photo-responsive drug delivery. These facts, together with the magnetic guidance and hyperthermia capabilities of the developed composite gel, may pave the way to a new era in the treatment of cancer and other diseases., (© 2024 European Peptide Society and John Wiley & Sons Ltd.)

Self-assembly of peptide building blocks offers unique opportunities for bottom-up preparation of exquisite nanostructures, nanoarchitectures, and nanostructured bulk materials, namely hydrogels. In this work we describe the synthesis, characterization, gelation, and rheological properties of new dehydrotripeptides, Cbz- L -Lys(Cbz)- L , D -Asp-∆Phe-OH and (2-Naph)- L -Lys(2-Naph)- L , D -Asp-∆Phe-OH, containing a N -terminal lysine residue N α , ε - bis -capped with carboxybenzyl (Cbz) and 2-Naphthylacetyl (2-Naph) aromatic moieties, an aspartic acid residue (Asp), and a C -terminal dehydrophenylalanine (∆Phe) residue. The dehydrotripeptides were obtained as diastereomeric mixtures ( L , L , Z and L , D ,Z), presumably via aspartimide chemistry. The dehydrotripeptides afforded hydrogels at exceedingly low concentrations (0.1 and 0.04 wt%). The hydrogels revealed exceptional elasticity (G' = 5.44 × 10 4 and 3.43 × 10 6 Pa) and self-healing properties. STEM studies showed that the diastereomers of the Cbz-capped peptide undergo co-assembly , generating a fibrillar 3D network, while the diastereomers of the 2-Naph-capped dehydropeptide seem to undergo self-sorting, originating a fibril network with embedded spheroidal nanostructures. The 2-Naph-capped hydrogel displayed full fast recovery following breakup by a mechanical stimulus. Spheroidal nanostructures are absent in the recovered hydrogel, as seen by STEM, suggesting that the mechanical stimulus triggers rearrangement of the spheroidal nanostructures into fibers. Overall, this study demonstrates that diastereomeric mixtures of peptides can be efficacious gelators. Importantly, these results suggest that the structure (size, aromaticity) of the capping group can have a directing effect on the self-assembly (co-assembly vs. self-sorting) of diastereomers. The cytotoxicity of the newly synthesized gelators was evaluated using human keratinocytes (HaCaT cell line). The results indicated that the two gelators exhibited some cytotoxicity, having a small impact on cell viability. In sustained release experiments, the influence of the charge on model drug compounds was assessed in relation to their release rate from the hydrogel matrix. The hydrogels demonstrated sustained release for methyl orange (anionic), while methylene blue (cationic) was retained within the network.

The formamidase (FMD) enzyme plays an important role in fungal thriving by releasing a secondary nitrogen source as a product of its activity. In Paracoccidioides species, previous studies have demonstrated the upregulation of this enzyme in a wide range of starvation and infective-like conditions. However, Paracoccidioides lutzii formamidase has not yet been defined as a virulence factor. Here, by employing in vivo infections using an fmd-silenced strain in Galleria mellonella larvae model, we demonstrate the influence of formamidase in P. lutzii's immune stimulation and pathogenicity. The formamidase silencing resulted in improper arrangement of the nodules, poor melanogenesis and decreased fungal burden. Thus, we suggest that formamidase may be a piece composing the process of molecular recognition by Galleria immune cells. Furthermore, formamidase silencing doubled the observed survival rate of the larvae, demonstrating its importance in fungal virulence in vivo. Therefore, our findings indicate that formamidase contributes to Galleria's immune incitement and establishes the role of this enzyme as a P. lutzii virulence factor., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pereira et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

(1) Background: We examined the effect of the acute administration of olive oil (EVOO), linseed oil (GLO), soybean oil (SO), and palm oil (PO) on gastric motility and appetite in rats. (2) Methods: We assessed food intake, gastric retention (GR), and gene expression in all groups. (3) Results: Both EVOO and GLO were found to enhance the rate of stomach retention, leading to a decrease in hunger. On the other hand, the reduction in food intake caused by SO was accompanied by delayed effects on stomach retention. PO caused an alteration in the mRNA expression of NPY, POMC, and CART. Although PO increased stomach retention after 180 min, it did not affect food intake. It was subsequently verified that the absence of an autonomic reaction did not nullify the influence of EVOO in reducing food consumption. Moreover, in the absence of parasympathetic responses, animals that received PO exhibited a significant decrease in food consumption, probably mediated by lower NPY expression. (4) Conclusions: This study discovered that different oils induce various effects on parameters related to food consumption. Specifically, EVOO reduces food consumption primarily through its impact on the gastrointestinal tract, making it a recommended adjunct for weight loss. Conversely, the intake of PO limits food consumption in the absence of an autonomic reaction, but it is not advised due to its contribution to the development of cardiometabolic disorders.

Background: Platynosomiasis in non-human primates kept under human care causes chronic disease of the bile ducts and liver, which initially presents with nonspecific signs and can culminate in the death of the animal. Diagnosing this disease is a challenge, and an ultrasound examination can be an excellent tool when it is suspected., Methods: This study describes the ultrasound findings from 57 marmosets with suspected infection by Platynosomum sp., the correlated hepatobiliary changes, and the anatomopathological findings that confirmed the occurrence of platynosomiasis., Results: In six marmosets (one C. aurita, two C. jacchus, and three Callithrix sp.), Platynosomum infection was confirmed macroscopically (presence of adult trematodes in the gallbladder) and microscopically (adults, larvae, and eggs in histological examinations and eggs in bile and feces). These findings were compatible with the hepatobiliary changes and with images suggestive of parasitic structures in ante-mortem assessments., Conclusion: Ultrasound examination demonstrated its usefulness within the clinical routine for investigating this parasitosis., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To provide information regarding the procedures, safety, tolerability, and measurement properties of the 6-min step test., Data Sources: MEDLINE, EMBASE, CINAHL, and SPORTDiscus (from inception until January 2024)., Review Methods: Studies that examined adults with acute or chronic diseases, and outcomes related to procedures, safety, tolerability, or measurement properties of the 6-min step test were included. Outcome data were summarized and combined in meta-analyses. The quality of included studies was assessed by the Consensus-based Standards for the selection of health Measurement Instruments checklist, and the quality of evidence was determined according to the Grading of Recommendations Assessment, Development, and Evaluation system., Results: Fourteen studies, involving 847 participants, were included. All studies performed the 6-min step test in 6 min; however, some studies varied the step height and the use of upper limb support. The test appears to be safe and well tolerated by individuals. Moderate- to high-quality evidence demonstrated appropriate results for test-retest reliability (4 studies; Intraclass correlation coefficient 0.96; 95% CI 0.91-0.98; n  = 125), criterion validity (4 studies; r  = 0.53; 95% CI 0.30-0.71; n  = 307), and construct validity (4 studies; r  = 0.63; 95% CI 0.52-0.73; n  = 233)., Conclusion: This review provides recommendations for applying the 6-min step test in clinical and research settings. No adverse events were reported, and the test appears to be well tolerated. Adequate results were found for test-retest reliability, criterion validity, and construct validity., Review Registration: PROSPERO (CRD42022347744)., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

In recent years, particularly following the definition of the UN Sustainable Development Goals (SDGs) for 2030, Nature-Based Solutions (NBS) have gained considerable attention, capturing the interest of both the scientific community and policymakers committed to addressing urban environmental issues. However, the need for studies to guide decision-makers in identifying suitable locations for NBS implementation within urban stormwater management is evident. To address this gap, the present study employs a methodological approach grounded in multi-criteria analysis integrated with Geographic Information Systems (GIS) to identify areas with potential for NBS implementation. In this process, ten NBS were proposed and tested in the drainage area of a shallow tropical urban lake in Londrina, southern Brazil. Additionally, the study investigates areas hosting lower-income populations, a relevant aspect for public managers given the diverse economic subsidies required to implement NBS. Furthermore, the study incorporates a preliminary analysis that evaluates the potential ecosystem benefits to determine the most suitable NBS for a specific site. The result shows that all the ten analyzed NBS were deemed suitable for the study area. Rain barrels had the highest percentage coverage in the study area (37.1%), followed by tree pits (27.9%), and rain gardens (25.4%). Despite having the highest distribution in the basin area, rain barrels exhibited only moderate ecosystem benefits, prompting the prioritization of other NBS with more significant ecological advantages in the final integrated map. In summary, the methodology proposed showed to be a robust approach to selecting optimal solutions in densely populated urban areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The effect of calorie restriction, fasting, and ketogenic diets on the treatment of liver cancer remains uncertain. Therefore, we conducted a systematic review to evaluate the effect of restrictive diets on the development and progression of liver cancer in animal models. We did a meta-analysis using the Cochrane Collaboration's Review Manager software, with the random effects model and the inverse variance technique. We examined 19 studies that were conducted between 1983 and 2020. Of these, 63.2% investigated calorie restriction, 21.0% experimented with a ketogenic diet, and 15.8% investigated the effects of fasting. The intervention lasted anything from 48 h to 221 weeks. Results showed that restrictive diets may reduce tumor incidence and progression, with a significant reduction in the risk of liver cancer development. Thereby, our results suggest that putting limits on what you eat may help treat liver cancer in more ways than one., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest that pertain to this work. PROSPERO registration: CRD42021267023., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Farnesol is a natural essential oil with antimicrobial properties. Complexation of farnesol in chitosan nanoparticles can be useful to improve its bioavailability and potentiate its antifungal capabilities such as inhibition of hyphal and biofilm formation. The aim of this study was to develop and characterize chitosan nanoparticles with farnesol (NF) and evaluate their toxicity and antifungal action on C. albicans in vivo. The NF were prepared by the ionic gelation method and showed physicochemical characteristics such as diameter less than 200 nm, monodisperse distribution, positive zeta potential, spherical morphology, and stability after 120 days of storage. In the evaluation of toxicity in Galleria mellonella, NF did not reduce the survival rate, indicating that there was no toxicity in vivo at the doses tested. In the assays with G. mellonella infected by C. albicans, the larvae treated with NF had a high survival rate after 48 h, with a significant reduction of the fungal load and inhibition of the formation of biofilms and hyphae. In the murine model of vulvovaginal candidiasis (VVC), histopathological analysis showed a reduction in inflammatory parameters, fungal burden, and hyphal inhibition in mice treated with NF. The produced nanoparticles can be a promising alternative to inhibit C. albicans infection., (© 2023. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Background:   Carduus marianus is a Mediterranean plant used for treating liver diseases. One of its properties is that it inhibits fat peroxidation, which can contribute toward the prevention of metabolites that are harmful to the liver., Objective:  The aim of this study was to describe the treatment of fatty liver disease in an axolotl ( Ambystoma mexicanum )., Methods:  An approximately 6-year-old female specimen of A. mexicanum , of length 21 cm and weight 153 g, presented edema in the rostral region and inappetence. Ultrasound showed hepatopathy and a gallbladder stone. A globule of C. marianus 6cH was diluted in 30 mL distilled water and administered in spray form over the animal twice a day., Results:  Twenty days after the beginning of the treatment, improvement of the facial edema and return of appetite were observed. Ultrasound showed improvement in the appearance of the liver and reduction in the size of the gallstone. The Modified Naranjo Criteria for Homeopathy score was +9 in this case, thus suggesting a causal relationship between the use of homeopathic medicine and the clinical outcome., Conclusion:   C. marianus 6cH appeared to be effective in treating fatty liver disease and gallstone in this specimen of A. mexicanum., Competing Interests: None declared., (Faculty of Homeopathy. This article is published by Thieme.)

Background: Folliculinum is a homeopathic sarcode medication that is mainly used for regulating the estrous cycle and reproductive function. In snakes, it is common to observe low frequencies of reproduction. Ovulation is related to follicular size and morphology, and follicle homogeneity may indicate the absence of problems such as dystocia (egg retention) or follicular stasis., Objective: The objective of the present study was to report on follicular stage changes in two ball pythons, Python regius (Shaw, 1802), which were treated using Folliculinum 6cH in a zoological park setting., Methods: Two female pythons - one weighing 2.8 kg, the other weighing 2.5 kg, and neither with a history of reproduction - were examined by ultrasound to enable viewing of ovarian follicles in different phases and sizes. Folliculinum 6cH, two globules diluted in 200 mL of water, was administered, targeted to the eyes and nostril regions., Results: Even given the slow metabolism of reptiles, ultrasound revealed an improvement in follicle homogeneity between 6 and 15 days after the start of homeopathy in both snakes; there was also improved weight gain in both animals. The MOdified NARanjo Criteria for Homeopathy (MONARCH) score was +8 in each of the cases, suggesting a causal relationship between the use of homeopathic medicine and clinical outcome., Conclusion: Folliculinum 6cH may have promoted stabilization of follicle size and enabled folliculogenesis in two ball pythons., Competing Interests: None declared., (Faculty of Homeopathy. This article is published by Thieme.)

The present study evaluated the seminal plasma metabolome of Bos indicus Guzerá bulls with good (n = 4) and poor (n = 5) sperm freezability. Animals were raised in natural pasture of a 'Caatinga' ecosystem, in the semi-arid region of Brazil. Seminal plasma samples were subjected to gas chromatography coupled to mass spectrometry and data, analysed using bioinformatics tools (Cytoscape with the MetScape plug-in). Sixty-two metabolites were identified in the bovine seminal plasma. Fatty acids and conjugates and organic compounds were the predominant seminal fluid metabolites, followed by carboxylic acids and derivatives, amino acids, benzenes and steroids and derivatives, carbohydrates and carbohydrate conjugates and prenol lipids. Multivariate analysis indicated a distinct separation of seminal plasma metabolomes from bulls with contrasting sperm freezability. Abundances of propanoic acid, d-ribose and glycine were greater in the seminal plasma of bulls with good sperm freezability. Heptadecanoic acid and undecanoic acid were the predominant in bulls of poor sperm freezability. Propanoic acid is an energy source for spermatozoa and may act as an antimicrobial component in semen. Glycine acts against oxidizing and denaturing reactions. d-ribose is also an energy source and reduces apoptosis and oxidative stress. Undecanoic acid may protect sperm against fungal damage. This study provides fundamental information approximately the seminal plasma metabolome of tropically adapted bulls and its association with sperm freezability. However, further studies with larger groups of animals are needed to validate those metabolites as markers of sperm freezability. This strategy could support the selection of sires with superior sperm cryoresistance., (© 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Self-assembled peptide-based hydrogels are archetypical nanostructured materials with a plethora of foreseeable applications in nanomedicine and as biomaterials. N-protected di- and tri-peptides are effective minimalist (molecular) hydrogelators. Independent variation of the capping group, peptide sequence and side chain modifications allows a wide chemical space to be explored and hydrogel properties to be tuned. In this work, we report the synthesis of a focused library of dehydrodipeptides N-protected with 1-naphthoyl and 2-naphthylacetyl groups. The 2-naphthylacetyl group was extensively reported for preparation of peptide-based self-assembled hydrogels, whereas the 1-naphthaloyl group was largely overlooked, owing presumably to the lack of a methylene linker between the naphthalene aromatic ring and the peptide backbone. Interestingly, dehydrodipeptides N-capped with the 1-naphthyl moiety afford stronger gels, at lower concentrations, than the 2-naphthylacetyl-capped dehydrodipeptides. Fluorescence and circular dichroism spectroscopy showed that the self-assembly of the dehydrodipeptides is driven by intermolecular aromatic π-π stacking interactions. Molecular dynamics simulations revealed that the 1-naphthoyl group allows higher order aromatic π-π stacking of the peptide molecules than the 2-naphthylacetyl group, together with hydrogen bonding of the peptide scaffold. The nanostructure of the gel networks was studied by TEM and STEM microscopy and was found to correlate well with the elasticity of the gels. This study contributes to understanding the interplay between peptide and capping group structure on the formation of self-assembled low-molecular-weight peptide hydrogels. Moreover, the results presented here add the 1-naphthoyl group to the palette of capping groups available for the preparation of efficacious low-molecular-weight peptide-based hydrogels.

Inflammation and endoplasmic reticulum (ER) stress are often hand in hand in the context of chronic disease. Both are activated upon perceived disturbances in homeostasis, being deleterious when intensely or chronically activated. Fisetin (FST) is a dietary flavonol that is known to possess multiple relevant bioactivities, raising the question of its potential health benefits and even its use in novel pharmacological approaches against ER stress and inflammation. To attain this prospect, some limitations to this molecule, namely its poor bioavailability and solubility, must be addressed. In an attempt to improve the biological properties of the parent molecule, we have synthesized a set of FST derivatives. These new molecules were tested along with the original compound for their ability to mitigate the activation of the signaling pathways underlying inflammation and ER stress. By reducing LPS-induced nuclear factor-kappa B (NF-κB) activation, cytokine release, inflammasome activation and reactive oxygen species (ROS) generation, FST has proven to be effective against the onset of inflammation. The molecule also decreases the activation of the unfolded protein response (UPR), as evidenced by the reduced expression of relevant UPR-related genes upon ER stress induction. Some of the tested derivatives are novel inhibitors of targets associated to inflammation and ER stress signaling, in some cases more potent than the parent compound. Furthermore, the reduced cytotoxicity of some of these molecules enabled the use of higher concentrations than that of FST, resulting in the observation of enhanced bioactivities., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Atmospheric pollutant data retrieved through satellite sensors are continually used to assess changes in air quality in the lower atmosphere. During the COVID-19 pandemic, several studies started to use satellite measurements to evaluate changes in air quality in many different regions worldwide. However, although satellite data is continuously validated, it is known that its accuracy may vary between monitored areas, requiring regionalized quality assessments. Thus, this study aimed to evaluate whether satellites could measure changes in the air quality of the state of São Paulo, Brazil, during the COVID-19 outbreak; and to verify the relationship between satellite-based data [Tropospheric NO 2 column density and Aerosol Optical Depth (AOD)] and ground-based concentrations [NO 2 and particulate material (PM; coarse: PM 10 and fine: PM 2.5 )]. For this purpose, tropospheric NO 2 obtained from the TROPOMI sensor and AOD retrieved from MODIS sensor data by using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm were compared with concentrations obtained from 50 automatic ground monitoring stations. The results showed low correlations between PM and AOD. For PM 10 , most stations showed correlations lower than 0.2, which were not significant. The results for PM 2.5 were similar, but some stations showed good correlations for specific periods (before or during the COVID-19 outbreak). Satellite-based Tropospheric NO 2 proved to be a good predictor for NO 2 concentrations at ground level. Considering all stations with NO 2 measurements, correlations >0.6 were observed, reaching 0.8 for specific stations and periods. In general, it was observed that regions with a more industrialized profile had the best correlations, in contrast with rural areas. In addition, it was observed about 57% reductions in tropospheric NO 2 throughout the state of São Paulo during the COVID-19 outbreak. Variations in air pollutants were linked to the region economic vocation, since there were reductions in industrialized areas (at least 50% of the industrialized areas showed >20% decrease in NO 2 ) and increases in areas with farming and livestock characteristics (about 70% of those areas showed increase in NO 2 ). Our results demonstrate that Tropospheric NO 2 column densities can serve as good predictors of NO 2 concentrations at ground level. For MAIAC-AOD, a weak relationship was observed, requiring the evaluation of other possible predictors to describe the relationship with PM. Thus, it is concluded that regionalized assessment of satellite data accuracy is essential for assertive estimates on a regional/local level. Good quality information retrieved at specific polluted areas does not assure a worldwide use of remote sensor data., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Taciana Toledo de Almeida Albuquerque reports financial support was provided by Federal University of Minas Gerais. Anderson Paulo Rudke reports financial support was provided by Coordination of Higher Education Personnel Improvement. Maria de Fatima Andrade reports financial support was provided by State of Sao Paulo Research Foundation. Daniela Sanches de Almeida reports financial support was provided by National Council for Scientific and Technological Development., (© 2023 Elsevier Inc. All rights reserved.)

Objective: The levonorgestrel intrauterine system treatment prevents 67.7% of surgeries in patients with heavy menstrual bleeding and enlarged uteri. To evaluate the effectiveness of the levonorgestrel intrauterine system in the treatment of patients with heavy menstrual bleeding and an enlarged uterus and to compare satisfaction and its complications with hysterectomy., Methods: This was a comparative cross-sectional observational study of women with heavy menstrual bleeding and an enlarged uterus. Sixty-two women were treated and followed up for four years. Insertion of the levonorgestrel intrauterine system was performed in Group 1, and laparoscopic hysterectomy was performed in Group 2., Results: In Group 1 (n=31), 21 patients (67.7%) showed improvement in the bleeding pattern, and 11 patients (35.5%) had amenorrhea. Five patients (16.1%) remained with heavy bleeding and were considered to have experienced treatment failure. There were seven expulsions (22.6%); in five patients, bleeding remained heavy, but in two patients the bleeding returned to that of normal menstruation. No relationship was found between treatment failure and greater hysterometries (p=0.40) or greater uterine volumes (p=0.50), whereas expulsion was greater in uteri with smaller hysterometries (p=0.04). There were 13 (21%) complications, seven (53.8%) in the group that underwent insertion of the levonorgestrel intrauterine system (all were device expulsions), and six (46.2%) in the surgical group, which were the most severe ones (p=0.76). Regarding satisfaction, 12 patients (38.7%) were dissatisfied with the levonorgestrel intrauterine system and one (3.23%) was dissatisfied with the surgical treatment (p=0.00)., Conclusion: Treatment with the levonorgestrel intrauterine system in patients with heavy menstrual bleeding and an enlarged uterus was effective, and when compared with laparoscopic hysterectomy, it had a lower rate of satisfaction and the same rate of complications, although less severe.

Mesenteric schwannomas are rare benign tumors that arise in the mesentery. Ileal diverticula and intestinal malrotation in adults are rare findings, since they are usually asymptomatic. We present the case of an 86-year-old man, without any known previously known medical conditions, who was admitted in the emergency department with recurrent abdominal distension and intense pain. The radiological study suggested an intestinal malrotation. An exploratory laparotomy confirmed the intestinal malrotation with intermesenteric bands, as well as a mesenteric mass adjacent to an ileal diverticulum. Following a segmental enterectomy, the histology of the mass reported a mesenteric schwannoma. To the best of our knowledge, this is the first report of such association. We therefore present this report to showcase the diagnostic and therapeutical challenges in managing these conditions.

Supramolecular peptide hydrogels have many important applications in biomedicine, including drug delivery applications for the sustained release of therapeutic molecules. Targeted and selective drug administration is often preferential to systemic drug delivery, as it can allow reduced doses and can avoid the toxicity and side-effects caused by off-target binding. New discoveries are continually being reported in this rapidly developing field. In this review, we report the latest developments in supramolecular peptide-based hydrogels for drug delivery, focusing primarily on discoveries that have been reported in the last four years (2018-present). We address clinical points, such as peptide self-assembly and drug release, mechanical properties in drug delivery, peptide functionalization, bioadhesive properties and drug delivery enhancement strategies, drug release profiles, and different hydrogel matrices for anticancer drug loading and release.

Employing amino acids and peptides as molecular building blocks provides unique opportunities for generating supramolecular hydrogels, owing to their inherent biological origin, bioactivity, biocompatibility, and biodegradability. However, they can suffer from proteolytic degradation. Short peptides (<8 amino acids) attached to an aromatic capping group are particularly attractive alternatives for minimalistic low molecular weight hydrogelators. Peptides with low critical gelation concentrations (CGCs) are especially desirable, as the low weight percentage required for gelation makes them more cost-effective and reduces toxicity. In this work, three dehydrodipeptides were studied for their self-assembly properties. The results showed that all three dehydrodipeptides can form self-standing hydrogels with very low critical gelation concentrations (0.05−0.20 wt%) using a pH trigger. Hydrogels of all three dehydrodipeptides were characterised by scanning tunnelling emission microscopy (STEM), rheology, fluorescence spectroscopy, and circular dichroism (CD) spectroscopy. Molecular modelling was performed to probe the structural patterns and interactions. The cytotoxicity of the new compounds was tested using human keratinocytes (HaCaT cell line). In general, the results suggest that all three compounds are non-cytotoxic, although one of the peptides shows a small impact on cell viability. In sustained release assays, the effect of the charge of the model drug compounds on the rate of cargo release from the hydrogel network was evaluated. The hydrogels provide a sustained release of methyl orange (anionic) and ciprofloxacin (neutral), while methylene blue (cationic) was retained by the network.

This work proposes an innovative method for the simultaneous upgrading of biogas streams and valorization of the separated CO 2 , through its conversion to renewable methane. To this end, two sorptive reactors were filled with a layered bed containing a CO 2 sorbent (K-promoted hydrotalcite) and a methanation catalyst (Ru/Al 2 O 3 ). The continuous cyclic operation of the parallel sorptive reactors was carried out by alternately feeding a biogas stream (CO 2 /CH 4 mixture) or H 2 . The CO 2 /CH 4 mixture is fed to the sorptive reactor during the sorption stage, with CO 2 being captured by the sorbent and CH 4 exiting as a purified stream (i.e., as biomethane). During the reactive regeneration stage, the inlet stream is switched to pure H 2 , which reacts with the previously captured CO 2 at the methanation catalyst active sites thus producing additional methane. For continuous operation, the two sorptive reactors were operated 180° out of phase and cyclic steady-state could be reached after ca. five cycles. The performance of the cyclic sorptive-reactive unit was assessed through a parametric study to evaluate the influence of different operating conditions, namely, the inlet flow rate and CO 2 content during the sorption stage, the hydrogen inlet flow rate during the reactive regeneration stage, the stage duration, and temperature. The inclusion of an inert purge after the reactive regeneration stage was also tested. The performance of the unit was compared to the case of direct hydrogenation of biogas, and conclusions were drawn regarding future optimization, with special attention being given to CH 4 productivity and purity. During the parametric study, a compromise between these process indicators, i.e., a productivity of 1.63 mol CH4 kg cat -1 h -1 with 70.3% of CH 4 purity, was obtained at 350 °C. However, biomethane purities above 80% were easily achieved, though at the expense of methane productivities., Competing Interests: The authors declare no competing financial interest., (© 2022 American Chemical Society.)

Short peptides capped on the N-terminus with aromatic groups are often able to form supramolecular hydrogels-self-assembled networks of fibrils able to trap water molecules. Typically, these hydrogelators can form stiff gels at concentrations of 0.1 to 1.0 wt%- i.e. they consist of mainly water. The properties of these soft materials mimic those of the extracellular matrix (ECM) of biological tissue and therefore they have found many biomedical uses in tissue engineering, wound healing, drug delivery, biosensing and bioprinting applications. In drug delivery strategies related to cancer therapy, injectable hydrogels can serve as a depot formulation, where a sustained release of the chemotherapeutic from near the tumour site allows reduced doses and, therefore, decreased side effects. To further target cancer cells, folic acid-conjugated hydrogels and nanostructures are often sought, to exploit the overexpression of folate receptors on cancer cells-an approach which can allow the selective cellular uptake of an encapsulated drug. In this present study, two known dipeptide folate receptor ligands (1 and 2) recently identified from a screen of a DNA-encoded compound library, were synthesised and investigated for their hydrogelation ability and cytotoxicity. Compound 1, containing a naproxen capping group, rapidly forms hydrogels at concentrations as low as 0.03 wt%-one of the lowest critical gelation concentrations (CGCs) known for a supramolecular hydrogelator. In contrast, compound 2, which contains a 3-indolepropionic acid capping group, was unable to form hydrogels under a range of conditions and concentrations, instead forming nanospheres with diameters of 0.5 μm. Hydrogels of 1 were characterised by STEM microscopy, rheology, fluorescence spectroscopy and circular dichroism. Both compounds 1 and 2 had no impact on the proliferation of kerotinocytes (HaCaT cells) at concentrations up to 100 μM. Compound 1, containing the NSAID, was tested for anti-inflammatory activity in a human cyclooxygenase-1/2 model. The rate of the release of model drug compounds from within hydrogels of 1 was also investigated.

Assessing the relative contribution of Land Use and Cover Changes (LUCC) and climate changes on runoff still represents a great challenge for water resources management. This issue is particularly critical for the Upper Paraná River Basin (UPRB), one of the most important basins in South America and responsible for most of the production of food, ethanol, and electricity generation in Brazil. In this paper, we used the Soil and Water Assessment Tool (SWAT) to quantitatively assess the relative contribution of both forcings. The simulation period included a time of great importance for climate studies, known as the 1970s global climate shift, and of great impact on river discharge within the UPRB. Three land use and cover scenarios were assigned to the 1961-1990 period of simulations, representing land use and cover during a pristine period (around the Year 1500), 1960, and 1985. Thirteen years of precipitation before and after the climate shift (considered to be the period 1974-1977) were analyzed and compared. Results showed a precipitation increase for the basin in general after the climate shift. The increase in rainfall reached up to 15% in many northern areas and more than 20% in the southern parts of the basin. By comparing all simulations, results indicate that both LUCC and precipitation increase due to the climate shift had a significant effect on the changes in annual discharge of the largest rivers of the UPRB. However, the results suggest that the impact of the precipitation increase on the discharge exceeded that of the LUCC. Between 1960 and 1985 the LUCC accounts for about 16% of the increase of the median annual discharge, whereas climate shift accounts for an increase of about 32%. These findings, suggesting a more relevant role for the climate, are consistent with two recent water crisis experienced by the country in the last decades, caused by prolonged below-normal rainfall throughout 2001/2002 and again in 2014/2015., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The COVID-19 pandemic has placed today's society in an unprecedented scenario. During Portugal's first home confinement period (March-July 2020), the online-based "COVID-19 in Trials and Tribulations" project was implemented to support families with school-aged children. The project was grounded on the self-regulation framework and delivered through Facebook ® and Instagram ® pages. Being responsive to ongoing developments of the pandemic, activities were conveyed in two phases. Phase 1 occurred during lockdown (school was suspended). Phase 2 occurred while students were enrolled in at-distance (online) school. The present study aimed to examine the reach of the project, while examining the content and format of delivery that generated the most engagement among the users (4500 Facebook ® effective followers; 1200 Instagram ® effective followers) during the confinement period. Results showed that, at the individual page level, Facebook ® had higher reach indicators compared to Instagram ® , except for video. At the Facebook ® post level, followers and users showed more engagement with the page prior to the at-distance schooling phase; however, videos still generated engagement ( p = 0.002). Both the post type ( p < 0.01) and frequency ( p < 0.001) of publication were suggested to be good predictors of engagement. The information gathered will help design and inform future interventions that may be implemented as new lockdowns are set in place.

The chemical composition of particulate material plays an important role in the atmosphere, providing cloud and ice nuclei for storm development. This study aims to evaluate and infer the sources of ions, metals, and metalloids in the fine atmospheric particulate matter (PM 2.5 ) from triple border Paraná, Santa Catarina (Brazil), and northeastern Argentina, which is among those with the highest hail incidence in the world. Among the ions, the concentrations presented the following sequence in decreasing order: [Formula: see text]> K + > [Formula: see text]> [Formula: see text]> Ca 2+ > Cl - > Na + > Mg 2+ . Regarding the metals and metalloid concentrations, the order was of S > Si > Al > Fe > P > Ti, Cr, Cu, and Zn > Br > Mn, and Ni. The main sources, supported by positive matrix factorization results, are soil and agricultural activities, as well as vehicular emissions due to the agricultural machinery and the displacement of residents. Besides, the influence of aerosols from biomass burning and industrial activities was observed, possibly come from long-distance transport. The composition of PM 2.5 presents one or more elements considered present ice nuclei (IN) activity, such as Al, Mn, Cu, Co, Ni, and V (in form of oxides), corroborating with other studies, also, with high hail incidence. However, further studies are needed to verify the role of aerosol characteristics in the formation of IN and, consequently, hail., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Gene therapy and DNA vaccination are among the most expected biotechnological and medical advances for the coming years. However, the lack of cost-effective large-scale production and purification of pharmaceutical-grade plasmid DNA (pDNA) still hampers their wide application. Downstream processing, which is mainly chromatography-based, of pDNA remains the key manufacturing step. Despite its high resolution, the scaling-up of chromatography is usually difficult and presents low capacity, resulting in low yields. Alternative methods that are based on aqueous two-phase systems (ATPSs) have been studied. Although higher yields may be obtained, its selectivity is often low. In this work, modified polymers based on poly(ethylene glycol) (PEG) derivatisation with amino groups (PEG-amine) or conjugation with positively charged amino acids (PEG-lysine, PEG-arginine, and PEG-histidine) were studied to increase the selectivity of PEG-dextran systems towards the partition of a model plasmid. A two-step strategy was employed to obtain suitable pure formulations of pDNA. In the first step, a PEG-dextran system with the addition of the affinity ligand was used with the recovery of the pDNA in the PEG-rich phase. Then, the pDNA was re-extracted to an ammonium-sulphate-rich phase in the second step. After removing the salt, this method yielded a purified preparation of pDNA without RNA and protein contamination.

The thermodynamic, kinetic, and structural properties of Ln 3+ complexes with the bifunctional DO3A-ACE 4- ligand and its amide derivative DO3A-BACE 4- (modelling the case where DO3A-ACE 4- ligand binds to vector molecules) have been studied in order to confirm the usefulness of the corresponding Gd 3+ complexes as relaxation labels of targeted MRI contrast agents. The stability constants of the Mg 2+ and Ca 2+ complexes of DO3A-ACE 4- and DO3A-BACE 4- complexes are lower than for DOTA 4- and DO3A 3- , while the Zn 2+ and Cu 2+ complexes have similar and higher stability than for DOTA 4- and DO3A 3- complexes. The stability constants of the Ln(DO3A-BACE) - complexes increase from Ce 3+ to Gd 3+ but remain practically constant for the late Ln 3+ ions (represented by Yb 3+ ). The stability constants of the Ln(DO3A-ACE) 4- and Ln(DO3A-BACE) 4- complexes are several orders of magnitude lower than those of the corresponding DOTA 4- and DO3A 3- complexes. The formation rate of Eu(DO3A-ACE) - is one order of magnitude slower than for Eu(DOTA) - , due to the presence of the protonated amine group, which destabilizes the protonated intermediate complex. This protonated group causes the Ln(DO3A-ACE) - complexes to dissociate several orders of magnitude faster than Ln(DOTA) - and its absence in the Ln(DO3A-BACE) - complexes results in inertness similar to Ln(DOTA) - (as judged by the rate constants of acid assisted dissociation). The 1 H NMR spectra of the diamagnetic Y(DO3A-ACE) - and Y(DO3A-BACE) - reflect the slow dynamics at low temperatures of the intramolecular isomerization process between the SA pair of enantiomers, R- Λ ( λλλλ ) and S- Δ ( δδδδ ). The conformation of the C α -substituted pendant arm is different in the two complexes, where the bulky substituent is further away from the macrocyclic ring in Y(DO3A-BACE) - than the amino group in Y(DO3A-ACE) - to minimize steric hindrance. The temperature dependence of the spectra reflects slower ring motions than pendant arms rearrangements in both complexes. Although losing some thermodynamic stability relative to Gd(DOTA) - , Gd(DO3A-BACE) - is still quite inert, indicating the usefulness of the bifunctional DO3A-ACE 4- in the design of GBCAs and Ln 3+ -based tags for protein structural NMR analysis.

Mobility restrictions are among actions to prevent the spread of the COVID-19 pandemic and have been pointed as reasons for improving air quality, especially in large cities. However, it is crucial to assess the impact of atmospheric conditions on air quality and air pollutant dispersion in the face of the potential variability of all sources. In this study, the impact of mobility restrictions on the air quality was analyzed for the most populous Brazilian State, São Paulo, severely impacted by COVID-19. Ground-based air quality data (PM 10 , PM 2.5 , CO, SO 2 , NO x , NO 2 , NO, and O 3 ) were used from 50 automatic air quality monitoring stations to evaluate the changes in concentrations before (January 01 - March 25) and during the partial quarantine (March 16 - June 30). Rainfall, fires, and daily cell phone mobility data were also used as supplementary information to the analyses. The Mann-Whitney U test was used to assess the heterogeneity of the air quality data during and before mobility restrictions. In general, the results demonstrated no substantial improvements in air quality for most of the pollutants when comparing before and during restrictions periods. Besides, when the analyzed period of 2020 is compared with the year 2019, there is no significant air quality improvement in the São Paulo State. However, special attention should be given to the Metropolitan Area of São Paulo (MASP), due to the vast population residing in this area and exposed to air pollution. The region reached an average decrease of 29% in CO, 28% in NO x , 40% in NO, 19% in SO 2 , 15% in PM 2.5 , and 8% in PM 10 concentrations during the mobility restrictions period compared to the same period in 2019. The only pollutant that showed an increase in concentration was ozone, with a 20% increase compared to 2019 during the mobility restrictions period. Before the mobility restrictions period, the region reached an average decrease of 30% in CO, 39% in NO x , 63% in NO, 12% in SO 2 , 23% in PM 2.5 , 18% in PM 10 , and 16% in O 3 concentrations when compared to the same period in 2019. On the other hand, Cubatão, a highly industrialized area, showed statistically significant increases above 20% for most monitored pollutants in both periods of 2020 compared to 2019. This study reinforces that the main driving force of pollutant concentration variability is the dynamics of the atmosphere at its various time scales. An abnormal rainy season, with above average rainfall before the restrictions and below average after it, generated a scenario in which the probable significant reductions in emissions did not substantially affect the concentration of pollutants., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The yeast Rhodosporidium toruloides NCYC 921 was used for lipid production, using Miscanthus biomass hydrolysate as carbon source. The hydrolysate was obtained by enzymatic hydrolysis of Miscanthus biomass (at high solids loading) previously subjected to a hydrothermal pre-treatment. Afterwards R. toruloides was grown on Miscanthus sp. hydrolysate (MH), undiluted and diluted, at the ratios of 1:4 (20 % v/v), 1:2 (33.3 % v/v) and 3:1 (75 % v/v). The best yeast performance was observed for MH 1:2 medium dilution, reaching the maximal biomass concentration of 6.3 g/L, the lipid content of 30.67 % w/w dry cell weight and the lipid concentration of 1.64 g/L. Flow cytometry demonstrated that R. toruloides cell membrane was massively damaged when the yeast was grown on undiluted MH, due to the presence of phenolic compounds; however, when the yeast was grown on diluted MH 1:2 and 1:4, the proportion of intact cells has increased during the yeast cultivation., Competing Interests: The authors report no declarations of interest., (© 2021 Published by Elsevier B.V.)

The self-assembly of nanometric structures from molecular building blocks is an effective way to make new functional materials for biological and technological applications. In this work, four symmetrical bolaamphiphiles based on dehydrodipeptides (phenylalanyldehydrophenylalanine and tyrosyldehydrophenylalanine) linked through phenyl or naphthyl linkers (terephthalic acid and 2,6-naphthalenedicarboxylic acid) were prepared, and their self-assembly properties were studied. The results showed that all compounds, with the exception of the bolaamphiphile of tyrosyldehydrophenylalanine and 2,6-naphthalene dicarboxylic acid, gave self-standing hydrogels with critical gelation concentrations of 0.3 wt % and 0.4 wt %, using a pH trigger. The self-assembly of these hydrogelators was investigated using STEM microscopy, which revealed a network of entangled fibers. According to rheology, the dehydrodipeptide bolaamphiphilic hydrogelators are viscoelastic materials with an elastic modulus G' that falls in the range of native tissue (0.37 kPa brain-4.5 kPa cartilage). In viability and proliferation studies, it was found that these compounds were non-toxic toward the human keratinocyte cell line, HaCaT. In sustained release assays, we studied the effects of the charge present on model drug compounds on the rate of cargo release from the hydrogel networks. Methylene blue (MB), methyl orange (MO), and ciprofloxacin were chosen as cationic, anionic, and overall neutral cargo, respectively. These studies have shown that the hydrogels provide a sustained release of methyl orange and ciprofloxacin, while methylene blue is retained by the hydrogel network.

Short peptides capped on the N -terminus with aromatic groups are often able to form supramolecular hydrogels, via self-assembly, in aqueous media. The rheological properties of these readily tunable hydrogels resemble those of the extracellular matrix (ECM) and therefore have potential for various biological applications, such as tissue engineering, biosensors, 3D bioprinting, drug delivery systems and wound dressings. We herein report a new photo-responsive supramolecular hydrogel based on a "caged" dehydropeptide (CNB-Phe-ΔPhe-OH 2 ), containing a photo-cleavable carboxy-2-nitrobenzyl (CNB) group. We have characterized this hydrogel using a range of techniques. Irradiation with UV light cleaves the pendant aromatic capping group, to liberate the corresponding uncaged model dehydropeptide (H-Phe-ΔPhe-OH 3 ), a process which was investigated by 1 H NMR and HPLC studies. Crucially, this cleavage of the capping group is accompanied by dissolution of the hydrogel (studied visually and by fluorescence spectroscopy), as the delicate balance of intramolecular interactions within the hydrogel structure is disrupted. Hydrogels which can be disassembled non-invasively with temporal and spatial control have great potential for specialized on-demand drug release systems, wound dressing materials and various topical treatments. Both 2 and 3 were found to be non-cytotoxic to the human keratinocyte cell line, HaCaT. The UV-responsive hydrogel system reported here is complementary to previously reported related UV-responsive systems, which are generally composed of peptides formed from canonical amino acids, which are susceptible to enzymatic proteolysis in vivo. This system is based on a dehydrodipeptide structure which is known to confer proteolytic resistance. We have investigated the ability of the photo-activated system to accelerate the release of the antibiotic, ciprofloxacin, as well as some other small model drug compounds. We have also conducted some initial studies towards skin-related applications. Moreover, this model system could potentially be adapted for on-demand "self-delivery", through the uncaging of known biologically active dehydrodipeptides.