Mário Antônio Alves da Cunha

The preservation of anatomical specimens is essential for teaching and research, enabling detailed analysis of tissue morphology and structure. Traditional methods such as formaldehyde fixation have been increasingly questioned due to their toxicity and associated health risks. Plastination offers a safer, more durable alternative, producing dry, odorless, permanently preserved specimens. This study evaluated polyvinyl acetate (PVAc) as an innovative, low-cost, and non-toxic polymer for the plastination of biological tissues. Acetic acid and glycerol were tested as additives, using bovine heart and kidney as anatomical models. The samples were characterized by ATR-FTIR, X-ray diffraction (XRD), thermogravimetric analysis (TGA), SEM-EDS, color analysis (CIELab), and histological examination. The optimal formulation consisted of 85% PVAc, 5% glycerol, and 10% acetic acid. Plastinated specimens preserved anatomical integrity and showed slightly darker, more saturated coloration compared to formalin-fixed samples. Thermal analysis indicated improved stability, and characteristic infrared bands confirmed polymer impregnation. Histological results demonstrated preserved cellular and structural organization. Overall, PVAc proved to be a viable, safe, and affordable alternative for plastination, with potential to replace formaldehyde-based methods and reduce environmental and occupational health risks.

β-Glucans are carbohydrate macromolecules with significant clinical and biotechnological applications, whose biological properties are enhanced through chemical modifications, such as sulfation. This study aimed to chemically engineer sulfated derivatives of the (1→6)-β-d-glucan lasiodiplodan and to evaluate how different degrees of sulfation influence its antioxidant, antimicrobial, and antiviral activities. The chemically engineered sulfated derivatives LAS-S1 (DS 0.11) and LAS-S2 (DS 0.51) were synthesized using the sulfating agent chlorosulfonic acid, with different solvents: N,N-dimethylformamide (solvent/stabilizer) and pyridine (proton-neutralizing agent). Sulfation improved the solubility and enhanced the biological activities of both derivatives. LAS-S2 demonstrated better antimicrobial and antiviral activity than LAS-S1. Sulfation was shown to contribute to ·OH and H₂O₂ scavenging activity, with a dose-dependent effect related to both the concentration of the sulfated compound and its degree of sulfation. The fungistatic and bacteriostatic effects were demonstrated against Escherichia coli, Listeria monocytogenes, Salmonella enterica Typhimurium, Candida albicans, and Candida tropicalis. LAS-S2 exhibited potent inhibition of respiratory syncytial virus (RSV) in vitro, with a high selectivity index (>724.63), and interfered with multiple stages of viral replication. These findings highlight sulfation as an effective strategy to enhance the biological functions of lasiodiplodan. LAS-S2 emerges as a safe (noncytotoxic) and promising candidate for biotechnological and pharmaceutical applications, including novel antimicrobial and antiviral treatments. Future studies should focus on elucidating structure–activity relationships, optimizing sulfation patterns, and evaluating the in vivo efficacy and pharmacological properties of sulfated lasiodiplodan derivatives.

The rapid growth of the microbrewery sector, driven by the increasing demand for craft beers, has highlighted the importance of managing brewing residues to ensure environmental and economic sustainability. This review explores the primary byproducts of beer productionbrewer’s spent grain (BSG), brewer’s spent yeast (BSY), and hot trubanalyzing their composition and potential for upcycling. By exploring the Brazilian microbrewery sector as a case study, this work highlights its growth and challenges, while drawing insights that resonate with the global interest in sustainable practices within the craft beer industry. Traditional applications, such as animal feed and fertilizer, are expanded with new approaches like biofuel production, biogas, biopolymer synthesis, prebiotics, and healthy food ingredient development. An emphasis on the applications of BSG in food formulations, such as bread, cookies, nutrition bars, beverages, meat analogs, yogurt, and others, highlights its nutritional value and functional properties for developing food products. By integrating sustainable practices and advanced processing technologies, brewing residues can be transformed into high-value products, reducing waste and fostering economic growth. This review concludes that adopting circular economy principles is essential for aligning microbrewery operations with global sustainability goals while unlocking the potential of brewing byproducts for diverse industrial applications.

Antimicrobial resistance is a major global public health challenge, motivating the search for new antimicrobial agents for biomedical and agricultural applications. This study reports the synthesis of a silver coordination assembly using a natural ligand derived from Pinus elliottii resin under mild temperature and pH conditions. The resulting brown solid was characterized by mass spectrometry, infrared spectroscopy, and complementary techniques. The characterization data suggest the formation of a silver(I)-abietate compound with bridging coordination through the carboxylate oxygen atoms. Antimicrobial activity was evaluated by minimum inhibitory concentration (MIC) and disk diffusion assays. MIC values were 3.9 µmol L-1 for Candida albicans, 15.6 µmol L-1 for Escherichia coli and Salmonella gallinarum, and 31.2 µmol L-1 for Staphylococcus aureus. For the phytopathogenic bacteria, MIC values were 31.2 µmol L-1 for Pectobacterium carotovorum and Xanthomonas citri, and 62.5 µmol L-1 for Ralstonia solanacearum. The disk diffusion assay yielded inhibition halos ranging from 14 to 20 mm against three pathogenic bacteria, one pathogenic fungus, and three phytopathogenic bacteria, indicating strong inhibitory activity. In toxicity assays using Drosophila melanogaster, Ag-abietate did not significantly affect survival, and an median lethal dose (LD₅₀) could not be determined within the tested concentration range. The results demonstrate that Ag-abietate is a promising candidate for both biomedical and agricultural applications, underscoring the potential of metal-based compounds in addressing antimicrobial resistance.

O objetivo deste estudo foi testar em um grupo de animais diabéticos, o efeito da b-(1→6)-D-glucana modificada quimicamente por carboximetilação sobre a glicemia sanguínea de ratos diabéticos. Foram utilizados 30 ratos wistar machos. A indução do diabetes foi realizada pela administração de Aloxana Monohidratado, na concentração de 125 mg/kg. De forma sub-crônica, os grupos de animais receberam 5 e 15 mg/kg de b-(1→6)-D-glucana produzida pelo fungo Lasiodiplodia theobromae MMPI em cultivo submerso, modificada quimicamente. A duração do respectivo tratamento foi de 28 dias. Foram realizadas análises bioquímicas quantificando os níveis de Colesterol, Triglicerídeos, TGO, TGP, Ureia, Creatinina e Glicose, além da avaliação histológica dos Rins, do Pâncreas e Fígado dos animais. O grau de peroxidação lipídica foi determinado pela medição da concentração de substâncias reativas ao ácido tiabarbitúrico (TBARS). Os resultados obtidos demonstraram que a Lasiodiplodana Carboximetilada (LC) na concentração de 5 mg/Kg, promoveu ao final do tratamento, uma redução dos níveis de glicose capilar ao jejum de ratos induzidos ao diabetes por aloxana (ALX); o teste oral de tolerância a glicose (TOTG) não apresentou mudança de comportamento nos grupos tratamento LC5 e LC15 quando comparados ao grupo Controle Salina (CS) e metformina (MET); a LC na concentração de 15 mg/Kg, promoveu redução da perda de peso nos animais diabéticos em 28% quando comparado aos animais diabético salina; a modificação química por carboximetilação da lasiodiplodana, gerou um dano superficial e profundo no tecido hepático nos animais do grupo tratamento de menor concentração; os níveis de creatinina sérica dos animais diabéticos tratados com a LC, demonstraram elevados quando comparados aos do grupo saudável e normais quando comparados ao grupo MET. Em conclusão, a LC mostrou efeitos hipoglicemiantes e antioxidantes em ratos diabéticos induzidos por aloxana. A dose de 5 mg/kg reduziu a glicose capilar em jejum e os níveis de TBARS no fígado e rins, mas causou danos hepáticos e reduziu proteínas totais e albumina. A dose de 15 mg/kg diminuiu a perda de peso em 28%, sem impactar significativamente a glicemia ou uréia. A LC apresenta potencial terapêutico, porém sua toxicidade hepática e renal requer atenção em estudos futuros.

In this study, we synthesized and characterized a novel Propolis-Cu (II) complex to enhance its photophysical and antimicrobial properties. The complex was characterized using UV–vis spectroscopy, FTIR, and scanning electron microscopy (SEM), revealing a distinct absorption profile and significantly enhancing Cu²⁺ absorption bands at 800–900 nm. FTIR reveals molecular interactions via carbonyl inhibition, and SEM indicate morphological changes with distinct crystalline structure formation. Although the Cu-PRO exhibits a significant decrease in antioxidant activity compared to propolis extract, the complex still retains considerable activity, which could be beneficial in future therapeutic applications. The antimicrobial activity of the Cu-PRO was significantly enhanced compared to pure propolis. While propolis alone exhibited strong activity against Escherichia coli (MIC = 12.5 μg·mL^–1) and good activity against Listeria monocytogenes (50.0 μg·mL^–1), the complex demonstrated an enhanced bactericidal action against Staphylococcus aureus at lower concentrations (50.0 μg·mL^–1) and good inhibitory activity against Salmonellagallinarum (50.0 μg·mL^–1) but not in E. coli and L. monocytogenes. Critically, toxicological assessment in Drosophila melanogaster revealed a chronic and dose-dependent toxicity profile, with lethal effects emerging only at doses >2.5 mg·mL^–1, in longer exposure, and a cumulative reduction in LC₅₀ over time (7.92 → 3.64 mg·mL^–1 in 6 days). However, toxicity was expressively lower than free Cu²⁺ salts, attributed to propolis-mediated chelation reducing free Cu²⁺ bioavailability and antioxidant activity, possibly mitigating oxidative stress. The complex’s improved antimicrobial properties against S. aureus and S. gallinarum, coupled with modulated toxicity, position it as a promising candidate for therapeutic applications; particularly, its enhanced visible-light absorption in 800–900 nm falls into the therapeutic window of Photodynamic Therapy (PDT). We speculate that the results presented here highlight the potential of this complex as an innovative approach for combined therapies. Future studies are focusing on exploring its mechanisms of action and potential for light-assisted therapies, such as PDT where it can be used to simultaneously promote wound healing and combat infections.

There is significant concern within the scientific community regarding the prevention and treatment of diseases caused by viruses and bacteria as well as the increasing resistance of these microorganisms to conventional medicines. Numerous studies have addressed this challenge to explore the antimicrobial potential of various compounds and improve existing drugs, aiming to counteract microbial mutations and prevent large-scale outbreaks. This study synthesized and characterized three metal–saccharin complexes (Fe, Co, and Ni) and investigated their application as antimicrobial activity pigments. The complexes were studied using molar conductivity, Fourier transform infrared spectroscopy, mass spectrometry, nuclear magnetic resonance (NMR ¹H), UV–vis spectroscopy, thermogravimetry, single-crystal X-ray diffraction, and colorimetry. The results confirmed the formation and composition of the metal complexes. The synthesized compounds exhibited antimicrobial activity in both solution and solid states, maintaining their efficacy when incorporated into acrylic paste and fabric paint. The Co–sac complex displayed superior antimicrobial activity among the tested complexes across all evaluations. It inhibited the growth of Salmonella typhimurium and Candida albicans at a MIC of 62.5 μg·mL^–1, with fungicidal and bactericidal effects confirmed at 125 μg·mL^–1. In disk diffusion assays, Co–sac (10%) in acrylic paste showed a maximum inhibition halo of 14.03 ± 0.39 mm against Staphylococcus aureus. When applied to face mask fabric, the same complex achieved inhibition halos of up to 11.65 ± 2.25 mm for Escherichia coli and 8.78 ± 2.34 mm for Listeria monocytogenes. Notably, the antimicrobial activity index reached values as high as 1.05, surpassing those of conventional antibiotics in specific tests.