COVID-19: Implications for plastic reduction, with a focus on Personal Protective Equipment (PPE).

With over 190 million cases reported and nearly 4.1 million deaths worldwide, COVID19 has been the center of global attention. This pandemic has changed many aspects of daily life and has, perhaps, indelibly changed the way we live and it is quite likely that there will be no full return to normality. Owing to its impacts across all societal aspects - from micro- and macroeconomics, information management and research, education, to governance, mental health and even territorial integrity and cohesion - the global ecosystem upon which modern society has evolved will have to be redesigned. Many have, indeed, pointed out that the economy will have to be restructured and growth will have to be defined as prosperity - not continuous growth. Perhaps nowhere is this more evident than in the environment.

Biotechnologically obtained nanocomposites: A practical application for photodegradation of Safranin-T under UV-Vis and solar light.

This research was undertaken to determine the potential of biologically obtained ZnS-TiO2 nanocomposites to be used as catalysts in the photodegradation of organic pollutants, namely, Safranin-T. The photocatalysts were prepared by modifying the surface of commercial TiO2 particles with naturally produced ZnS, using sulfide species produced by sulfate-reducing bacteria and metal contaminated wastewaters. Comparative studies using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), prior and after photodegradation, were carried out in order to monitor possible structural and morphological changes on the particles. Adsorption properties and specific areas were determined by the Brunauer-Emmet-Teller (BET) method. The final solutions were characterized by UV-Vis and chemical oxygen demand (COD) content in order to determine Safranin-T concentration and toxicity. The influence of the catalyst amount, initial pH and dye concentration was also evaluated. Finally, the efficiency of the precipitates as catalysts in sunlight-mediated photodegradation was investigated, performing two scale experiments by using different volumes of dye-contaminated water (150 mL and 10 L). All tested composites showed potential to be used as photocatalysts for the degradation of Safranin-T, although the ZnS-TiO2_0.06 composite (0.06 g of TiO2 per 50 mL of the zinc solution) was the most effective. This substantiates the applicability of these biologically obtained materials as efficient photocatalysts for the degradation of organic pollutants, in laboratorial conditions and under direct sunlight.

Magnetic chelating nanoprobes for enrichment and selective recovery of metalloproteases from human saliva.

New magnetic nanoprobes based on surface-functionalized magnetite particles were synthesized and used to selectively capture metalloproteases from human saliva samples. In addition to their high specific surface area, these nanoparticles have metal ion chelating moieties grafted on their surface by the reaction with the organosilane EDTA-TMS ((N-(trimethoxysilylpropyl)-ethylenediaminetriacetate trisodium salt). The most distinct feature of these particles is their capability to selectively recover metalloproteases even in highly diluted saliva samples. The high affinity of these materials for metalloproteases was attributed to the formation of chelates between the chelating moieties and the metal ions of metalloproteases. These magnetic particles exhibited high colloidal stability in the biological standard buffers MES, HEPES, TEAB and Tris-HCl, within a significant pH range (pH 5-9) and, due to their magnetic features, enabled a fast separation of the metalloproteases from the medium by simply applying an external magnetic field. Thus, these materials were proven to be valuable probes for the selective enrichment and rapid recovery of metalloproteases from human saliva, particularly when dealing with trace amounts of material.

Salivary peptidomic as a tool to disclose new potential antimicrobial peptides.

Antimicrobial peptides (AMPs) and peptidomimetics are among the new generation of antibiotics due to their broad spectrum of activity towards pathogenic agents. Considering the fact that the oral cavity is a relevant entryway for pathogenic microorganisms, it must be armed with several defenses in order to maintain homeostasis. Thus, we aimed at disclosing potential AMPs in saliva from humans, pigs and mice. We enriched salivary peptides by filtration and then separated and identified multiple peptides by nanoHPLC-MALDI-TOF/TOF. Using this approach, we identified 45 different peptides from mice's saliva and 94 from pig's saliva. Almost all peptides from pig and mice saliva were new assignments, encouraging the application of this technique to other mammals' saliva. The potential antimicrobial activity was then calculated in silico with an available CAMP's algorithm. Eight peptides from pig's basic proline-rich protein, as well as 6 peptides resulting from human's P-B peptide, 1 from P-C peptide fragmentation and 1 from statherin were found to have potential antimicrobial activity. Therefore, the peptides GPPPQGGRPQG and RFGYGYGPYQPVPEQPLYPQ were synthetically obtained and their antimicrobial properties evaluated in vitro for different bacterial strains. These showed to exert an antibacterial effect in Staphylococcus aureus. This report validates the prospection of mammal's saliva to find new alternatives to antibiotics. BIOLOGICAL SIGNIFICANCE: With the growing problem of antibiotic resistance, the identification of new routes in antibiotic therapy is on the scientific agenda worldwide. Antimicrobial peptides (AMPs) and peptidomimetics are among the new generation of antibiotics due to their broad spectrum of activity towards pathogenic agents and owing to a less probable microbial resistance that can arise from their use. Thus, we explored the saliva from humans, pigs and mice to identify potential AMPs using a peptidomic approach. At the end, eight peptides from pig's basic proline-rich protein, six peptides resulting from human's P-B peptide, one from P-C peptide fragmentation and one from statherin were found to have potential antimicrobial activity. From this, the peptides GPPPQGGRPQG and RFGYGYGPYQPVPEQPLYPQ were tested showing to have antibacterial effect in S. aureus which highlights the potential of mammal's saliva to find new alternatives to antibiotics.