Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nanobiotechnology, combined with green chemistry, has great potential for the development of novel and necessary products that benefit human health, environment, and industries. Green chemistry has an important role due to its contribution to unconventional synthesis methods of gold and silver nanoparticles from plant extracts, which have exhibited antimicrobial potential, among other outstanding properties. Biodiversity-rich countries need to collect and convert knowledge from biological resources into processes, compounds, methods, and tools, which need to be achieved along with sustainable use and exploitation of biological diversity. Therefore, this paper describes the relevant reported green synthesis of gold and silver nanoparticles from plant extracts and their capacity as antimicrobial agents within the agricultural field for fighting against bacterial and fungal pathogens that can cause plant, waterborne, and foodborne diseases. Moreover, this work makes a brief review of nanoparticles’ contribution to water treatment and the development of “environmentally-friendly” nanofertilizers, nanopesticides, and nanoherbicides, as well as presenting the harmful effects of nanoparticles accumulation in plants and soils.

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Nowadays, it has become urgently necessary to change the traditional methods of synthesis of metallic nanoparticles, and to start using safer and more eco-friendly approaches. In the present work a green synthesis of silver nanoparticles was carried out using mint leaf extract (Mentha piperita) as the reducing and stabilizing agent. Silver nanoparticles were synthesized using a 1 mM silver nitrate solution and varying the volume of the extract (150, 250, 350 L), at a temperature of 30 C for 24 h. The formation of silver nanoparticles was monitored by a UV-Visible spectrophotometer which showed absorption peaks ranging from 438-470 nm. Atomic Force Microscopy and Transmission Electron Microscopy analysis showed that the silver nanoparticles presented different morphologies. For the treatment with 150 l of extract, the silver nanoparticles were mostly spherical and for the other two treatments we observed spherical, triangular, hexagonal and irregular morphologies of the nanoparticles. Dynamic Light Scattering analysis determined a mean size of 50 nm for all of the treatments, with zeta potential values ranging from −20 to −23 mV. The results showed that the synthesized silver nanoparticles had antibacterial activity against pathogenic bacteria such as Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentration required for S. aureus was 11.1, 26.3 and 51.5 g · ml −1 , for the treatments of 150, 250 and 350 l of extract, respectively. All of these values were higher than for E. coli, which presented a Minimum Inhibitory Concentration of 2.49 g · ml −1 . This work offers a quick, simple and non-toxic method for the synthesis of silver nanoparticles.

Chronic and non-healing wounds demand personalized and more effective therapies for treating complications and improving patient compliance. Concerning that, this work aims to develop a suitable chitosan-based thermo-responsive scaffold to provide 24 h controlled release of Dexketoprofen trometamol (DKT). Three formulation prototypes were developed using chitosan (F1), 2:1 chitosan: PVA (F2), and 1:1 chitosan:gelatin (F3). Compatibility tests were done by DSC, TG, and FT-IR. SEM was employed to examine the morphology of the surface and inner layers from the scaffolds. In vitro release studies were performed at 32 °C and 38 °C, and the profiles were later adjusted to different kinetic models for the best formulation. F3 showed the most controlled release of DKT at 32 °C for 24 h (77.75 ± 2.72%) and reduced the burst release in the initial 6 h (40.18 ± 1.00%). The formulation exhibited a lower critical solution temperature (LCST) at 34.96 °C, and due to this phase transition, an increased release was observed at 38 °C (88.52 ± 2.07% at 12 h). The release profile for this formulation fits with Hixson–Crowell and Korsmeyer–Peppas kinetic models at both temperatures. Therefore, the developed scaffold for DKT delivery performs adequate controlled release, thereby; it can potentially overcome adherence issues and complications in wound healing applications.

Plastic accumulation's negative impact on aquatic ecosystems is a known and undeniable problem. Much of the scientific community's efforts are focused on the effects of the most common commodity plastics, but the consequences of the so-called biodegradable plastics in these ecosystems have been little discussed. Although their biodegradable characteristic generates the widespread belief that they are harmless to the environment, it has been proven many years ago that this property cannot be taken lightly. The material´s end-of-life fate is critical to classify it as biodegradable or not. In this context, many plastics classified as biodegradable do not meet the requirements of norms and standards to be considered biodegradable in aquatic ecosystems. Furthermore, during the last five years, the scientific community has shown that they can give rise to the formation of bio-microplastics during their degradation, which can have similar effects to those of conventional microplastics or even worse. This review will detail all recent information regarding how biodegradable plastics can influence aquatic ecosystems, causing adverse health effects in living beings or acting as vectors of chemical pollutants. Besides, the key points that must be addressed in greater depth will be identified, including the need to consider a greater variety of biodegradable plastics and develop systematic methods that allow quantifying and identifying the remains of these pollutants in living species. Another aspect to consider is the dynamics of arrival and mobilization of microplastics in the oceans. It should be studied how small animals fed by filterings, such as red crabs and other zooplankton organisms, move the microplastic through the water column and get into food webs. These particles are mistakenly ingested by the number of species at different trophic levels, where bioaccumulation in tissues must be considered a toxicity factor. Finally, a series of recommendations and future perspectives will be listed.