Nanocellulose (NC) is a promising material for drug delivery due to its high surface area-to-volume ratio, biocompatibility, biodegradability, and versatility in various formats (nanoparticles, hydrogels, microspheres, membranes, and films). In this study, nanocellulose films were derived from “Bolaina blanca” (Guazuma crinita) and combined with nanoporous silicon microparticles (nPSi) in concentrations ranging from 0.1% to 1.0% (w/v), using polyvinyl alcohol (PVA) as a binding agent to create NC/nPSi composite films for drug delivery systems. The physicochemical properties of the samples were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR–ATR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The mechanical properties and drug release capabilities were also evaluated using methylene blue (MB) as an antibacterial drug model. Antibacterial assays were conducted against S. aureus and E. coli bacteria. The results show that NC/nPSi composites with 1% nPSi increased the T_50% by 10 °C and enhanced mechanical properties, such as a 70% increase in the elastic modulus and a 372% increase in elongation, compared to NC films. Additionally, MB released from NC/nPSi composites effectively inhibited the growth of both bacteria. It was also observed that the diffusion coefficients were inversely proportional to the % nPSi. These findings suggest that this novel NC/nPSi-based material can serve as an effective controlled drug release system.

The north Patagonian lakes in their original stage were characterized by their marked oligotrophy, with high abundance of mixotrophic ciliates in lakes with native forest in their surrounding basins. Nevertheless, in the last decades, it was a replace of native forest of different kind of human activities, such as towns and agricultural zones, that generate a transition from oligotrophy to mesotrophy, being replaced the mixotrophic ciliates by different kind of phytoplankton. The aim of the present study was to propose a descriptive model using remote sensing techniques for determining the best model for predict the mixotrophic ciliates abundance in two North Patagonian Chilean lakes. In studies sites, only Caburgua lake has mixotrophic ciliates, that belong to the species Ophyridium naumanni, Stentor amethystinus and S. araucanus, whereas Villarrica lake has not mixotrophic ciliates. The multiple regression analysis revealed that for O.naumanni and S. amethystinus have significant direct associations between temperature, B01, B07 reflectances, S. araucanus abundances, and inverse associations with B02, B04 and B07, and the abundance of both species was significantly inverse. Finally, for S. araucanus was positive associations with B04 and S. amethystinus. The exposed results would be similar to the first descriptions of mixotrophic ciliates abundances for Argentinean and Chilean Patagonian lakes. On this basis, we propose the use of remote sensing techniques would be an important key tool for study the presence of these organism.

The amphipods of the genus Hyalella have many endemic species throughout South America, and these may have poorly studied associated species as epibionts. The aim of the present study was to review the literature on the presence of the protozoon Lagenophrys lenticulata (Kellicott, 1885) on species of Hyalella and contrast the results with the geographical distribution of the reported hosts. The literature records the presence of L. lenticulata on populations of H. azteca from Canada, Mexico and the United States of America, and on populations of H. curvispina from Uruguay. The literature also reports that H. curvispina is widespread throughout southern South America, including Argentina and Chile, and that it would be possible to find the presence of epibionts on other populations of H. curvispina. The corresponding biogeographical and evolutionary topics are discussed.

Freshwater amphipods of the genus Hyalella are widely distributed across continental Chile and exhibit marked geographical segregation associated with environmental gradients. The present study analyzed the latitudinal and altitudinal distribution patterns of Chilean Hyalella species using exploratory multivariate approaches based on published occurrence records. Geographic data from 139 records were compiled and analysed using non-parametric statistics and DBSCAN clustering methods. Significant differences among species were detected for both latitude and altitude ( ). The analyses revealed two main distributional assemblages. The first group included H. fossamanchini and H. kochi , species associated with high-altitude saline systems in northern Chile. The second assemblage grouped H. chiloensis , H. franciscae , H. patagonica , and H. simplex , which inhabit temperate and subantarctic freshwater environments in southern Chile. Hyalella costera showed partial overlap with H. chiloensis in coastal environments. The observed patterns suggest that latitudinal and altitudinal gradients are major ecological drivers influencing species segregation in Chilean Hyalella . Furthermore, the Andes may have acted both as a dispersal corridor and as a biogeographical barrier promoting diversification along continental Chile. These findings provide new insights into the geographical structuring of South American freshwater amphipods and contribute to the understanding of regional biogeographical processes in Andean freshwater ecosystems.

The ectosymbiont fauna associated with crustaceans in South American inland waters is characterized by a marked microendemism, as the species concerned appear to show high host specificity. The aim of the present study is to present a review of ciliated Protozoa reported as ectosymbionts on South American inland water malacostracans. The literature revealed the existence of three genera, Chilenophrys with one species, Lagenophrys with five species, and Operculigera with seven species. The main limiting factor is that many species descriptions require further validation, as the reports have not been confirmed. The literature reports the presence of Lagenophrys lenticulata associated with Hyalella curvispina from Uruguay. H. curvispina is widespread throughout southern South America, including Argentina and Chile, and it may be possible to find epibionts on other populations of H. curvispina , as well as on other Hyalella populations. Lagenophrys aegleae has been recorded on the genus Aegla in eastern and western South America; L. antichos on crayfishes in east and west South America; and L. lenticulata on amphipods in North America and Uruguay. Ecological and biogeographical topics are also addressed.