Differentiation of stem cells into insulin-producing cells under the influence of nanostructural polyoxometalates.

Two polyoxometalates (POMs) with W were synthesized by a two-step, self-assembling method. They were used for stimulation of mesenchymal stem cell differentiation into insulin-producing cells. The nanocompounds (tris(vanadyl)-substituted tungsto-antimonate(III) anions [POM1] and tris-butyltin-21-tungsto-9-antimonate(III) anions [POM2]) were characterized by analytical techniques, including ultraviolet-visible, Fourier transform infrared, nuclear magnetic resonance spectroscopy, and transmission electron microscopy. We found that these polyoxotungstates, with 2-4 nm diameters, did not present toxic effects at the tested concentrations. In vitro, POM1 stimulated differentiation of a greater number of dithizone-positive cells (also organized in clusters) than the second nanocompound (POM2). Based on our in vitro studies, we have concluded that both the POMs tested had significant biological activity acting as active stimuli for differentiation of stem cells into insulin-producing cells.

Ultrastructural Analysis of In Vivo Hypoglycemiant Effect of Two Polyoxometalates in Rats with Streptozotocin-Induced Diabetes.

Two polyoxometalates (POMs), synthesized through a self-assembling method, were used in the treatment of streptozotocin (STZ)-induced diabetic rats. One of these nanocompounds [tris(vanadyl)-substituted tungsto-antimonate(III)-anions­POM1] was previously described in the literature, whereas the second [tris-butyltin-21-tungsto-9-antimonate(III)-anions­POM2], was prepared by us based on our original formula. In rats with STZ-induced diabetes treated with POMs (up to a cumulative dose of 4 mg/kg bodyweight at the end of the treatments), statistically significant reduced levels of blood glucose were measured after 3 weeks, as compared with the diabetic control groups (DCGs). Ultrastructural analysis of pancreatic ß-cells (including the mean diameter of secretory vesicles and of their insulin granules) in the treated diabetic rats proved the POMs contribute to limitation of cellular degeneration triggered by STZ, as well as to the presence of increased amounts of insulin-containing vesicles as compared with the DCG. The two POMs also showed hepatoprotective properties when ultrastructural aspects of hepatocytes in the experimental groups of rats were studied. Based on our in vivo studies, we concluded that the two POMs tested achieved hypoglycemiant effects by preventing STZ-triggered apoptosis of pancreatic ß-cells and stimulation of insulin synthesis.

New Polyphenols Identified in Artemisiae abrotani herba Extract.

Artemisia abrotanum L. ("southernwood") belongs to the Artemisia genus and it is used in traditional medicine for the treatment of a variety of illnesses. Scarce data is available on the chemical composition of this medicinal plant, most research being focused on the quantitative and qualitative analyses of its essential oil. Our aim was to investigate the content and profile of polyphenols, flavonoids and hydroxycinnamic derivatives present in the Artemisiae abrotani herba extract. We conducted LC/MS analysis and we screened for 19 polyphenols, flavonoids and hydroxycinnamic derivatives. We determined the total content of these compounds and we screened for antioxidant activity. Most polyphenol acids, hydroxycinnamic derivatives and flavonoids were identified and quantified for the first time in this study. We found an original polyphenol distribution profile with high concentration of sinapic acid, rutin, quercetol, ferulic acid and patuletin. We measured the antioxidant activity, the ethanolic extract presenting a modest radical scavenging activity. The value of this study consists in its novelty as it adds new data on the chemical composition of A. abrotanum L. and it opens novel perspectives for medical and nutritional applications of this plant.

The Influence of Industrial Environmental Factors on Soft Robot Materials.

This work aims to identify the effects that a series of environmental factors, specific to the industrial conditions, have on the materials in the structure of soft robots and, therefore, on soft robotics systems. The purpose is to understand the changes in the mechanical characteristics of silicone materials, with the aim of transferring soft robotics applications from the sphere of services in the industrial field. Distilled water, hydraulic oil, cooling oil, and UV rays are the environmental factors considered in which the specimens were immersed/exposed for 24 h according to ISO-62/2008. The analysis was carried out on two of the most widely used materials in the field, belonging to the category of silicone rubber, which were subjected to uniaxial tensile tests on the strength testing machine Titan 2 Universal. The results show that the greatest impact on the characteristics of the two materials was when exposed to UV rays, while the other media tested had relatively little impact on the mechanical and elastic properties (tensile strength, elongation at break, and tensile modulus) of these materials.

Soft Robotics: A Systematic Review and Bibliometric Analysis.

In recent years, soft robotics has developed considerably, especially since the year 2018 when it became a hot field among current research topics. The attention that this field receives from researchers and the public is marked by the substantial increase in both the quantity and the quality of scientific publications. In this review, in order to create a relevant and comprehensive picture of this field both quantitatively and qualitatively, the paper approaches two directions. The first direction is centered on a bibliometric analysis focused on the period 2008-2022 with the exact expression that best characterizes this field, which is "Soft Robotics", and the data were taken from a series of multidisciplinary databases and a specialized journal. The second direction focuses on the analysis of bibliographic references that were rigorously selected following a clear methodology based on a series of inclusion and exclusion criteria. After the selection of bibliographic sources, 111 papers were part of the final analysis, which have been analyzed in detail considering three different perspectives: one related to the design principle (biologically inspired soft robotics), one related to functionality (closed/open-loop control), and one from a biomedical applications perspective.

In Vitro Antibacterial Susceptibility of Different Pathogens to Thirty Nano-Polyoxometalates.

Due to their unique properties, nano-polyoxometalates (POMs) can be alternative chemotherapeutic agents instrumental in designing new antibiotics. In this research, we synthesized and characterized "smart" nanocompounds and validated their antibacterial effects in order to formulate and implement potential new drugs. We characterized thirty POMs in terms of antibacterial activity-structure relationship. The antibacterial effects of these compounds are directly dependent upon their structure and the type of bacterial strain tested. We identified three POMs that presented sound antibacterial activity against S. aureus, B. cereus, E. coli, S. enteritidis and P. aeruginosa strains. A newly synthesized compound K6[(VO)SiMo2W9O39]·11H2O (POM 7) presented antibacterial activity only against S. aureus (ATCC 6538P). Twelve POMs exerted antibacterial effects against both Gram-positive and Gram-negative strains. Only one POM (a cluster derivatized with organometallic fragments) exhibited a stronger effect compared to amoxicillin. New studies in terms of selectivity and specificity are required to clarify these extremely important aspects needed to be considered in drug design.