Antibacterial and Chemical Characterization of Silica-Quercetin-PEG Hybrid Materials Synthesized by Sol-Gel Route

Antibacterial and Photocatalytic Activities of LDH-Based Sorbents of Different Compositions

Layered double hydroxides (LDHs) play a fundamental role in the processes for the abatement of pollutants in water, with reference to heavy metal decontamination. The research on the topic is multiobjective target oriented, aiming at combining environmental remediation with the possibility of reusing a sorbent as many times as possible, turning it into a renewable resource. In this study, the antibacterial and catalytic properties of a ZnAl-SO₄ LDH and its resulting product after being subjected to a Cr(VI) remediation process are compared. Both solid substrates have also been tested after undergoing a thermal annealing process. The sorbent (previously described and tested for remediation) has been investigated for its antibacterial activity in view of further surgery and drug delivery applications. Finally, its photocatalytic properties have been experimentally tested in the degradation of a model pollutant, i.e., Methyl Orange (MO), under solar-simulated light. Identifying the best recycling strategy for these materials requires an accurate knowledge of their physicochemical properties. The results show that both the antimicrobial activity and the photocatalytic performance may considerably improve after thermal annealing.

Antibacterial and Cytotoxic Silica-Polycaprolactone-Chlorogenic Acid Hybrids by Sol-Gel Route

Organic-inorganic hybrid materials were synthesized by a sol-gel route, using silicon alkoxide together with low molecular weight polycaprolactone and caffetannic acid. The synthesized hybrids were characterized by scanning Fourier-transform infrared (FTIR) spectroscopy, and their surface morphology was acquired by scanning electron microscopy (SEM) analysis. The hybrids were investigated for their antiradical capacity using the DPPH and ABTS tests, while the Kirby-Bauer test was used to evaluate their effects on the growth of Escherichia coli and Enterococcus faecalis. Furthermore, a biologically active hydroxyapatite layer has been observed to form on the surface of intelligently synthesized materials. The MTT direct test showed that the hybrid materials are biocompatible with NIH-3T3 fibroblast cells, while they were cytotoxic towards colon, prostate, and brain tumor cell lines. These results shed new light on the suitability of the synthesized hybrids in the medical field, thus affording knowledge on the features of the bioactive silica-polycaprolactone-chlorogenic acid hybrids.

Discovery, Validation, and Target Prediction of Antibacterial and Antidiabetic Components of Archidendron clypearia Based on a Combination of Multiple Analytical Methods

Archidendron clypearia (A. clypearia), a Fabaceae family member, is widely used as an anti-inflammatory herbal medicine; however, its antibacterial and antidiabetic properties have not been extensively investigated. This study aimed to systematically analyze the antibacterial and antidiabetic components of A. clypearia by utilizing a combination of analytical methods. First, ten different polarity extracts were analyzed through ultra-performance liquid chromatography (UPLC), and their antibacterial and antidiabetic activities were evaluated. Then the spectrum-effect relationship between the biological activity and UPLC chromatograms was analyzed by partial least squares regression and gray relational analysis, followed by corresponding validation using isolated components. Finally, network pharmacology and molecular docking were implemented to predict the main antibacterial target components of A. clypearia and the enzyme inhibition active sites of α-amylase and α-glucosidase. P15, P16, and P20 were found to be the antibacterial and antidiabetic active components. The inhibitory effect of 7-O-galloyltricetiflavan (P15) on six bacterial species may be mediated through the lipid and atherosclerosis pathway, prostate cancer, adherens junctions, and targets such as SRC, MAPK1, and AKT1. The molecular docking results revealed that 7-O-galloyltricetiflavan and 7,4'-di-O-galloyltricetiflavan (P16/P20) can bind to α-amylase and α-glucosidase pockets with binding energies lower than -6 kcal/mol. Our study provides guidance for the development of antibacterial and antidiabetic products based on A. clypearia and can be used as a reference for the evaluation of bioactivity of other herbs.

Suitability of Porous Inorganic Materials from Industrial Residues and Bioproducts for Use in Horticulture: A Multidisciplinary Approach

This study follows a circular economy approach through the preliminary implementation of a coated porous inorganic material (PIM), studied as sustainable controlled release fertilizer, and its application for lettuce Lactuca sativa L. cultivar Chiara growth. The PIM was made of pumice scraps that partially replaced clay as a natural raw material, spent coffee grounds as a porous agent, bovine bone ash and potassium carbonate to provide phosphorus (P) and potassium (K) nutrients, respectively. A coating made with defatted black soldier fly prepupae biomass was used as a nitrogen (N) source. Most of the ingredients used were industrial residues, with the aim of valorizing the raw waste materials present locally. The suitability of PIMs as a fertilizer was investigated with an interdisciplinary approach, which included the first chemical and physical characterization of the material, the evaluation of its antibacterial properties and of its use in horticulture through lettuce growth tests. As tests were carried out indoors, a specific LED lighting device was used to grow the lettuce. The release of nutrients into the soil was estimated by measuring the main elements in the fertilizers before and after their use in the soil. The first results from this characterization study support PIMs’ suitability for agronomic applications. The use of the PIMs suggested average higher dry weight (49%), fresh weight (112%), and leaf area (48%), compared to those with the use of a standard fertilizer soil, without the release of any dangerous element for the plant in the soil. These results are a promising beginning for the development of further studies already in progress on sustainable controlled-release fertilizers.