Poly-L-Lysine and Human Plasmatic Fibronectin Films as Proactive Coatings to Improve Implant Biointegration

The success of stable and long-term implant integration implies the promotion, control, and respect of the cell microenvironment at the site of implantation. The key is to enhance the implant–host tissue cross talk by developing interfacial strategies that guarantee an optimal and stable seal of soft tissue onto the implant, while preventing potential early and late infection. Indeed, implant rejection is often jeopardized by lack of stable tissue surrounding the biomaterial combined with infections which reduce the lifespan and increase the failure rate of implants and morbidity and account for high medical costs. Thin films formed by the layer-by-layer (LbL) assembly of oppositely charged polyelectrolytes are particularly versatile and attractive for applications involving cell–material contact. With the combination of the extracellular matrix protein fibronectin (Fn, purified from human plasma) and poly-L-lysine (PLL, exhibiting specific chain lengths), we proposed proactive and biomimetic coatings able to guarantee enhanced cell attachment and exhibiting antimicrobial properties. Fn, able to create a biomimetic interface that could enhance cell attachment and promote extracellular cell matrix remodeling, is incorporated as the anionic polymer during film construction by the LbL technic whereas PLL is used as the cationic polymer for its capacity to confer remarkable antibacterial properties.

Induction of antimicrobial peptides from Bacillus thuringiensis challenged Spodoptera litura larvae and investigation of the antimicrobial properties of hemolymph samples

Antimicrobial peptides constitute key factors in insect humoral immune response against invading microorganisms. In this study, biochemical approach was identified antimicrobial peptides which appeared in larval hemolymph of Spodoptera litura after bacterial challenge. HPLC profile showed two major peaks in two samples, Brassica oleracea and Ricinus communis fed S. litura that were collected at 5 min interval. It was shown to be active against Gram-positive and Gram-negative bacteria. The highest zone of inhibition was observed in Staphylococcus aureus and Escherichia coli in B. oleracea fed S. litura hemolymph fraction II and R. communis fed S. litura hemolymph fraction I and it also contributes the increased antioxidant, lysozyme, and less hemolytic activity were increase in treated groups. TLC activity was tested with hemolymph extract samples, pink color pots was identified the protein present in the samples. An SDS-PAGE result shows that high expression of antimicrobial peptide present in the treated sample. The appearance of peptides with such different properties in insect hemolymph in response to immune challenge indicates the complexity of the insect immune system.

Thymoquinone-Loaded Chitosan Nanoparticles as Natural Preservative Agent in Cosmetic Products

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, the natural terpene thymoquinone was encapsulated in chitosan nanoparticles. The nanoparticles were characterized by DLS and TEM, showing a particle size of 20 nm. The chemical structure, thermal properties, and release profile of thymoquinone were evaluated and showed a successful stabilization and sustained release of terpenes. The antimicrobial properties of the nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing high antimicrobial properties. Furthermore, natural moisturizing cream inoculated with the aforementioned microorganisms was formulated with thymoquinone-chitosan nanoparticles to evaluate the preservative efficiency, indicating its promising use as a preservative in cosmetics.

Food Products with High Antioxidant and Antimicrobial Activities and Their Sensory Appreciation

(1) Background: The demand for healthy and nutritious food is growing worldwide. Fermented dairy products are highly valued by consumers for their health benefits. Kefir is a fermented dairy product that brings many benefits to the consumer due to its antioxidant, anticancer, antidiabetic, antihypertensive and antimicrobial properties. Extracts from various plants in the form of volatile oils have a beneficial efct on consumer health. their antioxidant and antimicrobial activities were demonstrated. (2) Methods: In the present study, the main purpose was to obtain a fermented dairy product with a high nutritional value; therefore, kefir, enriched with three types of volatile oils, namely, volatile mint oil, volatile fennel oil and volatile lavender oil, was made. The kefir samples obtained were sensory and texturally analyzed. The beneficial effect on health must also be studied in terms of the acceptability of these products by consumers from a sensory point of view. A non-numerical method based on several multi-personal approval criteria was used to interpret the results obtained in the sensory analysis. In the textural analysis, the consistency, cohesiveness and firmness of the kefir samples were analyzed. (3) Results: The samples enriched with volatile oils obtained superior results compared to the control sample in both conducted examinations. Kefir samples with volatile oils retained their sensory and textural characteristics for a longer time during storage. (4) Conclusions: The volatile oils added to kefir positively influenced the sensory and textural characteristics of the finished product.

The antimicrobial activity of zinc against group B Streptococcus is strain-dependent across diverse sequence types, capsular serotypes, and invasive versus colonizing isolates

Background Streptococcus agalactiae or Group B Streptococcus (GBS) is an encapsulated gram-positive bacterial pathobiont that commonly colonizes the lower gastrointestinal tract and reproductive tract of human hosts. This bacterium can infect the gravid reproductive tract and cause invasive infections of pregnant patients and neonates. Upon colonizing the reproductive tract, the bacterial cell is presented with numerous nutritional challenges imposed by the host. One strategy employed by the host innate immune system is intoxication of bacterial invaders with certain transition metals such as zinc. Methodology Previous work has demonstrated that GBS must employ elegant strategies to circumnavigate zinc stress in order to survive in the vertebrate host. We assessed 30 strains of GBS from diverse isolation sources, capsular serotypes, and sequence types for susceptibility or resistance to zinc intoxication. Results Invasive strains, such as those isolated from early onset disease manifestations of GBS infection were significantly less susceptible to zinc toxicity than colonizing strains isolated from rectovaginal swabs of pregnant patients. Additionally, capsular type III (cpsIII) strains and the ST-17 and ST-19 strains exhibited the greatest resilience to zinc stress, whereas ST-1 and ST-12 strains as well as those possessing capsular type Ib (cpsIb) were more sensitive to zinc intoxication. Thus, this study demonstrates that the transition metal zinc possesses antimicrobial properties against a wide range of GBS strains, with isolation source, capsular serotype, and sequence type contributing to susceptibility or resistance to zinc stress.

Evaluation of physicochemical, sensory, and antimicrobial properties of small-scale produced fruit vinegars

Hungarian fruit vinegars were characterised in terms of physicochemical attributes (total polyphenol content, antioxidant characteristics/FRAP, CUPRAC, ABTS/, ascorbic acid content, pH, total soluble solids), sensory profiles, and antimicrobial properties. Both compositional and sensory profiles showed distinct patterns depending on the type of vinegar (Tokaj wine, balsamic or apple) and the additional fruit used. Balsamic vinegars maturated on rosehip, sea buckthorn, and raspberry showed outstanding antioxidant performances. Rosehip, raspberry, and quince vinegars, as well as vinegars produced from Tokaji aszú and balsamic apple obtained high scores for fruity and sweet notes. Antimicrobial activities were tested on Gram-negative and Gram-positive organisms, including probiotic bacteria. Generally, only weak activities were obtained, which was attributed to the natural sugar content of the samples, depending on the type of the vinegar and the fruit. Similar results, but more pronounced bacterial growth inhibitions were obtained for probiotic strains, however, some probiotic strains were resistant to at least two of the vinegars. Based on these, balsamic apple, raspberry, rosehip, quince, and sea buckthorn may qualify as potential functional components of probiotic preparations containing some of the strains tested.

Microbiological Assessment of Wheat and Buckwheat Sprouting Process

Introduction. Sprouted grain can cause food poisoning, since inappropriate conditions can promote the growth of pathogenic microorganisms on the grain surface. As a result, products of long-term storage use thermally-treated sprouted grain, the parameters of which depend on the initial bacteria content. There are different ways to reduce bacterial contamination of sprouted grain, each of which has its own advantages and disadvantages. Natural substances with antimicrobial properties, such as medicinal herbs, can serve as decontaminators. However, no scientific research has been performed so far to determine the exact temperature of grain sprouting to minimize its microbiological contamination. The research objective was to investigate the effect of antimicrobial agents and sprouting conditions on the microflora of wheat and buckwheat grain. Study objects and methods. The study featured wheat grain and green buckwheat grain. A set of experiments was performed to define the effect of antimicrobial agents and sprouting conditions on the quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), molds, and yeasts. During sprouting at 10–30°C for 90 h, the grain was irrigated with distilled water, potassium permanganate solution (KMnO4), calendula infusion, and celandine i nfusion. QMAFAnM and the count of molds and yeasts were determined by standard methods; the qualitative analysis of the microflora was based on their morphological and cultural characteristics. Results and discussion. Microflora development during sprouting of wheat and buckwheat grains was controlled by selecting appropriate conditions and grain treatment methods. The herbal infusions for sprouting reduced the total microbial insemination of grain during sprouting by 52–68%; the calendula infusion reduced the contamination with molds by 47–51%, yeasts – by 100%. Conclusion. The research revealed the total microbial count and the count of mold and yeast colonies in dry sprouted grain. The optimal temperature of sprouting wheat and buckwheat was 20 ± 2°C in the infusion of medicinal herbs: it minimized the microflora of sprouted grain and reduced the sprouting time to 46 h. Calendula infusion could be recommended for commercial use in order reduce the microbiological contamination of sprouted grain. The initial microbial population of the product was found to affect the mode of heat treatment in long-term storage products.

Excess Zinc Supply Reduces Cadmium Uptake and Mitigates Cadmium Toxicity Effects on Chloroplast Structure, Oxidative Stress, and Photosystem II Photochemical Efficiency in Salvia sclarea Plants

Salvia sclarea L. is a Cd2+ tolerant medicinal herb with antifungal and antimicrobial properties cultivated for its pharmacological properties. However, accumulation of high Cd2+ content in its tissues increases the adverse health effects of Cd2+ in humans. Therefore, there is a serious demand to lower human Cd2+ intake. The purpose of our study was to evaluate the mitigative role of excess Zn2+ supply to Cd2+ uptake/translocation and toxicity in clary sage. Salvia plants were treated with excess Cd2+ (100 μM CdSO4) alone, and in combination with Zn2+ (900 μM ZnSO4), in modified Hoagland nutrient solution. The results demonstrate that S. sclarea plants exposed to Cd2+ toxicity accumulated a significant amount of Cd2+ in their tissues, with higher concentrations in roots than in leaves. Cadmium exposure enhanced total Zn2+ uptake but also decreased its translocation to leaves. The accumulated Cd2+ led to a substantial decrease in photosystem II (PSII) photochemistry and disrupted the chloroplast ultrastructure, which coincided with an increased lipid peroxidation. Zinc application decreased Cd2+ uptake and translocation to leaves, while it mitigated oxidative stress, restoring chloroplast ultrastructure. Excess Zn2+ ameliorated the adverse effects of Cd2+ on PSII photochemistry, increasing the fraction of energy used for photochemistry (ΦPSII) and restoring PSII redox state and maximum PSII efficiency (Fv/Fm), while decreasing excess excitation energy at PSII (EXC). We conclude that excess Zn2+ application eliminated the adverse effects of Cd2+ toxicity, reducing Cd2+ uptake and translocation and restoring chloroplast ultrastructure and PSII photochemical efficiency. Thus, excess Zn2+ application can be used as an important method for low Cd2+-accumulating crops, limiting Cd2+ entry into the food chain.