Nanoparticles have been attracting growing interest for both their antioxidant and toxic effects. Their exact action on cells strongly depends on many factors, including experimental conditions, preparation, and solvents used, which have contributed to the confusion regarding their safety and possible health benefits. In order to clarify the biological effects of the most abundant fullerene C₆₀, its impact on the Escherichia coli model has been studied. The main question was if C₆₀ would have any antioxidant influence on the cell and, if yes, whether and to which extent it would be concentration-dependent. An oxidative stress induced by adding hydrogen peroxide was measured with an E. coli MG1655 pKatG-lux strain sensor, with its time evolution being recorded in the presence of fullerene C₆₀ suspensions of different concentrations. Optimal conditions for the fullerene C₆₀ solubilization in TWEEN 80 2% aqueous solution, together with resulting aggregate sizes, were determined. Results obtained for the bacterial model can be extrapolated on eukaryote mitochondria. The ability of C₆₀ to penetrate through biological membranes, conduct protons, and interact with free radicals is likely responsible for its protective effect detected for E. coli. Thus, fullerene can be considered as a mitochondria-targeted antioxidant, worth further researching as a prospective component of novel medications.

Background: Effective regenerative therapeutics for acute and chronic wounds remain a critical unmet need in biomedicine. Objectives: This study aimed to develop novel collagen–cerium oxide nanoparticle hydrogels designed to enhance cellular metabolism, proliferation, and antioxidant/antimutagenic activity, accelerating wound regeneration in vivo. Methods: Collagen–nanocerium composites were synthesized by combining a collagen extract with cerium oxide nanoparticles at defined concentrations. In vitro assays using human fibroblasts identified two formulations that enhanced proliferation and metabolic activity by 42–50%. FTIR spectroscopy confirmed chemical interactions within the composite matrix. Toxicity, antioxidant, and antigenotoxic effects were evaluated using Escherichia coli MG1655 lux-biosensors to assess their general toxicity, antioxidant and pro-oxidant activities, and antigenotoxic and promutagenic effects. In vivo efficacy was tested in Wistar rats with full-thickness skin wounds. Treated groups were compared to untreated controls and Dexpanthenol-treated positive controls. On days 3, 7, and 14, healing was assessed clinically, histologically, and morphometrically. Results: Biosensor analysis demonstrated non-toxicity and antigenotoxic activity of the nanocomposites, reduced DNA damage by up to 45%, providing 31–49% protection against H₂O₂ and 15–23% against O₂⁻ radicals. The animal study results demonstrated significantly accelerated healing with both nanocomposites versus control and comparison groups, evidenced by improved tissue regeneration, reduced inflammation, and increased fibroblast infiltration. Conclusions: The developed hydrogels exhibit promising pharmacological profiles, including antioxidant, antimutagenic, anti-inflammatory, and pro-regenerative effects validated across in vitro and in vivo models.

Hibernation in mammals entails profound physiological changes that are known to impact host-associated microbial communities, yet its effects on the gut microbiota of synanthropic bats remain underexplored. In this study, we investigated the gut bacterial composition and diversity of Nyctalus noctula before and during hibernation using high-throughput 16S rRNA amplicon sequencing. Fecal samples from individually banded bats were collected under controlled conditions at a rehabilitation center and analyzed for alpha and beta diversity, as well as differential taxonomic abundance. Hibernation was associated with a marked reduction in microbial diversity according to the Shannon and Simpson indices and a distinct restructuring of gut communities based on the Bray–Curtis dissimilarity index. Active bats exhibited a diverse microbiota enriched in facultative anaerobes, including Lactococcus, Enterococcus, and Escherichia–Shigella, while hibernating individuals were dominated by obligate anaerobes, such as Romboutsia and Paeniclostridium. These findings suggest a contraction and functional specialization of the gut microbiota during torpor, potentially reflecting adaptations to fasting, hypothermia, and reduced gut motility. Our results demonstrate that the bat’s gut microbiome is highly responsive to physiological status and underscore the importance of microbial ecology for understanding the host’s energy balance and health under seasonal contexts.

The study aimed to evaluate bottom sediments as a promising source of probiotic bacteria for aquaculture applications. Bacillus strains were selected as the most suitable bacterial species for application in the food industry. Initially, seven Bacillus spp. strains were isolated from the intestinal contents of healthy sterlet specimens; however, none of them demonstrated high potential probiotic properties. Subsequently, bottom sediments were considered as a source of probiotic strains. In the bottom sediments, bacilli exist in a vegetative form and constitute an integral part of the microbial community. A total of 120 Bacillus spp. strains were isolated and comprehensively analyzed. Proteolytic and amylolytic activities were detected at moderate levels in almost all isolated strains. Most isolates exhibited low or negligible antioxidant, DNA-protective, and antimicrobial activities; however, a small group of strains showed high values of these properties. Principal component and cluster analyses indicated the co-existence of three life strategies of bacilli in bottom sediments. These findings highlight the high probiotic potential of bacilli from bottom sediments and support their suitability as novel probiotics for enhancing the health and productivity of aquatic organisms in aquaculture.