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Cellulose nanofibers gained increasing interest in the production of medical devices such as mucoadhesive nanohydrogels due to their ability to retain moisture (high hydrophilicity), flexibility, superior porosity and durability, biodegradability, non-toxicity, and biocompatibility. In this work, we aimed to compare the suitability of selected bacterial and vegetal nanocellulose to form hydrogels for biomedical applications. The vegetal and bacterial cellulose nanofibers were synthesized from brewer's spent grains (BSG) and kombucha membranes, respectively. Two hydrogels were prepared, one based on the vegetal and the other based on the bacterial cellulose nanofibers (VNC and BNC, respectively). VNC was less opaque and more fluid than BNC. The cytocompatibility and in vitro antioxidant activity of the nanocellulose-based hydrogels were investigated using human gingival fibroblasts (HGF-1, ATCC CRL-2014). The investigation of the hydrogel–mucin interaction revealed that the BNC hydrogel had an approx. 2× higher mucin binding efficiency than the VNC hydrogel at a hydrogel/mucin ratio (mg/mg) = 4. The BNC hydrogel exhibited the highest potential to increase the number of metabolically active viable cells (107.60 ± 0.98% of cytotoxicity negative control) among all culture conditions. VNC reduced the amount of reactive oxygen species (ROS) by about 23% (105.5 ± 2.2% of C−) in comparison with the positive control, whereas the ROS level was slightly higher (120.2 ± 3.9% of C−) following the BNC hydrogel treatment. Neither of the two hydrogels showed antibacterial activity when assessed by the diffusion method. The data suggest that the BNC hydrogel based on nanocellulose from kombucha fermentation could be a better candidate for cytocompatible and mucoadhesive nanoformulations than the VNC hydrogel based on nanocellulose from brewer's spent grains. The antioxidant and antibacterial activity of BNC and both BNC and VNC, respectively, should be improved. [ABSTRACT FROM AUTHOR]

Yeasts have emerged as an important resource of bioactive compounds, proteins and peptides, polysaccharides and oligosaccharides, vitamin B, and polyphenols. Hundreds of thousands of tons of spent brewer's yeast with great biological value are produced globally by breweries every year. Hence, streamlining the practical application processes of the bioactive compounds recovered could close a loop in an important bioeconomy value-chain. Cell lysis is a crucial step in the recovery of bioactive compounds such as (glyco)proteins, vitamins, and polysaccharides from yeasts. Besides the soluble intracellular content rich in bioactive molecules, which is released by cell lysis, the yeast cell walls β-glucan, chitin, and mannoproteins present properties that make them good candidates for various applications such as functional food ingredients, dietary supplements, or plant biostimulants. This literature study provides an overview of the lysis methods used to valorize spent brewer's yeast. The content of yeast extracts and yeast cell walls resulting from cellular disruption of spent brewer's yeast are discussed in correlation with the biological activities of these fractions and resulting applications. This review highlights the need for a deeper investigation of molecular mechanisms to unleash the potential of spent brewer's yeast extracts and cell walls to become an important source for a variety of bioactive compounds. [ABSTRACT FROM AUTHOR]

The aim of the article was to design and develop new thermodynamically stable starch-based compounds, with scalable properties, that are melt-processable into finished products by classic or 3D printing methods. This is based on phenomena of de-structuring, entanglement compatibilization, and re-structuring of starch, along with the modification of the polymer, polyvinyl alcohol (PVA), by following an experimental sequence involving pre-treatment and melt compounding in two stages. The new compounds selection was made considering the dependence of viscoelastic properties on formulation and flowing conditions in both the melted and solid states. Starting from starch with 125 °C glass transition and PVA with a Tg at 85 °C, and following the mentioned experimental sequence, new starch-PVA compounds with a high macromolecular miscibility and proven thermodynamic stability for at least 10 years, with glass transitions ranging from −10 °C to 50 °C, optimal processability through both classical melt procedures (extrusion, injection) and 3D printing, as well as good scalability properties, were achieved. The results are connected to the approaches considering the relationship between miscibility and the lifetime of compounds with renewable-based polymer content. By deepening the understanding of the thermodynamic stability features characterizing these compounds, it can be possible to open the way for starch usage in medium-life compositions, not only for short-life applications, as until now. [ABSTRACT FROM AUTHOR]

In recent years, algae have emerged as a promising feedstock for biofuel production, due to their eco-friendly, sustainable, and renewable nature. Various methods, including chemical, biochemical, and thermochemical processes, are used to convert algal biomass into biofuels. Pyrolysis, a widely recognized thermochemical technique, involves high temperature and pressure to generate biochar and bio-oil from diverse algal sources. Various pyrolytic processes transform algal biomass into biochar and bio-oil, including low pyrolysis, fast pyrolysis, catalytic pyrolysis, microwave-assisted pyrolysis, and hydropyrolysis. These methods are utilized to convert a range of microalgae and cyanobacteria into biochar and bio-oil. In this publication, we will discuss catalytic pyrolysis using mesoporous materials, such as SBA-15. Mesoporous catalysts have earned significant attention for catalytic reactions, due to their high surface area, facilitating the better distribution of impregnated metal. Pyrolysis conducted in the presence of a mesoporous catalyst is viewed more as efficient, compared to reactions occurring within the smaller microporous cavities of traditional zeolites. SBA-15 supports with incorporated Zr and/or Ce were synthesized using the direct hydrothermal synthesis method. The catalyst was characterized using structural and morphological technical analysis and utilized for the pyrolysis reaction of the algal biomass. [ABSTRACT FROM AUTHOR]

Selenium nanoparticles (SeNPs) have specific properties that result from their biosynthesis particularities. Chitosan can prevent pathogenic biofilm development. A wide palette of bacterial nanocellulose (BNC) biological and physical-chemical properties are known. The aim of this study was to develop a hydrogel formulation (SeBNCSFa) based on ferulic acid-grafted chitosan and bacterial nanocellulose (BNC) enriched with SeNPs from Kombucha fermentation (SeNPsK), which could be used as an adjuvant for oral implant integration and other applications. The grafted chitosan and SeBNCSFa were characterized by biochemical and physical-chemical methods. The cell viability and proliferation of HGF-1 gingival fibroblasts were investigated, as well as their in vitro antioxidant activity. The inflammatory response was determined by enzyme-linked immunosorbent assay (ELISA) of the proinflammatory mediators (IL-6, TNF-α, and IL-1β) in cell culture medium. Likewise, the amount of nitric oxide released was measured by the Griess reaction. The antimicrobial activity was also investigated. The grafting degree with ferulic acid was approximately 1.780 ± 0.07% of the total chitosan monomeric units, assuming single-site grafting per monomer. Fourier-transform infrared spectroscopy evidenced a convolution of BNC and grafted chitosan spectra, and X-ray diffraction analysis highlighted an amorphous rearrangement of the diffraction patterns, suggesting multiple interactions. The hydrogel showed a high degree of cytocompatibility, and enhanced antioxidant, anti-inflammatory, and antimicrobial potentials. [ABSTRACT FROM AUTHOR]

Several strategies promote phyllosphere colonization by soil-born Trichoderma plant-beneficial strains. One of these strategies is foliar spraying with suspensions containing large amounts of chlamydospores—spores with thick cell wall structures that make them highly resistant to harsh environmental conditions. Trichoderma biomass was produced by cultivation on a cornmeal medium and compared with the biomass produced on potato dextrose broth by microscopic and thermogravimetric analyses. The analyses revealed increased chlamydospore content and thermostability in the fungal biomass produced on the corn meal medium. The Trichoderma suspension rich in chlamydospores was sprayed on bitter gourd (Momordica charantia) leaves at two inoculant concentrations, 106 and 108 ufc/mL. The effect of these treatments on the plant physiological parameters, leaf photosynthetic pigments, polyphenol and flavonoid contents, antioxidant activities of the leaves and fruits, and yield was compared to the control (plants sprayed with water) and to the experimental treatment involving spraying with 108 ufc/mL of propagules produced in potato dextrose broth. The effect of chlamydospore-rich suspensions on plant physiological parameters was more pronounced and long-lasting compared with the other treatments. The treatment with chlamydospore-rich suspension enhanced the accumulation of polyphenols and flavonoids in the leaves (by 17% and 50%, respectively) and fruits (by 18% and 31%, respectively) and increased the antioxidant activity. The Trichoderma treatment increased the yield by +25.33–53.07%. The application of the foliar treatment with Trichoderma suspensions did not modify the cytocompatibility of the extracts from the fruits determined on the L929 cells. [ABSTRACT FROM AUTHOR]

In this study, we investigated the use of functionalized deep eutectic solvents (DESs) as a medium for CO2 capture integrated with CO2 desorption and biofixation in microalgal culture, as an approach for carbon capture, utilization, and storage (CCUS). The newly devised DES formulation—comprising choline chloride, ethylene glycol, and monoethanolamine—demonstrated a significant advancement in CO2 absorption capacity compared with conventional solvents. Effective CO2 desorption from the solvent was also achieved, recovering nearly 90% of the captured CO2. We then examined the application of the functionalized DESs to promote microalgal cultivation using a Chlorella sp. strain. The experimental results indicated that microalgae exposed to DES-desorbed CO2 exhibited heightened growth rates and enhanced biomass production, signifying the potential of DES-driven CO2 capture for sustainable microalgal biomass cultivation. This research contributes to the growing field of CCUS strategies, offering an avenue for efficient CO2 capture and conversion into valuable biomasses, thereby contributing to both environmental sustainability and bioresource use. [ABSTRACT FROM AUTHOR]

This article compares two exfoliation options of multilayered silicate, one considering the action of shear stress and temperature during melt compounding and another taking into account the action of the thermo-mechanical pretreatment of multilayered silicate in a plasticizer common to the starch and polyvinyl alcohol (PVOH), the two polymers from the compound. Increasing the action time of the shear stress and temperature during melt compounding proved to be an ineffective method for silicate exfoliation following the high degradability of starch and PVOH under thermo-mechanical conditions and the loss of hydration of the multilayered silicate under thermo-mechanical conditions. The obtained results prove that, by pretreating before embedding into the desired starch-PVOH matrix, it was possible to cancel the electrostatic attractions between the component lamellae of a multilayered silicate. During melt compounding with the two polymers, new attractions between the obtained lamellae and the polar groups of each polymer from the blend were settled, and so, without the usage of a liquid plasticizer, exfoliated intercalated nanocomposites were achieved. The improved properties and the practical importance of the new nanocomposites regards the obtaining of a non-degradable material that has a white color, better elastic properties and thermal stability, and a higher dissipation capacity of deformation energy. [ABSTRACT FROM AUTHOR]

The formation of biogenic selenium nanoparticles (SeNPs) through microbial activities is a promising technique that can contribute to the development of reliable, non-toxic and environmentally friendly synthesis methods. Among these, under optimal conditions, myconanotechnology confers particular characteristics due to the generation of bioactive fungal metabolites with various bioactivities. The formed SeNPs are known to be stabilized by the biomolecules of the microorganism, forming a so-called bio-corona or capping structure. The composition of this bio-corona greatly impacts the SeNPs activity, but investigations have been limited to date. The SeNPs produced by Trichoderma sp. have potential applications in crops and environmental management, as both selenium and Trichoderma are known to benefit cultivated plants and phytoremediation. This review summarizes the biosynthesis of SeNPs by Trichoderma sp. and contextualizes the possible correlations between SeNPs and biomolecules produced by Trichoderma; it also provides a missing analysis that could help understand and optimize this process. Biosynthesis methods and probable mechanisms are briefly discussed as well as the role and applications of trichogenic SeNPs as plant protectants, plant biostimulants, and safe biofortifying agents. The knowledge gaps related to mechanisms of trichogenic SeNPs biosynthesis, the control of the desired characteristics for a specific agricultural function, and technology scale-up are discussed in connection with the needed future research directions. [ABSTRACT FROM AUTHOR]

Phytosynthesized selenium nanoparticles (SeNPs) are less toxic than the inorganic salts of selenium and show high antioxidant and antibacterial activity. Chitosan prevents microbial biofilm formation and can also determine microbial biofilm dispersal. Never-dried bacterial nanocellulose (NDBNC) is an efficient carrier of bioactive compounds and a flexible nanofibrillar hydrophilic biopolymer. This study aimed to develop a selenium-enriched hydrogel nanoformulation (Se-HNF) based on NDBNC from kombucha fermentation and fungal chitosan with embedded biogenic SeNPs phytosynthesized by an aqueous extract of sea buckthorn leaves (SbLEx)—SeNPsSb—in order to both disperse gingival dysbiotic biofilm and prevent its development. We determined the total phenolic content and antioxidant activity of SbLEx. Liquid chromatography–mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC) were used for the identification of polyphenols from SbLEx. SeNPsSb were characterized by transmission electron microscopy–energy-dispersive X-ray spectroscopy (TEM-EDX), dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) in small- and wide-angle X-ray scattering (SAXS and WAXS). The hydrogel nanoformulation with embedded SeNPsSb was characterized by SEM, FTIR, XRD, rheology, mucin binding efficiency, contact angle and interfacial tension measurements. We also assessed the in vitro biocompatibility, antioxidant activity and antimicrobial and antibiofilm potential of SeNPsSb and Se-HNF. TEM, DLS and SAXS evidenced polydisperse SeNPsSb, whereas FTIR highlighted a heterogeneous biocorona with various biocompounds. The contact angle on the polar surface was smaller (52.82 ± 1.23°) than that obtained on the non-polar surface (73.85 ± 0.39°). The interfacial tension was 97.6 ± 0.47 mN/m. The mucin binding efficiency of Se-HNF decreased as the amount of hydrogel decreased, and the SEM analysis showed a relatively compact structure upon mucin contact. FTIR and XRD analyses of Se-HNF evidenced an interaction between BNC and CS through characteristic peak shifting, and the rheological measurements highlighted a pseudoplastic behavior, 0.186 N adhesion force and 0.386 adhesion energy. The results showed a high degree of cytocompatibility and the significant antioxidant and antimicrobial efficiency of SeNPsSb and Se-HNF. [ABSTRACT FROM AUTHOR]

Biocompatible drug-delivery systems for soft tissue applications are of high interest for the medical and pharmaceutical fields. The subject of this research is the development of hydrogels loaded with bioactive compounds (inulin, thyme essential oil, hydro-glycero-alcoholic extract of Vitis vinifera, Opuntia ficus-indica powder, lactic acid, citric acid) in order to support the vaginal microbiota homeostasis. The nanofibrillar phyto-hydrogel systems developed using the biocompatible polymers chitosan (CS), never-dried bacterial nanocellulose (NDBNC), and Poloxamer 407 (PX) incorporated the water-soluble bioactive components in the NDBNC hydrophilic fraction and the hydrophobic components in the hydrophobic core of the PX fraction. Two NDBNC-PX hydrogels and one NDBNC-PX-CS hydrogel were structurally and physical-chemically characterized using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and rheology. The hydrogels were also evaluated in terms of thermo-responsive properties, mucoadhesion, biocompatibility, and prebiotic and antimicrobial effects. The mucin binding efficiency of hydrogel base systems was determined by the periodic acid/Schiff base (PAS) assay. Biocompatibility of hydrogel systems was determined by the MTT test using mouse fibroblasts. The prebiotic activity was determined using the probiotic strains Limosilactobacillus reuteri and Lactiplantibacillus plantarum subsp. plantarum. Antimicrobial activity was also assessed using relevant microbial strains, respectively, E. coli and C. albicans. TEM evidenced PX micelles of around 20 nm on NDBNC nanofibrils. The FTIR and XRD analyses revealed that the binary hydrogels are dominated by PX signals, and that the ternary hydrogel is dominated by CS, with additional particular fingerprints for the biocompounds and the hydrogel interaction with mucin. Rheology evidenced the gel transition temperatures of 18–22 °C for the binary hydrogels with thixotropic behavior and, respectively, no gel transition, with rheopectic behavior for the ternary hydrogel. The adhesion energies of the binary and ternary hydrogels were evaluated to be around 1.2 J/m2 and 9.1 J/m2, respectively. The hydrogels exhibited a high degree of biocompatibility, with the potential to support cell proliferation and also to promote the growth of lactobacilli. The hydrogel systems also presented significant antimicrobial and antibiofilm activity. [ABSTRACT FROM AUTHOR]

The increasing need for sustainable waste management and food fortification requires continuous agri-food biotechnological innovation. Spent brewer's yeast (SBY) is a mass-produced underutilized by-product of the brewery industry and has elevated bioactive potential. The current study presents a streamlined ultrasonic SBY cell lysis method, with the main goal of bioactive compound valorization. The influence of selected ultrasonication parameters on protein release and, implicitly, on the cell disruption efficiency, was assessed. The SBY derivatives resulting from the ultrasonic cell lysis were SBY extracts (SBYEs) and cell walls (SBYCWs), which were evaluated in terms of protein content, antioxidant activity (AOA) and total polyphenol content. Scanning electron microscopy (SEM) and FT-IR spectroscopy were used to characterize SBYCWs in relation to the morphological and chemical transformations that follow ultrasonic yeast cell disruption. The optimal ultrasonication conditions of 6.25% SBY concentration, 40 °C and 33.33% duty cycle (DC) ensured the most efficient lysis. The SBY derivatives with the most elevated antioxidant activity were obtained at temperatures below 60 °C. SBYCWs had the highest polyphenol content and a relatively high content of β-glucan under these parameters. Optical microscopy and SEM confirmed the release of intracellular content and separation of SBYCWs. [ABSTRACT FROM AUTHOR]

The growing prevalence of obesity and chronic diseases has heightened interest in the potential health benefits of natural antioxidants. This study aims to explore the antioxidant capacities of various recipes of honey-infused apple cider vinegar macerates containing plant extracts. Eight different recipes were formulated using apple cider vinegar, acacia honey, and a variety of plant extracts including ginger, green tea, dandelion root, and chicory root. The mixtures were allowed to macerate for 24 and 48 hours at room temperature (21°C), followed by centrifugation and antioxidant capacity analysis using a specialized ACW kit and a PHOTOCHEM device. The antioxidant capacities varied significantly among the eight recipes, ranging from 0.25±0.001 to 1.88±0.008 µg/g (Equivalent Vit C). Generally, an increase in antioxidant capacity was observed from 24 to 48 hours of maceration. Recipes with multiple plant extracts showed remarkably higher antioxidant capacities, indicating potential synergistic effects. The study reveals substantial variations in antioxidant capacities among different recipes, influenced by both the type and combination of plant extracts used, as well as maceration time. [ABSTRACT FROM AUTHOR]

There is an ever-growing interest in recovering and recycling waste materials due to their hazardous nature to the environment and human health. Recently, especially since the beginning of the COVID-19 pandemic, disposable medical face masks have been a major source of pollution, hence the rise in studies being conducted on how to recover and recycle this waste. At the same time, fly ash, an aluminosilicate waste, is being repurposed in various studies. The general approach to recycling these materials is to process and transform them into novel composites with potential applications in various industries. This work aims to investigate the properties of composites based on silico-aluminous industrial waste (ashes) and recycled polypropylene from disposable medical face masks and to create usefulness for these materials. Polypropylene/ash composites were prepared through melt processing methods, and samples were analyzed to get a general overview of the properties of these composites. Results showed that the polypropylene recycled from face masks used together with silico-aluminous ash can be processed through industrial melt processing methods and that the addition of only 5 wt% ash with a particle size of less than 90 µm, increases the thermal stability and the stiffness of the polypropylene matrix while maintaining its mechanical strength. Further investigations are needed to find specific applications in some industrial fields. [ABSTRACT FROM AUTHOR]