Iskanje po katalogu digitalne knjižnice

Opis: We present a scalable platform for the fabrication of multifunctional bioactive materials by integrating, polysaccharide-based matrices, green extraction and additive manufacturing. In this work, bioactive 3D-printed structures were fabricated using inks composed of nanofibrillated cellulose (NFC), alginate (Alg), and curcumin extracts. Bioactive compounds were efficiently recovered from turmeric via solvent-free supercritical carbon dioxide extraction, yielding up to 6.57 mg/100 g curcuminoids and 232.45 mg/100 g total phenols. The extracts exhibited robust antioxidant activity (DPPH• IC50: 23.24 mg/mL; ABTS+• IC50: 3.59 mg/mL) and broad-spectrum antimicrobial efficacy against Staphylococcus aureus, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa (MIC: 9.38 mg/mL). Incorporation into NFC-Alg inks exhibited excellent shear-thinning properties suitable for direct-ink-writing 3D printing. Post-printing CaCl2 crosslinking further reinforced the hydrogel network, enhancing mechanical robustness and shape fidelity. The resulting constructs featured a highly porous, grid-like architecture with intricate surface morphology, highlighting significant potential for biomedical and tissue engineering applications.
Ključne besede: nanocellulose, alginate, curcumin extract, supercritical-CO2, antioxidant, antimicrobial properties, 3D-printing
Objavljeno v DKUM: 08.12.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (7,77 MB)

Opis: Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is however under-recognised that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.
Ključne besede: antimicrobial, bio-hydrogen, phytopathogen, organic acids, food preservation, waste valorisation
Objavljeno v DKUM: 28.08.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (2,40 MB)
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Opis: Proper processing of natural material is crucial to obtain an extract with high content of biologically active components. Dried, grinded ginger roots were extracted by ultrasonic method and supercritical extraction with CO2 . The aim of the study was to determine if a mixture of the two types of extracts attained by different methods and solvents exhibits better bioavailability than each extract itself. Therefore, both extracts were analytically evaluated and then mixed in a ratio of 1:1. The supercritical extract (SCG extract) and the mixed extract (mixG extract) had high antioxidant activity (78% and 73%) and total phenols (827 mg/g ext. and 1455 mg/g ext.), which is also consistent with the levels of gingerol (303 mg/g ext. and 271 g/g ext.) and shogaol (111 mg/g ext. and 100 g/g ext.) in the extracts. In comparison to both pure extracts higher levels of total phenols were found in the extract mixG. This could be the reason for the significant inhibition of melanoma cells and antimicrobial potential (against Staphylococcus aureus, Escherichia coli, and Candida albicans). The combination of the extracts resulted in a significant increase in the inhibition of selected microbial and melanoma cells WM-266-4 compared to the control. Cell viability decreased below 60% when mixG extract was applied. Antimicrobial activity has been confirmed.
Ključne besede: ginger, supercritical fluid extraction, ultrasound-assisted extraction, antimicrobial activity
Objavljeno v DKUM: 09.05.2025; Ogledov: 0; Prenosov: 14
Celotno besedilo (1,59 MB)
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Opis: In this study, the extraction efficiency of natural deep eutectic solvents (NADES) based on choline chloride as a hydrogen bond acceptor (HBA) and five different hydrogen bond donors (HBD; lactic acid, 1,4-butanediol, 1,2-propanediol, fructose and urea) was evaluated for the first time for the isolation of valuable bioactive compounds from Achillea millefolium L. The phytochemical profiles of NADES extracts obtained after ultrasound-assisted extraction were evaluated both spectrophotometrically (total phenolic content (TPC) and antioxidant assays) and chromatographically (UHPLC-MS and HPLC-UV). The results were compared with those obtained with 80% ethanol, 80% methanol, and water. The highest TPC value was found in the lactic acid-based NADES (ChCl-LA), which correlated with the highest antioxidant activity determined by the FRAP analysis. On the other hand, the highest antiradical potential against ABTS$^{+•}$ was determined for urea-based NADES. Phenolic acids (chlorogenic acid and dicaffeoylquinic acid isomers), flavones (luteolin and apigenin), and their corresponding glucosides were determined as the dominant individual phenolic compounds in all extracts. The antibacterial and antifungal properties of the extracts obtained against four bacterial cultures and two yeasts were evaluated using two methods: the agar dilution method to obtain the minimum inhibitory concentration (MIC) and the minimum bactericidal or fungicidal concentration (MBC or MFC), and the disc diffusion method. ChCl-LA had the lowest MIC and MBC/MFC with respect to all microorganisms, with an MIC ranging from 0.05 mg mL$^{−1}$ to 0.8 mg mL$^{−1}$, while the water extract had the weakest inhibitory activity with MIC and MBC/MFC higher than 3.2 mg mL$^{−1}$.
Ključne besede: viskoznost, fenoli, antioksidanti, natural deep eutectic solvents (NADES), density and viscosity, yarrow, phenolic compounds, antioxidant activity, antimicrobial activity
Objavljeno v DKUM: 09.04.2025; Ogledov: 0; Prenosov: 9
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Opis: Novel bioactive bacterial nanocellulose (BnC) membranes were developed for effective, non-surgical debridement and infection-prevention in burn wound healing. Membranes were modified in situ with carboxymethyl cellulose (CMC) and ex situ with the proteolytic enzyme bromelain (Br) and antimicrobial peptide nisin (N). Post-processing into stable cellulose nanocrystal dispersions (ζ = -26 mV), enables assembly of model films for demonstration of high, irreversible bromelain (95 %) and nisin (99.5 %) adsorption. The BnC-CMC and BnC-CMC-N membranes were in vitro cytocompatible for HaCaT cells and induced faster cell proliferation with cell viability exceeding 100 % after 24 h incubation. The innovative aspect of this study lies in the ex vivo evaluation using an advanced human skin explant model with induced burns, providing a realistic, physiologically relevant assessment of membrane performance. Ex vivo experiments indicated the cytocompatibility of the BnC-CMC membrane with no acute toxicity or skin irritation, while nisin presence resulted in moderate irritating effect. Notably, the BnC-CMC-Br membrane showed digestion of intercellular junctions in the epidermis, while not inducing acute toxicity and skin irritation. By leveraging this innovative ex vivo human skin model in novel BnC-based membranes testing, the study provides a crucial translational step, bridging in vitro assessments and clinical applications for burn wound treatment.
Ključne besede: bacterial nanocellulose, Bromelain, Nisin, Carboxymethyl cellulose, antimicrobial function, bioactive, burn wound treatment
Objavljeno v DKUM: 01.04.2025; Ogledov: 0; Prenosov: 13
Celotno besedilo (24,82 MB)
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