Iskanje po katalogu digitalne knjižnice

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: 6
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Opis: Nanocellulose is considered a promising and sustainable biomaterial, with excellent properties of biorenewability with improved mechanical properties. As a unique natural biopolymer, it has been applied to many different industries, where efficient and environmentally friendly productions are in demand. For the first time, ferns from the class Polypodiopsida were used for the isolation of cellulose fibers, which was performed using a chemo-mechanical method. As chemical treatment plays a crucial role in the isolation of nanocellulose, it affects the efficiency of the extraction process, as well as the properties of the resulting nanocellulose. Therefore, mechanical fibrillation was performed via grinding, while the chemical process consisted of three different treatments: alkali treatment, bleaching, and acid hydrolysis. In three different experiments, each treatment was separately prolonged to investigate the differing properties of isolated nanocellulose. Structural analysis and morphological analysis were investigated by SEM, EDS, FT-IR, and DLS. The thermal stability of cellulose fibers was investigated by TGA/DSC. The morphology of obtained nanocellulose was confirmed via SEM analysis for all samples, with particles ranging from 20 nm up to 600 nm, while the most consistent sizes were observed for NC3, ranging from 20 to 60 nm. FT-IR spectra showed prominent absorption peaks corresponding to cellulose, as well as the absence of absorption peaks, corresponding to lignin and hemicellulose. The EDS confirmed the elemental purity of nanocellulose, while TGA/DSC indicated higher thermal stability of nanocellulose, compared to untreated fern, which started to degrade earlier than nanocellulose. Such characteristics with unique properties make nanocellulose a versatile biomaterial for the industrial production of cellulosic materials.
Ključne besede: nanocellulose, isolation, Polypodiophyta fern, chemo-mechanical method, biomaterial, biopolymers
Objavljeno v DKUM: 31.01.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (3,75 MB)

Ključne besede: 3D printing, anisotropy nanocomposites, biomedical applications, mechanical properties, nanocellulose alginate
Objavljeno v DKUM: 03.06.2024; Ogledov: 132; Prenosov: 15
Celotno besedilo (4,26 MB)
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Opis: Cellulose nanofibrills (CNFs) are attractive biocompatible, natural nanomaterials for wide biomedical applications. However, the immunological mechanisms of CNFs have been poorly investigated. Considering that dendritic cells (DCs) are the key immune regulatory cells in response to nanomaterials, our aim was to investigate the immunological mechanisms of CNFs in a model of DC-mediated immune response. We found that non-toxic concentrations of CNFs impaired the differentiation, and subsequent maturation of human monocyte-derived (mo)-DCs. In a co-culture with CD4+T cells, CNF-treated mo-DCs possessed a weaker allostimulatory and T helper (Th)1 and Th17 polarizing capacity, but a stronger capacity to induce Th2 cells and CD4+CD25hiFoxP3hi regulatory T cells. This correlated with an increased immunoglobulin-like transcript-4 and indolamine dioxygenase-1 expression by CNF-treated mo-DCs, following the partial internalization of CNFs and the accumulation of CD209 and actin bundles at the place of contacts with CNFs. Cumulatively, we showed that CNFs are able to induce an active immune tolerance by inducing tolerogenic DCs, which could be beneficial for the application of CNFs in wound healing and chronic inflammation therapies.
Ključne besede: nanocellulose, cytotoxicity, T-cell proliferation, cytokine production, in vitro
Objavljeno v DKUM: 23.06.2017; Ogledov: 1538; Prenosov: 392
Celotno besedilo (2,87 MB)
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