Iskanje po katalogu digitalne knjižnice

Opis: Effective microvascular tissue engineering requires fibroblasts that remain phenotypically stable and secrete extracellular matrix (ECM) proteins and growth factors relevant for vascularization. This study evaluated 3D printed hydrogels based on sodium alginate (ALG) and carboxymethyl cellulose (CMC) to assess their ability to sustain fibroblast phenotype, ECM deposition, and angiogenic growth factor secretion during long-term culture. Seven formulations – including one with nanofibrillated cellulose – were compared by encapsulating fibroblasts and crosslinking with CaCl₂ or SrCl₂. All scaffolds were printable and exhibited comparable degradation profiles. Mechanical testing indicated stable compressive response, with Sr2+-crosslinked hydrogels generally showing higher apparent compressive modulus, while Ca2+-crosslinked scaffolds supported slightly higher cell viability. Encapsulated fibroblasts retained their phenotype for 30 days, evidenced by steadily increasing collagen I/III and fibronectin deposition, alongside sustained expression of specific fibroblast markers. After 30 days, all groups produced comparable levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2), with one formulation yielding a significantly higher FGF-2 output. This multiparametric study demonstrates that scaffold composition and crosslinker chemistry influence fibroblast phenotype maintenance, ECM deposition, and growth factor secretion. To our knowledge, this is the first systematic, 30-day screening of ALG-CMC hydrogels – tuned by polymer content, NFC addition, and Ca2+/Sr2+ crosslinking – specifically for their ability to sustain fibroblast phenotype, extracellular matrix deposition, and growth factor secretion, providing design considerations to guide bioink development for microvascular models.
Ključne besede: 3D bioprinting, alginate, cellulose, skin fibroblast, microvasculature, angiogenesis
Objavljeno v DKUM: 18.12.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (10,79 MB)
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Opis: This study involved oxygen plasma activation of PVC and its effect on alginate coating adhesion, analyzed using a quartz crystal microbalance with dissipation (QCM-D). The results demonstrated improved adhesion of alginate on plasma-activated PVC due to an increase of oxidized functional groups. Wettability measurements, conducted using optical contact angle goniometry and QCM-D, showed a significant increase in the wettability of PVC after alginate coating, with contact angles decreasing from 81.4 ± 1.1◦ to 37.3 ± 3.1◦ 3D-profilometry mapping revealed a uniform distribution of alginate on the PVC film. Real-time antifouling studies using QCM-D with two model proteins, bovine serum albumin and bovine fibrinogen, were performed to elucidate the surface interactions involved in protein inhibition. The results indicated a substantial reduction in protein adhesion on alginate-coated PVC. This reduction in protein adhesion is attributed to the high hydrophilicity of the alginate coatings and partial removal of the alginate, which together contribute to poor protein adhesion. This comprehensive approach advances the development of effective solutions for mitigating biofilm-related issues on PVC-based medical devices, offering significant implications for improving patient outcomes.
Ključne besede: alginate, coatings, polyvinyl chloride, biofouling, quartz crystal microbalance, protein adhesion
Objavljeno v DKUM: 10.03.2025; Ogledov: 0; Prenosov: 10
Celotno besedilo (6,24 MB)
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Opis: Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.
Ključne besede: alginate beads, encapsulation, Mangifera indica, mango peels, characterization, in vitro release, antbacterial activity
Objavljeno v DKUM: 02.08.2024; Ogledov: 104; Prenosov: 26
Celotno besedilo (6,98 MB)

Ključne besede: in vitro drug release testing, Franz diffusion cells, simulation, naproxen, alginate
Objavljeno v DKUM: 16.02.2023; Ogledov: 684; Prenosov: 76
Celotno besedilo (219,93 KB)
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