Pokročilé biomateriály


Recent Submissions

Now showing 1 - 5 of 25
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    Liposomes Affect Protein Release and Stability of ITA-Modified PLGA-PEG-PLGA Hydrogel Carriers for Controlled Drug Delivery
    (AMER CHEMICAL SOC, 2023-12-22) Kadlecová, Zuzana; Sevriugina, Veronika; Lysáková, Klára; Rychetský, Matěj; Chamradová, Ivana; Vojtová, Lucy
    Fat grafting, a key regenerative medicine technique, often requires repeat procedures due to high-fat reabsorption and volume loss. Addressing this, a novel drug delivery system uniquely combines a thermosensitive, FDA-approved hydrogel (itaconic acid-modified PLGA-PEG-PLGA copolymer) with FGF2-STAB, a stable fibroblast growth factor 2 with a 21-day stability, far exceeding a few hours of wild-type FGF2's stability. Additionally, the growth factor was encapsulated in "green" liposomes prepared via the Mozafari method, ensuring pH protection. The system, characterized by first-order FGF2-STAB release, employs green chemistry for biocompatibility, bioactivity, and eco-friendliness. The liposomes, with diameters of 85.73 +/- 3.85 nm and 68.6 +/- 2.2% encapsulation efficiency, allowed controlled FGF2-STAB release from the hydrogel compared to the unencapsulated FGF2-STAB. Yet, the protein compromised the carrier's hydrolytic stability. Prior tests were conducted on model proteins human albumin (efficiency 80.8 +/- 3.2%) and lysozyme (efficiency 81.0 +/- 2.7%). This injectable thermosensitive system could advance reconstructive medicine and cosmetic procedures.
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    A synergistic effect of fibrous carboxymethyl cellulose with equine collagen improved the hemostatic properties of freeze-dried wound dressings
    (Springer Nature, 2023-08-23) Sedlář, Marian; Verčimáková, Katarína; Fohlerová, Zdenka; Izsák, Dávid; Chalupová, Marta; Suchý, Pavel; Dohnalová, Marcela; Sopuch, Tomáš; Vojtová, Lucy
    Bleeding is one of the most commonly occurring injuries; it can be painful and even life-threatening condition. The hemostats are substances that promote blood clotting and fasten hemostasis. In this paper, we evaluated the hemostatic effect of freeze-dried wound dressings based on equine collagen, porcine collagen, fibrous carboxymethyl cellulose (CMC) and their mixtures. The wound dressings were investigated for their morphological structure, chemical structure, absorption properties, in vitro hemostasis, cytotoxicity assay and lastly, for in vivo hemostasis. We have found out that adding fibrous CMC into collagen-based hemostatic wound dressings creates a strong synergistic effect, which significantly improves absorption capacity by almost doubling it, as well as supports clotting time. Based on the in vivo studies on partial nephrectomy in rats, the time needed for achieving hemostasis was significantly lower due to the synergy of collagen and CMC. Our materials were compared to the commonly used hemostatic sealing patch on the market (Tachosil) during the in vivo testing, and sample of a mixture of equine collagen and CMC showed better hemostatic efficacy.
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    Antimicrobial Cost-Effective Transparent Hydrogel Films from Renewable Gum Karaya/Chitosan Polysaccharides for Modern Wound Dressings
    (American Chemical Society, 2023-04-14) Drápalová, Eva; Michlovská, Lenka; Poštulková, Hana; Chamradová, Ivana; Lipový, Břetislav; Holoubek, Jakub; Vacek, Lukáš; Růžička, Filip; Hanslianová, Markéta; Svobodová, Táňa; Černá, Eva; Hrdličková, Barbara; Vojtová, Lucy
    The newest trends in wound healing management and the development of the next generation of dressings are pointing toward natural polymeric materials with important beneficial properties such as antimicrobial effects, renewability, easier process of preparation, and biological activity. Here, we present the preparation and in vitro evaluation of a unique biopolymeric blend composed of natural polymers based on the positively charged polysaccharide chitosan and negatively charged gum karaya. A plate lysis assay of gum karaya and chitosan solution mixtures proved the synergistic antimicrobial effect against specific strains of both Gram-positive and Gram-negative bacteria and yeast. This polymeric mixture was used for hydrogel film preparation and determination of the composition effect on physical properties (swelling behavior in different solvents, pH, diffusion mechanism, hydrolytic stability, mechanical and optical properties). While the pure gum karaya with poly(vinyl alcohol) exhibited the highest hydrolytic degradation (68%), the mixture of poly(vinyl alcohol) and gum karaya with chitosan (in the 25:75 ratio) exhibited the lowest degradation value (41%) due to the strong physical interactions. Cytotoxicity tests performed with hydrogel extracts using two different in vitro models, adherent fibroblasts (NIH3T3) and non-adherent suspension B-lymphocytes (BaF3), exhibited excellent biocompatibility and no cytotoxicity. As expected, the antimicrobial activity of 3-day film extracts showed a significantly improved antimicrobial effect of mixtures involving a chitosan biopolymer. The physical and biological properties of prepared biopolymer-based hydrogels meet the requirements of modern wound dressings.
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    Accelular nanofbrous bilayer scafold intrapenetrated with polydopamine network and implemented into a full-thickness wound of a white-pig model afects infammation and healing process
    (BioMed Central, 2023-03-07) Kacvinská, Katarína; Pavliňáková, Veronika; Poláček, Petr; Michlovská, Lenka; Hefka Blahnová, Veronika; Filová, Eva; Knoz, Martin; Lipový, Břetislav; Holoubek, Jakub; Faldyna, Martin; Pavlovský, Zdeněk; Vícenová, Monika; Cvanová, Michaela; Jarkovský, Jiří; Vojtová, Lucy
    Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1-2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor beta (TGF beta 1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts.
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    The centrifugal spinning of vitamin doped natural gum fibers for skin regeneration
    (Elsevier, 2022-10-15) Říhová, Martina; Lepcio, Petr; Čičmancová, Veronika; Frumarová, Božena; Hromádko, Luděk; Bureš, Filip; Vojtová, Lucy; Macák, Jan
    The study investigates the use of fiber carriers, based on biopolymeric gums as potential candidates for cosmetic and dermatological applications, in particular for skin regeneration. Gum arabic (GA), xanthan gum (XA), and gum karaya (GK) were used as the main gum materials for the fibers, which were prepared by centrifugal spinning from an aqueous solution. These solutions of different mass gum ratios were blended with poly (ethylene oxide) (PEO) for better spinnability. Finally, vitamins E and C were added to selected solutions of gums. The resulting fibers were extensively investigated. The morphology and structure of all fibers were investigated by scanning electron microscopy and Fourier transformed infrared spectroscopy. Most importantly, they were characterized by the release of vitamin E loaded in the fibers using UV-VIS spectroscopy. The presentation will show that the newly prepared fibers from GA and PEO represent a very promising material for cosmetic and dermatologic applications.