BACKGROUND/AIM: This study investigated the therapeutic potential of lipophosphonoxin (LPPO), an antibacterial agent, loaded into polycaprolactone nanofiber dressings (NANO-LPPO) for full-thickness wound healing. Using a porcine model, we aimed to assess the impact of areal weight of the dressing (10, 20 and 30 g/m2) on wound-healing outcomes and validate findings from previous murine studies. MATERIALS AND METHODS: Full-thickness wounds were created on porcine skin and treated with the NANO-LPPO dressings of differing thickness. Positive control (Aquacel Ag+) and standard control (Jelonet) groups were included for comparison. Wound-healing progression was evaluated macroscopically and on the histological level. RESULTS: Macroscopic observations indicated no signs of infection in any group, with wounds covered by scabs by day 14. Thicker dressings (areal weights of 30 and 20 g/m2) demonstrated superior performance in promoting the formation of granulation tissue and healing compared to the thinner version (areal weight of 10 g/m2). LPPO-loading enhanced scaffold wettability and biodegradability without impairing healing outcomes. Both control groups exhibited similar healing characteristics. CONCLUSION: The findings underscore the importance of optimizing dressing thickness for effective wound healing. NANO-LPPO dressings exhibit translational potential as a therapeutic option for full-thickness wounds, warranting further preclinical and regulatory evaluation to support clinical application.

• MeSH
• antibakteriální látky farmakologie   aplikace a dávkování   chemie   MeSH
• hojení ran * účinky léků   MeSH
• kůže účinky léků   patologie   MeSH
• lipoxiny * chemie   farmakologie   aplikace a dávkování   MeSH
• modely nemocí na zvířatech MeSH
• nanovlákna * chemie   MeSH
• obvazy * MeSH
• polyestery * chemie   MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The quantification of cellular metabolic activity via MTT assay has become a widespread practice in eukaryotic cell studies and is progressively extending to bacterial cell investigations. This study pioneers the application of MTT assay to evaluate the metabolic activity of biofilm-forming cells within bacterial biofilms on nanofibrous materials. The biofilm formation of Staphylococcus aureus and Escherichia coli on nanomaterials electrospun from polycaprolactone (PCL), polylactic acid (PLA), and polyamide (PA) was examined. Various parameters of the MTT assay were systematically investigated, including (i) the dissolution time of the formed formazan, (ii) the addition of glucose, and (iii) the optimal wavelength for spectrophotometric determination. Based on interim findings, a refined protocol suitable for application to nanofibrous materials was devised. We recommend 2 h of the dissolution, the application of glucose, and spectrophotometric measurement at 595 nm to obtain reliable data. Comparative analysis with the reference CFU counting protocol revealed similar trends for both tested bacteria and all tested nanomaterials. The proposed MTT protocol emerges as a suitable method for assessing the metabolic activity of bacterial biofilms on PCL, PLA, and PA nanofibrous materials.

• MeSH
• biofilmy * růst a vývoj   MeSH
• Escherichia coli * fyziologie   MeSH
• glukosa metabolismus   MeSH
• nanovlákna * chemie   MeSH
• nylony chemie   MeSH
• polyestery * chemie   MeSH
• spektrofotometrie metody   MeSH
• Staphylococcus aureus * fyziologie   MeSH
• tetrazoliové soli * metabolismus   chemie   MeSH
• thiazoly metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

Electrospinning is a widely employed manufacturing platform for tissue engineering applications because it produces structures that closely mimic the extracellular matrix. Herein, we demonstrate the potential of poly(vinyl alcohol) (PVA) electrospun nanofibers as scaffolds for tissue engineering. Nanofibers were created by needleless direct current electrospinning from PVA with two different degrees of hydrolysis (DH), namely 98% and 99% and subsequently heat treated at 180 °C for up to 16 h to render them insoluble in aqueous environments without the use of toxic cross-linking agents. Despite the small differences in the PVA chemical structure, the changes in the material properties were substantial. The higher degree of hydrolysis resulted in non-woven supports with thinner fibres (285 ± 81 nm c.f. 399 ± 153 nm) that were mechanically stronger by 62% (±11%) and almost twice as more crystalline than those from 98% hydrolysed PVA. Although prolonged heat treatment (16 h) did not influence fibre morphology, it reduced the crystallinity and tensile strength for both sets of materials. All samples demonstrated a lack or very low degree of haemolysis (<5%), and there were no notable changes in their anticoagulant activity (≤3%). Thrombus formation, on the other hand, increased by 82% (±18%) for the 98% hydrolysed samples and by 71% (±10%) for the 99% hydrolysed samples, with heat treatment up to 16 h, as a direct consequence of the preservation of the fibrous morphology. 3T3 mouse fibroblasts showed the best proliferation on scaffolds that were thermally stabilised for 4 and 8 h. Overall these scaffolds show potential as 'greener' alternatives to other electrospun tissue engineering materials, especially in cases where they may be used as delivery vectors for heat tolerant additives.

• Publikační typ
• časopisecké články MeSH

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

• MeSH
• hojení ran MeSH
• jizva etiologie   prevence a kontrola   chirurgie   MeSH
• kůže patologie   MeSH
• lidé MeSH
• popálení * chirurgie   patologie   MeSH
• transplantace kůže metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Léčba diabetických ran je problematická, časově i finančně náročná a omezující pro pacienty. Krevní destičky jsou fyziologicky přítomné v procesu hojení akutní rány, kde produkují růstové a angiogenní faktory, cytokiny, chemokiny, molekuly zprostředkující adhesi buněk a další bioaktivní látky napomáhající hojení. Lyzát připravený z plazmy obohacené o krevní destičky bude zabudován do degradovatelných i nedegradovatelných nanovlákenných nosičů připravených ze syntetických i přirozených polymerů dále modifikovaných fibrinem, a to s cílem postupného uvolňování růstových faktorů a dalších biologicky aktivních látek. Bioaktivita těchto nanovlákenných krytů bude hodnocena in vitro v kulturách lidských keratinocytů, dermálních fibroblastů, cévních endotelových buněk a kmenových buněk tukové tkáně. Nanovlákenné kryty s nejlepšími vlastnostmi budou aplikovány in vivo na rány u diabetických potkanů, a následně bude hodnocena jejich schopnost stimulace hojení ran.; Treatment of diabetic wounds is problematic, long-lasting, expensive and restrictive for patients. Platelets are physiologically present in the process of healing of acute wounds, where they secret growth and angiogenic factors, cytokines, chemokines, cell adhesion-mediating molecules and other bioactive substances that support healing. Lysate prepared from platelet-rich plasma will be incorporated into degradable and non-degradable nanofibrous dressings, prepared from synthetic and natural polymers further modified with fibrin, in order to assure controlled release of growth factors and other bioactive substances. Bioactivity of these dressings will be evaluated in vitro in cultures of human keratinocytes, dermal fibroblasts, vascular endothelial cells and adipose tissue-derived stem cells. Nanofibrous dressings with the best properties will be applied in vivo on wounds of diabetic rats, and their ability to stimulate wound healing will be evaluated.

• Klíčová slova
• řízené uvolňování, diabetické rány, lyzát z trombocytů, diabetický potkan, hojení ran, wound healing, diabetic wounds, platelet lysate, control release, diabetic rat, plasma obohacená destičkami, epidermální keratinocyty, dermální fibroblasty, kmenové buňky tukové tkáně, platelet-rich plasma, epidermal keratinocytes, dermal fibroblasts, adipose-tissue stem cells,

• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

INTRODUCTION: The formation of diabetic ulcers (DU) is a common complication for diabetic patients resulting in serious chronic wounds. There is therefore, an urgent need for complex treatment of this problem. This study examines a bioactive wound dressing of a biodegradable electrospun nanofibrous blend of poly(L-lactide-co-ε-caprolactone) and poly(ε-caprolactone) (PLCL/PCL) covered by a thin fibrin layer for sustained delivery of bioactive molecules. METHODS: Electrospun PLCL/PCL nanofibers were coated with fibrin-based coating prepared by a controlled technique and enriched with human platelet lysate (hPL), fibroblast growth factor 2 (FGF), and vascular endothelial growth factor (VEGF). The coating was characterized by scanning electron microscopy and fluorescent microscopy. Protein content and its release rate and the effect on human saphenous vein endothelial cells (HSVEC) were evaluated. RESULTS: The highest protein amount is achieved by the coating of PLCL/PCL with a fibrin mesh containing 20% v/v hPL (NF20). The fibrin coating serves as an excellent scaffold to accumulate bioactive molecules from hPL such as PDGF-BB, fibronectin (Fn), and α-2 antiplasmin. The NF20 coating shows both fast and a sustained release of the attached bioactive molecules (Fn, VEGF, FGF). The dressing significantly increases the viability of human saphenous vein endothelial cells (HSVECs) cultivated on a collagen-based wound model. The exogenous addition of FGF and VEGF during the coating procedure further increases the HSVECs viability. In addition, the presence of α-2 antiplasmin significantly stabilizes the fibrin mesh and prevents its cleavage by plasmin. DISCUSSION: The NF20 coating supplemented with FGF and VEGF provides a promising wound dressing for the complex treatment of DU. The incorporation of various bioactive molecules from hPL and growth factors has great potential to support the healing processes by providing appropriate stimuli in the chronic wound.

• MeSH
• alfa-2-antiplasmin MeSH
• endoteliální buňky MeSH
• hojení ran MeSH
• lidé MeSH
• nanovlákna * MeSH
• obvazy MeSH
• polyestery farmakologie   MeSH
• vaskulární endoteliální růstový faktor A * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The aim of this work is to determine the biological activity of ellagitannins rich extracts from leaves of raspberry (Rubus idaeus L.) and wild strawberry (Fragaria vesca L.) in relation to cells and cell membranes. Detailed qualitative and quantitative analysis of phenolic compounds of the extract was made using chromatographic methods. Cytotoxic and antioxidant activities of tested extracts in relation to erythrocytes and human vascular endothelial cells (HMEC-1) were determined by using fluorimetric and spectrophotometric methods. In order to establish the influence of the extracts on the physical properties of the membrane, such as osmotic resistance and erythrocytes shapes, mobility and/or hydration of polar heads and fluidity of hydrocarbon chains of membrane lipids, microscopic and spectroscopic methods were used. The results showed that the extracts are non-toxic for erythrocytes and HMEC-1 cells (up to concentration of 50 μg/mL), but they effectively protect cells and their membranes against oxidative damage. The increase in osmotic resistance of erythrocytes, formation of echinocytes and changes only in the polar part of the membrane caused by the extracts demonstrate their location mainly in the hydrophilic part of the membrane. The results indicate that tested extracts have high biological activities and may be potentially used in delaying the ageing process of organisms and prevention of many diseases, especially those associated with oxidative stress.

• MeSH
• antioxidancia chemie   farmakologie   MeSH
• endoteliální buňky MeSH
• erytrocyty MeSH
• hydrolyzovatelné taniny MeSH
• jahodník * chemie   MeSH
• lidé MeSH
• membránové lipidy MeSH
• oxidační stres MeSH
• rostlinné extrakty chemie   farmakologie   MeSH
• Rubus * chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Úvod: Kardiovaskulární choroby jsou zodpovědné za významnou morbiditu i mortalitu ve společnosti. Užití umělých cévních materiálů je často nezbytnou součástí v rámci chirurgické léčby, ať již je tato radikální nebo paliativní. V současné době dochází k vývoji řady nových biodegradabilních materiálů určených pro tyto účely. Preklinické testování každého nového materiálu je naprosto nezbytné, je prováděno jak in vitro, tak in vivo. Z tohoto důvodu jsou zvířecí experimentální modely nadále nutnou součástí testování před klinickým užitím. Cílem této práce je prezentovat možnosti užití různých zvířecích modelů na poli kardiovaskulární chirurgie a jejich extrapolace do klinické medicíny. Metody: Autoři prezentují jejich obecné zkušenosti s experimentální chirurgií, na jejich podkladě diskutují optimální výběr zvířecího modelu pro testování nových materiálů pro kardiovaskulární chirurgii a stejně tak optimální lokalitu implantace. Výsledky: Jako optimální experimentální zvířecí modely pro testování hemokompatibility a degradability nových materiálů uvádějí autoři modely potkana, králíka a prasete. Intraperitoneální implantace u potkana je snadná a lehce proveditelná procedura, stejně tak jako arteriální bandáž na aortě králíka či prasete. Rovněž karotické tepny jsou dobře využitelné. Bandáž na prasečí pulmonální tepně je již složitější zákrok s četnějšími komplikacemi. Explantované bandážované cévy po předem definované době jsou vhodné pro další mechanické testování ve smyslu biomechanických analýz, např. inflačně-extenzního testu. Závěr: V posledních fázích preklinického testování nových materiálů se nelze nadále obejít bez in-vivo experimentů. Naší snahou je však striktně dodržovat koncept 3R – Replacement, Reduction a Refinement. V tomto smyslu je třeba využít co nejvíce potenciál každého zvířete tak, abychom mohli redukovat počty zvířat.

Introduction: Cardiovascular diseases are responsible for significant morbidity and mortality in the population. Artificial vascular grafts are often essential for surgical procedures in radical or palliative treatment. Many new biodegradable materials are currently under development. Preclinical testing of each new material is imperative, both in vitro and in vivo, and therefore animal experiments are still a necessary part of the testing process before any clinical use. The aim of this paper is to present the options of using various experimental animal models in the field of cardiovascular surgery including their extrapolation to clinical medicine. Methods: The authors present their general experience in the field of experimental surgery. They discuss the selection process of an optimal experimental animal model to test foreign materials for cardiovascular surgery and of an optimal region for implantation. Results: The authors present rat, rabbit and porcine models as optimal experimental animals for material hemocompatibility and degradability testing. Intraperitoneal implantation in the rat is a simple and feasible procedure, as well as aortic banding in the rabbit or pig. The carotid arteries can also be used, as well. Porcine pulmonary artery banding is slightly more difficult with potential complications. The banded vessels, explanted after a defined time period, are suitable for further mechanical testing using biomechanical analyses, for example, the inflation-extension test. Conclusion: An in vivo experiment cannot be avoided in the last phases of preclinical research of new materials. However, we try to strictly observe the 3R concept – Replacement, Reduction and Refinement; in line with this concept, the potential of each animal should be used as much as possible to reduce the number of animals.

• MeSH
• biokompatibilní materiály MeSH
• biologicky odbouratelné plasty * MeSH
• kardiovaskulární chirurgické výkony * MeSH
• králíci MeSH
• modely u zvířat MeSH
• potkani Wistar MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

Polycaprolactone (PCL) was electrospun with the addition of arginine (Arg), an α-amino acid that accelerates the healing process. The efficient needleless electrospinning technique was used for the fabrication of the nanofibrous layers. The materials produced consisted mainly of fibers with diameters of between 200 and 400 nm. Moreover, both microfibers and beads were present within the layers. Higher bead sizes were observed with the increased addition of arginine. The arginine content within the layers as well as the weight of the resultant electrospun materials were enhanced with the increased addition of arginine to the electrospinning solution (1, 5 and 10 wt%). The PCL + 1% Arg nanofibrous layer contained 5.67 ± 0.04% of arginine, the PCL + 5% Arg layer 22.66 ± 0.24% of arginine and the PCL + 10% Arg layer 37.33 ± 0.39% of arginine according to the results of the elemental analysis. A high burst release within 5 h of soaking was recorded for the PCL + 5% and PCL + 10% nanofibrous layers. However, the release rate of arginine from the PCL + 1% Arg was significantly slower, reaching a maximum level after 72 h of soaking. The resulting materials were hydrophobic. Hemocompatibility testing under static conditions revealed no effect on hemolysis following the addition of arginine and the prolongation of the prothrombin time with the increased addition of arginine, thus exerting an influence on the extrinsic and common pathway of coagulation activation. The results of the dynamic hemocompatibility assessment revealed that the numbers of blood cells and platelets were not affected significantly by the various electrospun samples during incubation. The TAT, β-thromboglobulin and SC5-b9 concentrations were characterized by a moderate increase in the PCL group compared to those of the control group. The presence of arginine resulted in a decrease in the investigated hemocompatibility markers. The PMN elastase levels were comparable with respect to all the groups.

• MeSH
• arginin chemie   MeSH
• biokompatibilní materiály chemie   MeSH
• elektřina MeSH
• hemolýza * MeSH
• hojení ran * MeSH
• lidé MeSH
• nanovlákna chemie   MeSH
• polyestery chemie   MeSH
• protrombinový čas MeSH
• testování materiálů metody   MeSH
• tkáňové inženýrství MeSH
• tkáňové podpůrné struktury chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Background: Repairs to deep skin wounds continue to be a difficult issue in clinical practice. A promising approach is to fabricate full-thickness skin substitutes with functions closely similar to those of the natural tissue. For many years, a three-dimensional (3D) collagen hydrogel has been considered to provide a physiological 3D environment for co-cultivation of skin fibroblasts and keratinocytes. This collagen hydrogel is frequently used for fabricating tissue-engineered skin analogues with fibroblasts embedded inside the hydrogel and keratinocytes cultivated on its surface. Despite its unique biological properties, the collagen hydrogel has insufficient stiffness, with a tendency to collapse under the traction forces generated by the embedded cells. Methods: The aim of our study was to develop a two-layer skin construct consisting of a collagen hydrogel reinforced by a nanofibrous poly-L-lactide (PLLA) membrane pre-seeded with fibroblasts. The attractiveness of the membrane for dermal fibroblasts was enhanced by coating it with a thin nanofibrous fibrin mesh. Results: The fibrin mesh promoted the adhesion, proliferation and migration of the fibroblasts upwards into the collagen hydrogel. Moreover, the fibroblasts spontaneously migrating into the collagen hydrogel showed a lower tendency to contract and shrink the hydrogel by their traction forces. The surface of the collagen was seeded with human dermal keratinocytes. The keratinocytes were able to form a basal layer of highly mitotically-active cells, and a suprabasal layer. Conclusion: The two-layer skin construct based on collagen hydrogel with spontaneously immigrated fibroblasts and reinforced by a fibrin-coated nanofibrous membrane seems to be promising for the construction of full-thickness skin substitute.

• MeSH
• fibrin farmakologie   MeSH
• fibroblasty cytologie   účinky léků   MeSH
• hydrogely farmakologie   MeSH
• keratinocyty cytologie   účinky léků   MeSH
• kolagen farmakologie   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• membrány umělé * MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• nanovlákna chemie   MeSH
• novorozenec MeSH
• pohyb buněk účinky léků   MeSH
• polyestery farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• škára cytologie   MeSH
• umělá kůže * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• novorozenec MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH