The alveolar-capillary interface is the key functional element of gas exchange in the human lung, and disruptions to this interface can lead to significant medical complications. However, it is currently challenging to adequately model this interface in vitro, as it requires not only the co-culture of human alveolar epithelial and endothelial cells but mainly the preparation of a biocompatible scaffold that mimics the basement membrane. This scaffold should support cell seeding from both sides, and maintain optimal cell adhesion, growth, and differentiation conditions. Our study investigates the use of polycaprolactone (PCL) nanofibers as a versatile substrate for such cell cultures, aiming to model the alveolar-capillary interface more accurately. We optimized nanofiber production parameters, utilized polyamide mesh UHELON as a mechanical support for scaffold handling, and created 3D-printed inserts for specialized co-cultures. Our findings confirm that PCL nanofibrous scaffolds are manageable and support the co-culture of diverse cell types, effectively enabling cell attachment, proliferation, and differentiation. Our research establishes a proof-of-concept model for the alveolar-capillary interface, offering significant potential for enhancing cell-based testing and advancing tissue-engineering applications that require specific nanofibrous matrices.
The aim of this study was to develop multifunctional magnetic poly(ε-caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three-step approach. Then, a series of PCL-based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow-derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS-2 osteoblast-like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention.
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Escherichia coli drug effects MeSH
- Bone and Bones MeSH
- Rats MeSH
- Ascorbic Acid * chemistry pharmacology MeSH
- Humans MeSH
- Magnetite Nanoparticles chemistry MeSH
- Cell Line, Tumor MeSH
- Nanocomposites chemistry MeSH
- Osteoblasts metabolism cytology MeSH
- Osteosarcoma pathology MeSH
- Polyesters * chemistry MeSH
- Staphylococcus aureus * drug effects growth & development MeSH
- Materials Testing MeSH
- Tissue Engineering * MeSH
- Tissue Scaffolds chemistry MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article 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
- Biofilms * growth & development MeSH
- Escherichia coli * physiology MeSH
- Glucose metabolism MeSH
- Nanofibers * chemistry MeSH
- Nylons chemistry MeSH
- Polyesters * chemistry MeSH
- Spectrophotometry methods MeSH
- Staphylococcus aureus * physiology MeSH
- Tetrazolium Salts * metabolism chemistry MeSH
- Thiazoles metabolism MeSH
- Publication type
- Journal Article MeSH
PURPOSE: The aim of this study was to evaluate the antibacterial efficacy of surface-treated hernia implants modified by a hybrid nanolayer with incorporated Ag, Cu, and Zn cations using the sol-gel method. METHODS: The materials (polypropylene, polyester, and polyvinylidene difluoride) were activated by vacuum plasma treatment or UV C radiation, then modified and tested for bacterial strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). The AATCC 100 (2019) method for quantitative and the ISO 20645 agar plate propagation method for qualitative evaluation of microbiological efficacy were used. The gradual release of incorporated ions was monitored over time in simulated body fluids (blood plasma, peritoneal fluid) and physiological saline using an inductively coupled plasma mass spectrometer. The thickness and the homogeneity of the layers were measured for individual random samples with scanning electron microscope analysis (SEMA) and evaluated with an elemental analysis. RESULTS: Qualitative and quantitative microbiological tests clearly show the great suitability of vacuum plasma and UV C with sol AD30 (dilution 1:1) surface treatment of the implants. The absolute concentration of Ag, Cu, and Zn cations in leachates was very low. SEMA showed a high degree of homogeneity of the layer and only very rare nanocracks by all tested materials appear after mechanical stress. CONCLUSION: This study confirms that surface treatment of meshes using the sol-gel method significantly increases the antibacterial properties. The nanolayers are sufficiently mechanically resistant and stable and pose no threat to health.
- Publication type
- Journal Article MeSH
Previously, a new biodegradable poly(ester urethane urea) was synthesized based on polycaprolactone-diol and fish gelatin (PU-Gel). In this work, the potential of this new material for neural tissue engineering is evaluated. Membranes with randomly oriented fibers and with aligned fibers are produced using electrospinning and characterized regarding their mechanical behavior under both dry and wet conditions. Wet samples exhibit a lower Young's modulus than dry ones and aligned membranes are stiffer and more brittle than those randomly oriented. Cyclic tensile tests are conducted and high values for recovery ratio and resilience are obtained. Both membranes exhibited a hydrophobic surface, measured by the water contact angle (WCA). Human mesenchymal stem cells from umbilical cord tissue (UC-MSCs) and human neural stem cells (NSCs) are seeded on both types of membranes, which support their adhesion and proliferation. Cells stained for the cytoskeleton and nucleus in membranes with aligned fibers display an elongated morphology following the alignment direction. As the culture time increased, higher cell viability is obtained on randomfibers for UC-MSCs while no differences are observed for NSCs. The membranes support neuronal differentiation of NSCs, as evidenced by markers for a neuronal filament protein (NF70) and for a microtubule-associated protein (MAP2).
- MeSH
- Biocompatible Materials chemistry pharmacology MeSH
- Cell Adhesion drug effects MeSH
- Cell Differentiation drug effects MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Mesenchymal Stem Cells * cytology drug effects metabolism MeSH
- Neural Stem Cells * cytology drug effects metabolism MeSH
- Tensile Strength MeSH
- Polyesters * chemistry pharmacology MeSH
- Polyurethanes * chemistry pharmacology MeSH
- Cell Proliferation drug effects MeSH
- Materials Testing MeSH
- Tissue Engineering * methods MeSH
- Tissue Scaffolds chemistry MeSH
- Cell Survival drug effects MeSH
- Gelatin * chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
A film-forming system (FFS) represents a convenient topical dosage form for drug delivery. In this study, a non-commercial poly(lactic-co-glycolic acid) (PLGA) was chosen to formulate an FFS containing salicylic acid (SA) and methyl salicylate (MS). This unique combination is advantageous from a therapeutic point of view, as it enabled modified salicylate release. It is beneficial from a technological perspective too, because it improved thermal, rheological, and adhesive properties of the in situ film. DSC revealed complete dissolution of SA and good miscibility of MS with the polymer. MS also ensures optimal viscoelastic and adhesive properties of the film, leading to prolonged and sustained drug release. The hydrolysis of MS to active SA was very slow at skin pH 5.5, but it apparently occurred at physiological pH 7.4. The film structure is homogeneous without cracks, unlike some commercial preparations. The dissolution study of salicylates revealed different courses in their release and the influence of MS concentration in the film. The formulated PLGA-based FFS containing 5 % SA and 10 % MS is promising for sustained and prolonged local delivery of salicylates, used mainly for keratolytic and anti-inflammatory actions and pain relief.
- MeSH
- Administration, Cutaneous MeSH
- Administration, Topical MeSH
- Chemistry, Pharmaceutical methods MeSH
- Hydrogen-Ion Concentration MeSH
- Polylactic Acid-Polyglycolic Acid Copolymer * chemistry MeSH
- Skin metabolism MeSH
- Lactic Acid * chemistry MeSH
- Polyglycolic Acid * chemistry MeSH
- Salicylic Acid * administration & dosage chemistry pharmacokinetics MeSH
- Drug Delivery Systems * methods MeSH
- Delayed-Action Preparations MeSH
- Solubility MeSH
- Salicylates * administration & dosage chemistry pharmacokinetics MeSH
- Drug Liberation MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS: In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS: Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS: The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.
- MeSH
- Cytochrome P-450 CYP1A2 MeSH
- Double-Blind Method MeSH
- Cross-Over Studies MeSH
- Caffeine * pharmacology MeSH
- Lactic Acid MeSH
- Humans MeSH
- Polyesters MeSH
- Dietary Supplements MeSH
- Reaction Time MeSH
- Athletic Performance * physiology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Randomized Controlled Trial MeSH
Poly-β-hydroxybutyrate (PHB) is a potential source of biodegradable plastics that are environmentally friendly due to their complete degradation to water and carbon dioxide. This study aimed to investigate PHB production in the cyanobacterium Synechocystis sp. PCC6714 MT_a24 in an outdoor bioreactor using urban wastewater as a sole nutrient source. The culture was grown in a thin-layer raceway pond with a working volume of 100 L, reaching a biomass density of up to 3.5 g L-1 of cell dry weight (CDW). The maximum PHB content was found under nutrient-limiting conditions in the late stationary phase, reaching 23.7 ± 2.2% PHB per CDW. These data are one of the highest reported for photosynthetic production of PHB by cyanobacteria, moreover using urban wastewater in pilot-scale cultivation which multiplies the potential of sustainable cultivation approaches. Contamination by grazers (Poterioochromonas malhamensis) was managed by culturing Synechocystis in a highly alkaline environment (pH about 10.5) which did not significantly affect the culture growth. Furthermore, the strain MT_a24 showed significant wastewater nutrient remediation removing about 72% of nitrogen and 67% of phosphorus. These trials demonstrate that the photosynthetic production of PHB by Synechocystis sp. PCC6714 MT_a24 in the outdoor thin-layer bioreactor using urban wastewater and ambient carbon dioxide. It shows a promising approach for the cost-effective and sustainable production of biodegradable carbon-negative plastics. KEY POINTS: • High PHB production by cyanobacteria in outdoor raceway pond • Urban wastewater used as a sole source of nutrients for phototrophic growth • Potential for cost-effective and sustainable production of biodegradable plastics.
- MeSH
- Biodegradable Plastics * MeSH
- Hydroxybutyrates MeSH
- Wastewater MeSH
- Carbon Dioxide MeSH
- Polyesters MeSH
- Ponds MeSH
- Synechocystis * MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: The aim of this work was the evaluation of surface modification in surgery of normally used hernia implants and thus improving their antimicrobial properties. The modification consisted of applying hybrid nanolayers with immobilized antiseptic substances (metal cations of Ag, Cu, and Zn) by sol-gel method which ensures prolonged effect of these substances and thus enables a greater resistance of the implant towards infection. In this work, attention is drawn to the issue of applying hybrid nanolayers, activation of mesh surfaces by physical plasma modification or ultraviolet C (UV C) radiation, and influence of these modifications on the mechanical properties of the final meshes. Next work will continue concentrating on the issue of antimicrobial efficacy and eventual toxicity of the prepared layers. MATERIALS AND METHODS: Present-day materials of the most commonly used types of implants for reconstruction of the abdominal wall in surgery (polypropylene, polyester, polyvinylidenefluoride) were tested. Optimum conditions of application of nanolayers by sol-gel method and their thermal stabilization were examined first. Surface modification was verified by scanning electron microscope. The surface of implants was first activated for better adhesion by plasma treatment or UV radiation after preliminary tests. Maximum strength and ductility after activation and hybrid nanolayer modification were objectively measured on a universal Testometric tensile testing machine. RESULTS: The results of surface activation of the meshes (by both plasma treatment or UV C radiation) provided similar and satisfactory results, and particular conditions differed based on the type of material of the mesh. Usage of antimicrobial sol AD30 diluted by isopropyl alcohol in 1:1 proportion appear to be optimal. All tested cases of meshes activated by plasma treatment or UV C radiation and with applied nanolayer concluded in a slight reduction of mechanical properties in modified meshes in comparison with the original ones. However, a slight reduction of test values was not of clinical importance. CONCLUSION: It was verified that surface modification of implants by sol-gel method is effective and technically possible, providing hopeful results.
In response to the growing need for development of modern biomaterials for applications in regenerative medicine strategies, the research presented here investigated the biological potential of two types of polymer nanocomposites. Graphene oxide (GO) and partially reduced graphene oxide (rGO) were incorporated into a poly(ε-caprolactone) (PCL) matrix, creating PCL/GO and PCL/rGO nanocomposites in the form of membranes. Proliferation of osteoblast-like cells (human U-2 OS cell line) on the surface of the studied materials confirmed their biological activity. Fluorescence microscopy was able to distinguish the different patterns of interaction between cells (depending on the type of material) after 15 days of the test run. Raman micro-spectroscopy and two-dimensional correlation spectroscopy (2D-COS) applied to Raman spectra distinguished the nature of cell-material interactions after only 8 days. Combination of these two techniques (Raman micro-spectroscopy and 2D-COS analysis) facilitated identification of a much more complex cellular response (especially from proteins) on the surface of PCL/GO. The presented approach can be regarded as a method for early study of the bioactivity of membrane materials.
- MeSH
- Graphite * pharmacology chemistry MeSH
- Humans MeSH
- Osteoblasts MeSH
- Polyesters chemistry MeSH
- Polymers MeSH
- Spectrum Analysis, Raman MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
