Search

In the present work, a solution blow spun nanofibrous mat comprised of chitosan (CS) and poly(ethylene oxide) (PEO) was obtained as vaginal platform for tenofovir disoproxil fumarate (TDF) to prevent sexually transmitted infections. Apart from physicochemical and mechanical analysis, the specific steps involved studies on nanofibrous mat mucoadhesive and swelling characteristics upon pH fluctuations over the physiological range. Physicochemical analysis showed uniform drug distribution within the CS/PEO mat volume and pointed toward physical interactions between the drug and polymers. TDF-loaded CS/PEO nanofibrous mat was shown potentially safe when evaluated by the MTT metabolic activity and JC-1 assays in human vaginal epithelial cells VK2-E6/E7. In vitro antiviral studies indicated inhibition efficacy of TDF-CS/PEO nanofibrous mat toward HSV-2 virus and proved the SBS process does not change the microbicidal activity of drug molecule. Fluctuations in the physiological vaginal pH range of 3.8 to 5.0 substantially affected mucoadhesive and swelling behavior of chitosan which in turn impacted drug dissolution rate from polymer carrier. The rate of permeation and accumulation of TDF in vaginal tissue differed in response to vaginal pH. Faster drug permeation assessed at pH 5.0 suggests that an increase in vaginal pH could improve TDF bioavailability at earlier time points., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Incorporation of hydrophobic component into amphiphilic polycations structure is frequently accompanied by an increase of antimicrobial activity. There is, however, a group of relatively hydrophilic polycations containing quaternary ammonium moieties along mainchain, ionenes, which also display strong antimicrobial and limited hemolytic properties. In this work, an influence of a hydrophobic side group length on antimicrobial mechanism of action is investigated in a series of novel amphiphilic ionenes. High antimicrobial activity was found by determination of minimum inhibitory concentration (MIC) and minimum bactericidal, and fungicidal concentration (MBC and MFC) in both growth media and a buffer. Biocompatibility was estimated by hemolytic and mammalian cells viability assays. Mechanistic studies were performed using large unilamellar vesicles (LUVs) with different lipid composition, as simplified models of cell membranes. The investigated ionenes are potent and selective antimicrobial molecules displaying a decrease of antimicrobial activity correlated with increase of hydrophobicity. Studies using LUVs revealed that the cardiolipin is an essential component responsible for the lipid bilayer permeabilization by investigated ionens. In contrast to relatively hydrophilic ionenes, more hydrophobic polymers showed an ability to stabilize membranes composed of lipids with negative spontaneous curvature in a certain range of polymer to lipid ratio. The results substantially contribute to the understanding of antimicrobial activity of the investigated class of polymers., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Nano- and microemulsions have found various applications in pharmaceutical and medical areas both in research field as well as in applied solutions for drug delivery or diagnostic agents. However, production of stable and bio- / hemocompatible nanoemulsions are still challenging. New group of ionic surfactants have been synthesized with perfluorohexyl- or perfluorooctyl-groups as hydrophobic tail. The CMC and the parametres of the O/W emulsion (the particle size distribution and the zeta-potential) were determined. The influence of the surfactants on in vitro proliferation of human endothelial cell lines HMEC-1, murine fibroblasts L929 and hemolysis were investigated as characteristic for biocompatibility. Three candidates of surfactants were selected for pre-clinical tests on a small animal model (adult Sprague Dawley rats) on the basis of preliminary studies. This allowed to obtain nanoemulsions with narrow droplets size (average droplet diameter 141-147 nm with PDI index 0.059 - 0.065) and showed better stability over time in comparison to the commercially available surfactants. Neither cytotoxic nor hemolytic potential were observed during incubation of obtained fluorosurfactans with model cell lines L929 and HMEC-1 (average cell viability above 85 % after incubation with 1% solutions) and erythrocytes (hemolysis rate below 3.1 % for all 0.5 % solutions). During acute toxicity test on rat model, it was found that all three tested surfactant solutions showed no significant differences in controlled parameters and survival rate with control group (p > 0.05). Presented surfactants are dedicated but not limited to emulsification of organic fluorocompounds., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The main purpose of the work was to assess the haemocompatible properties of polyurethane discs with a modified surface dedicated to cardiovascular system regeneration. They were coated with acrylic acid-based material to inhibit the activation of the blood coagulation cascade. This coating improved the wettability of the material, leading to the prevention of protein adsorption on the surface. The blood-material interaction was analyzed in dynamic conditions with a specially designed tester, which helps to control blood-material interaction under high shear stress conditions. The corresponding numerical model of the tester was also developed by finite volume method (FVM). The 3D FVM model allows the determination of shear stresses applying different flow and boundary conditions representing blood-material interactions. The haemocompatibility analyses were performed through in vitro tests using a blood flow simulator. They revealed a low probability of activation of blood coagulation and low leukocyte activation. The original mechanical set-up to test the blood-material interaction helped to prove that acrylic acid-based coatings expressed good haemocompatible properties., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In case of benign and malignant tumours affecting the maxillofacial region, the resection of jawbone reflects the standard therapy in more than 5.000 cases per year within the European Union. The resulting large bone defects lead to scarred, mangled facial appearance, loss of mastication and probably speech, requiring aesthetic and functional surgery as a basis for physical and physiological rehabilitation. Although autologous vascularized bone autografts reflect the current golden standard, the portion of bone available for the procedure is limited and subsequent high-dose anti-cancer chemo-/radiotherapy can lead to local tissue necrosis. Autologous vascularized bone from fibular or iliac-crest autografts is current golden standard in jawbone resection post-treatment, however, the portion of transplantable bone is limited and subsequent high-dose anti-cancer chemo-/radiotherapy often results in tissue necrosis Our research focuses on alternative treatment techniques: tissue reconstruction via novel patient-specifically manufactured maxillofacial implant that stimulates bone tissue growth. The planned neoformation of vascularized bone in such implants within the patient's own body as "bioreactor" is the safest approach in tissue engineering. The works described herein included the design of the metallic substrate of the implant with the use of computed tomography basing on real patients scans and then 3D-printing the substrates from the Ti6Al7Nb powder. The metal core was then evaluated in terms of structural characteristic, cytotoxicity and gene expression through the in vitro tests. Further experiments were focused on fabrication of the biocompatible coating for outer surface of the bone implant that would enhance the healing process and accelerate the tissue growth. Functional polymeric granulate dedicated for osteoconductive, osteoinductive and osteogenesis properties were elaborated. Another approach including the coating for the implant surface with two-phase biocompatible layer including polymeric microspheres and hydrogel carrier, which would provide long-time release of bone and cartilage growth factors around the implant were also done. The polymeric granulate containing βTCP improved bone cells growth, but it some modification has to be done in order to improve structural pores to ensure for better osteoconductivity. The biocompatible coating including PVP hydrogel and polymeric microspheres is still in the development process., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Known techniques for modification of polypropylene membranes (PPm) often require modification of the membrane in its entire volume (i.e. at the manufacturing stage), which may affect its properties. In the present work, the authors proposed a simple method for PPm hydrophilization. The process involves a two-step Fenton-type reaction, with ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent and cumene hydroperoxide (CHP) as a source of free radicals. This hydrogel coating aims to enhance membrane hemocompatible and biocompatible properties. The biggest advantage of the proposed technique is the change of materials' surface properties, without interfering with its internal structure. Microscopic (SEM) and spectroscopic (FTIR-ATR) analyses confirmed the presence of hydrogel coating on PPm surfaces. Additionally, the evaluation of the surface density of the coating showed that the thickness of the coating increases with the reaction time and CHP concentration. The applied coatings significantly increase surface hydrophilicity (contact angle for PPm: 128.58° ± 0.52°, for all modified surfaces <53.31° ± 2.03°). The cytotoxicity test (XTT assay) proved biocompatibility of the PVP coating - cell viability remained above 90% for all variants tested. The modification resulted in a decrease in fibrinogen adsorption (of at least about 16%) and in a number of surface-adhered platelets. The assay evaluating the amount of secreted cell adhesion molecules (ICAM-1) showed a significant reduction (of at least about 50%) in the expression of ICAM-1 for all hydrogel-modified surfaces., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

The presented study describes a method for the preparation and modification of cylindrical polyurethane structures with polyvinylpyrrolidone (PVP) hydrogel coating. The modified polyurethane scaffolds were fabricated using the phase-inversion technique and intended to be used as a vascular prosthesis. The proposed modification method involves a two-step Fenton-type reaction. Physicochemical analysis (Fourier transform infrared spectroscopy, scanning electron microscopy) confirmed the presence of the hydrogel coating. The influence of PVP and polymerization initiator (cumene hydroperoxide) concentrations on hydrogel's properties were examined. The higher concentrations of reagent were used, the thicker coating was obtained. After modification, the material's surface becomes more hydrophilic in comparison to pristine polyurethane. Cytotoxicity assay (MTT test) confirmed that PVP-coating is not toxic. The introduction of hydrogel coating resulted in a significant decrease in the fibrinogen adsorbed to the material's surface as compared to a non-modified polymer. Platelet adhesion assay demonstrated almost no platelet adhesion to the modified surfaces., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) is one of the preeminent metal chelator applied for diagnostic and therapeutic purposes, however to date there is no versatile and reliable nonradioisotopic method for its precise determination. In this technical note, we present a novel and sensitive fluorimetric assay for quantitative determination of DOTA based on the luminescence quenching of the highly luminescent europium ions complex with trioctyl phosphine oxide and naphthoyl trifluoroacetone sensitizing activators. The assay is carried out in two simple steps and enables the determination of DOTA in the nanomolar range providing a superior tool compared to commonly applied spectrophotometric assay with Arsenazo-III reagent., (Copyright © 2019. Published by Elsevier Inc.)

The aim of this work was to elaborate the 3D printed polylactide (PLA) polymeric scaffolds and, subsequently, study the possibility of coating thereof with a biomedical polyvinylpyrrolidone (PVP) hydrogel through the previously patented protocol. Such materials have a potential to be applied in biomedical engineering, e.g. for tissue regeneration. PVP layer according to the present paper could constitute a useful biocompatible supporting layer for drug delivering implant surfaces of any shape. Polylactide (PLA) both in forms of flat foils and 3D-printed scaffolds was used to be coated with PVP layer with the Fenton-type reaction that enables the polymeric scaffold grafting with hydrogel in two easy steps. The study revealed that PVP was successfully grafted to PLA substrates. Most optimal parameters for PVP grafting process were selected. The PLA-PVP materials were found to be hydrophilic and non-toxic which is promising considering their biomedical application. The method comprising well-tested PLA scaffolds printing and then grafting them with PVP layer has a promising potential to be brought in to the industrial production due to its simplicity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lecithin is a mixture of phospholipids (PLs) that are found in living organisms. It gained the interest as a bio- and hemocompatible modifying agent for biomaterials. In this paper, we focused on the elaboration of a simple and well-described technology of metals coating with low-cost substance that could be useful in biomaterials industry. We studied the utility of lecithin suspension for stainless steel coating by electrophoretic deposition method. Our goal was to find a relationship between the conditions of lecithin suspension preparation, obtained suspension properties (vesicles size and structure, zeta potential, electrophoretic mobility) and lecithin coating features (topography, roughness). We found that final pH value, zeta potential and electrophoretic mobility of lecithin suspensions were not altered by initial solution pH value. However, the presence of hydrated Na + ions forced forming of large multi-layered vesicles. We obtained uniform lecithin coatings with the use of electrophoretic deposition, which has a great potential to be used in a large scale., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Current metal implants (e.g. stents) covered with drug-eluting coatings are not robust for long-term usage. Other types and methods of coatings are needed, especially ones that are not prone to activity loss in vivo. In this paper, the method of stainless steel (SS) coating with poly(ethylene glycol) dimethacrylate (PEGDMA) with the use of electropolymerization (EP) is presented. The application of a specific and simple reaction mixture enabled the production of SS-PEGDMA materials that possessed a homogenous surface. The polymer coating was durable for 28 days of constant washing. The resulting materials were non-toxic and haemolysis did not occur after incubation with blood. Moreover, because the coating filled up scratches present on bare SS and hydrophilized the SS surface, it reduced fibrinogen adsorption five times in comparison to SS and, unlike on SS, no platelet activation was detected. The presented method is a very promising candidate for scale up due to its simplicity and low cost., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This paper presents a comparison and evaluation of cardiac cell proliferation on poly(l-lactic acid) (PLLA) and polyurethane (PU) nanofibrous mats fabricated by solution blow spinning (SBS). Three different cardiac cell lines: rat cardiomyoblasts (H9C2 line), human (HCM) and rat cardiomyocytes (RCM) were used for experiments. Cell morphology, orientation and proliferation were investigated on non-modified and protein-modified (fibronectin, collagen, gelatin, laminin, poly-l-lysine) surfaces of both types of nanofibers. Obtained results of cell culture on nanofibers surfaces were compared to the results of cell culture on polystyrene (PS) surfaces modified in the same way. The results indicated that in most cases polymeric nanofibers (PLLA and PU) are better substrates for cardiac cell culture than PS surfaces. All types of investigated cells, cultured on nanofibers (PLLA and PU), had more elongated shape than cells cultured on PS surfaces. Moreover, cells were arranged in parallel to each other, according to fibers orientation. Additionally, it was shown that the protein modifications of investigated surfaces influenced on cell proliferation. Therefore, we suggest that the cardiac cell culture on nanofibrous mats fabricated by SBS could be more advanced experimental in vitro model for studies on the effect of various cardiac drugs than traditional culture on PS surface., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The paper presents method for chemical immobilization of arginine-glutamic acid-aspartic acid-valine (REDV) peptide on polyurethane surface. The peptide has been covalently bonded using silanes as a spacer molecules. The aim of this work was to investigate the proposed modification process and assess its biological effectiveness, especially in contact with blood and endothelial cells. Physicochemical properties were examined in terms of wettability, atomic composition and density of introduced functional groups and peptide molecules. Experiments with blood showed that material coating reduced number of surface-adhered platelets and fibrinogen molecules. In contrast to polyurethane (PU), there were no blood components deposited on REDV-modified materials (PU-REDV); fibrinogen adsorption on PU-REDV surface has been strongly reduced compared to PU. Analysis of cell adhesion after 1, 2, 3, 4, and 5 days of culture showed a significant increase of the cell-coated area on PU-REDV compared to PU. However, an intense cell growth appeared also on the control surface modified without the addition of REDV. Thus, the positive effect of REDV peptide on the adhesion of HUVEC could not be unequivocally confirmed., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In the article the authors present hydrogel coatings prepared from polyvinylpyrrolidone (PVP) macromolecules, which are chemically bonded to polyurethane (PU) substrate. The coating is designed to improve the surface hemocompatibility of blood-contacting medical devices. The coating was characterized in terms of physical properties (swelling ratio, hydrogel density, surface morphology, coating thickness, coating durability). In order to examine surface hemocompatibility, the materials were contacted with whole human blood under arterial flow simulated conditions followed by calculation of platelet consumption and the number of platelet aggregates. Samples were also contacted with platelet-poor plasma; the number of surface-adsorbed fibrinogen molecules was measured using ELISA assay. Finally, the inflammatory reaction after implantation was assessed, using New Zealand rabbits. The designed coating is characterized by high water content and excellent durability in aqueous environment - over a 35-day period, no significant changes in coating thickness were observed. Experiments with blood proved twice the reduction in adsorption of serum-derived fibrinogen together with a moderate reduction in the number of platelet aggregates formed during the contact of the material with blood. The analysis of an inflammatory reaction after the implantation confirmed high biocompatibility of the fabricated materials - studies have shown no toxic effects of the implanted material on the surrounding animal tissues., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In this paper the authors present a simple method of coating polyurethane (PU) surface with poly(vinyl pirrolidone) (PVP) hydrogel. The hydrogel-coated materials were designed for use in biomedical applications, especially in blood-contacting devices. The coating is formed due to free radical macromolecular grafting-crosslinking. Polymer surface was first immersed in an organic solution containing radical source: cumene hydroperoxide (CHP) with an addition of a branching and anchoring agent: ethylene glycol dimethylacrylate (EGDMA). In the second step, the substrate was immersed in a water solution containing given concentration of PVP and Fe(2+). The novelty of the process consists in the fact that free radicals are formed mostly at the polymer/solution interface, what assures high grafting efficiency together with the formation of covalent bonds between polymer substrate and modifying layer. The process was optimized for reagents concentrations. The coating properties: thickness and the swelling ratio were strongly influenced by CHP, Fe(2+), PVP and EGMDA concentrations. The chemical composition of the surface analyzed with FTIR-ATR spectroscopy confirmed the presence of PVP coating. In vitro biocompatibility tests with L929 fibroblasts confirmed non-cytotoxicity of the coatings. Hydrogel coating significantly improved polyurethane hemocompatibility. Studies with human whole blood revealed that both, the platelet consumption and the level of platelet activation were as low as for negative control., (Copyright © 2012 Elsevier B.V. All rights reserved.)