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The gut microbiota dysbiosis that often occurs in cancer therapy requires more efficient treatment options to be developed. In this concern, the present research approach is to develop drug delivery systems based on magnetite nanoparticles (MNPs) as nanocarriers for bioactive compounds. First, MNPs were synthesized through the spraying-assisted coprecipitation method, followed by loading bee pollen or bee bread extracts and an antitumoral drug (5-fluorouracil/5-FU). The loaded-MNPs were morphologically and structurally characterized through transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Dynamic Light Scattering (DLS), and thermogravimetric analysis. UV-Vis spectroscopy was applied to establish the release profiles and antioxidant activity. Furthermore, the antibacterial and antitumoral activity of loaded-MNPs was assessed. The results demonstrate that MNPs with antioxidant, antibacterial, antiproliferative, and prebiotic properties are obtained. Moreover, the data highlight the improvement of 5-FU antibacterial activity by loading on the MNPs' surface and the synergistic effects between the anticancer drug and phenolic compounds (PCs). In addition, the prolonged release behavior of PCs for many hours (70-75 h) after the release of 5-FU from the developed nanocarriers is an advantage, at least from the point of view of the antioxidant activity of PCs. Considering the enhancement of L. rhamnosus MF9 growth and antitumoral activity, this study developed promising drug delivery alternatives for colorectal cancer therapy.
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Bee bread has received attention due to its high nutritional value, especially its phenolic composition, which enhances life quality. The present study aimed to evaluate the chemical and antimicrobial properties of bee bread (BB) samples from Romania. Initially, the bee bread alcoholic extracts (BBEs) were obtained from BB collected and prepared by Apis mellifera carpatica bees. The chemical composition of the BBE was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and the total phenols and flavonoid contents were determined. Also, a UHPLC-DAD-ESI/MS analysis of phenolic compounds (PCs) and antioxidant activity were evaluated. Furthermore, the antimicrobial activity of BBEs was evaluated by qualitative and quantitative assessments. The BBs studied in this paper are provided from 31 families of plant species, with the total phenols content and total flavonoid content varying between 7.10 and 18.30 mg gallic acid equivalents/g BB and between 0.45 and 1.86 mg quercetin equivalents/g BB, respectively. Chromatographic analysis revealed these samples had a significant content of phenolic compounds, with flavonoids in much higher quantities than phenolic acids. All the BBEs presented antimicrobial activity against all clinical and standard pathogenic strains tested. Salmonella typhi, Candida glabrata, Candida albicans, and Candida kefyr strains were the most sensitive, while BBEs' antifungal activity on C. krusei and C. kefyr was not investigated in any prior research. In addition, this study reports the BBEs' inhibitory activity on microbial (bacterial and fungi) adhesion capacity to the inert substratum for the first time.
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The aim of the present study was to obtain antimicrobial dressings from bacterial cellulose loaded with nutmeg and of fir needle essential oils. The attractive properties of BC, such as biocompatibility, good physicochemical and mechanical stability, and high water absorption, led to the choice of this material to be used as a support. Essential oils have been added to provide antimicrobial properties to these dressings. The results confirmed the presence of oils in the structure of the bacterial cellulose membrane and the ability of the materials to inhibit the adhesion of Staphylococcus aureus and Escherichia coli. By performing antibacterial tests on membranes loaded with fir needle essential oil, we demonstrated the ability of these membranes to inhibit bacterial adhesion to the substrate. The samples loaded with nutmeg essential oil exhibited the ability to inhibit the adhesion of bacteria to the surface of the materials, with the 5% sample showing a significant decrease. The binding of essential oils to the membrane was confirmed by thermal analysis and infrared characterization.
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Since the water pollution problem still affects the environmental system and human health, the need to develop innovative membranes has become imperious. Lately, researchers have focused on developing novel materials to help diminish the contamination problem. The aim of present research was to obtain innovative adsorbent composite membranes based on a biodegradable polymer, alginate, to remove toxic pollutants. Of all pollutants, lead was chosen due to its high toxicity. The composite membranes were successfully obtained through a direct casting method. The silver nanoparticles (Ag NPs) and caffeic acid (CA) from the composite membranes were kept at low concentrations, which proved enough to bestow antimicrobial activity to the alginate membrane. The obtained composite membranes were characterised by Fourier transform infrared spectroscopy and microscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TG-DSC). Swelling behaviour, lead ion (Pb2+) removal capacity, regeneration and reusability were also determined. Further, the antimicrobial activity was tested against selected pathogenic strains (S. aureus, E. faecalis sp., P. aeruginosa, E. coli and C. albicans). The presence of Ag NPs and CA improves the antimicrobial activity of the newly developed membranes. Overall, the composite membranes are suitable for complex water treatment (removal of heavy metal ions and antimicrobial treatment).
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The aim of the present study was to obtain a hydrogel-based film as a carrier for the sustained and controlled release of vancomycin, an antibiotic commonly used in various types of infections. Considering the high-water solubility of vancomycin (>50 mg/mL) and the aqueous medium underlying the exudates, a prolonged release of vancomycin from an MCM-41 carrier was sought. The present work focused on the synthesis of malic acid coated magnetite (Fe3O4/malic) by co-precipitation, synthesis of MCM-41 by a sol-gel method and loading of MCM-41 with vancomycin, and their use in alginate films for wound dressing. The nanoparticles obtained were physically mixed and embedded in the alginate gel. Prior to incorporation, the nanoparticles were characterized by XRD, FT-IR and FT-Raman spectroscopy, TGA-DSC and DLS. The films were prepared by a simple casting method and were further cross-linked and examined for possible heterogeneities by means of FT-IR microscopy and SEM. The degree of swelling and the water vapor transmission rate were determined, considering their potential use as wound dressings. The obtained films show morpho-structural homogeneity, sustained release over 48 h and a strong synergistic enhancement of the antimicrobial activity as a consequence of the hybrid nature of these films. The antimicrobial efficacy was tested against S. aureus, two strains of E. faecalis (including vancomycin-resistant Enterococcus, VRE) and C. albicans. The incorporation of magnetite was also considered as an external triggering component in case the films were used as a magneto-responsive smart dressing to stimulate vancomycin diffusion.
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Cancer remains the most devastating disease, being one of the main factors of death and morbidity worldwide since ancient times. Although early diagnosis and treatment represent the correct approach in the fight against cancer, traditional therapies, such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy, have some limitations (lack of specificity, cytotoxicity, and multidrug resistance). These limitations represent a continuous challenge for determining optimal therapies for the diagnosis and treatment of cancer. Cancer diagnosis and treatment have seen significant achievements with the advent of nanotechnology and a wide range of nanoparticles. Due to their special advantages, such as low toxicity, high stability, good permeability, biocompatibility, improved retention effect, and precise targeting, nanoparticles with sizes ranging from 1 nm to 100 nm have been successfully used in cancer diagnosis and treatment by solving the limitations of conventional cancer treatment, but also overcoming multidrug resistance. Additionally, choosing the best cancer diagnosis, treatment, and management is extremely important. The use of nanotechnology and magnetic nanoparticles (MNPs) represents an effective alternative in the simultaneous diagnosis and treatment of cancer using nano-theranostic particles that facilitate early-stage detection and selective destruction of cancer cells. The specific properties, such as the control of the dimensions and the specific surface through the judicious choice of synthesis methods, and the possibility of targeting the target organ by applying an internal magnetic field, make these nanoparticles effective alternatives for the diagnosis and treatment of cancer. This review discusses the use of MNPs in cancer diagnosis and treatment and provides future perspectives in the field.
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Two types of mesoporous materials, MCM-41 and MCM-48, were functionalized by the soft-template method using (3-aminopropyl)triethoxysilane (APTES) as a modifying agent. The obtained mesoporous silica materials were loaded with trans-ferulic acid (FA). In order to establish the morphology and structure of mesoporous materials, a series of specific techniques were used such as: X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer-Emmet-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). We monitored the in vitro release of the loaded FA at two different pH values, by using simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Additionally, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231 were used to evaluate the antimicrobial activity of FA loaded mesoporous silica materials. In conclusion such functionalized mesoporous materials can be employed as controlled release systems for polyphenols extracted from natural sources.
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As it is used in all aspects of human life, water has become more and more polluted. For the past few decades, researchers and scientists have focused on developing innovative composite adsorbent membranes for water purification. The purpose of this research was to synthesize a novel composite adsorbent membrane for the removal of toxic pollutants (namely heavy metals, antibiotics and microorganisms). The as-synthesized chitosan/TiO2 composite membranes were successfully prepared through a simple casting method. The TiO2 nanoparticle concentration from the composite membranes was kept low, at 1% and 5%, in order not to block the functional groups of chitosan, which are responsible for the adsorption of metal ions. Nevertheless, the concentration of TiO2 must be high enough to bestow good photocatalytic and antimicrobial activities. The synthesized composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and swelling capacity. The antibacterial activity was determined against four strains, Escherichia coli, Citrobacter spp., Enterococcus faecalis and Staphylococcus aureus. For the Gram-negative strains, a reduction of more than 5 units log CFU/mL was obtained. The adsorption capacity for heavy metal ions was maximum for the chitosan/TiO2 1% composite membrane, the retention values being 297 mg/g for Pb2+ and 315 mg/g for Cd2+ ions. These values were higher for the chitosan/TiO2 1% than for chitosan/TiO2 5%, indicating that a high content of TiO2 can be one of the reasons for modest results reported previously in the literature. The photocatalytic degradation of a five-antibiotic mixture led to removal efficiencies of over 98% for tetracycline and meropenem, while for vancomycin and erythromycin the efficiencies were 86% and 88%, respectively. These values indicate that the chitosan/TiO2 composite membranes exhibit excellent photocatalytic activity under visible light irradiation. The obtained composite membranes can be used for complex water purification processes (removal of heavy metal ions, antibiotics and microorganisms).
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The ability of TiO2 to generate reactive oxygen species under UV radiation makes it an efficient candidate in antimicrobial studies. In this context, the preparation of TiO2 microparticles coated with Ca- and Cu-based composite layers over which Cu(II), Cu(I), and Cu(0) species were identified is presented here. The obtained materials were characterized by a wide range of analytical methods, such as X-ray diffraction, electron microscopy (TEM, SEM), X-ray photoelectron (XPS), and UV-VIS spectroscopy. The antimicrobial efficiency was evaluated using qualitative and quantitative standard methods and standard clinical microbial strains. A significant aspect of this composite is that the antimicrobial properties were evidenced both in the presence and absence of the light, as result of competition between photo and electrical effects. However, the antibacterial effect was similar in darkness and light for all samples. Because no photocatalytic properties were found in the absence of copper, the results sustain the antibacterial effect of the electric field (generated by the electrostatic potential of the composite layer) both under the dark and in light conditions. In this way, the composite layers supported on the TiO2 microparticles' surface can offer continuous antibacterial protection and do not require the presence of a permanent light source for activation. However, the antimicrobial effect in the dark is more significant and is considered to be the result of the electric field effect generated on the composite layer.
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Luz , Titânio , Antibacterianos/química , Antibacterianos/farmacologia , Catálise , Microscopia Eletrônica de Varredura , Titânio/química , Titânio/farmacologiaRESUMO
This paper evaluated the chemical and biological properties of bee pollen samples from Romania. Firstly, the bee pollen alcoholic extracts (BPEs) were obtained from raw bee pollen harvested by Apis mellifera carpatica bees. The chemical composition of BPE was obtained by determination of total phenol content and total flavonoid content, UHPLC-DAD-ESI/MS analysis of phenolic compounds, and GC-MS analysis of fatty acids, esters, and terpenes. Additionally, the antioxidant activity was evaluated by the Trolox Equivalent Antioxidant Capacity method. Furthermore, the biological properties of BPE were evaluated (antimicrobial and cytotoxic activity). The raw BP samples studied in this paper had significant phenolic acid and flavonoid content, and moderate fatty acid, ester, and terpene content. P1, P2, and P4 have the highest TPC and TFC levels, and the best antioxidant activity. All BPEs studied had antimicrobial activity on pathogenic strains isolated from the clinic or standard strains. A synergistic antimicrobial effect of the BPEs was observed along with the soluble compounds of L. rhamnosus MF9 and E. faecalis 2M17 against some pathogenic (clinical) strains and, considering the tumour proliferation inhibitory activity, makes BP a potential prebiotic and antitumour agent for the gut environment.
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In the past year, researchers have focused their attention on developing new strategies for understanding how the coronavirus affects human health and developing novel biomaterials to help patients with cardiovascular disease, which greatly increases the risk of complications from the virus. Natural biopolymers have been investigated, and it has been proven that alginate-based materials have important features. This review presents an overview of alginate-based materials used for developing innovative biomaterial platforms for biomedical applications to mitigate the effects of the coronavirus. As presented in this review, COVID-19 affects the cardiovascular system, not only the lungs. The first part of the review presents an introduction to cardiovascular diseases and describes how they have become an important problem worldwide. In the second part of the review, the origin and unique properties of the alginate biopolymer are presented. Among the properties of alginate, the most important are its biocompatibility, biodegradability, low cost, nontoxicity, unique structure, and interesting features after chemical modification. The third section of the review illustrates some of the functions of alginate in biomedical, pharmaceutical, and drug delivery applications. Researchers are using alginate to develop new devices and materials for repairing heart tissues that have been damaged by the coronavirus. Further, insights regarding how cardiovascular disease affects COVID-19 patients are also discussed. Finally, we conclude the review by presenting a summary of the impacts of COVID-19 on cardiovascular patients, their implications, and several hypothetical alginate-based treatments for infected patients.
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Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey's biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health. The review also presents some mechanisms of action and the medical applications of honey, such as wound healing dressings, skin grafts, honey-based nanofibers, and cochlear implants, as the most promising wound healing tools. This extensive review has been written to highlight honey's applications in medicine; its composition with the most important bioactive compounds also illustrates its synergistic effect with other natural products having remarkable therapeutic properties in wound healing.
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In this study, zinc oxide nanoparticles were synthesized through a simple co-precipitation method starting from zinc acetate dihydrate and sodium hydroxide as reactants. The as-obtained ZnO nanoparticles were morphologically and structurally characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photocatalytic activity, and by determining the antimicrobial activity against Gram-negative and Gram-positive bacteria. The XRD pattern of the zinc oxide nanoparticles showed the wurtzite hexagonal structure, and its purity highlighted that the crystallinity correlated with the presence of a single product, zinc oxide. The ZnO nanoparticles have an average crystallite size of 19 ± 11 nm, which is in accordance with the microscopic data. ZnO nanoparticles were tested against methyl orange, used as a model pollutant, and it was found that they exhibit strong photocatalytic activity against this dye. The antibacterial activity of ZnO nanoparticles was tested against Gram-negative and Gram-positive strains (Escherichia coli, Staphylococcus aureus, and Candida albicans). The strongest activity was found against Gram-positive bacteria (S. aureus).
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Antimicrobial resistance is one of the major public health threats at the global level, urging the search for new antimicrobial molecules. The fluorene nucleus is a component of different bioactive compounds, exhibiting diverse pharmacological actions. The present work describes the synthesis, chemical structure elucidation, and bioactivity of new O-aryl-carbamoyl-oxymino-fluorene derivatives and the contribution of iron oxide nanoparticles to enhance the desired biological activity. The antimicrobial activity assessed against three bacterial and fungal strains, in suspension and biofilm growth state, using a quantitative assay, revealed that the nature of substituents on the aryl moiety are determinant for both the spectrum and intensity of the inhibitory effect. The electron-withdrawing inductive effect of chlorine atoms enhanced the activity against planktonic and adhered Staphylococcus aureus, while the +I effect of the methyl group enhanced the anti-fungal activity against Candida albicans strain. The magnetite nanoparticles have substantially improved the antimicrobial activity of the new compounds against planktonic microorganisms. The obtained compounds, as well as the magnetic core@shell nanostructures loaded with these compounds have a promising potential for the development of novel antimicrobial strategies.
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Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Fluorenos/farmacologia , Nanopartículas Magnéticas de Óxido de Ferro/química , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Fluorenos/química , Fungos/efeitos dos fármacos , Nanopartículas Magnéticas de Óxido de Ferro/ultraestrutura , Magnetometria , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
During the past few years, researchers have focused their attention on developing innovative nanocomposite polymeric membranes with applications in water purification. Natural and synthetic polymers were considered, and it was proven that chitosan-based materials presented important features. This review presents an overview regarding diverse materials used in developing innovative chitosan-based nanocomposite polymeric membranes for water purification. The first part of the review presents a detailed introduction about chitosan, highlighting the fact that is a biocompatible, biodegradable, low-cost, nontoxic biopolymer, having unique structure and interesting properties, and also antibacterial and antioxidant activities, reasons for using it in water treatment applications. To use chitosan-based materials for developing nanocomposite polymeric membranes for wastewater purification applications must enhance their performance by using different materials. In the second part of the review, the performance's features will be presented as a consequence of adding different nanoparticles, also showing the effect that those nanoparticles could bring on other polymeric membranes. Among these features, pollutant's retention and enhancing thermo-mechanical properties will be mentioned. The focus of the third section of the review will illustrate chitosan-based nanocomposite as polymeric membranes for water purification. Over the last few years, researchers have demonstrated that adsorbent nanocomposite polymeric membranes are powerful, important, and potential instruments in separation or removal of pollutants, such as heavy metals, dyes, and other toxic compounds presented in water systems. Lastly, we conclude this review with a summary of the most important applications of chitosan-based nanocomposite polymeric membranes and their perspectives in water purification.
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New packaging materials based on biopolymers are gaining increasing attention due to many advantages like biodegradability or existence of renewable sources. Grouping more antimicrobials agents in the same packaging can create a synergic effect, resulting in either a better antimicrobial activity against a wider spectrum of spoilage agents or a lower required quantity of antimicrobials. In the present work, we obtained a biodegradable antimicrobial film that can be used as packaging material for food. Films based on chitosan as biodegradable polymer, with ZnO and Ag nanoparticles as filler/antimicrobial agents were fabricated by a casting method. The nanoparticles were loaded with citronella essential oil (CEO) in order to enhance the antimicrobial activity of the nanocomposite films. The tests made on Gram-positive, Gram-negative, and fungal strains indicated a broad-spectrum antimicrobial activity, with inhibition diameters of over 30 mm for bacterial strains and over 20 mm for fungal strains. The synergic effect was evidenced by comparing the antimicrobial results with chitosan/ZnO/CEO or chitosan/Ag/CEO simple films. According to the literature and our preliminary studies, these formulations are suitable as coating for fruits. The obtained nanocomposite films presented lower water vapor permeability values when compared with the chitosan control film. The samples were characterized by SEM, fluorescence and UV-Vis spectroscopy, FTIR spectroscopy and microscopy, and thermal analysis.
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The use of bacterial cellulose (BC) in skin wound treatment is very attractive due to its unique characteristics. These dressings' wet environment is an important feature that ensures efficient healing. In order to enhance the antimicrobial performances, bacterial-cellulose dressings were loaded with amoxicillin and bacitracin as antibacterial agents. Infrared characterization and thermal analysis confirmed bacterial-cellulose binding to the drug. Hydration capacity showed good hydrophilicity, an efficient dressing's property. The results confirmed the drugs' presence in the bacterial-cellulose dressing's structure as well as the antimicrobial efficiency against Staphylococcus aureus and Escherichia coli. The antimicrobial assessments were evaluated by contacting these dressings with the above-mentioned bacterial strains and evaluating the growth inhibition of these microorganisms.
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Amoxicilina/farmacologia , Antibacterianos/farmacologia , Bacitracina/farmacologia , Bactérias/química , Celulose/farmacologia , Celulose/ultraestrutura , Contagem de Colônia Microbiana , Escherichia coli/efeitos dos fármacos , Cinética , Testes de Sensibilidade Microbiana , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Água/químicaRESUMO
Background and objectives: Medical devices such as catheters are used on a large scale to treat heart and cardiovascular diseases. Unfortunately, they present some important drawbacks (structure failure, calcifications, infections, thrombosis, etc.), with the main side effects occurring due to adhesion and proliferation of bacteria and living cells on the surface of the implanted devices. The aim of this work is to modify the surface of polyvinyl chloride (PVC), an affordable biocompatible material, in order to reduce these aforementioned side effects. Materials and Methods: The surface of PVC was modified by depositing a thin layer also of PVC that incorporates an active substance, dicoumarol (a well-known anticoagulant), by spin coating process. The modified surfaces were analyzed by Fourier-transform infrared (FT-IR) microscopy, Fourier-transform infrared (FT-IR) spectroscopy, Ultraviolet-visible spectroscopy (UV-VIS), and Scanning electron microscopy (SEM) in order to determine the surface morphology and behavior. The samples were tested for Gram-positive (S. aureus ATCC 25923) and Gram-negative (P. aeruginosa ATCC 27853) standard strains from American Type Culture Collection (ATCC). Results: The material obtained had a smooth surface with a uniform distribution of dicoumarol, which is released depending on the deposition parameters. The concentration of dicoumarol at the surface of the material and also the release rate is important for the applications for which the surface modification was designed. PVC modified using the proposed method showed a good ability to prevent salt deposition and decreased the protein adhesion, and the resistance to bacterial adherence was improved compared with standard PVC.