Hybrid Materials Obtained by Immobilization of Biosynthesized Ag Nanoparticles with Antioxidant and Antimicrobial Activity.

Ag nanoparticles (AgNPs) were biosynthesized using sage (Salvia officinalis L.) extract. The obtained nanoparticles were supported on SBA-15 mesoporous silica (S), before and after immobilization of 10% TiO2 (Degussa-P25, STp; commercial rutile, STr; and silica synthesized from Ti butoxide, STb). The formation of AgNPs was confirmed by X-ray diffraction. The plasmon resonance effect, evidenced by UV-Vis spectra, was preserved after immobilization only for the sample supported on STb. The immobilization and dispersion properties of AgNPs on supports were evidenced by TEM microscopy, energy-dispersive X-rays, dynamic light scattering, photoluminescence and FT-IR spectroscopy. The antioxidant activity of the supported samples significantly exceeded that of the sage extract or AgNPs. Antimicrobial tests were carried out, in conditions of darkness and white light, on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Higher antimicrobial activity was evident for SAg and STbAg samples. White light increased antibacterial activity in the case of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). In the first case, antibacterial activity increased for both supported and unsupported AgNPs, while in the second one, the activity increased only for SAg and STbAg samples. The proposed antibacterial mechanism shows the effect of AgNPs and Ag+ ions on bacteria in dark and light conditions.

Bee Bread: A Promising Source of Bioactive Compounds with Antioxidant Properties-First Report on Some Antimicrobial Features.

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.

Pathogenesis, Prophylaxis, and Treatment of Candida auris.

Candida auris poses a serious threat to infection control and patient care since it can produce invasive infections that have a high fatality rate, has been linked to outbreaks in hospital environments, and is typically resistant to several antifungal medications. Since its first description in 2009, six clades have been described. The emerging fungal pathogen possesses adhesins that allow it to adhere to host tissues and medical devices, can form biofilms, produces various hydrolytic enzymes, employs several strategies to evade host immune responses, and exhibits high genetic diversity, which may contribute to its ability to adapt to different environmental conditions and evade host defenses. C. auris is very resistant to various disinfectants and may be difficult to detect.

Improving the Hydrophobicity of Plasticized Polyvinyl Chloride for Use in an Endotracheal Tube.

An endotracheal tube (ETT) is a greatly appreciated medical device at the global level with widespread application in the treatment of respiratory diseases, such as bronchitis and asthma, and in general anesthesia, to provide narcotic gases. Since an important quantitative request for cuffed ETTs was recorded during the COVID-19 pandemic, concerns about infection have risen. The plasticized polyvinyl chloride (PVC) material used to manufacture ETTs favors the attachment of microorganisms from the human biological environment and the migration of plasticizer from the polymer that feeds the microorganisms and promotes the growth of biofilms. This leads to developing infections, which means additional suffering, discomfort for patients, and increased hospital costs. In this work, we propose to modify the surfaces of some samples taken from commercial ETTs in order to develop their hydrophobic character using surface fluorination by a plasma treatment in SF6 discharge and magnetron sputtering physical evaporation from the PTFE target. Samples with surfaces thus modified were subsequently tested using XPS, ATR-FTIR, CA, SEM + EDAX, profilometry, density, Shore A hardness, TGA-DSC, and biological antimicrobial and biocompatibility properties. The obtained results demonstrate a successful increase in the hydrophobic character of the plasticized PVC samples and biocompatibility properties.

Novel Microemulsions with Essential Oils for Environmentally Friendly Cleaning of Copper Cultural Heritage Artifacts.

Cleaning represents an important and challenging operation in the conservation of cultural heritage, and at present, a key issue consists in the development of more sustainable, "green" materials and methods to perform it. In the present work, a novel xylene-in-water microemulsion based on nonionic surfactants with low toxicity was obtained, designed as low-impact cleaning agent for metallic historic objects. Phase diagram of the mixtures containing polyoxyethylene-polyoxypropilene triblock copolymer Pluronic P84 and D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) as surfactants, water, ethanol and xylene was studied, and a microemulsion with low surfactant content was selected as suitable cleaning nanosystem. Essential oils (EOs) from thyme and cinnamon leaf were added to the selected microemulsion in order to include other beneficial properties such as anticorrosive and antifungal protection. The microemulsions with or without EOs were characterized by size, size distribution and zeta potential. The cleaning efficacy of the tested microemulsions was assessed based on their ability to remove two types of artificial dirt by using X-ray energy dispersion spectrometry (EDX), scanning electron microscopy (SEM), contact angle measurements and color analysis. Microemulsions exhibit high capacity to remove artificial dirt from model copper coupons in spite of very low content of the organic solvent. Both thyme and cinnamon oil loading microemulsions prove to significantly reduce the corrosion rate of treated metallic plates compared to those of bare copper. The antifungal activity of the novel type of microemulsion was evaluated against Aspergillus niger, reported as main treat in biocorrosion of historic copper artifacts. Application of microemulsion with small amounts of EOs on Cu plates inhibits the growth of fungi, providing a good fungicidal effect.

Antimicrobial Wound Dressings based on Bacterial Cellulose and Independently Loaded with Nutmeg and Fir Needle Essential Oils.

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.

Microwave-Assisted Hydrothermal Treatment of Multifunctional Substituted Hydroxyapatite with Prospective Applications in Bone Regeneration.

Orthopedic bone graft infections are major complications in today's medicine, and the demand for antibacterial treatments is expanding because of the spread of antibiotic resistance. Various compositions of hydroxyapatite (HAp) in which Calcium (Ca2+) ions are substituted with Cerium (Ce3+) and Magnesium (Mg2+) are herein proposed as biomaterials for hard tissue implants. This approach gained popularity in recent years and, in the pursuit of mimicking the natural bone mineral's composition, over 70 elements of the Periodic Table were already reported as substituents into HAp structure. The current study aimed to create materials based on HAp, Hap-Ce, and Hap-Mg using hydrothermal maturation in the microwave field. This route has been considered a novel, promising, and effective way to obtain monodisperse, fine nanoparticles while easily controlling the synthesis parameters. The synthesized HAp powders were characterized morphologically and structurally by XRD diffraction, Dynamic light scattering, zeta potential, FTIR spectrometry, and SEM analysis. Proliferation and morphological analysis on osteoblast cell cultures were used to demonstrate the cytocompatibility of the produced biomaterials. The antimicrobial effect was highlighted in the synthesized samples, especially for hydroxyapatite substituted with cerium. Therefore, the samples of HAp substituted with cerium or magnesium are proposed as biomaterials with enhanced osseointegration, also having the capacity to reduce device-associated infections.

Resistance, Tolerance, Virulence and Bacterial Pathogen Fitness-Current State and Envisioned Solutions for the Near Future.

The current antibiotic crisis and the global phenomena of bacterial resistance, inherited and non-inherited, and tolerance-associated with biofilm formation-are prompting dire predictions of a post-antibiotic era in the near future. These predictions refer to increases in morbidity and mortality rates as a consequence of infections with multidrug-resistant or pandrug-resistant microbial strains. In this context, we aimed to highlight the current status of the antibiotic resistance phenomenon and the significance of bacterial virulence properties/fitness for human health and to review the main strategies alternative or complementary to antibiotic therapy, some of them being already clinically applied or in clinical trials, others only foreseen and in the research phase.

Role of interferons in the antiviral battle: from virus-host crosstalk to prophylactic and therapeutic potential in SARS-CoV-2 infection.

Mammalians sense antigenic messages from infectious agents that penetrate the respiratory and digestive epithelium, as well as signals from damaged host cells through membrane and cytosolic receptors. The transduction of these signals triggers a personalized response, depending on the nature of the stimulus and the host's genetics, physiological condition, and comorbidities. Interferons (IFNs) are the primary effectors of the innate immune response, and their synthesis is activated in most cells within a few hours after pathogen invasion. IFNs are primarily synthesized in infected cells, but their anti-infective effect is extended to the neighboring cells by autocrine and paracrine action. The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in 2019 was a stark reminder of the potential threat posed by newly emerging viruses. This pandemic has also triggered an overwhelming influx of research studies aiming to unveil the mechanisms of protective versus pathogenic host immune responses induced by SARS-CoV-2. The purpose of this review is to describe the role of IFNs as vital players in the battle against SARS-CoV-2 infection. We will briefly characterize and classify IFNs, present the inductors of IFN synthesis, their sensors, and signaling pathways, and then discuss the role of IFNs in controlling the evolution of SARS-CoV-2 infection and its clinical outcome. Finally, we will present the perspectives and controversies regarding the prophylactic and therapeutic potential of IFNs in SARS-CoV-2 infection.

Synthesis, Characterization, DFT Study and Antifungal Activities of Some Novel 2-(Phenyldiazenyl)phenol Based Azo Dyes.

In recent decades, there has been an increased interest in azo compounds with special optical and biological properties. In this work, we report the preparation of novel azo-compounds with two and three -N=N- double bonds, using the classical method of synthesis, diazotization and coupling. The compounds were characterized by 1H-NMR, 13C-NMR, FTIR, UV-VIS and fluorescence spectra. DFT calculations were employed for determining the optical parameters, polarizability α, the total static dipole moment µtot, the quadrupole moment Q and the mean first polarizability ßtot. All azo derivatives show strong fluorescence emission in solutions. The antioxidant and antifungal activities were determined and the influence of the number of azo bonds was discussed. The synthesized compounds exhibit remarkable efficiency in the growth reduction of standard and clinical isolated Candida strains, suggesting future applications as novel antifungal.

Essential Oils as Antimicrobial Active Substances in Wound Dressings.

Wound dressings for skin lesions, such as bedsores or pressure ulcers, are widely used for many patients, both during hospitalization and in subsequent treatment at home. To improve the treatment and shorten the healing time and, therefore, the cost, numerous types of wound dressings have been developed by manufacturers. Considering certain inconveniences related to the intolerance of some patients to antibiotics and the antimicrobial, antioxidant, and curative properties of certain essential oils, we conducted research by incorporating these oils, based on polyvinyl alcohol/ polyvinyl pyrrolidone (PVA/PVP) biopolymers, into dressings. The objective of this study was to study the potential of a polymeric matrix for wound healing, with polyvinyl alcohol as the main material and polyvinyl pyrrolidone and hydroxypropyl methylcellulose (HPMC) as secondary materials, together with additives (plasticizers poly(ethylene glycol) (PEG) and glycerol), stabilizers (Zn stearate), antioxidants (vitamin A and vitamin E), and four types of essential oils (fennel, peppermint, pine, and thyme essential oils). For all the studied samples, the combining compatibility, antimicrobial, and cytotoxicity properties were investigated. The obtained results demonstrated a uniform morphology for almost all the samples and adequate barrier properties for contact with suppurating wounds. The results show that the obtained samples containing essential oils have a good inhibitory effect on, or antimicrobial properties against, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The MTT assay showed that the tested samples were not toxic and did not lead to cell death. The results showed that the essential oils used provide an effective solution as active substances in wound dressings.

Influence of the Hydrophobicity of Pluronic Micelles Encapsulating Curcumin on the Membrane Permeability and Enhancement of Photoinduced Antibacterial Activity.

Apart from its well-known activity as an antimicrobial agent, Curcumin (CURC) has recently started to arouse interest as a photosensitizer in the photodynamic therapy of bacterial infections. The aim of the present study was to evidence the influence of the encapsulation of Curcumin into polymeric micelles on the efficiency of photoinduced microbial inhibition. The influence of the hydrophobicity of the selected Pluronics (P84, P123, and F127) on the encapsulation, stability, and antimicrobial efficiency of CURC-loaded micelles was investigated. In addition, the size, morphology, and drug-loading capacity of the micellar drug delivery systems have been characterized. The influence of the presence of micellar aggregates and unassociated molecules of various Pluronics on the membrane permeability was investigated on both normal and resistant microbial strains of E. coli, S. aureus, and C. albicans. The antimicrobial efficiency on the common pathogens was assessed for CURC-loaded polymeric micelles in dark conditions and activated by blue laser light (470 nm). Significant results in the reduction of the microorganism's growth were found in cultures of C. albicans, even at very low concentrations of surfactants and Curcumin. Unlike the membrane permeabilization effect of the monomeric solution of Pluronics, reported in the case of tumoral cells, a limited permeabilization effect was found on the studied microorganisms. Encapsulation of the Curcumin in Pluronic P84 and P123 at very low, nontoxic concentrations for photosensitizer and drug-carrier, produced CURC-loaded micelles that prove to be effective in the light-activated inhibition of resistant species of Gram-positive bacteria and fungi.

Antimicrobial Efficiency of Some Essential Oils in Antibiotic-Resistant Pseudomonas aeruginosa Isolates.

Pseudomonas aeruginosa is a non-fermentative Gram-negative opportunistic pathogen, frequently encountered in difficult-to-treat hospital-acquired infections and also wastewaters. The natural resistance of this pathogen, together with the frequent occurrence of multidrug-resistant strains, make current antibiotic therapy inefficient in treating P. aeruginosa infections. Antibiotic therapy creates a huge pressure to select resistant strains in clinical settings but also in the environment, since high amounts of antibiotics are released in waters and soil. Essential oils (EOs) and plant-derived compounds are efficient, ecologic, and sustainable alternatives in the management of various diseases, including infections. In this study, we evaluated the antibacterial effects of four commercial essential oils, namely, tea tree, thyme, sage, and eucalyptus, on 36 P. aeruginosa strains isolated from hospital infections and wastewaters. Bacterial strains were characterized in terms of virulence and antimicrobial resistance. The results show that most strains expressed soluble pore toxin virulence factors such as lecithinase (89-100%) and lipase (72-86%). All P. aeruginosa strains were positive for alginate encoding gene and 94.44% for protease IV; most of the strains were exotoxin producers (i.e., 80.56% for the ExoS gene, 77.78% for the ExoT gene, while the ExoU gene was present in 38.98% of the strains). Phospholipase-encoding genes (plc) were identified in 91.67/86.11% of the cases (plcH/plcN genes). A high antibiotic resistance level was identified, most of the strains being resistant to cabapenems and cephalosporins. Cabapenem resistance was higher in hospital and hospital wastewater strains (55.56-100%) as compared to those in urban wastewater. The most frequently encountered encoding genes were for extended spectrum ß-lactamases (ESBLs), namely, blaCTX-M (83.33% of the strains), blaSHV (80.56%), blaGES (52.78%), and blaVEB (13.89%), followed by carbapenemase-encoding genes (blaVIM, 8.33%). Statistical comparison of the EOs' antimicrobial results showed that thyme gave the lowest minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentrations (MBEC) in P. aeruginosa-resistant isolates, making this EO a competitive candidate for the development of efficient and ecologic antimicrobial alternatives.

Modulation of Gut Microbiota by Essential Oils and Inorganic Nanoparticles: Impact in Nutrition and Health.

Microbiota plays a crucial role in human health and disease; therefore, the modulation of this complex and yet widely unexplored ecosystem is a biomedical priority. Numerous antibacterial alternatives have been developed in recent years, imposed by the huge problem of antibioresistance, but also by the people demand for natural therapeutical products without side effects, as dysbiosis, cyto/hepatotoxicity. Current studies are focusing mainly in the development of nanoparticles (NPs) functionalized with herbal and fruit essential oils (EOs) to fight resistant pathogens. This is due to their increased efficiency against susceptible, multidrug resistant and biofilm embedded microorganisms. They are also studied because of their versatile properties, size and possibility to ensure a targeted administration and a controlled release of bioactive substances. Accordingly, an increasing number of studies addressing the effects of functional nanoparticles and plant products on microbial pathogens has been observed. Regardless the beneficial role of EOs and NPs in the treatment of infectious diseases, concerns regarding their potential activity against human microbiota raised constantly in recent years. The main focus of current research is on gut microbiota (GM) due to well documented metabolic and immunological functions of gut microbes. Moreover, GM is constantly exposed to micro- and nano-particles, but also plant products (including EOs). Because of the great diversity of both microbiota and chemical antimicrobial alternatives (i.e., nanomaterials and EOs), here we limit our discussion on the interactions of gut microbiota, inorganic NPs and EOs. Impact of accidental exposure caused by ingestion of day care products, foods, atmospheric particles and drugs containing nanoparticles and/or fruit EOs on gut dysbiosis and associated diseases is also dissected in this paper. Current models developed to investigate mechanisms of dysbiosis after exposure to NPs/EOs and perspectives for identifying factors driving EOs functionalized NPs dysbiosis are reviewed.

Antimicrobial Properties of TiO2 Microparticles Coated with Ca- and Cu-Based Composite Layers.

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.

Bee Pollen Extracts: Chemical Composition, Antioxidant Properties, and Effect on the Growth of Selected Probiotic and Pathogenic Bacteria.

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.

Additives Imparting Antimicrobial Properties to Acrylic Bone Cements.

PMMA bone cements are mainly used to fix implanted prostheses and are introduced as a fluid mixture, which hardens over time. The problem of infected prosthesis could be solved due to the development of some new antibacterial bone cements. In this paper, we show the results obtained to develop four different modified PMMA bone cements by using antimicrobial additives, such as gentamicin, peppermint oil incorporated in hydroxyapatite, and silver nanoparticles incorporated in a ceramic glass matrix (2 and 4%). The structure and morphology of the modified bone cements were investigated by SEM and EDS. We perform experimental measurements on wettability, hydration degree, and degradation degree after immersion in simulated body fluid. The cytotoxicity was evaluated by MTT assay using the human MG-63 cell line. Antimicrobial properties were checked against standard strains Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The addition of antimicrobial agents did not significantly affect the hydration and degradation degree. In terms of biocompatibility assessed by the MTT test, all experimental PMMA bone cements are biocompatible. The performance of bone cements with peppermint essential oil and silver nanoparticles against these two pathogens suggests that these antibacterial additives look promising to be used in clinical practice against bacterial infection.

Facile In Situ Synthesis of ZnO Flower-like Hierarchical Nanostructures by the Microwave Irradiation Method for Multifunctional Textile Coatings.

ZnO nanoparticle-based multifunctional coatings were prepared by a simple, time-saving microwave method. Arginine and ammonia were used as precipitation agents, and zinc acetate dehydrate was used as a zinc precursor. Under the optimized conditions, flower-like morphologies of ZnO aggregates were obtained. The prepared nanopowders were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and UV/Visible spectroscopy. The developed in situ synthesis with microwave irradiation enabled significant ZnO nanoparticle deposition on cotton fabrics, without additional steps. The functionalized textiles were tested as a photocatalyst in methylene blue (MB) photodegradation and showed good self-cleaning and UV-blocking properties. The coated cotton fabrics exhibited good antibacterial properties against common microbial trains (Staphylococcus aureus, Escherichia coli, and Candida albicans), together with self-cleaning and photocatalytic efficiency in organic dye degradation. The proposed microwave-assisted in situ synthesis of ZnO nanocoatings on textiles shows high potential as a rapid, efficient, environmentally friendly, and scalable method to fabricate functional fabrics.

Preliminary Study on Light-Activated Antimicrobial Agents as Photocatalytic Method for Protection of Surfaces with Increased Risk of Infections.

Preventing and controlling the spread of multidrug-resistant (MDR) bacteria implicated in healthcare-associated infections is the greatest challenge of the health systems. In recent decades, research has shown the need for passive antibacterial protection of surfaces in order to reduce the microbial load and microbial biofilm development, frequently associated with transmission of infections. The aim of the present study is to analyze the efficiency of photocatalytic antimicrobial protection methods of surfaces using the new photocatalytic paint activated by light in the visible spectrum. The new composition is characterized by a wide range of analytical methods, such as UV-VIS spectroscopy, electron microscopy (SEM), X-ray powder diffraction (PXRD) or X-ray photoelectron spectroscopy (XPS). The photocatalytic activity in the UV-A was compared with the one in the visible light spectrum using an internal method developed on the basis of DIN 52980: 2008-10 standard and ISO 10678-2010 standard. Migration of metal ions in the composition was tested based on SR EN1186-3: 2003 standard. The new photocatalytic antimicrobial method uses a type of photocatalytic paint that is active in the visible spectral range and generates reactive oxygen species with inhibitory effect against all tested microbial strains.

Mixed Pluronic-Cremophor Polymeric Micelles as Nanocarriers for Poorly Soluble Antibiotics-The Influence on the Antibacterial Activity.

In this work, novel polymeric mixed micelles from Pluronic F127 and Cremophor EL were investigated as drug delivery systems for Norfloxacin as model antibiotic drug. The optimal molar ratio of surfactants was determined, in order to decrease critical micellar concentration (CMC) and prepare carriers with minimal surfactant concentrations. The particle size, zeta potential, and encapsulation efficiency were determined for both pure and mixed micelles with selected composition. In vitro release kinetics of Norfloxacin from micelles show that the composition of surfactant mixture generates tunable extended release. The mixed micelles exhibit good biocompatibility against normal fibroblasts MRC-5 cells, while some cytotoxicity was found in all micellar systems at high concentrations. The influence of the surfactant components in the carrier on the antibacterial properties of Norfloxacin was investigated. The drug loaded mixed micellar formulation exhibit good activity against clinical isolated strains, compared with the CLSI recommended standard strains (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922). P. aeruginosa 5399 clinical strain shows low sensitivity to Norfloxacin in all tested micelle systems. The results suggest that Cremophor EL-Pluronic F127 mixed micelles can be considered as novel controlled release delivery systems for hydrophobic antimicrobial drugs.