Vrozený chylothorax je závažné a obtížně léčitelné onemocnění s vysokou mortalitou. Použitím chemické pleurodézy lze omezit nutnost chirurgické léčby, avšak dosud není kvůli nedostatku důkazů jednoznačná shoda nad optimální chemickou látkou. Ve dvou kazuistikách popisujeme vlastní zkušenost s chemickou pleurodézou jodovaným povidonem u novorozenců s vrozeným chylothoraxem. Pacientům jsme podali 2 ml/kg roztoku 4% jodovaného povidonu intrapleurálně cestou hrudního drénu, který byl po podání na 4 hodiny zasvorkován. V obou případech bylo nutné opakované podání k úplnému potlačení tvorby chylu. Podle našich zkušeností použití chemické pleurodézy jodovaným povidonem rychle, účinně a bez nežádoucích účinků zabrání další tvorbě pleurálního výpotku. Od prvního použití této metody v roce 2003 bylo publikováno 20 případů aplikace novorozencům v léčbě kongenitálního chylothoraxu. Jejich přehled a zhodnocení jsou součástí sdělení. Celková úspěšnost i procento přežití dosahují 80 %.
Congenital chylothorax is a serious neonatal condition with high mortality and difficult management. Chemical pleurodesis can limit the need for surgical treatment, but there is no consensus on the optimal chemical agent for the lack of solid evidence. We report our experience with povidone-iodine (PVI) chemical pleurodesis in two neonates with congenital chylothorax. Pleurodesis consisted in the injection of 2 ml/kg of a 4% povidone iodine solution inside the pleural space, leaving the pleural tube clamped for the subsequent 4 hours. In both cases, repeated doses of povidone-iodine were required to completely stop chyle formation. Based on our experience, chemical pleurodesis with povidone-iodine promptly and definitely stopped pleural effusion, with no side effect observed. Since its first use in 2003, we provide analysis of all published neonatal case reports concerning PVI chemical pleurodesis in congenital chylothorax (n = 20), with both success and survival rate at 80 %.
- MeSH
- chylotorax * terapie MeSH
- jodovaný povidon terapeutické užití MeSH
- lidé MeSH
- novorozenec MeSH
- pleurodéza metody MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
There is a growing interest in using deep eutectic solvents (DES) as a pharmaceutical delivery system for poorly water-soluble compounds. To reduce the risk of drug precipitation following oral administration, this study addresses the hypothesis that directly including a polymeric precipitation inhibitor (PI) in a DES mixture could obtain a polymer-embedded deep eutectic system (PEDES) as a novel bio-enabling formulation principle. Following broad formulation screening, a PEDES embedding 15% w/w of polyvinyl pyrrolidone K30 (PVP) in L-carnitine:ethylene glycol (1:4, molar ratio) DES was successfully formulated as a supersaturating formulation using indomethacin as model compound. The drug solubility of 175.6 mg/mL obtained in DES was remarkably high, and upon release (phosphate buffer, pH 6.5) a maximum supersaturation factor of 9.8 was recorded, whereby the release kinetics displayed a suitable "parachute effect". The formulation was further characterized to include a molecular dynamics simulation. It can be concluded that PEDES appears to be a viable novel formulation approach, setting solid grounds for further research to assess the full potential of this novel type of supersaturating drug delivery system.
- MeSH
- chylotorax * farmakoterapie vrozené MeSH
- hrudník MeSH
- jodovaný povidon * terapeutické užití MeSH
- lidé MeSH
- pleurodéza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- dopisy MeSH
- komentáře MeSH
Silver nanoparticles are versatile platforms with a variety of applications in the biomedical field. In this framework, their presence in biological media inevitably leads to the interaction with proteins thus conducting to the formation of biomolecular coronas. This feature alters the identity of the nanomaterial and may affect many biological events. These considerations motivated the investigation of protein adsorption onto the surface of polymer-stabilized AgNPs. The metallic colloids were coated by polyethyleneimine (PEI), polyvinylpyrrolidone (PVP), and poly(2-vinyl pyridine)-b-poly(ethylene oxide) (PEO-b-P2VP), and nanoparticle-protein interaction was probed by using a library of analytical techniques. The experimental data revealed a higher extent of protein adsorption at the surface of AgNPs@PVP whereas PEO-b-P2VP coating conducted to the least amount. The main component of the protein coronas was evidenced to be bovine serum albumin (BSA), which is indeed the protein at the highest abundancy in the model biological media. We have further demonstrated reduced cytotoxicity of the silver colloids coated by biomolecular coronas as compared to the pristine counterparts. Nevertheless, the protein coatings did not notably reduce the antimicrobial performance of the polymer-stabilized AgNPs. Accordingly, although the protein-repelling property is frequently targeted towards longer in vivo circulation of nanoparticles, we herein underline that protein coatings, which are commonly treated as artifacts to be avoided, may indeed enhance the biological performance of nanomaterials. These findings are expected to be highly relevant in the design of polymer-stabilized metallic colloids intended to be used in healthcare.
- MeSH
- antibakteriální látky farmakologie MeSH
- ethylenoxid MeSH
- koloidy MeSH
- kovové nanočástice * MeSH
- polyethylenimin farmakologie MeSH
- polymery farmakologie MeSH
- povidon farmakologie MeSH
- proteinová korona * metabolismus MeSH
- pyridiny MeSH
- sérový albumin hovězí MeSH
- stříbro farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to investigate the molecular structures of tadalafil solid dispersions prepared by different techniques and further to relate them to surface free energy information indicating the final amorphousness of the product. Thus, we tried to complement the existing knowledge of solid dispersion formation. Poorly water-soluble tadalafil was combined with different polymers, i.e. Kollidon® 12 PF, Kollidon® VA 64 and Soluplus®, to form model systems. To assess the extent of drug-polymer miscibility, we studied model solid dispersion surface energy using inverse gas chromatography and phase micro-structure using confocal Raman microscopy. The selection of the preparation method was found to play a crucial role in the molecular arrangement of the incorporated drug and the polymer in resulting solid dispersion. Our results showed that a lower surface free energy indicated the formation of a more homogeneous solid dispersion. Conversely, a higher surface free energy corresponded to the heterogeneous systems containing tadalafil amorphous clusters that were captured by Raman mapping. Thus, we successfully introduced a novel evaluation approach of the drug molecular arrangement in solid dispersions that is especially useful for examining the miscibility of the components when the conventional characterizing techniques are inconclusive or yield variable results.
- MeSH
- chromatografie plynová MeSH
- polymery * chemie MeSH
- povidon * chemie MeSH
- rozpustnost MeSH
- tadalafil chemie MeSH
- Publikační typ
- časopisecké články MeSH
We report that the immunogenicity of colloidal gold nanoparticles coated with polyvinylpyrrolidone (PVP-AuNPs) in a model organism, the sea urchin Paracentrotus lividus, can function as a proxy for humans for in vitro immunological studies. To profile the immune recognition and interaction from exposure to PVP-AuNPs (1 and 10 μg mL-1), we applied an extensive nano-scale approach, including particle physicochemical characterisation involving immunology, cellular biology, and metabolomics. The interaction between PVP-AuNPs and soluble proteins of the sea urchin physiological coelomic fluid (blood equivalent) results in the formation of a protein "corona" surrounding the NPs from three major proteins that influence the hydrodynamic size and colloidal stability of the particle. At the lower concentration of PVP-AuNPs, the P. lividus phagocytes show a broad metabolic plasticity based on the biosynthesis of metabolites mediating inflammation and phagocytosis. At the higher concentration of PVP-AuNPs, phagocytes activate an immunological response involving Toll-like receptor 4 (TLR4) signalling pathway at 24 hours of exposure. These results emphasise that exposure to PVP-AuNPs drives inflammatory signalling by the phagocytes and the resolution at both the low and high concentrations of the PVP-AuNPs and provides more details regarding the immunogenicity of these NPs.
Co-milling of a drug with a co-former is an efficient technique to improve the solubility of drugs. Besides the particle size reduction, the co-milling process induces a structural disorder and the creation of amorphous regions. The extent of drug solubility enhancement is dependent on the proper choice of co-milling co-former. The aim of this work was to compare the effects of different co-formers (meglumine and polyvinylpyrrolidone) on the dissolution rates of glass forming (indomethacin) and non-glass forming (mefenamic acid) model drugs. A positive impact of the co-milling on the dissolution behavior was observed in all co-milled mixtures, even if no substantial amorphization was observed. While meglumine exhibited pronounced effects on the dissolution rate of both drugs, the slightest enhancement was observed in mixtures with polyvinylpyrrolidone. The evaluation of specific release rate revealed the surface activation of drug particle is responsible for improving the dissolution rate of both drug types, but for the glass former, this surface activation could be persistent while maintaining a high dissolution rate even until a high fraction of drug is released. Our results, therefore, indicate that adequate co-former choice and consideration of drug glass forming ability are important for a successful co-milling approach to poorly water-soluble drugs.
- MeSH
- indomethacin MeSH
- léčivé přípravky * MeSH
- povidon * MeSH
- příprava léků MeSH
- rozpustnost MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
The use of noble metal nanoparticles in biomedical and biotechnological applications is nowadays well established. Particularly, silver nanoparticles (AgNPs) were proven to be effective for instance as a biocide agent. They also find applications in tumor therapies and sensing applications being encouraging tools for in-vivo imaging. In this framework, whenever they are in contact with living systems, they are rapidly coated by a protein corona thereby influencing a variety of biological events including cellular uptake, blood circulation lifetime, cytotoxicity and, ultimately, the therapeutic effect. Taking these considerations into account, we have explored the behavior of polymer-coated AgNPs in model protein environments focusing on the self-development of protein coronas. The polymers polyethyleneimine (PEI), polyvinylpyrrolidone (PVP) and poly(2-vinyl pyridine)-b-poly(ethylene oxide) (PEO-b-P2VP) were used as stabilizing agents. The chemical nature of the polymer capping remarkably influences the behavior of the hybrid nanomaterials in protein environments. The PEO-b-P2VP and PVP-stabilized AgNPs are essentially inert to the model proteins adsorption. On the other hand, the PEI-stabilized AgNPs interact strongly with bovine serum albumin (BSA). Nevertheless, the same silver colloids were evidenced to be stable in IgG and lysozyme environments. The BSA adsorption into the PEI-stabilized AgNPs is most probably driven by hydrogen bonding and van der Waals interactions as suggested by isothermal titration calorimetry data. The development of protein coronas around the AgNPs may have relevant implications in a variety of biological events. Therefore, further investigations are currently underway to evaluate the influence of its presence on the cytotoxicity, hemolytic effects and biocide properties of the produced hybrid nanomaterials.
- MeSH
- adsorpce MeSH
- dynamický rozptyl světla MeSH
- fluorescenční spektrometrie MeSH
- kalorimetrie MeSH
- koloidy chemie MeSH
- kur domácí MeSH
- nanočástice ultrastruktura MeSH
- polyethylenimin chemie MeSH
- polymery chemie MeSH
- povidon chemie MeSH
- proteinová korona chemie MeSH
- sérový albumin hovězí chemie MeSH
- skot MeSH
- spektrofotometrie ultrafialová MeSH
- stříbro chemie MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tungsten oxide-based bulk and nanocrystalline materials are widely used as photocatalytic and photo- and electrochromic materials, as well as materials for biomedical applications. In our work, we focused our attention on the effect of sodium cations on the structure and photochromic properties of the WO3@PVP aqueous sols. To establish the effect, the sols were synthesized by either simple pH adjusting of sodium or ammonium tungstates' solutions, or using an ion exchange technique to remove the cations from the materials to the greatest possible extent. We showed that the presence of sodium cations in WO3@PVP favors the formation of reduced tungsten species (W+5) upon UV irradiation of the materials, strongly affecting their photochromic and photocatalytic properties. The pronounced photoreductive properties of WO3@PVP sols in photocatalytic reactions were demonstrated. Due to photoreductive properties, photochromic sols of tungsten oxide can act as effective photoprotectors in photooxidation processes. We believe that our work provides a considerable contribution to the elucidation of photochromic and redox phenomena in WO3-based materials.
- MeSH
- difrakce rentgenového záření MeSH
- fotochemické procesy MeSH
- katalýza MeSH
- kationty MeSH
- koncentrace vodíkových iontů MeSH
- maloúhlový rozptyl MeSH
- molekulární struktura MeSH
- nanočástice chemie MeSH
- oxidy chemie MeSH
- povidon chemie MeSH
- sodík chemie MeSH
- ultrafialové záření MeSH
- velikost částic MeSH
- wolfram chemie MeSH
- Publikační typ
- časopisecké články MeSH
