Jedním z problémů při kloubních náhradách jsou komplikace spojené s pooperačními infekcemi. Infekce způsobené bakteri-emi, které tvoří biofilmy na površích, se nazývají infekce související s biofilmem (biofilm related infections, BRI). V důsledku následné biologické odezvy organismu dochází k silným patofyziologickým změnám vmikroklimatu kolem takto postiženého povrchu (pokles pH, tvorba různých reaktivních forem kyslíku (ROS), vyčerpání iontů železa a zvýšení koncentrace vápenatých iontů). Vytvořili jsme robustní selektivní polymerní potenciometrický senzor ROS a pH senzor pro detekci změn způsobených sterilním zánětem a bakteriálními a plísňovými infekcemi. Senzor ROS se skládá z vodivé polymerní vrstvy na bázi polythiofenu se zabudovaným komplexem porfyrin-kov, který potenciometricky deteguje přítomnost ROS, jak bylo demonstrováno na peroxi-du vodíku. Tento senzor je kovalentně potažen vrstvou odolnou biopasivaci (non-biofouling layer, NBL) tvořenou poly(2-methyl--2-oxazolin)em, která funguje jako biokompatibilizátor.Bylo prokázáno, že potenciometrický senzor vykazuje rychlou odezvu naperoxid vodíku, nezaznamenává interferenci s hovězím sérovým albuminem jako modelovým sérovým proteinem a je schopenplně reverzibilně detegovat ROS s lineární odezvou v širokém rozsahu biologicky relevantních koncentrací (od 0,05μM do10μM). Polymerní pH senzor na bázi polyanilinu a poly(2-methyl-2-oxazolinu) na nosiči z titanové slitiny byl vyvinut pro po-tenciometrickou detekci změn pHv okolí implantátu, aby bylo možné včas detegovat výše uvedené záněty. Vyvinuté elektrody měří změnu pH v rozsahu pH5 až 8, tedy vrozmezí relevantním pro jednotlivé infekce baktériemi a kvasinkami.
One of the problems occurring after the joint replace-ment is connected with the post-surgery infections which are caused by bacteria that form biofilms on surfaces and are referred to as biofilm-related infections (BRI). It is also worth noting that due to the bioresponse, strong path-ophysiologicalchangesinthemicroclimateofanaffectedsurface occur (decrease in pH, formation of various reac-tive oxygen species (ROS), depletion of Fe ions, and in-crease in the concentration of Ca ions). In this work we have prepared a robust selective potentiometric sensorof ROS and pH sensor for the detection of pH changes caused by sterile inflammation and bacterial and fungal infections. The ROS sensor consists of a conductive poly-mer layer based on polythiophene with an incorporated porphyrin-metal complex that potentiometrically detects the presence of ROS (H2O2and ClO–ions). This sensor is connected by the covalent bonds with a non-biofouling layer of poly(2-methyl-2-oxazoline), which works as abio-compa-tibilizer. It was shown that the potentiometric sen-sor shows a rapid response to hydrogen peroxide, does not record any interference with bovine serum albumin as amodel serum protein, and is able to fully reversibly de-tect ROS with a linear response within a wide range of biological relevant concentrations (from 0.05 μM to 10μM). The sensing electrode based on polyaniline and poly(2-methyl-2-oxazoline) on a titanium alloy support was developed for the potentiometric detection of peri-implant pH changes to enable early detection of the afore-mentioned pathologies. The developed electrodes show the changing of pH in the range between 5 and 8 for the individual pathogenic bacteria or pathogenic yeast, with aNernstian slope of −59.6/pH.
- Keywords
- potenciometrický senzor,
- MeSH
- Biofilms MeSH
- Joints surgery microbiology MeSH
- Hydrogen-Ion Concentration MeSH
- Humans MeSH
- Potentiometry * methods instrumentation MeSH
- Joint Prosthesis microbiology MeSH
- Reactive Oxygen Species analysis MeSH
- Research MeSH
- Inflammation diagnosis etiology prevention & control MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Several studies have reported on application of cellulose particles for stabilizing Pickering emulsions (PE). Here we employ an original approach that involves using these particles as a part of advanced composite colloids made of conducting polymer polyaniline (PANI) and cellulose nanocrystals (CNC) or nanofibrils (CNF). PANI/cellulose particles were prepared using oxidative polymerization of aniline in situ in the presence of CNC or CNF. The type and amount of celluloses (CNC vs CNF) and concentration of precursors (aniline monomer and oxidant) used in the reaction determined properties of the colloidal particles, such as size, morphology and content of PANI. The particles demonstrated intriguing biological characteristics, including no cytotoxicity, antibacterial activity against Staphylococcus aureus and Escherichia coli, antioxidant activity and related immunomodulatory activity. For the first time, such composites were used to successfully stabilize oil-in-water PE with undecane or capric/caprylic triglyceride oils. The properties of the emulsions were determined by the PANI/cellulose particles and oil used. The key finding of the study is the demonstrated ability of PANI/cellulose particles to stabilize PE, as well as the excellent antioxidant activity and ROS scavenging action originating from PANI presence, indicating potential of such systems for use in biomedicine, particularly for wound healing.
Bio-inspired conductive scaffolds composed of sodium hyaluronate containing a colloidal dispersion of water-miscible polyaniline or polypyrrole particles (concentrations of 0.108, 0.054 and 0.036% w/w) were manufactured. For this purpose, either crosslinking with N-(3-dimethylaminopropyl-N-ethylcarbodiimide hydrochloride and N-hydroxysuccinimid or a freeze-thawing process in the presence of poly(vinylalcohol) was used. The scaffolds comprised interconnected pores with prevailing porosity values of ~ 30% and pore sizes enabling the accommodation of cells. A swelling capacity of 92-97% without any sign of disintegration was typical for all samples. The elasticity modulus depended on the composition of the scaffolds, with the highest value of ~ 50 kPa obtained for the sample containing the highest content of polypyrrole particles. The scaffolds did not possess cytotoxicity and allowed cell adhesion and growth on the surface. Using the in vivo-mimicking conditions in a bioreactor, cells were also able to grow into the structure of the scaffolds. The technique of scaffold preparation used here thus overcomes the limitations of conductive polymers (e.g. poor solubility in an aqueous environment, and limited miscibility with other hydrophilic polymer matrices) and moreover leads to the preparation of cytocompatible scaffolds with potentially cell-instructive properties, which may be of advantage in the healing of damaged electro-sensitive tissues.
Fabrication of adsorbents with excellent adsorption capacity, outstanding stability, easy separation ability, excellent recyclability and widely generality for organic dyes removal from wastewater remains challenging. Herein, three-dimensional polyaniline/poly(vinyl alcohol)/montmorillonite (PANI/PVAL/MMT) hybrid aerogels with easy separation performance and highly effective reusable adsorption on both anionic and cationic dyes were fabricated by a simple in-situ polymerization method. As-prepared hybrid aerogels were characterized via infrared and Raman spectra, scanning electron microscopy, energy dispersive spectra mapping, small and wide-angle X-ray scattering, thermogravimetric analysis, mercury intrusion porosimetry and elemental analysis. The results showed that MMT particles were successfully incorporated into aerogel matrix. Well-defined hierarchical structure, where PANI nanofibers are coated on the skeleton wall, can be observed for PANI/PVAL/MMT when the incorporation amount of MMT was around 11.1 wt%. The adsorption performance of as-prepared hybrid aerogels on both anionic and cationic dyes was systemically carried out at different solution pH, adsorbent dosage and initial dye concentration. The data analysis showed that the adsorption process for PVAL/PANI/MMT aerogel for Reactive Black 5, methyl orange and safranin followed Freundlich isotherm and the maximum experimental adsorption capacities were found to be 199, 251 and 57.0 mg g-1 at 25 °C, respectively. Mechanism studies indicated that the electrostatic interaction is the main driving force for the adsorption of dyes. The results demonstrated that the fabricated hybrid aerogel is an efficient adsorbent for the removal of both anionic and cationic organic dyes.
- Publication type
- Journal Article MeSH
Novel composite films combining biocompatible polysaccharides with conducting polyaniline (PANI) were prepared via the in-situ polymerization of aniline hydrochloride in the presence of sodium hyaluronate (SH) or chitosan (CH). The composite films possess very good cytocompatibility in terms of adhesion and proliferation of two lines of human induced pluripotent stem cells (hiPSC). Moreover, the cardiomyogenesis and even formation of beating clusters were successfully induced on the films. The proportion of formed cardiomyocytes demonstrated excellent properties of composites for tissue engineering of stimuli-responsive tissues. The testing also demonstrated antibacterial activity of the films against E. coli and PANI-SH was able to reduce bacterial growth from 2 × 105 to < 1 cfu cm-2. Physicochemical characterization revealed that the presence of polysaccharides did not notably influence conductivities of the composites being ∼1 and ∼2 S cm-1 for PANI-SH and PANI-CH respectively; however, in comparison with neat PANI, it modified their topography making the films smoother with mean surface roughness of 4 (PANI-SH) and 14 nm (PANI-CH). The combination of conductivity, antibacterial activity and mainly cytocompatibility with hiPSC opens wide application potential of these polysaccharide-based composites.
- MeSH
- Aniline Compounds chemistry MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Biocompatible Materials chemistry pharmacology MeSH
- Cell Adhesion drug effects MeSH
- Cell Line MeSH
- Chitosan chemistry MeSH
- Electric Conductivity MeSH
- Escherichia coli drug effects MeSH
- Induced Pluripotent Stem Cells drug effects metabolism MeSH
- Hyaluronic Acid chemistry MeSH
- Humans MeSH
- Nanocomposites chemistry MeSH
- Polymerization MeSH
- Surface Properties MeSH
- Cell Proliferation drug effects MeSH
- Staphylococcus aureus drug effects MeSH
- Tissue Engineering methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Conducting polymers (CP) can be used as pH- and/or electro-responsive components in various bioapplications, for example, in 4D smart scaffolds. The ability of CP to maintain conductivity under physiological conditions is, therefore, their crucial property. Unfortunately, the conductivity of the CP rapidly decreases in physiological environment, as their conducting salts convert to non-conducting bases. One of the promising solutions how to cope with this shortcoming is the use of alternative "doping" process that is not based on the protonation of CP with acids but on interactions relying in acidic hydrogen bonding. Therefore, the phosphonates (dimethyl phosphonate, diethyl phosphonate, dibutyl phosphonate, or diphenyl phosphonate) were used to re-dope two most common representatives of CP, polyaniline (PANI) and polypyrrole (PPy) bases. As a result, PANI doped with organic phosphonates proved to have significantly better stability of conductivity under different pH. It has also been shown that cytotoxicity of studied materials determined on embryonic stem cells and their embryotoxicity, determined as the impact on cardiomyogenesis and erythropoiesis, depend both on the polymer and phosphonate types used. With the exception of PANI doped with dibutyl phosphonate, all PPy-based phosphonates showed better biocompatibility than the phosphonates based on PANI.
- MeSH
- Aniline Compounds chemistry pharmacology MeSH
- Biocompatible Materials chemistry pharmacology MeSH
- Cell Differentiation drug effects MeSH
- Cell Line MeSH
- Electric Conductivity MeSH
- Hydrogen-Ion Concentration MeSH
- Mouse Embryonic Stem Cells MeSH
- Mice MeSH
- Organophosphonates chemistry MeSH
- Polymers chemistry pharmacology MeSH
- Pyrroles chemistry pharmacology MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Conducting polymers (CP), namely polyaniline (PANI) and polypyrrole (PPy), are promising materials applicable for the use as biointerfaces as they intrinsically combine electronic and ionic conductivity. Although a number of works have employed PANI or PPy in the preparation of copolymers, composites, and blends with other polymers, there is no systematic study dealing with the comparison of their fundamental biological properties. The present study, therefore, compares the biocompatibility of PANI and PPy in terms of cytotoxicity (using NIH/3T3 fibroblasts and embryonic stem cells) and embryotoxicity (their impact on erythropoiesis and cardiomyogenesis within embryonic bodies). The novelty of the study lies not only in the fact that embryotoxicity is presented for the first time for both studied polymers, but also in the elimination of inter-laboratory variations within the testing, such variation making the comparison of previously published works difficult. The results clearly show that there is a bigger difference between the biocompatibility of the respective polymers in their salt and base forms than between PANI and PPy as such. PANI and PPy can, therefore, be similarly applied in biomedicine when solely their biological properties are considered. Impurity content detected by mass spectroscopy is presented. These results can change the generally accepted opinion of the scientific community on better biocompatibility of PPy in comparison with PANI.
- MeSH
- Aniline Compounds * adverse effects pharmacology MeSH
- NIH 3T3 Cells MeSH
- Embryoid Bodies metabolism pathology MeSH
- Erythropoiesis drug effects MeSH
- Myocytes, Cardiac metabolism pathology MeSH
- Mouse Embryonic Stem Cells metabolism pathology MeSH
- Mice MeSH
- Polymers * adverse effects pharmacology MeSH
- Pyrroles * adverse effects pharmacology MeSH
- Materials Testing * MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
Polyaniline cryogel is a new unique form of polyaniline combining intrinsic electrical conductivity and the material properties of hydrogels. It is prepared by the polymerization of aniline in frozen poly(vinyl alcohol) solutions. The biocompatibility of macroporous polyaniline cryogel was demonstrated by testing its cytotoxicity on mouse embryonic fibroblasts and via the test of embryotoxicity based on the formation of beating foci within spontaneous differentiating embryonic stem cells. Good biocompatibility was related to low contents of low-molecular-weight impurities in polyaniline cryogel, which was confirmed by liquid chromatography. The adhesion and growth of embryonic stem cells, embryoid bodies, cardiomyocytes, and neural progenitors prove that polyaniline cryogel has the potential to be used as a carrier for cells in tissue engineering or bio-sensing. The surface energy as well as the elasticity and porosity of cryogel mimic tissue properties. Polyaniline cryogel can therefore be applied in bio-sensing or regenerative medicine in general, and mainly in the tissue engineering of electrically excitable tissues.
- MeSH
- Algorithms MeSH
- Aniline Compounds chemistry MeSH
- Biocompatible Materials chemistry MeSH
- Cell Culture Techniques MeSH
- Electric Conductivity MeSH
- Fibroblasts MeSH
- Cryogels chemistry MeSH
- Mechanical Phenomena MeSH
- Elastic Modulus MeSH
- Mice MeSH
- Porosity MeSH
- Models, Theoretical MeSH
- Materials Testing MeSH
- Tissue Engineering MeSH
- Cell Survival MeSH
- Chromatography, High Pressure Liquid MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Conducting polyaniline can be prepared and modified using several procedures, all of which can significantly influence its applicability in different fields of biomedicine or biotechnology. The modifications of surface properties are crucial with respect to the possible applications of this polymer in tissue engineering or as biosensors. Innovative technique for preparing polyaniline films via in-situ polymerization in colloidal dispersion mode using four stabilizers (poly-N-vinylpyrrolidone; sodium dodecylsulfate; Tween 20 and Pluronic F108) was developed. The surface energy, conductivity, spectroscopic features, and cell compatibility of thin polyaniline films were determined using contact-angle measurement, the van der Pauw method, Fourier-transform infrared spectroscopy, and assay conducted on mouse fibroblasts, respectively. The stabilizers significantly influenced not only the surface and electrical properties of the films but also their cell compatibility. Sodium dodecylsulfate seems preferentially to combine both the high conductivity and good cell compatibility. Moreover, the films with sodium dodecylsulfate were non-irritant for skin, which was confirmed by their in-vitro exposure to the 3D-reconstructed human tissue model.
- MeSH
- Aniline Compounds adverse effects chemistry MeSH
- Fibroblasts drug effects MeSH
- Colloids adverse effects chemistry MeSH
- Membranes, Artificial * MeSH
- Mice MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Polyaniline shows great potential and promises wide application in the biomedical field thanks to its intrinsic conductivity and material properties, which closely resemble natural tissues. Surface properties are crucial, as these predetermine any interaction with biological fluids, proteins and cells. An advantage of polyaniline is the simple modification of its surface, e.g., by using various dopant acids. An investigation was made into the adhesion, proliferation and migration of mouse embryonic fibroblasts on pristine polyaniline films and films doped with sulfamic and phosphotungstic acids. In addition, polyaniline films supplemented with poly (2-acrylamido-2-methyl-1-propanesulfonic) acid at various ratios were tested. Results showed that the NIH/3T3 cell line was able to adhere, proliferate and migrate on the pristine polyaniline films as well as those films doped with sulfamic and phosphotungstic acids; thus, utilization of said forms in biomedicine appears promising. Nevertheless, incorporating poly (2-acrylamido-2-methyl-1-propanesulfonic) acid altered the surface properties of the polyaniline films and significantly affected cell behavior. In order to reveal the crucial factor influencing the surface/cell interaction, cell behavior is discussed in the context of the surface energy of individual samples. It was clearly demonstrated that the lesser the difference between the surface energy of the sample and cell, the more cyto-compatible the surface is.
- MeSH
- Aniline Compounds chemistry pharmacology MeSH
- Biocompatible Materials chemistry pharmacology MeSH
- Cell Adhesion drug effects MeSH
- NIH 3T3 Cells MeSH
- Mice MeSH
- Cell Movement drug effects MeSH
- Surface Properties MeSH
- Cell Proliferation drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
