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
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
Polyaniline (PANI) belongs to a group of conducting polymers that show numerous properties useful in biomedical applications. Although PANI has long been studied in terms of interaction with human tissue, the published studies are mostly focused on composites of polyaniline with other polymers, not allowing for generalization of the obtained results. The present study is focused on the adhesion of human liver cells to a conducting and nonconducting polyaniline films. The ability of human liver cells to attach to both types of the tested surfaces was confirmed. Cell proliferation on the PANI surfaces was monitored in relation to material biocompatibility and to its practical applications. The results showed statistically significant differences in cell proliferation depending on the type of PANI film. The study thus points out the need to test materials in their neat forms, which allow for better generalization of the test results leading to their broader applications.
PURPOSE: To investigate the optimal use of XR-RV3 GafChromic(®) films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. METHODS: XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patient skin dose in interventional procedures. As film dosimetry can be associated with high uncertainty, this paper presents the EURADOS WG 12 initiative to carry out a comprehensive study of film characteristics with a multisite approach. The considered sources of uncertainties include scanner, film, and fitting-related errors. The work focused on studying film behavior with clinical high-dose-rate pulsed beams (previously unavailable in the literature) together with reference standard laboratory beams. RESULTS: First, the performance analysis of six different scanner models has shown that scan uniformity perpendicular to the lamp motion axis and that long term stability are the main sources of scanner-related uncertainties. These could induce errors of up to 7% on the film readings unless regularly checked and corrected. Typically, scan uniformity correction matrices and reading normalization to the scanner-specific and daily background reading should be done. In addition, the analysis on multiple film batches has shown that XR-RV3 films have generally good uniformity within one batch (<1.5%), require 24 h to stabilize after the irradiation and their response is roughly independent of dose rate (<5%). However, XR-RV3 films showed large variations (up to 15%) with radiation quality both in standard laboratory and in clinical conditions. As such, and prior to conducting patient skin dose measurements, it is mandatory to choose the appropriate calibration beam quality depending on the characteristics of the x-ray systems that will be used clinically. In addition, yellow side film irradiations should be preferentially used since they showed a lower dependence on beam parameters compared to white side film irradiations. Finally, among the six different fit equations tested in this work, typically used third order polynomials and more rational and simplistic equations, of the form dose inversely proportional to pixel value, were both found to provide satisfactory results. Fitting-related uncertainty was clearly identified as a major contributor to the overall film dosimetry uncertainty with up to 40% error on the dose estimate. CONCLUSIONS: The overall uncertainty associated with the use of XR-RV3 films to determine skin dose in the interventional environment can realistically be estimated to be around 20% (k = 1). This uncertainty can be reduced to within 5% if carefully monitoring scanner, film, and fitting-related errors or it can easily increase to over 40% if minimal care is not taken. This work demonstrates the importance of appropriate calibration, reading, fitting, and other film-related and scan-related processes, which will help improve the accuracy of skin dose measurements in interventional procedures.
- MeSH
- Algorithms MeSH
- Radiation Dosage MeSH
- Film Dosimetry instrumentation methods MeSH
- Calibration MeSH
- Skin radiation effects MeSH
- Uncertainty MeSH
- X-Rays MeSH
- Publication type
- Journal Article MeSH
The cytocompatibility of cardiomyocytes derived from embryonic stem cells and neural progenitors, which were seeded on the surface of composite films made of graphene oxide (GO) and polypyrrole (PPy-GO) or poly(3,4-ethylenedioxythiophene) (PEDOT-GO) are reported. The GO incorporated in the composite matrix contributes to the patterning of the composite surface, while the electrically conducting PPy and PEDOT serve as ion-to-electron transducers facilitating electrical stimulation/sensing. The films were fabricated by a simple one-step electropolymerization procedure on electrically conducting indium tin oxide (ITO) and graphene paper (GP) substrates. Factors affecting the cell behaviour, i.e. the surface topography, wettability, and electrical surface conductivity, were studied. The PPy-GO and PEDOT-GO prepared on ITO exhibited high surface conductivity, especially in the case of the ITO/PPy-GO composite. We found that for cardiomyocytes, the PPy-GO and PEDOT-GO composites counteracted the negative effect of the GP substrate that inhibited their growth. Both the PPy-GO and PEDOT-GO composites prepared on ITO and GP significantly decreased the cytocompatibility of neural progenitors. The presented results enhance the knowledge about the biological properties of electroactive materials, which are critical for tissue engineering, especially in context stimuli-responsive scaffolds.
- MeSH
- Bridged Bicyclo Compounds, Heterocyclic chemistry MeSH
- Electric Conductivity * MeSH
- Electrochemistry * MeSH
- Graphite pharmacology MeSH
- Myocytes, Cardiac cytology drug effects MeSH
- Mice MeSH
- Neural Stem Cells cytology drug effects MeSH
- Neurogenesis drug effects MeSH
- Polymers chemistry pharmacology MeSH
- Pyrroles chemistry MeSH
- Water chemistry MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Polyaniline is a promising conducting polymer with still increasing application potential in biomedicine. Its surface modification can be an efficient way how to introduce desired functional groups and to control its properties while keeping the bulk characteristics of the material unchanged. The purpose of the study was to synthetize thin films of pristine conducting polyaniline hydrochloride, non-conducting polyaniline base and polyaniline modified with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) and investigate chosen parameters of their hemocompatibility. The modification was performed either by introduction of PAMPSA during the synthesis or by reprotonation of polyaniline base. The polyaniline hydrochloride and polyaniline base had no impact on blood coagulation and platelet adhesion. By contrast, the polyaniline reprotonated with PAMPSA completely hindered coagulation thanks to its interaction with coagulation factors Xa, Va and IIa. The significantly lower platelets adhesion was also found on this surface. Moreover, this film maintains its conductivity at pH of 6, which is an improvement in comparison with standard polyaniline hydrochloride losing most of its conductivity at pH of 4. Polyaniline film with PAMPSA introduced during synthesis had an impact on platelet adhesion but not on coagulation. The combined conductivity, anticoagulation activity, low platelet adhesion and improved conductivity at pH closer to physiological, open up new possibilities for application of polyaniline reprotonated by PAMPSA in blood-contacting devices, such as catheters or blood vessel grafts.
The increasing application of conductive polymers in electronics requires a precise and controlled deposition of these materials in thin layers. The article provides a brief description of the method, the principle and properties of both the source polymer and the matrix; also the experimental conditions necessary for successful thin layer pre¬paration are presented. Matrix-assisted pulsed laser eva¬poration of polypyrrole was carried out at different laser fluences (0.10.6 J cm2) with KrF excimer laser (λ = 248 nm) from water and dimethyl sulfoxide matrices and also with Nd:YAG laser (λ = 266 nm) for comparison. The layer thickness was hundreds of nanometers. The relations of the laser wavelength, laser fluence and the used matrix on the one hand and chemical composition of the layers (analyzed by FTIR) on the other were studied. The ablation threshold was 0.250.30 J cm2 for dimethyl sulfoxide matrix.
The aim of the presented research was to formulate, prepare and evaluate novel film wound dressings containing lidocaine hydrochloride. The conversion of partially substituted fibrous sodium carboxymethylcellulose (CMC) to an acidic form of CMC enabled the formation of an insoluble matrix which consequently provided the prepared films with excellent handling properties in their wet state. The drug concentration which was incorporated into an external layer of the film was 5 mg/cm2. The films demonstrated satisfactory mass and drug content uniformity as well as an acidic surface pH advantageous for wound application. An in vitro drug release test proved that the insoluble CMC matrix served as a reliable carrier without slowing down the release of lidocaine hydrochloride − more than 90% of the drug was released during the first 15 min, indicating a quick rate of anesthetic action. The prepared films could be potential wound dressings for comfortable and efficient topical anesthesia before/after procedures on the wound.
- MeSH
- Anesthetics, Local * MeSH
- Pain drug therapy MeSH
- Chemistry, Pharmaceutical MeSH
- Dosage Forms MeSH
- Lidocaine MeSH
- Anesthesia, Local MeSH
- Drug Carriers chemical synthesis chemistry MeSH
- Bandages * MeSH
- Surface Properties MeSH
- Wounds and Injuries therapy MeSH
- Carboxymethylcellulose Sodium * chemistry MeSH
- Drug Delivery Systems MeSH
- In Vitro Techniques MeSH
- Drug Liberation MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
