Combining the unique properties of peptides as versatile tools for nano- and biotechnology with lead halide perovskite nanoparticles can bring exceptional opportunities for the development of optoelectronics, photonics, and bioelectronics. As a first step towards this challenge sub 10 nm methylammonium lead bromide perovskite colloidal nanoparticles have been synthetizes using commercial cyclic peptide Cyclo(RGDFK), containing 5 amino acids, as a surface stabilizer. Perovskite nanoparticles passivated with Cyclo(RGDFK) possess charge transfer from the perovskite core to the peptide shell, resulting in lower photoluminescence quantum yields, which however opens a path for the application where charge transfer is favorable.
Flavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.
Biocompatibility tests and a study of the electrical properties of thin films prepared from six electroactive polymer ink formulations based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) were performed. The aim was to find a suitable formulation of PEDOT:PSS and conditions for preparing thin films in order to construct printed bioelectronic devices for biomedical applications. The stability and electrical properties of such films were tested on organic electrochemical transistor (OECT)-based sensor platforms and their biocompatibility was evaluated in assays with 3T3 fibroblasts and murine cardiomyocytes. It was found that the thin films prepared from inks without an additive or any thin film post-treatment provide limited conductivity and stability for use in biomedical applications. These properties were greatly improved by using ethylene glycol and thermal annealing. Addition or post-treatment by ethylene glycol in combination with thermal annealing provided thin films with electrical resistance and a stability sufficient to be used in sensing of animal cell physiology. These films coated with collagen IV showed good biocompatibility in the assay with 3T3 fibroblasts when compared to standard cell culture plastics. Selected films were then used in assays with murine cardiomyocytes. We observed that these cells were able to attach to the PEDOT:PSS films and form an active sensor element. Spontaneously beating clusters were formed, indicating a good physiological status for the cardiomyocyte cells. These results open the door to construction of cheap printed electronic devices for biointerfacing in biomedical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1121-1128, 2018.
- MeSH
- bicyklické sloučeniny heterocyklické chemie MeSH
- biokompatibilní materiály farmakologie MeSH
- buněčné linie MeSH
- buňky 3T3 MeSH
- elektrická impedance MeSH
- elektřina * MeSH
- inkoust * MeSH
- myši MeSH
- polymery chemie MeSH
- polystyreny chemie MeSH
- testování materiálů * MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Oligonucleotides conduct electric charge via various mechanisms and their characterization and understanding is a very important and complicated task. In this work, experimental (temperature dependent steady state fluorescence spectroscopy, time-resolved fluorescence spectroscopy) and theoretical (Density Functional Theory) approaches were combined to study charge transfer processes in short DNA/DNA and RNA/DNA duplexes with virtually equivalent sequences. The experimental results were consistent with the theoretical model - the delocalized nature of HOMO orbitals and holes, base stacking, electronic coupling and conformational flexibility formed the conditions for more effective short distance charge transfer processes in RNA/DNA hybrids. RNA/DNA and DNA/DNA charge transfer properties were strongly connected with temperature affected structural changes of molecular systems - charge transfer could be used as a probe of even tiny changes of molecular structures and settings.
The conductivity of DNA covalently bonded to a gold surface was studied by means of the STM technique. Various single- and double-stranded 32-nucleotide-long DNA sequences were measured under ambient conditions so as to provide a better understanding of the complex process of charge-carrier transport in natural as well as chemically modified DNA molecules. The investigations focused on the role of several features of DNA structure, namely the role of the negative charge at the backbone phosphate group and the related complex effects of counterions, and of the stacking interactions between the bases in Watson-Crick and other types of base pairs. The measurements have indicated that the best conductor is DNA in its biologically most relevant double-stranded form with Watson-Crick base pairs and charged phosphates equilibrated with counterions and water. All the studied modifications, including DNA with non-Watson-Crick base pairs, the abasic form, and especially the form with phosphate charges eliminated by chemical modifications, lower the conductivity of natural DNA.
- MeSH
- DNA chemie metabolismus MeSH
- elektrická vodivost MeSH
- financování organizované MeSH
- fosfáty chemie metabolismus MeSH
- jednovláknová DNA chemie MeSH
- oligodeoxyribonukleotidy chemie metabolismus MeSH
- párování bází MeSH
- rastrovací tunelová mikroskopie MeSH
- sekvence nukleotidů MeSH
- vodíková vazba MeSH
- zlato chemie MeSH
