In this study, spherical or hexagonal NaYF4:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay. The comet assay was used to determine the oxidative damage of the UCNPs. An in vivo study on mice determined the elimination route and potential accumulation of UCNPs in the body. The results showed that the L- and S-UCNPs were internalized into cells in the lumen of endosomes. The proliferation assay revealed that the L-UCNPs were less toxic than S-UCNPs. The viability of rMSCs incubated with particles decreased in the order S-UCNP@Ale-(PDMA-AEA) > S-UCNP@Ale-PEG > S-UCNPs > S-UCNP@PMVEMA. Similar results were obtained in C6 cells. The oxidative damage measured by the comet assay showed that neat L-UCNPs caused more oxidative damage to rMSCs than all coated UCNPs while no difference was observed in C6 cells. An in vivo study indicated that L-UCNPs were eliminated from the body via the hepatobiliary route; L-UCNP@Ale-PEG particles were almost eliminated from the liver 96 h after intravenous application. Pilot fluorescence imaging confirmed the limited in vivo detection capabilities of the nanoparticles.

• MeSH
• krysa rodu rattus MeSH
• mezenchymální kmenové buňky * metabolismus   účinky léků   cytologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nanočástice chemie   MeSH
• oxidační stres účinky léků   MeSH
• polyethylenglykoly chemie   MeSH
• velikost částic MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Stability and cytotoxicity of PEGylated Au NPs is crucial for biomedical application. In this study, we have focused on thermal stability of PEGylated Au NPs at 4 and 37 °C and after sterilization in autoclave. Gold nanoparticles were prepared by direct sputtering of gold into PEG and PEG-NH2. Transmission electron microscopy revealed that NPs exhibit a spherical shape with average dimensions 3.8 nm for both AuNP_PEG and AuNP_PEG-NH2. The single LSPR band at wavelength of 509 nm also confirmed presence of spherical Au NPs in both cases. Moreover, according to UV-Vis spectra, the Au NPs were overall stable during aging or thermal stressing and even after sterilization in autoclave. Based on gel electrophoresis results, the higher density of functionalizing ligands and the higher stability is assumed on AuNP_PEG-NH2. Changes in concentration of gold did not occur after thermal stress or with aging. pH values have to be adjusted to be suitable for bioapplications - original pH values are either too alkaline (AuNP_PEG-NH2, pH 10) or too acidic (AuNP_PEG, pH 5). Cytotoxicity was tested on human osteoblasts and fibroblasts. Overall, both Au NPs have shown good cytocompatibility either freshly prepared or even after Au NPs' sterilization in the autoclave. Prepared Au NP dispersions were also examined for their antiviral activity, however no significant effect was observed. We have synthesized highly stable, non-cytotoxic PEGylated Au NPs, which are ready for preclinical testing.

• Publikační typ
• časopisecké články 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
• aniliny chemie   farmakologie   MeSH
• biokompatibilní materiály chemie   farmakologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčné linie MeSH
• elektrická vodivost MeSH
• koncentrace vodíkových iontů MeSH
• myší embryonální kmenové buňky MeSH
• myši MeSH
• organofosfonáty chemie   MeSH
• polymery chemie   farmakologie   MeSH
• pyrroly chemie   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Biohydrogels, composed of naturally occurring biopolymers are typically preferred over their synthetic analogues in bioapplications thanks to their biocompatibility, bioactivity, mechanical or degradation properties. Shaping biohydrogels on the single-cell length scales (micrometers) is a key ability needed to create bioequivalent artificial cell/tissue constructs and cannot be achieved with current methods. This work introduces a method for photolithographic synthesis of arbitrarily shaped microgels composed purely of a biopolymer of choice. The biopolymer is mixed with a sacrificial photocrosslinkable polymer, and the mixture is photocrosslinked in a lithographic process, yielding anisotropic microgels with the biopolymer entrapped in the network. Subsequent ionic or covalent biopolymer crosslinking followed by template cleavage yields a microgel composed purely of a biopolymer with the 3D shape dictated by the photocrosslinking process. Method feasibility is demonstrated with two model polysaccharide biopolymers (alginate, chitosan) using suitable crosslinking methods. Next, alginate microgels were used as microtaggants on a pharmaceutical oral solid dose formulation to prevent its counterfeiting. Since the alginate is approved as an additive in the food and pharmaceutical industries, the presented tagging system can be implemented in practical use much easier than systems comprising synthetic polymers.

• MeSH
• algináty chemie   MeSH
• biopolymery chemie   MeSH
• dextrany chemie   MeSH
• fluorescence MeSH
• hydrogely chemie   MeSH
• iridoidy chemie   MeSH
• methakryláty chemie   MeSH
• mikrogely chemie   MeSH
• Publikační typ
• časopisecké články MeSH

The cytotoxicity of methacrylate-based biopolymers crosslinked by in situ photopolymerization has been attributed mainly to residual methacrylate monomers released due to incomplete polymerization. The residual monomers, primarily triethyleneglycol dimethacrylate or 2-hydroxyethyl methacrylate, may irritate adjacent tissue, or be released into the bloodstream and reach practically all tissues. Increased production of reactive oxygen species, which may be connected to concomitant glutathione depletion, has been the most noticeable effect observed in vitro following the exposure of cells to methacrylates. Radical scavengers such as glutathione or N-acetylcysteine represent the most important cellular strategy against methacrylate-induced toxicity by direct adduct formation, resulting in monomer detoxification. Reactive oxygen species may participate in methacrylate-induced genotoxic or pro-apoptotic effects and cell-cycle arrest via induction of corresponding molecular pathways in cells. A deeper understanding of the biological mechanisms and effects of methacrylates widely used in various bioapplications may enable a better estimation of potential risks and thus, selection of a more appropriate composition of polymer material to eliminate potentially harmful substances such as triethyleneglycol dimethacrylate.

• MeSH
• acetylcystein farmakologie   MeSH
• biokompatibilní materiály chemie   toxicita   MeSH
• glutathion metabolismus   MeSH
• kyseliny polymethakrylové chemie   toxicita   MeSH
• lidé MeSH
• methakryláty chemie   toxicita   MeSH
• polyethylenglykoly chemie   toxicita   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• scavengery volných radikálů farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Modification of polymer substrates can essentially change the properties of material and thereby it allows their usage in attractive fields of material research. Laser treatment can be successfully applied for change in physico-chemical surface properties and/or for selective change of surface morphology with pattern construction. Three major applications of laser induced structures were described, cytocompatibility control, application as anti-bacterial substrate and plasmonic-based detection system. The construction of a second generation antibacterials using the synergic effect of either nanopatterning of polymers by application of a laser or noble metals deposition and consequent modification of nanostructures was presented.

• MeSH
• antiinfekční látky chemie   farmakologie   MeSH
• biosenzitivní techniky přístrojové vybavení   MeSH
• buněčná adheze MeSH
• buněčné kultury přístrojové vybavení   metody   MeSH
• DNA analýza   MeSH
• lasery MeSH
• lipidy analýza   MeSH
• nádory patologie   MeSH
• nanostruktury chemie   MeSH
• nanotechnologie metody   MeSH
• polymery chemie   MeSH
• povrchové vlastnosti MeSH
• Ramanova spektroskopie přístrojové vybavení   metody   MeSH
• tkáňové inženýrství metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates.

• MeSH
• Candida enzymologie   MeSH
• chitosan chemie   MeSH
• enzymy imobilizované chemie   MeSH
• fungální proteiny chemie   MeSH
• imobilizované buňky cytologie   metabolismus   MeSH
• kyseliny polymethakrylové chemie   MeSH
• lipasa chemie   MeSH
• magnetismus * MeSH
• Saccharomyces cerevisiae cytologie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

Magnetoferritin is a metalloprotein composed of a protein coat (apoferritin) surrounding the magnetic iron oxide nanoparticles. Physicochemical characterization of magnetic, structural and morphological properties, size distribution and stability of magnetoferritin have been extensively investigated. Magneto-optical properties of magnetic nanoparticles in magnetoferritin can be applied in in vivo diagnosis of various diseases associated with the formation of magnetite in pathological processes in tissues. In addition, the confirmed peroxidase activity enables magnetoferritin to be used in important bioapplications.

• Klíčová slova
• magnetoferritin, magnetit, magneto-optické vlastnosti,
• MeSH
• apoferritiny * farmakologie   chemie   MeSH
• nanočástice MeSH
• oxidace-redukce MeSH
• oxidy farmakologie   chemie   MeSH
• železo farmakologie   chemie   MeSH
• Publikační typ
• práce podpořená grantem MeSH

Fluorescent nanodiamonds (NDs) attracted attention as a new promising type of nanoparticles for bioapplications. This carbon nanomaterial with low-toxicity is able to accommodate fluorescent nitrogen-vacancy (N-V) color centers, prime examples of non-photobleachable defects of diamond crystal lattice. An overview of ND applications in bioimaging is presented. NDs are compared with other fluorescent probes and their specific chemical and colloidal properties were shown. The biologically relevant properties of fluorescent NDs such as toxicity, biocompatibility and their cellular localization and internalization are discussed.

• MeSH
• cílená molekulární terapie využití   MeSH
• fluorescence * MeSH
• fluorescenční barviva chemie   MeSH
• lékové transportní systémy využití   MeSH
• lidé MeSH
• luminiscence MeSH
• molekulární sondy - techniky MeSH
• molekulární zobrazování * MeSH
• nanodiamanty * chemie   MeSH
• nanostruktury MeSH
• Ramanova spektroskopie MeSH
• receptory umělé * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

Members of the galectin family of endogenous lectins are potent adhesion/growth-regulatory effectors. Their multifunctionality opens possibilities for their use in bioapplications. We studied whether human galectins induce the conversion of human dermal fibroblasts into myofibroblasts (MFBs) and the production of a bioactive extracellular matrix scaffold is suitable for cell culture. Testing a panel of galectins of all three subgroups, including natural and engineered variants, we detected activity for the proto-type galectin-1 and galectin-7, the chimera-type galectin-3 and the tandem-repeat-type galectin-4. The activity of galectin-1 required the integrity of the carbohydrate recognition domain. It was independent of the presence of TGF-β1, but it yielded an additive effect. The resulting MFBs, relevant, for example, for tumor progression, generated a matrix scaffold rich in fibronectin and galectin-1 that supported keratinocyte culture without feeder cells. Of note, keratinocytes cultured on this substratum presented a stem-like cell phenotype with small size and keratin-19 expression. In vivo in rats, galectin-1 had a positive effect on skin wound closure 21 days after surgery. In conclusion, we describe the differential potential of certain human galectins to induce the conversion of dermal fibroblasts into MFBs and the generation of a bioactive cell culture substratum.

• MeSH
• extracelulární matrix metabolismus   MeSH
• fibroblasty metabolismus   MeSH
• galektin 1 metabolismus   MeSH
• galektin 3 metabolismus   MeSH
• galektin 4 metabolismus   MeSH
• galektiny metabolismus   MeSH
• hojení ran MeSH
• keratin-19 metabolismus   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• myofibroblasty metabolismus   MeSH
• tkáňové inženýrství metody   MeSH
• transformující růstový faktor beta1 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH