The composition and arrangement of extracellular matrix (ECM) components in adult cardiac tissue plays a key role in the organization and alignment of synchronously and functionally beating cardiomyocytes.
Following Heart failure (HF) - the end stage of cardiac pathologies in which cardiac muscle is not able to pump adequate blood to the organism – critical changes in mechanics and nanotopography occur along with the composition of cardiac ECM.
Such modifications in ECM compliance and nanotopography – collectively defined as remodelling - are deemed to hinder local cell viability and function. Following the formation of a fibrotic scar, the surrounding tissue will lose its compliance and contractility.
The Hippo signaling pathway effectors YAP/TAZ have been shown to be sensitive to changes in ECM mechanical properties while influencing stem cell shape, homeostasis and differentiation. Hippo pathway has been shown to play a pivotal role during heart development by controlling cardiogenesis by cardiac cell hyperplasia, with its deregulation being crucial to the onset and progression of cardiac hypertrophy. This axis works by controlling the shuttling of the proteins YAP/TAZ from the cytoplasm to the nucleus, where they act as transcriptional co-activators.
YAP and TAZ paralog proteins are not expressed in mature cardiomyocytes in vivo, while are re-expressed right after myocardial infarction in cardiomyocytes and cardiac fibroblasts at the infarction border zone. Conversely, ex vivo adherent cells of any derivation display a marked nuclear staining for YAP and TAZ when plated on stiff surfaces like glass or polystyrene. In this study we aimed at investigating the possibility to control the known mechanosensors YAP/TAZ through the dynamic modification of surface mechanics and nanotopography.
DNA and RNA have recently become an important material in structural nanotechnology. They are popular for their controlled self recognition properties that can be exploited to construct DNA and RNA self assemblies with desirable shape. The fact that the DNA and RNA self assemblies can vary the shape and mechanical stiffness is very attractive for pharmacy as it opens considerable new ways of drug delivery [1]. Current studies of the DNA and RNA self assemblies have shown some unexpected structural behaviour of prepared motifs [2]. Therefore, we have decided to determine basic properties of these structures, using theoretical molecular modelling, especially the molecular dynamics (MD) methods. In this work, we study a self assembled RNA DNA hybrid forming a double crossover (DX) motif that contains two Holliday junctions (HJs) [2]. Two neighbouring DX motifs can associate with each other into large coplanar assemblies. We prepared two models of this DX motif (full DNA model and RNA DNA hybrid model) for atomistic MD simulations. A significant conformational change was observed at the Holliday junctions (HJs) in both models therefore structures of a single HJ were also studied in details to explain its conformational behaviour. Many structural and dynamical parameters describing the structure of HJ were also calculated and most of them correlate with experimental data. Prepared atomistic models of self assembled RNA and DNA molecules will be used in our future research where we will analyze mechanical properties of these structures.
REFERENCES: [1] Halley, P. D.; Lucas, C. R.; McWilliams, E. M.; Webber, M. J.; Patton, R. A.; Kural, C.; Lucas, D. M.; Byrd, J. C.; Castro, C. E. DNA Origami: Daunorubicin-Loaded DNA Origami Nanostructures Circumvent Drug-Resistance Mechanisms in a Leukemia Model (Small 3/2016). Small 2016, 12 (3), 307–307.; [2] Ko, S. H.; Su, M.; Zhang, C.; Ribbe, A. E.; Jiang, W.; Mao, C. Synergistic Self-Assembly of RNA and DNA Molecules. Nat. Chem. 2010, 2 (12), 1050–1055.
Nitric Oxide is a very interesting molecule suitable for applications in vascular grafts. Between the various functions that NO may be involved in function is relaxation smoothly-muscle cell, suppression thrombogenicity and also contributes to the proper function of the immune system. This work focuses on the fictionalization of biodegradable materials used to prepare vascular grafts by donors nitric oxide. In the first part of the experiment was optimized components biodegradable product. Layers were formed from the aliphatic polyester polycaprolactone (PCL), and nitric oxide donors S-nitrosoacetyl N-penicillamine (SNAPs). This work is starting study that deals only with planar layers PCL with incorporated SNAPs. Work was divided into several parts. In the first part were prepared donors nitric oxide S-nitrosoacetyl-N-penicilamine (SNAPs). The next step was the optimization screening method (Griess assay), which is a method that can monitor the kinetics of NO release. Subsequently then were prepared planar nanofiber layers from PCL 45,000 g / mol with fiber diameter approximately 300 nm. Planar nanofiber layers were prepared by three layers. The first of which did not contain any donor, the second and the third contained 0.2% and 0.4% SNAPs. These layers were prepared using machines Nanospider NS1WS500U. Spinning electrode was a wire. Subsequently, the layer was tested by the in-vitro MTT method and SEM microscopy. Materials were tested with smooth-muscle and endothelial cells. In the last part, it was monitored the influence of sterilization methods on NO release from layers.
The development of nanotechnologies has attracted a lot of interest since it brings new possibilities in the field of nanomedical applications, from diagnostic methods to targeted nanotransporters. Gold nanoparticles (AuNPs) belong to a group of nanomaterials with significant peroxidase-like activity. We have successfully synthesized AuNPs thermally over a range of temperatures from 20 to 100 °C. The AuNPs size varied from 17 to 37 nm and the zeta potential was found to vary from -32 to -44 mV, in which the maximum absorption maximum was detected at 529 nm. Peroxidase-like activity was monitored in the presence of TMB (1 mM) and hydrogen peroxide (10 mM). The proposed system based on peroxidase-like activity was further evaluated in immune detection of human IgG, in which anti-IgG antibody was modified with AuNPs.
Tissue inflammation leads to the recruitment and activation of several cell types, which cooperate to create a particular microenvironment that determines the regression of the pathology or its perpetuation (chronic inflammation). Mesenchymal stem cells (MSCs) are multipotent cells present in the stromal fraction of many tissues (i.e umbilical cord blood, placenta, adipose tissue). Several studies are now showing MSCs potential in tissue engineering, especially because of their ability to differentiate onto nanostructure surface. However the effect of nanostructure on MSCs immune properties is not properly characterized. The aim of the project is to develop MSCs reporter lines for transcription factors associated to inflammation, in order to monitor their activity once the cells are seeded onto nanostructure. This will be helpful to understand which materials are more suitable in term of tissue regeneration.
Due to their good biocompatibility and corrosion resistance, titanium and its alloys have drawn scientists’ attention as implantable materials. It is possible to create the TiO2 layers via an anodization process. The formed nanoporous anodic titanium oxide (ATO) layer not only improves the osteoblast cell adhesion and possesses apatite-forming abilities, but also can be used as a drug delivery system [1].
Nanoporous TiO2 layers were synthesized via a three-step anodization process in an ethylene glycol electrolyte containing NH4F and H2O. The duration of the third step was: 10, 5 and 2 min in order to obtain the different thicknesses of nanoporous layers. In order to obtain the anatase phase, the as-prepared amorphous TiO2 layers were annealed in air at 400 °C for 2 h. Two drugs, water-insoluble ibuprofen and water-soluble gentamicin, were used in the research. Drugs were loaded according to three different loading procedures: (i) first ibuprofen, then gentamicin, (ii) first gentamicin, then ibuprofen, and (iii) simultaneously both drugs. The release studies were carried out in a phosphate buffer solution (PBS, pH = 7.2) at 37 °C. The apatite-forming abilities of ATO layers were examined for amorphous, anatase and mixed anatase and rutile oxide phases. The samples were immersed in the stimulated body fluid (SBF) for the appropriate time. The osteoblast cell adhesion were examined using the osteoblast-like cell line MG-63. The structural and morphological characterizations of modified ATO layers were performed using a field emission scanning electron microscope (SEM).
The aim of our study was to prepare and characterize nanocarriers obtained from a block copolymer of etylene glycol and lactide-co-glycolide (PEG:PLGA 2 000:11 500). Physico-chemical properties (size and surface potential) of the PEG:PLGA nanostructures were examined using dynamic light scattering (DLS) and zeta potential measurements. Cryo-transimission electron microscopy (cryo-TEM) was used to visualize the morphology of the objects.
In the next step, we attempted to apply the PEG:PLGA nanostructures as nanocarriers. Firstly, we investigated the interaction between the nanostructures and selected bioactive substances or dyes, either hydrophobic (eg . piroxicam, porphyrins, perylene) and hydrophilic (eg . fluorescein). The affinity of the given compound to the hydrophobic core of the nanostructures was described by a so-called binding constant. UV-Vis spectrophotometric and spectrofluorimetric measurements were used in these studies.
This paper deals with electrostatic association of cationic micelles (CTAB or Septonex) with hyaluronan. Hyaluronan as negatively charged polyelectrolyte can interact with positively charged surfactant micelles via electrostatic interactions to form nano-core-shell like aggregates. These self-assembly nanoparticles can solubilize hydrophobic active substances and therefore, they are potential carriers in drug delivery applications. The cationic micelle/hyaluronan complexes were studied using turbidimetry and fluorescence spectroscopy method. Turbidimetric titration was chosen as an indicator of component aggregation which is related to the loss of transmitted light intensity due to the scattering effect. Fluorescent probe pyrene was selected for spectroscopy experiments because of its unique sensitivity to polarity of the medium, so this fluorescence method was used as an indicator of presence of hydrophobic domains in the system. Effect of components concentration and molecular weight of hyaluronan were evaluated. Results of turbidimetry revealed that aggregates formation (turbidity increasing) depends especially on a charge ratio of surfactant molecules and hyaluronan carboxyl groups. It was found a difference in association of low molecular weight and high molecular weight of hyaluronan. Fluorescence results confirmed presence and stability of micellar aggregates in studied systems.
This paper deals with the fluorescence anisotropy study of hydrophobic nanodomains formed by interaction between hyaluronan and cationic surfactant cetyltrimethylammonium bromide (CTAB) below critical micelle concentration in aqueous solution and the effect of sodium chloride addition to this system. Hyaluronan as negatively charged polyelectrolyte can interact with cationic surfactants via electrostatic interactions to form aggregates, which could be potential used for targeted drug delivery. Two fluorescence probes, which are solubilized in hydrophobic region, were used – perylene and diphenylhexatrien (DPH). The excitation and emission spectra, intensity of fluorescence and steady-state anisotropy of fluorescence in the samples were measured. It was observed that initial addition of CTAB to hyaluronan aqueous solution leads to forming some small hydrophobic domains linked to hyaluronan chains. Then an increasing concentration of CTAB causes phase separation and formation of a condensed phase. Addition of sodium chloride to the samples leads to reorganization of this system – the condensed phase is dissolved and probably free micelles are formed in the solution.
While it is known that recruitment of cells and mediators is altered during impaired wound healing, thereby delaying this process, little is performed to find a potential compound to outcome this problem. Thus, we investigated the correlation of wound healing events in older rats, and the impact of different molecular weight of hyaluronan without silver nanoparticles; (low-HA1), (High-HA2), (Medium- HA3) and with silver nanoparticles (High-HA4). The superior compounds of HA were selected to be further investigated onto diabetic wounds. Our results pointed to a marked deficiency in the granulation in the wounds of older rats, which was accompanied with impairment of the healing process. In the group of older rats treated with HA2 or HA4, granulation and dermal construction in the wounds were improved. Furthermore, the number of the pathogenic bacteria on wounds was declined throughout the first 24 hours after wounding by HA2 and HA4. The wound size in HA4-treated older rats was significantly smaller than that in other HA1, HA2 or HA3-treated older ones. On the other hand, diabetes impaired the level of inflammatory cytokine, represented by interferon gamma (INF-γ) in the diabetic model. On contrary, HA4 was found to normalize the level of the inflammatory cytokine, INF-γ at D1 after wounding in the diabetic model. Furthermore, HA4 was found to recover all oxidative and toxicity markers in diabetic models. This data confirms the critical role of HA4 to improve granulation and inflammatory mediators in impaired older and diabetic rat wound healing. ACKNOWLEDGEMENTS: This research was carried out under the project CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and Sports of the Czech Republic under the National Sustainability Programme II.
The current work deals with preparation and characterization of electrically lossy ferrofluid which can be used as a mediator for radio frequency (RF) - capacitive hyperthermia method. To this end, ferrofluid that can absorb the energy of alternating electrical field at the frequencies commonly employed in RF-capacitive hyperthermia (13.56 and 27.12 MHz) has been prepared by co-precipitation method. This ferrofluid comprises of electrically conductive component with core-shell structure, i.e. magnetite nanoparticles coated by dextran, organized in chain-like structure. The effect of RF – capacitive hyperthermia in the presence of mediator was studied on the series of tests performed on HaCaT and HepG2 cell lines using MMT test. The Electrical field of 13.56 MHz with controllable power output was applied using the EHY-110 SA (Oncotherm group) to increase the temperature of samples from 37 °C up to target temperature of 45 °C. The results of in-vitro test clearly indicate that the usage of capacitive heating of ferrofluid obtained substantially contribute to cytotoxic effect of hyperthermia treatment.
Acknowledgement. ACKNOWLEDGEMENTS: This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic – Program NPU I (LO1504).
In this study, we prepared CdTe quantum dots using microwave synthesis method (300 W/4 min) and monitored the effect of CdTe on the germination of maize (Zea mays L.) at defined time intervals (24, 48, and 72 h). All experiments were standardized to a single concentration of cadmium (Cd; 100 µM) and were carried out in three independent experiments (100 caryopses per variant, darkness, temperature 23 ± 2 °C, humidity 55 ± 5%). The potential effect of solvent on the germination was also studied. Germination was 58.4 ± 6.1 % in the control variant (n = 3). Cd alone inhibited germination rate for 10 ± 1.5%; whereas, 18 ± 1.8 % and 14.8 ± 1.6 % germination rates were recorded for CdTe QDs in distilled water and tap water, respectively. The germinative energy and coefficient velocity germination were concluded as the most sensitive parameters for determining the effect of CdTe QDs on Z. mays.
Nanoparticle visualization has an extensive potential for their utilization in targeted drug delivery tracking in a wide range of biological environments. In this regard, quantum dot nanoparticles may represent a suitable option as they are characterized by excellent fluorescent properties. This project is focused on application of quantum dot nanoparticles for fluorescence imaging in plants. A series of in vivo experiments was carried out on leaves of sunflower plant (Helianthus annuus). Leaves were let to soak in a water solution of CdTe and CdTe/ZnS quantum dots and were monitored (ʎem 700 nm and 600 nm respectively) for 5 hours at time- intervals of 60 minutes using In Vivo Xtreme Imaging System (Bruker, USA). Captured images were further processed and the intensity of fluorescence analyzed by Bruker Molecular Imaging Software. Fluorescence imaging of plants encounters difficulties due to autofluorescence of biomolecules present in plants, including chlorophyll, carotene and/or xanthophyll. However, this can be suppressed by using an adequate excitation and emission filters for fluorescence images acquisition. Moreover, visualization of nanoparticles in plants can be enhanced by multispectral imaging and spectral modeling for autofluorescence unmixing. In this study, evaluation regarding optimal characteristics and modifications of quantum dot nanoparticles for fluorescence imaging in plants is provided as well as recommendations on image acquisition setting and further image postprocessing.
Prior to translation of engineered iron oxide nanoparticles (IONP) to clinical application, detailed pharmacokinetic and metabolic studies must be necessarily undertaken. Precise information about bio distribution profile can be obtained when radiolabelled IONP are employed. In this study, two different approaches were assessed for preparation of 59Fe-radiolabelled iron oxide nanoparticles. The first method comprises post-synthetic isotope exchange (59Fe IONPex) while the second on is based on precursor labelling (59Fe IONPpre). Nanoparticle cores were prepared by high-temperature decomposition synthesis and are stabilized with triethylene glycol. Incorporation efficiencies of these two methods are comparable - 83 % and 90 % for precursor labelling and post-synthetic isotope exchange, respectively. Scanning electron microscopy, X-ray diffraction (XRD) and dynamic light scattering (DLS) measurements showed no impact of radiolabelling on nanoparticle size or morphology. In vitro radiochemical stability was assessed under physiological conditions. The results showed that 59Fe IONPpre exhibited much higher radiochemical stability in citrated human plasma.
Nano-ceria usage has been developed in the medical field as a great free radical scavenger especially in the radiotherapy as a protector for the healthy tissues from the bad effect of gamma rays.
The ionizing radiation effect of each plasma and gamma rays on cerium oxide nanoparticles had been studied.
Cerium oxide nanoparticles have been prepared via simple co-precipitation method. A change in the ceria structure and a significant increase in the relative fraction (%) of Ce3+ has been found when the prepared particles exposed to plasma for not less than 60 min. or a plasma discharge current more than 30(mA). Gamma radiation hasn’t the same effect on the relative fraction (%) of Ce3+ and it had reduced the ceria crystallinity.
Cerium oxide nanoparticles role as a free radical scavenger were improved when exposed to pseudo plasma and its scavenging ability didn’t disappear when exposed to gamma radiation.
The vermiculite nanocomposites are particular materials with defined particle size and surface. Their various morphologies and surface properties are investigated as drug carriers for the delivery of a variety of pharmaceutical molecules because of their antibacterial, biocompatible, osteoconductive, nontoxic and noninflammatory properties for various medical applications.
Vermiculite nanocomposites on the base of vermiculite/zinc oxide were prepared by the mechanochemical process. Different concentrations of zinc oxide in vermiculite matrix were prepared after calcined on 350 and 650 °C for 1.5 hour. Nanocomposite particles morphology and shape were studied using scanning electron microscopy (SEM). Elemental chemical composition was determined using X-ray fluorescence analysis (XRFS). Structural and phase analysis was performed using X-ray diffraction method (XRD). The nanocomposite particles size was characterized by the median particle size (d50), volume-weighted mean diameter (d43), mode diameter (dm) and span value. The surface changes were evaluated using zeta-potential measurements as a function of particle electrophoretic mobility (µ). Antibacterial activities were tested on Staphylococcus aureus and Klebsiella pneumoniae bacterial strains.
This study deals with modifications of inorganic-organic nanofibers to optimize the manufacturing process and to ensure long-term antibacterial activity of the nanofibers. The nanofibers material is combination of poly(vinyl alcohol) and silica. There are presented two methods of nanofibers´ structure modifications: i) surface functionalization of the nanofibers by silver and copper nanoparticles, and ii) modification of initial sol by antiseptic additive. The both modifications methods ensure significant antibacterial activity of inorganic-organic nanofibers, which was proven by in-vitro antibacterial tests. This novel material shows a big potential for wound dressing applications.
The potassium titanate nano-wires or fibres are synthesized in bulk by hydrothermal method using one step hydrothermal reaction of TiO2 and KOH at 200 oC temperature. The potassium titanate nano-wires of the diameters in the range of 8 to 90 nm and of lengths up to several microns are formed. The product so formed was annealed at various temperature ranging from 400 to 1000 oC to observe the effect of annealing on the fibres. A reasonably high yield of the fibrous structures is obtained without any catalyst and seedlings. These nano fibers are characterized by a range of methods including UV-VIS spectrophotometer, RAMAN, XRD, SEM, and HRTEM. The results of characterization indicate that the product formed was mainly K2Ti6O13 when annealed at 800 oC. At lower temperatures some other phases of the material are also found to be present. The total yield of product was very good at 47% by weight. The degradation effect on the product by ultraviolet light was also investigated and discussed here. The band gap of the material is found as ~ 3.4eV indicating the anatase phase of the synthesized material. The DFT calculations of band gap using GGA functional are also in good agreement with the experimental values.
The advent of nanotechnology has driven the improvement of materials with new properties for use as antimicrobial agents. Accordingly, ZnO in nanoscale has shown antimicrobial properties because of its activity against extensive variety of microorganisms and high imperviousness to extreme handling conditions. Zinc oxide nanoparticles (ZnO NPs) were prepared by a simple chemical synthesis route by making use of sodium alginate as anti-agglomeration. The surface modification of the synthesized ZnO NPs with SiO2 nanoparticles was conducted as per to sol-gel process. Moreover, APS was effectively covered the surface of SiO2/ZnO NPs. The synthesized ZnO NPs, SiO2/ZnO NPs and APS@ SiO2/ZnO NPs were characterized by FT-IR, XRD, TEM, DLS and SEM-EDS. The data obtained demonstrate that the formation of an interfacial chemical bond between ZnO and SiO2 which affirmed by FT-IR. TEM, FT-IR and SEM- EDS showed that the surface of ZnO NPs particles was evenly coated by amorphous SiO2 and APS layer.
Potential application of nanofibers in drug delivery has attracted a huge attention recently highlighting their properties including increased surface reactivity, high specific surface and improved drug bioavailability. Cardiac regenerative therapy, whereby pro-regenerative cells, drugs or growth factors are administered to myocardium has demonstrated significant potential in post-operative therapy. One of the main conditions applied on drug delivery system materials are cardiac biocompatibility, tolerability, treatment efficacy.
Our objective in this study was to develop a nanofibrous patch with a short degradation time for cardiac drug delivery and evaluate its properties relevant for the application site. Silk fibroin based nanofibres were manufactured from Bombyx mori raw cocoons by degum procedure, ionic liquid dissolution and subsequent needle-less electrospinning. The electrospun nanofibres were crosslinked by alcohol dehydration. Stabilized and unstabilized nanofibrous patches were characterized in terms of morphology, chemical composition and degradation kinetics. The main objective was focused on cardiac cytotoxic effect of nanofibres and its evaluation on H9C2 rat myoblastic cell line.
Daidzein, genistein and quercetin are plant-derived flavonoids showing estrogenic, antioxidative and antineoplastic activity. One of strategies for improving their limited bioavailability is the formation of water-soluble complexes, such as those formed by cyclodextrins and their derivatives.
We prepared cationic derivatives of cyclodextrins substituted with ethylenediamine, 1,3-propanediamine and 1,4-butanediamine.
Flavonoids complexes were prepared with the freeze drying method and their formation was confirmed with circular dichroism measurements. Parallel artificial membrane permeability assay and experiments on neoplastic cell cultures revealed improved bioavailability of complexed flavonoids. This beneficial effect of complexation was apparent only for genistein and daidzein - substances which are initially practically insoluble in water.
This study describes the production, biological functionalization and in vitro testing of biodegradable fibrous scaffolds for the bone tissue engineering. All scaffolds were produced from semicrystaline polyester polycaprolactone as a mixture of micro and nanofibers, where nanofibers are formed by electrospinning and microfibers by meltblown technology. These materials have big potential in the field of tissue engineering because fibrous structure mimics natural extracellular matrix with good porosity. One way to improve the cell viability and proliferation into this 3D structure of scaffolds is the use of biologically active molecules, e.g. growth factors. Therefore some scaffolds were functionalized by native platelets in PRP (platelet rich plasma) obtained from buffy coats as a reservoir of the growth factors before seeding of cells. The effect of the different ratios of microfibers and nanofibers and the functionalization with platelet on adhesion and proliferation of osteoblasts in vitro was investigated. It was evaluated by colorimetric assay (MTT), fluorescence microscopy and scanning electron microscopy (SEM).
This study deals with the evaluation of wound dressings by using conventional textile methods, which are used practically for determining the properties of fabrics. New kinds of the nonwoven wound dressings represent biodegradable bandages, on which can be also fixed the effective bioactive medical substances such as antibiotics, analgesics, steroids and enzymes for better healing or pain relief in wound. These wound dressings are primary used in medicine to protect open wounds, especially extensive burns, venous ulcers and other skin defects.
The suitable wound dressing reduces loss of liquids, proteins and electrolytes from the wound. It promotes regeneration of the epithelium, serves as a protective barrier against clogging wound or bacteria and also allows the wound to breathe sufficiently. Thanks to the generally known unique properties, such as breathability and optimal pore size and for example high surface area, are just nanofibrous layers appropriate for this usage.
Regarding to the properties which would the nanofiber wound dressings would meet, there is nowadays no set group of methods for the evaluation of the nanofibrous layers. The aim of this study was therefore to assemble a group of commonly available measurement methods. Using these methods will be possible to fully evaluation the nanofibrous layers. Thank to the resulting wound dressing fulfills its function best for the aim.
Pure silica nanofibers prepared by electrospinning from the sol-gel were reported to be successfully used in tissue engineering due to their biocompatibility, non-toxicity and biodegradability. This study deals with the possible mechanical degradation of silica nanofibers in vitro that have been pulverized down to the size of nanoparticles. The resulting fragments prepared in distilled water were compared to those that were removed up after two weeks of dissolution in saline adjusted to pH 7.4 and at 37 °C (values simulating the environment of some body fluids). The nanoparticles were measured using the Zetasizer device and compared to data obtained by scanning electron microscope (SEM).
The improvement of the healthcare quality requires the development of novel materials for wound healing, tissue engineering and other biomedical applications. The biodegradable electrospun nanofibers are the ideal candidates for such applications thanks to their nanostructure which is very similar to the extracellular matrix. However, the preparation of the electrospun nanofibers exhibiting sufficient mechanical properties, good bio-compatibility and biodegradability can be very challenging. The polycaprolactone/polyethylene glycol (PCL/PEG) electrospun nanofibers were prepared by electrospinning of the PCL/PEG solutions containing various ratios of PCL:PEG polymers ranging from 5:95 to 75:25. The X-ray photoelectron spectroscopy (XPS) analysis revealed that by changing the PCL:PEG ratio in the original solution the chemical composition and thus also properties of final electrospun polymer varied, resulting in PEG-like or PCL-like structures for extreme values of the ratio. The PCL:PEG ratio influenced the biodegradability and the mechanical properties of the nanofibers. Our results showed that the increase of the PEG percentage led to a decrease of the fibers strength and an increase of the degradation rate of nanofibers in water. In order to improve the biocompatibility of the nanofibers we deposited a thin amine layer by means of the cyclopropylamine plasma polymerization in RF capacitively coupled discharge. The XPS analysis revealed that the amine layer was deposited through the entire nanofibrous mesh. The presence of the amine groups is supposed to enhance the adhesion and proliferation of the cells, thus enhancing the properties of nanofibers for biomedical applications.
This article deals with the development of fibrous non-biodegradable drainage device for drain of fluid in glaucoma disease. Currently produced implants are often associated with hypotony, undesired fibrosis, tissue damage around the implant and many others [1]. Nanofiber implant has great potential to alleviate or completely eliminate these problems. The main goal of this work was to create a drain for safety drainage of intraocular fluid from the patient eye to achieve a normal intraocular pressure. The small-diameter tubular implant (<1 mm) was developed by using the electrospinning technology. The structure was composed of two components, by using special types of collectors. The outer part was formed of non-biodegradable material that was resistant to cell growth. The inner supporting part was formed of a hydrophilic material which is also resistant to cell growth. This part prevents the compression of the outer material and a total blockage of the drain. The special structure supports the drainage of fluid. Material was subjected to morphological structures, liquid transport tests and in-vitro cell adhesion tests. The first results show great potential in the use of the implant in treatment of glaucoma disease.
Two antioxidants with relatively strong reducing properties, tannic acid and ascorbic acid, were used for the preparation of the cotton fabric with copper (I) oxide (Cu2O) nanoparticles from cupric ions sorbed into the cotton fabric. Different reducing powers of tannic acid and ascorbic acid, various concentrations of the substances used, and different reaction temperatures had an influence on the size of resulting nanoparticles and also on the resulting colour of the fabric. Its antifungal properties were investigated with the use of mixture of several fungi (genus Penicillium, Cladosporium and Chaetomium).
In burns and necrotic wounds is removal of the necrotic tissue as the first step to successful treatment. Effective wound cleansing and debridement are essential for granulation and re-epithelization. Now it is possible to replace a current very painful surgical removal with the enzymatic or autolytic debridement. Especially enzymatic debridement is a highly selective method that uses naturally occurring proteolytic enzymes. The reason why the surgical removal has not yet been replaced by painless enzymatic debridement, are low enzyme stability and a lot of factors affecting enzymes activity (type of substrate, pH, temperature, etc.).
One way of solving this problem is the enzyme immobilization on the suitable material – e.g. nanofibers with a lot of functional groups for covalent binding of the enzymes. As a supporting biocompatible and biodegradable material for immobilization of several types of enzymes were chosen electrospun silica nanofibers. Proteolytic activity of immobilized enzymes were tested under different conditions and this activity was compared with the activity in the native state.
This study presents the advantages of the combination of three-dimensional biodegradable scaffolds with the cell bioprinting. This combination uses the synergic effect of the individual components properties - a very favorable mechanical and structural properties of the fiber scafolds from polycaprolactone and the target bioprinting of hydrogel cell suspension with a high hydrophilicity.This properties very positively promotes the inner cell proliferation and the ability to create compact tissue. Scaffolds were composed of mixture of microfibers produced by meltblown technology ensuring optimal three dimensional porous structure and sufficient mechanical properties, and electrospun nanofibers for good cell adhesion. The scaffolds were suitable for combination with bioprinting due to their mechanical properties, because the only nanofibers scaffold were deformed during the bioprinting. Bioprinting was realized by CNC manipulator with a heated print head, that enabled exact dosing of hydrogel cell suspension, into the scaffolds. Hyaluron hydrogel created a favorable hydrophilic ambience after filling of the fiber structure. The preliminary in-vitro tests showed the high potential of this combination in TE - good structural and mechanical properties of the tested material allows osteoblasts to proliferate into the sample inner structure with the significant contribution of bioprinting hydrogel cell suspension to cell proliferation rate.
SPRi (Surface Plasmon Resonance Imaging) biosensors are used for real time protein detection with advantage of processing large number parallel measurements in medicine applications. Our overall goal is fast detection of low concentrations of ovalbumin and similar proteins in complex solutions (e.g. urine). A low concentration testing of proteins in urea or blood serum is needed for clinical practice. The current SPRi method has significant problems with interpretation of measurement in urine and other human fluids. These complex solutions contain different ions, which are responsible for false responses. This article shows how can artificial neural networks work as multi-parameter calibration curve to eliminate effect of ions on the measurement results.
Collagen is one of the most important part of extracellular matrix and connective tissue. Collagen type I accounts for up to 90 % of the collagen found in the body, it can be isolated and purified in large quantities and can be processed into a variety of forms. In the process of collagen treatment into nano-fibrous or submicron-fibrous form, severe conditions should be avoided which cause the denaturation of collagen and thus the gelatine content. Centrifugal spinning or electrospinning processes appear to be a promising method for spinning of collagen solutions. This paper deals with comparison of various methods applied to process collagen, mainly needle and needle-less centrifugal spinning technology and electrospinning technology. The effect of process parameters and conditions of collagen solutions on final form of material was analysed. Spun layers were prepared based on collagen type I isolated form calf skin. Nano-structured layers were prepared employing the spinning of 4–16 wt% collagen solutions in phosphate buffer saline and ethanol. Prepared layers were characterized by means of scanning electron microscopy and Fourier transform infrared spectroscopy.
Magnetic multicore iron oxide particles are nowadays intensively studied for application in magnetic hyperthermia. These particles compose of superparamagnetic iron oxide cores densely packed due to magnetic interactions. The magnetic interaction leads to the increase of energy barrier of magnetization reversal and therefore the heating losses in alternating magnetic field (AMF) can be enhanced. However, the magnetization dynamics of such systems in AMF remains unclear. Apparently, the main parameters influencing the interaction with magnetic field are the morphology of cores and multicore particles as well as the intercore and interparticle magnetic interaction. In the current study, we investigate the effect of multicore interparticle interactions. Two types of multicore particles were prepared: naked multicore particles displaying dipole-dipole interactions and (b) multicore particles with surface coating preventing the interaction of multicores. Both types of multicore particles were composed of 13 nm iron oxide cores and have the hydrodynamic size of about 85 nm. To study the absorption of AMF energy, multicore particles were dispersed in media with different viscosity (water and agarose). It was demonstrated that covered multicore particles display significantly higher heating efficiency in both media than naked particles, which is associated with the elimination of dipole-dipole interaction between multicores. ACKNOWLEDGEMENTS: This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic – Program NPU I (LO1504).
This study is aimed at silica (Si)-based carriers for drug delivery systems modified with chitosan (CS) and chitosan grafted polylactic acid (CS-g-PLA). The properties of synthesized carriers were studied through TGA, FTIR, SEM, TEM methods and the optimal reaction time, pH and concentration parameters for drug loading of doxorubicin (DOX) were established.
Si carrier showed quick and full release with burst release effect. On the other hand, pH-dependent DOX sorption efficiency on Si-Cs carrier and its subsequent release rate without an initial burst effect indicates that the polymer modifier plays a key role in the drug release process.
Surface modification of Si with CS-g-PLA influenced the DOX adsorption capacity and its release rate showing delayed and pH-dependent release trend.
Results show that surface modification of Si can serve as a simple tool to control loading and release of drugs.
ACKNOWLEDGMENTS
This work was funded by the Czech Science Foundation (grant No. 15-08287Y) and Ministry of Education, Youth and Sports of the Czech Republic (grant No. LO1504 and CZ.1.05/2.1.00/19.0409) and Internal Grant Agency IGA CPS/2016/004.
Herein we report a theranostic system based on iron oxide-gadolinium nanoparticles coated by chitosan as a dual contrast agent for magnetic resonance imaging and controlled delivery application. Iron oxide nanoparticles were prepared by reduction of iron (III) chloride followed by surface modification using arenediazonium tosylate and diethylenetriaminepentaacetic acid for Gd(III) complexation. Nanoparticles were loaded with the anticancer drug doxorubicin and coated by low molecular weight chitosan to improve stability in solution and control the release of the drug. Dynamic light scattering, -potential, thermogravimetric analysis, attenuated total refraction infrared spectroscopy and magnetic hysteresis curves reveal the success of surface modification and coating process. The amount of Gd(III) complexed and doxorubicin loaded were assessed by UV-Vis. Release studies were carried out in simulated physiological conditions. Results indicate that the obtained iron oxide-Gd(III)nanoparticles coated by chitosan are stable up to one month in physiological conditions and magnetic response is slightly decreased. The MRI analysis, doxorubicin high encapsulation efficiency and sustained release trend suggests that the presented system represents an interesting platform for the development of future theranostic agents.
Biopolymers such as polyhydroxybutyrate (PHB) occupy an important place in regenerative medicine and pharmacy and appropriate material treatment may contribute to application improvement and enhancement. This work is focused on PHB foils modification by plasma treatment for the purposes of tissue engineering. The substrates were treated by high power plasma under different conditions (plasma power, time exposure and working gas). The applied plasma power was from 50 to 200 W and as a working gas argon and oxygen were employed. Another important part of the work was the investigation of surface changes caused by the plasma treatment. The chemical analyses and changes in surface composition were performed by FTIR for the detection of new functional groups creation and XPS or RBS for the detection of element concentration. The changes of morphology were studied by AFM and FIB-SEM techniques, and also the roughness was determined by AFM. It was observed by the FIB-SEM technique that the interesting spongy structures were constructed by high power plasma modification. The treatment caused also the significant increase of surface roughness.
Currently, it is well known that metallothioneins (MTs) play substantial role in many pathophysiological processes, including carcinogenesis and they can serve as diagnostic biomarkers. In order to increase the applicability of MT in diagnostics, an easy-to-use and rapid detection method is required. The aim study was to develop a fully automated and high-throughput assay for the estimation of MT levels. We focused on the design and fabrication of a method based on isolation of MTs using paramagnetic particles (functionalized nanomaghemite γ-Fe2O3 core) with consequent detection by differential pulse voltammetry (DPV) utilizing Brdicka electrolyte. We designed and tested six types of particles, which differed in the surface functionalization [polyvinylpyrrolidone and HAuCl4; polyethyleneimine; polytheleneglycol (MW 1500 and 4000) and HAuCl4; poly(4-styrenesulfonic acid and HAuCl4; and polyacrylamide and HAuCl4]. The best conditions were employed in the automation of isolation and detection procedure, which made it simple and fast. As a proof-of-concept we successfully applied our protocol for isolation and detection of MT in serum collected from Wistar rats. The designed easy-to-use, cost-effective and fully automated procedure for the isolation of MT coupled with a simple electrochemical detection can serve for the construction of a diagnostic instrument, which would be appropriate for the monitoring of carcinogenesis or MT-related chemoresistance of tumors.
Viral-like particles that express Ebola glycoprotein on surface are very sophisticated and risky techniques for developing diagnostics and study of the virus biology. On the other hand, liposome nanoparticles are easy to prepare and have customized lipid content to encapsulate preferred cargo inside while chemically modified to carry other molecules on their surface. The aim of this study was to prepare Ebola liposome viral-like nanoparticles encapsulated with nucleic acid and to develop a polymerase chain reaction (PCR) method to quantitate liposomes without extraction. Liposomes containing equal ratios of three lipids (cholesterol, 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) and phosphatidylcholine) and carrying two fragments of Ebola partial and whole GP gene (700 bp and 2031 bp, respectively) were synthesized. Liposome size was estimated in the range of 80-100 nm. Zeta potential analysis showed a negative charge of liposome particles in the ranges of -30 and -70 mV. Direct PCR method was developed to avoid fragment loss during extraction. Several additives were tested to improve PCR detection of liposomes including DMSO, glycerol, triton X-100, tween 20 and tween 80. The addition of triton X-100 (as low as 0.5% per reaction) has showed significant improvement in amplification. The addition of MgCl2 (>50 mM per reaction) in presence of triton X-100 also improved amplification. Although a complete specific product was not obtained, the amplification was semi-quantitative at 5 orders of serial dilution. By employing PCR with shorter product sizes, we believe it is possible to develop more accurate method in the future.
Poly(N-isopropylacrylamide-acrylamide-methacrylic acid) microgels were prepared by precipitation polymerization. Silver nanoparticles were loaded inside the microgel network by in-situ reduction of silver ions using chemical reduction method. Pure and hybrid microgels were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy, Dynamic light scattering, Transmission electron microscopy and X-Ray diffraction analysis. It was found that silver nanoparticles loaded into the microgels do not affect the temperature responsive behavior of the microgels. Reduction of 4-Nitroaniline to 4-Aminoaniline was carried out in the presence of silver-poly(N-isopropylacrylamide-acrylamide-methacrylic acid) hybrid microgels to investigate their catalytic activity. The progress of reaction was monitored by UV-Visible spectrophotometry under different concentrations of hybrid microgels, NaBH4, 4-Nitroaniline and different temperature of the medium. Thermodynamic and kinetic parameters of 4-Nitroaniline reduction were evaluated to explore reaction mechanism. Catalytic activity of the hybrid system was found to be thermally tunable under a wide temperature range.
Poly(N-isopropylacrylamide-2-Hydroxyethylmethacrylate-Acrylicacid)[p(NIPAAm-HEMA-AAc)] polymer microgels were used as micro-reactors for fabrication of silver nanoparticles . Precipitation polymerization was employed to synthesize p(NIPAAm-HEMA-AAc) polymer microgels. Ag NPs were successfully fabricated within the microgels by in situ reduction method. Microgels and hybrid microgels were characterized by FTIR, UV-Visible Spectroscopy and X-Ray Diffraction analysis. Transmission Electron Microscopy (TEM) was used to determine the size of AgNPs loaded into microgels. Dynamic Light Scattering (DLS) measurements were employed to study the pH responsive nature of microgels and hybrid microgels. Effect of pH of the medium on optical properties of Ag NPs was investigated by UV-Visible spectroscopy under various pH values. Ag-p(NIPAAm-HEMA-AAc) hybrid microgels were used as catalyst for reduction of 4-NP. The effect of concentrations of NaBH4, catalyst and 4-NP on catalytic reduction of 4-NP was studied. Mechanism of catalytic reduction of 4-NP in the presence of hybrid microgels was explored on the basis of kinetic data.
The aim of this work was to evaluate the effect of four natural prebiotics (inulin, psyllium, apple fiber and hemp fiber) on viability of probiotic bacteria. Two probiotic strains, namely Lactobacillus acidophilus (CCM 4833) and Bifidobacterium breve (CCM 7825T) were co-encapsulated with selected prebiotics into alginate particles. The viability of encapsulated microorganisms during storage in acidic conditions was analysed. Also, the physicochemical evaluation of prepared particles and the viability of cells during simulated gastrointestinal conditions were tested. To analysis of probiotics light/fluorescence microscopy and flow cytometry were used. Results indicated significant improvement in survival of co-encapsulated cells compared to free cells. As the best prebiotic for co-encapsulation the hemp fiber was found. The hemp fiber exhibited the highest increase of cells count and the high viability of encapsulated bacterial cells during long-term storage. The co-encapsulation of probiotics into alginate particles leads to increased tolerance of bacteria to acidic environment. Particles also maintained their integrity during passage through the gastrointestinal tract until they reached their target destination. Therefore, prepared particles could be used in foods or food supplements with targeted transport of probiotic bacteria; ACKNOWLEDGEMENTS: This work was supported by project “Materials Research Centre – Sustainability and Development” No. LO1211 (Ministry of Education, Youth and Sport of the Czech Republic).
Many materials, like polymers, silicates, glass, play crucial role in many areas of industry, medicine or our common life due to their properties. But their surface properties can limit their further use in some areas. Physical or chemical modification of these surfaces can change their chemical composition and subsequent better adhesion of grafted compounds. We can use this for development of new materials for electronics, optics or bioapplication. We have modified surfaces of polymers (foils or powder) and glass by chemical methods and we studied the changes of surface properties. The surfaces were activated with Piranha solution. The activated surfaces were grafted with selected chemical compounds and subsequently with different boron compounds. The surface properties of the modified materials changed significantly and were studied using various techniques. Some antimicrobial tests have been applied on selected samples.
Nowadays, biocompatible polymers are sought-after materials in health-care industry. Their long-term applications, however, lead to the development of infection which must be often suppressed by antibiotic therapy. Resulting problem of resistance of pathogenic bacteria to conventional antibiotics can be effectively solved by antibacterial treatment of medical devices. Nanostructured noble metals, such as Ag and Pd, could be advantageously used. We report on antibacterial activity of Ag and Pd nanostructures prepared by DC sputtering on polymeric foils (PI, PEN). Such metal nanolayers of variable thicknesses were transformed by low-temperature post-deposition annealing into discrete nanoislands homogeneously distributed over the underlying polymer. The possibility of managing nanostructure size via controlling the thickness of metal nanolayers prior to the annealing was shown. The surface of engineered metal/polymer composites was characterized and achieved results were discussed with regard to structural changes induced by annealing. Antibacterial properties of these composites were evaluated using Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli as model bacterial strains. The way of nanoisland formation and subsequent antibacterial response of prepared metal/polymer composites significantly differ in case of Ag/PI and Pd/PEN.
The present work is focused on preparation of polysaccharide films, which were doped with silver nanoparticles for enhancement of antibacterial properties. Silver nanoparticles (AgNPs) were prepared and stabilized by reduction of silver nitrate with chitosan without adding reducing agents. The presence of AgNPs was studied by X-ray photoelectron spectroscopy. Wettability and water absorption of the films were evaluated. Antibacterial activity of solid films with AgNPs was tested by disc diffusion test on two bacterial strains, Gram-positive (Staphylococcus epidermidis) and Gram-negative (Escherichia coli). Solid films were dissolved and then the solution was observed by the ultraviolet–visible spectroscopy and transmission electron microscopy. Aging of the solutions which were stored in day light and in a dark were tested. The presence of AgNPs was confirmed both in the solid films and in the solutions by the above mentioned methods and the films exhibited antibacterial activity against both bacterial strains. The research was aiming on use of these films in medicine as a new type of wound dressing with antibacterial properties. These films could be used as a wound dressing, antimicrobial packaging material or as a long-term storage of AgNPs for various applications.
Polyethylene (PE) is a synthetic polymer used for biomedical applications and tissue engineering. Surface modification of this material relates to changes of its surface hydrophilicity, chemistry, morphology, microstructure, roughness, and topography, all influencing its biological response. This our research was focused on modification of PE by argon plasma discharge and then grafting with biologically active polyethylene glycol (PEG) with the aim to enhance its cytocompatibility of the cell lines L929 of mouse fibroblast. The surface properties of pristine PE and its grafted counterparts were studied by different experimental techniques: X-ray spectroscopy, goniometry, Atomic Force Microscopy and electrokinetic analysis (zeta potential). Our results show that grafting of PEG leads to higher wettability, surface roughness, and thus the adhesion and proliferation of cultured cells.
Nowadays nanofibers become an integral part of any field of science. One of the most popular methods for producing nanofibers is electrospinning. In our research work, we also used this method. Traditional static collector was replaced with rotating consisting of several metal bars which have been placed in a circle. In these way metallic elements catches nanofibers like tradition collector and wounds it. In the end we eventually obtained layer consisting of parallel directed nanofibers. Further the material is collected and sent to the post-processing. It is planned to be used in medicine, in particular for producing implants for treating glaucoma disease. Experimentally it was revealed that the shape, size, material of which the rods of the collecting head play an important role on the fiber collection efficiency.
This article describes an experiment in which several different types of collecting heads were used. The experiment was conducted at the same temperature and humidity. Polyvinyl alcohol was used as the polymer solution.
In this study we present immunosensing microarray glass chip based on newly developed high affinity binders of human serum albumin (HSA). We compare two newly synthesized recombinant binders with one commercially avaliable protein Affibody. First binder (PAB) contain one albumin binding domain of the protein G (ABD) fused with TolA chain and one biotin per molecule. Second binder (SI-SA) contain four ABD domains fused with streptavidin. Commercial protein Affibody (AF) is based on the scaffold of one of the IgG-binding domains of Protein A and it was obtained in biotinylated form.
Designed chips offered 24 independent testing zones. The surfaces of glass chips were micropatterened by UV-photolitography techniques on sputtered chromium layers. Recombinant proteins were selectively captured in oriented manner using heterofunctional polyetgylenglycols into active zones of micropatterns modified by (3-aminopropyl)trietoxysilane (APTES).
The detection capability of the immunosensor was tested by performing detection of fluorescently labelled HSA in the presence of 1% bovine serum albumin (BSA) and 6% fetal serum (FBS). Results obtained in performed assays show that SI-SA binder has lower LOD and PAB binder has similar LOD to commertial Affibody Prepared immunosensing chips can estimate HSA in range 2-30 µg/ml in urine samples in competition assays and does not require any pre-treatment. Presented chip can be further developed for bioanalytical purposes in medicine and can be used to identify HSA, which presence in urine samples is often connected to kidney damage.
A novel design of the thermal based biosensor has been developed and characterised. Its detection method is based on the heat transfer method (HTM), which has been developed within the institute. This method detects the change of the heat transfer, which is caused by the change of thermal resistivity of the bioreceptor.
The new design uses the transient plane source (TPS) as the transducer. It is an electrically conductive meander trace that produces heat when sourcing current through it. That heat will increase the temperature of the TPS itself which can be monitored by monitoring the change of the trace’s electrical resistance. By relating the amount of current to the level and rate of change of the temperature, the thermal resistivity of the receptor can be determined.
An increased sensitivity has been established over the first setup that was employed to prove the heat transfer method. Furthermore the sensor has decreased in size, does not require the addition of reagents and is much cheaper.
The experiments carried out in this work were performed with a sensor functionalized with molecularly imprinted polymers (MIPs) for the detection of chloramphenicol. However, the sensor has the possibility to employ different bioreceptors and detect different biological events. In addition, the sensor can also be exploited to characterise fluids, for example the fat concentration of milk.
The new design is an important step in valorising the thermal based biosensor. Indeed, for marketing purposes low cost and small size are important advantages.
Polyaniline (PANI) is an organic polymer which possesses metallic conductivity and can be grown 1-dimensionally in the form of a nanowire. In this research the potentiostatic method was applied at the constant potential of 0.75 V to electrochemically deposit PANI nanowires on the stainless steel electrode. Morphological studies of the sample was carried out by transmission electron microscopy (TEM) and it was observed that nanowires with 30–50 nm diameters were fabricated. Cyclic voltammetry (CV), scanning electron microscopy (SEM), and UV–vis absorption spectra were applied to characterize the PANI nanowires, and the results revealed that ultra-thin nanowires displayed high electrochemical activity. A single stranded Deoxyribonucleic acid (ssDNA) was fixed on PANI nanowires to investigate the efficiency of the system as a biosensor platform. Sensitivity of the PANI electrode was detected by measuring peak currents in differential pulse voltammetry (DPV) after hybridization with different concentrations of the ssDNA. It was concluded that the system worked well even at low concentrations, and large peak current values at the order of mA were produced. Electrochemical impedance spectroscopy (EIS) of the sensor electrode was carried out with an Autolab-30 potentiostat/galvanostat to understand chemical transformations and processes associated with conducting polymer supported electrodes. The changes in impedance indicated that the system was extremely effective at low (10−16M) concentrations.
Altered and dysregulated glycosylation is an universal attribute of pathological processes and malignant transformation in a human body [1]. Thus, analysis of altered glycans decorating the protein are becoming a reliable diagnostic tool for early-stage cancer diagnosis. Integration of antibodies as biological recognition elements, lectins as proteins capable to bind towards specific glycan components within an ultrasensitive label-free biosensing platform (electrochemical impedance spectroscopy - EIS) [2] is a promising approach for discovery of novel cancer glyco-biomarkers. In this study, we focus on the fabrication of sensitive lectin-based immunoassay with final lectin glycoprofiling. The glycan analysis was performed with lectins as proteins capable of binding to specific sub-glycoproteome (i.e. differentiation of terminal α-2,3- and α-2,6-sialic acid present on glycan). Here we discuss key optimization steps of sandwich biosensor platform, a specificity of our label-free approach, a reduction of non-specific binding and importantly glycoprofiling of depleted (IgG/HSA) serum samples from healthy controls and patients suffering prostate cancer [3]. Fabricated label-free biosensor was executed with EIS with investigation of changes in charge transfer resistance (Rct). Moreover, the results were correlated with lectin microarray experiments and enzyme-linked lectin assays (ELLA). ACKNOWLEDGEMENTS: This work was supported by the National Priorities Research Program (Qatar National Research Fund), number of project NPRP 6-381-1-078. REFERENCES: [1] Varki A., Cummings R.D., Esko J.D., et al. (2009). Cold Spring Harbor Laboratory Press.; [2] Pihikova D., Belicky Š., Kasák P., et al. (2015). Analyst 141, p. 1044-1051.; [3] Pihikova D., Kasak P., Kubanikova P., et al. (2016). Analytica Chimica Acta 934, p. 72-79.
Due to their quasi solid state and plenty of electrolyte solution within, hydrogel electrolytes have great potential to be used in flexible supercapacitors (SCs) which is one important group of energy storage systems for portable devices. However, most hydrogels are not appropriate because of their low mechanical properties and bad contact with flexible electrodes, especially under various deformations. Therefore, in our research attention has been given for the preparation of a novel hydrogel electrolyte having a double network structure created by ploy acrylic acid (PAA), sodium alginate (SA) and bacterial cellulose (BC), designated as “PAA-SA-BC”. This “PAA-SA-BC” hydrogel was formed due to polymerization of a chemically crosslinked polymer poly(ethylene glycol) diacrylate (PEGDA) and acrylic acid (AA) where SA was ionicaly crosslinked and then finally reinforced by BC cluster (composed of BC nanofibers). The resultant hydrogel “PAA-SA-BC” was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) which confirmed the presence of PAA, SA and BC nanofibers. Mechanical properties, ionic conductivity as well as shrinkage properties of “PAA-SA-BC” in presence of potassium chloride (KCl) were investigated. Finally, a flexible SC was achieved by in-situ preparing this hydrogel electrolyte (PAA-SA-BC) directly on two graphene based flexible electrodes. The electrochemical performances of this SC were consequently studied. The observed results, revealed that the novel PAA-SA-BC hydrogel electrolyte has a promising use in flexible SCs.; ACKNOWLEDGEMENTS: This work is supported by (IGA/CPS/2016/003), (LH 14273 KONTAKT II) as well as Open Project of East China University of Science and Technology.