Článek pojednává o nejčastějších možnostech využití povrchové elektromyografie. Shrnuje především biomechanické a kineziologické aplikace: pozorování timingu (načasování svalového zapojení), velikosti aktivace a únavy svalu. Sledování funkce svalů umožňuje analýzu lidského pohybu. Je však nutné respektovat vliv dalších faktorů, které se na vzniku signálu podílejí. Studie upozorňuje na omezené možnosti i perspektivy využití v souvislosti se sledováním a hodnocením neuromuskulárních poruch.
The paper deals with the most frequent possibilities of application of surface electromyography. It summarizes above all biomechanical and kinesiological applications: observation of the timing of muscle involvement, magnitude of muscle activation and fatigue. Investigation of muscular function makes analysis of human motion possible. It is however necessary to respect the influence of further factors which participate in the development of the signal. The investigation draws attention to the limited possibilities and perspectives of application in conjunction with the investigation and evaluation of neuromuscular disorders.
- MeSH
- Electromyography methods utilization MeSH
- Humans MeSH
- Muscle Fatigue physiology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Specifically designed and functionalized nanoparticles hold great promise for biomedical applications. Yet, the applicability of nanoparticles is critically predetermined by their surface functionalization and biodegradability. Here we demonstrate that amino-functionalized polystyrene nanoparticles (PS-NH2), but not amino- or hydroxyl-functionalized silica particles, trigger cell death in hepatocellular carcinoma Huh7 cells. Importantly, biodegradability of nanoparticles plays a crucial role in regulation of essential cellular processes. Thus, biodegradable silica nanoparticles having the same shape, size and surface functionalization showed opposite cellular effects in comparison with similar polystyrene nanoparticles. At the molecular level, PS-NH2 obstruct and amino-functionalized silica nanoparticles (Si-NH2) activate the mTOR signalling in Huh7 and HepG2 cells. PS-NH2 induced time-dependent lysosomal destabilization associated with damage of the mitochondrial membrane. Solely in PS-NH2-treated cells, permeabilization of lysosomes preceded cell death. Contrary, Si-NH2 nanoparticles enhanced proliferation of HuH7 and HepG2 cells. Our findings demonstrate complex cellular responses to functionalized nanoparticles and suggest that nanoparticles can be used to control activation of mTOR signaling with subsequent influence on proliferation and viability of HuH7 cells. The data provide fundamental knowledge which could help in developing safe and efficient nano-therapeutics.
- MeSH
- Adsorption MeSH
- Amines chemistry MeSH
- Carcinoma, Hepatocellular metabolism pathology MeSH
- Protein Conformation MeSH
- Lysosomes metabolism MeSH
- Cell Line, Tumor MeSH
- Liver Neoplasms metabolism pathology MeSH
- Nanoparticles chemistry MeSH
- Silicon Dioxide chemistry MeSH
- Permeability MeSH
- Polystyrenes chemistry MeSH
- Surface Properties MeSH
- Cell Proliferation MeSH
- Ribonucleases metabolism MeSH
- Serum Albumin, Bovine metabolism MeSH
- Signal Transduction * MeSH
- Cattle MeSH
- TOR Serine-Threonine Kinases metabolism MeSH
- Animals MeSH
- Check Tag
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The non-specific binding of non-target species to functionalized surfaces of biosensors continues to be challenge for biosensing in real-world media. Three different low-fouling and functionalizable surface platforms were employed to study the effect of functionalization on fouling resistance from several types of undiluted media including blood plasma and food media. The surface platforms investigated in this work included two polymer brushes: hydroxy-functional poly(2-hydroxyethyl methacrylate) (pHEMA) and carboxy-functional poly(carboxybetaine acrylamide) (pCBAA), and a standard OEG-based carboxy-functional alkanethiolate self-assembled monolayer (AT-SAM). The wet and dry polymer brushes were analyzed by AFM, ellipsometry, FT-IRRAS, and surface plasmon resonance (SPR). The surfaces were functionalized by the covalent attachment of antibodies, streptavidin, and oligonucleotides and the binding and biorecognition characteristics of the coatings were compared. We found that functionalization did not substantially affect the ultra-low fouling properties of pCBAA (plasma fouling of ~20 ng/cm(2)), a finding in contrast with pHEMA that completely lost its resistance to fouling after the activation of hydroxyl groups. Blocking a functionalized AT-SAM covalently with BSA decreased fouling down to the level comparable to unblocked pCBAA. However, the biorecognition capability of blocked functionalized AT-SAM was poor in comparison with functionalized pCBAA. Limits of detection of Escherichia coli O157:H7 in undiluted milk were determined to be 6×10(4), 8×10(5), and 6×10(5) cells/ml for pCBAA, pHEMA, and AT-SAM-blocked, respectively. Effect of analyte size on biorecognition activity of functionalized coatings was investigated and it was shown that the best performance in terms of overall fouling resistance and biorecognition capability is provided by pCBAA.
- MeSH
- Adsorption MeSH
- Acrylamides chemistry MeSH
- Escherichia coli isolation & purification MeSH
- Limit of Detection MeSH
- Milk microbiology MeSH
- Polyhydroxyethyl Methacrylate chemistry MeSH
- Polymers chemistry MeSH
- Surface Plasmon Resonance methods MeSH
- Surface Properties MeSH
- Sulfhydryl Compounds chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Práca poskytuje prehľad najnovších poznatkov o funkcii Eustachovej trubice v súvislosti s povrchovoaktívnym materiálom – surfaktantom, ktorý vystieľa jej povrch. Zdôrazňuje sa vzťah medzi poškodením surfaktantového systému a dysfunkciou Eustachovej trubice s následným rozvojom zápalu stredného ucha. Diskutujú sa výsledky štúdií, ktoré naznačujú možné trendy vo využití exogénneho surfaktantu v liečbe otitis media.
The authors give a review of the current knowledge on the function of the Eustachian tube (ET) regarding the surface-active material - surfactant – present at its mucosal surface. Detergent-like surface properties of ET linning fluid act to support ET function by facilitating the intermittent opening and closure of its lumen. Specialized cells in ET epithelium express surfactant specific proteins SP-A and SP-D and these proteins are secreted into the ET lumen. They play a role in local immune mechanisms by clearance of pathogenes and acting as immunomodulators. Dysfunction of the local mucosal immunity in the ET may predispose infants to recurrent otitis media. Administration of surfactant improves mechanical properties of ET and restores the impaired local immunity. The authors further discuss the results of the experimental studies in order to indicate the future trends in the use of exogenous surfactant for the treatment of otitis media.
- MeSH
- Biomedical Research MeSH
- Humans MeSH
- Finger Injuries MeSH
- Fingers surgery MeSH
- Transplantation methods MeSH
- Check Tag
- Humans MeSH
Scaffolds populated with human cardiac progenitor cells (CPCs) represent a therapeutic opportunity for heart regeneration after myocardial infarction. In this work, square-grid scaffolds are prepared by melt-extrusion additive manufacturing from a polyurethane (PU), further subjected to plasma treatment for acrylic acid surface grafting/polymerization and finally grafted with laminin-1 (PU-LN1) or gelatin (PU-G) by carbodiimide chemistry. LN1 is a cardiac niche extracellular matrix component and plays a key role in heart formation during embryogenesis, while G is a low-cost cell-adhesion protein, here used as a control functionalizing molecule. X-ray photoelectron spectroscopy analysis shows nitrogen percentage increase after functionalization. O1s and C1s core-level spectra and static contact angle measurements show changes associated with successful functionalization. ELISA assay confirms LN1 surface grafting. PU-G and PU-LN1 scaffolds both improve CPC adhesion, but LN1 functionalization is superior in promoting proliferation, protection from apoptosis and expression of differentiation markers for cardiomyocytes, endothelial and smooth muscle cells. PU-LN1 and PU scaffolds are biodegraded into non-cytotoxic residues. Scaffolds subcutaneously implanted in mice evoke weak inflammation and integrate with the host tissue, evidencing a significant blood vessel density around the scaffolds. PU-LN1 scaffolds show their superiority in driving CPC behavior, evidencing their promising role in myocardial regenerative medicine.
- MeSH
- Biomimetics MeSH
- Stem Cells cytology physiology MeSH
- Cells, Cultured MeSH
- Middle Aged MeSH
- Humans MeSH
- Myocardium MeSH
- Mice MeSH
- Polyurethanes chemistry MeSH
- Guided Tissue Regeneration methods MeSH
- Heart Atria cytology MeSH
- Materials Testing MeSH
- Tissue Engineering * MeSH
- Tissue Scaffolds * MeSH
- Stem Cell Transplantation * MeSH
- Animals MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Composite materials based on a titanium support and a thin, alginate hydrogel could be used in bone tissue engineering as a scaffold material that provides biologically active molecules. The main objective of this contribution is to characterize the activation and the functionalization of titanium surfaces by the covalent immobilization of anchoring layers of self-assembled bisphosphonate neridronate monolayers and polymer films of 3-aminopropyltriethoxysilane and biomimetic poly(dopamine). These were further used to bind a bio-functional alginate coating. The success of the titanium surface activation, anchoring layer formation and alginate immobilization, as well as the stability upon immersion under physiological-like conditions, are demonstrated by different surface sensitive techniques such as spectroscopic ellipsometry, infrared reflection-absorption spectroscopy and X-ray photoelectron spectroscopy. The changes in morphology and the established continuity of the layers are examined by scanning electron microscopy, surface profilometry and atomic force microscopy. The changes in hydrophilicity after each modification step are further examined by contact angle goniometry.
- Publication type
- Journal Article MeSH
