This study investigates various microfluidic chip fabrication techniques, highlighting their applicability and limitations in the context of urgent diagnostic needs showcased by the COVID-19 pandemic. Through a detailed examination of methods such as computer numerical control milling of a polymethyl methacrylate, soft lithography for polydimethylsiloxane-based devices, xurography for glass-glass chips, and micromachining-based silicon-glass chips, we analyze each technique's strengths and trade-offs. Hence, we discuss the fabrication complexity and chip thermal properties, such as heating and cooling rates, which are essential features of chip utilization for a polymerase chain reaction. Our comparative analysis reveals critical insights into material challenges, design flexibility, and cost-efficiency, aiming to guide the development of robust and reliable microfluidic devices for healthcare and research. This work underscores the importance of selecting appropriate fabrication methods to optimize device functionality, durability, and production efficiency.
- MeSH
- COVID-19 * virologie MeSH
- design vybavení MeSH
- dimethylpolysiloxany chemie MeSH
- laboratoř na čipu * MeSH
- lidé MeSH
- mikrofluidika metody přístrojové vybavení MeSH
- mikrofluidní analytické techniky přístrojové vybavení metody MeSH
- polymethylmethakrylát chemie MeSH
- SARS-CoV-2 izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
OBJECTIVE: The aim of the study was to demonstrate that an administration of mucolytic solution with a maximum dose of simethicone and n -acetylcysteine before upper endoscopy improves mucosal visibility compared to a group without administration of mucolytic solution or water. METHODS: This study was a double-blind, randomized controlled trial. Patients were randomized into four groups, with the administration of 100 ml of water + 600 mg n -acetylcysteine + 400 mg simethicone, 100 ml of water + 400 mg n -acetylcysteine + 20 mg simethicone, 100 ml of water, and without any water or mucolytic solution. During the examination, a total of 10 images were taken in the defined areas. The overall visibility score was given by the sum of the 0-5 scores of the five areas and was assessed by the endoscopist performing the procedure and the blinded endoscopists using static images. RESULTS: A total of 129 patients were randomized. The group of patients did not differ in age, sex distribution, and indications significantly. The overall visibility score as assessed by the endoscopist performing the procedure was significantly higher in the group with the maximum dose of mucolytic solution compared to the group without solution or water (18.9 ± 2.9 vs. 16.6 ± 3.3, P = 0.023). This difference was not evident by the blinded evaluation of static photographs. CONCLUSION: Administration of mucolytic solution with a maximum dose of n -acetylcysteine and simethicone before upper endoscopy improved mucosal visibility in the upper gastrointestinal tract compared with the group without any preparation while evaluated by performing endoscopist.
- MeSH
- acetylcystein * MeSH
- dvojitá slepá metoda MeSH
- expektorancia * MeSH
- gastrointestinální endoskopie metody MeSH
- lidé MeSH
- simethikon MeSH
- voda MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
Hydrophobic fibrous slippery liquid-infused porous surfaces (SLIPS) were fabricated by electrospinning polydimethylsiloxane (PDMS) and polystyrene (PS) as a carrier polymer on plasma-treated polyethylene (PE) and polyurethane (PU) substrates. Subsequent infusion of blackseed oil (BSO) into the porous structures was applied for the preparation of the SLIPS. SLIPS with infused lubricants can act as a repellency layer and play an important role in the prevention of biofilm formation. The effect of polymer solutions used in the electrospinning process was investigated to obtain well-defined hydrophobic fibrous structures. The surface properties were analyzed through various optical, macroscopic and spectroscopic techniques. A comprehensive investigation of the surface chemistry, surface morphology/topography, and mechanical properties was carried out on selected samples at optimized conditions. The electrospun fibers prepared using a mixture of PDMS/PS in the ratio of 1:1:10 (g/g/mL) using tetrahydrofuran (THF) solvent showed the best results in terms of fiber uniformity. The subsequent infusion of BSO into the fabricated PDMS/PS fiber mats exhibited slippery behavior regarding water droplets. Moreover, prepared SLIPS exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli bacterium strains.
- MeSH
- dimethylpolysiloxany * MeSH
- Escherichia coli MeSH
- polymery chemie MeSH
- polystyreny * MeSH
- poréznost MeSH
- Publikační typ
- časopisecké články MeSH
Typically, polymeric composites containing nanoparticles are realized by incorporating pre-made nanoparticles into a polymer matrix by using blending solvent or by the reduction of metal salt dispersed in the polymeric matrix. Generally, the production of pre-made Au NPs occurs in liquids with two-step processes: producing the gold nanoparticles first and then adding them to the liquid polymer. A reproducible method to synthetize Au nanoparticles (NPs) into polydimethylsiloxane (PDMS) without any external reducing or stabilizing agent is a challenge. In this paper, a single-step method is proposed to synthetize nanoparticles (NPs) and at the same time to realize reproducible porous and bulk composites using laser ablation in liquid. With this single-step process, the gold nanoparticles are therefore produced directly in the liquid polymer. The optical properties of the suspensions of AuNPs in distilled water and in the curing agent have been analyzed by the UV-VIS spectroscopy, employed in the transmission mode, and compared with those of the pure curing agent. The electrical dc conductivity of the porous PDMS/Au NPs nanocomposites has been evaluated by the I-V characteristics. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis have monitored the composition and morphology of the so-obtained composites and the size of the fabricated Au nanoparticles. Atomic force microscopy (AFM) has been used to determine the roughness of the bulk PDMS and its Au NP composites.
A microfluidic device made of polydimethylsiloxane was developed for continuous evaluation of natural migration mobility of many eukaryotic cells in relaxed and deformed state. The device was fabricated by standard photolithography and soft lithography techniques using the SU-8 3010 negative photoresist on a glass wafer as the master mold. The simple flow-free device exploits the chemotactic movement of cells through a set of mechanical barriers in the direction of concentration gradients of attractants. The barriers are formed by arrays of circular cross-section pillars with decreasing spacing 7, 5, and 3 μm. To pass through the obstacles, the cells are deformed and change their cytoskeletal architecture. The instantaneous migration velocities of cells are monitored in a time-lapse setup of the scanning confocal microscope. Thus, the cellular deformability and migratory activity can easily be evaluated. The functionality of the device was tested with model HeLa cells stably transfected with fluorescent Premo FUCCI Cell Cycle Sensor. The designed device has the potential to be implemented for testing the tendency of patients' tumors to metastasis.
- MeSH
- buněčné kultury přístrojové vybavení MeSH
- design vybavení MeSH
- dimethylpolysiloxany chemie MeSH
- HeLa buňky MeSH
- konfokální mikroskopie MeSH
- lidé MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- pohyb buněk fyziologie MeSH
- tvar buňky fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Despite great efforts, the design of antibacterial surfaces is still a challenge. In this work, results of structural, mechanical, cytotoxic and antibacterial activities of hydrophobic carbon quantum dots/polydimethylsiloxane surfaces are presented. Antibacterial action of this surface is based on the generation of reactive oxygen species which cause bacteria damage by oxidative stress. At the same time, this surface was not cytotoxic towards the NIH/3T3 cells. Swelling-encapsulation-shrink method is applied for encapsulation of hydrophobic carbon quantum dots in medical grade silicone-polydimethylsiloxane. XPS and photoluminescence spectroscopy analyses confirm that hydrophobic carbon quantum dots have been encapsulated successfully into polydimethylsiloxane polymer matrix. Based on stress-strain test the improvement of mechanical properties of these nanocomposites is established. It is shown by electron paramagnetic resonance spectroscopy and luminescence method that nanocomposite generates singlet oxygen initiated by 470 nm blue light irradiation. Antibacterial testing shows the nanocomposite in the form of foil kills Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae and is very effective after only a 15 min irradiation.
- MeSH
- dimethylpolysiloxany farmakologie MeSH
- Escherichia coli účinky léků MeSH
- fotochemoterapie metody MeSH
- Klebsiella pneumoniae účinky léků MeSH
- kvantové tečky terapeutické užití MeSH
- myši MeSH
- nanokompozity terapeutické užití MeSH
- povrchové vlastnosti MeSH
- singletový kyslík metabolismus MeSH
- Staphylococcus aureus účinky léků MeSH
- uhlík farmakologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- Clensia,
- MeSH
- fixní kombinace léků MeSH
- hodnocení léčiv MeSH
- kolonoskopie ošetřování MeSH
- lidé MeSH
- předoperační péče MeSH
- projímadla * farmakologie terapeutické užití MeSH
- simethikon farmakologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Klíčová slova
- alverin, METEOSPASMYL,
- MeSH
- fixní kombinace léků MeSH
- hodnocení léčiv MeSH
- lidé MeSH
- metaanalýza jako téma MeSH
- parasympatolytika farmakologie terapeutické užití MeSH
- propylaminy farmakologie terapeutické užití MeSH
- randomizované kontrolované studie jako téma MeSH
- simethikon farmakologie terapeutické užití MeSH
- syndrom dráždivého tračníku * farmakoterapie MeSH
- Check Tag
- lidé MeSH
Methods for the separation and determination of terpenes (mono- and sesqui-) and phenylpropanoids such as eugenol and methyleugenol from samples of allspice berries have been developed. Chromatographic analyses of isolated groups of compounds were carried out by means of gas chromatography coupled with mass spectrometry. A comparison of various types of solid-phase microextraction fibers was performed. The highest yields of terpenes were extracted by polydimethylsiloxane and divinylbenzene/Carboxen/polydimethylsiloxane fibers (almost the same for these two fibers), approximately twice as much as by Carbowax/divinylbenzene fiber. The highest amounts of monoterpenes were extracted by divinylbenzene/Carboxen/polydimethylsiloxane fiber, and the highest amounts of sesquiterpenes were extracted by polydimethylsiloxane fiber. Moreover, the effect of water addition on extraction yields as well as time and temperature of extraction were tested. Aroma profiles of extracts obtained by solid-phase microextraction and essential oil obtained by hydrodistillation of allspice berries were compared. The aroma profile of the divinylbenzene/Carboxen/polydimethylsiloxane fiber extract was similar to the aroma profile of essential oil. Particular characteristics of volatile allspice matters were presented. The linear retention indices for each compound were calculated.
- MeSH
- destilace MeSH
- dimethylpolysiloxany chemie MeSH
- mikroextrakce na pevné fázi metody MeSH
- monoterpeny chemie MeSH
- oleje prchavé MeSH
- Pimenta (rod) chemie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- polyethylenglykoly chemie MeSH
- seskviterpeny chemie MeSH
- teplota MeSH
- terpeny analýza chemie MeSH
- vinylové sloučeniny chemie MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
A deep understanding of the interaction between cancerous cells and surfaces is particularly important for the design of lab-on-chip devices involving the use of polydimethylsiloxane (PDMS). In our studies, the effect of PDMS substrate stiffness on mechanical properties of cancerous cells was investigated in conditions where the PDMS substrate is not covered with any of extracellular matrix proteins. Two human prostate cancer (Du145 and PC-3) and two melanoma (WM115 and WM266-4) cell lines were cultured on two groups of PDMS substrates that were characterized by distinct stiffness, i.e. 0.75 ± 0.06 MPa and 2.92 ± 0.12 MPa. The results showed the strong effect on cellular behavior and morphology. The detailed analysis of chemical and physical properties of substrates revealed that cellular behavior occurs only due to substrate elasticity.
- MeSH
- biomechanika MeSH
- dimethylpolysiloxany chemie farmakologie MeSH
- fibrinogen chemie MeSH
- lidé MeSH
- mechanické jevy * MeSH
- melanom patologie MeSH
- mikročipové analytické postupy MeSH
- nádorové buněčné linie MeSH
- nádory prostaty patologie MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- pružnost MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
