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

Repairing and regenerating damaged tissues or organs, and restoring their functioning has been the ultimate aim of medical innovations. 'Reviving healthcare' blends tissue engineering with alternative techniques such as hydrogels, which have emerged as vital tools in modern medicine. Additive manufacturing (AM) is a practical manufacturing revolution that uses building strategies like molding as a viable solution for precise hydrogel manufacturing. Recent advances in this technology have led to the successful manufacturing of hydrogels with enhanced reproducibility, accuracy, precision, and ease of fabrication. Hydrogels continue to metamorphose as the vital compatible bio-ink matrix for AM. AM hydrogels have paved the way for complex 3D/4D hydrogels that can be loaded with drugs or cells. Bio-mimicking 3D cell cultures designed via hydrogel-based AM is a groundbreaking in-vivo assessment tool in biomedical trials. This brief review focuses on preparations and applications of additively manufactured hydrogels in the biomedical spectrum, such as targeted drug delivery, 3D-cell culture, numerous regenerative strategies, biosensing, bioprinting, and cancer therapies. Prevalent AM techniques like extrusion, inkjet, digital light processing, and stereo-lithography have been explored with their setup and methodology to yield functional hydrogels. The perspectives, limitations, and the possible prospects of AM hydrogels have been critically examined in this study.

• MeSH
• 3D tisk MeSH
• bioprinting metody   MeSH
• buněčné kultury MeSH
• hydrogely * chemie   MeSH
• lékové transportní systémy MeSH
• lidé MeSH
• techniky 3D buněčné kultury metody   MeSH
• tkáňové inženýrství * metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Live cells act as biological lenses and can be employed as real-world optical components in bio-hybrid systems. Imaging at nanoscale, optical tweezers, lithography and also photonic waveguiding are some of the already proven functionalities, boosted by the advantage that cells are fully biocompatible for intra-body applications. So far, various cell types have been studied for this purpose, such as red blood cells, bacterial cells, stem cells and yeast cells. White Blood Cells (WBCs) play a very important role in the regulation of the human body activities and are usually monitored for assessing its health. WBCs can be considered bio-lenses but, to the best of our knowledge, characterization of their optical properties have not been investigated yet. Here, we report for the first time an accurate study of two model classes of WBCs (i.e., monocytes and lymphocytes) by means of a digital holographic microscope coupled with a microfluidic system, assuming WBCs bio-lens characteristics. Thus, quantitative phase maps for many WBCs have been retrieved in flow-cytometry (FC) by achieving a significant statistical analysis to prove the enhancement in differentiation among sphere-like bio-lenses according to their sizes (i.e., diameter d) exploiting intensity parameters of the modulated light in proximity of the cell optical axis. We show that the measure of the low intensity area (S: Iz

• MeSH
• holografie * metody   MeSH
• lidé MeSH
• lymfocyty MeSH
• mikroskopie * metody   MeSH
• monocyty MeSH
• optika a fotonika MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Many dynamic interactions within the cell microenvironment modulate cell behavior and cell fate. However, the pathways and mechanisms behind cell-cell or cell-extracellular matrix interactions remain understudied, as they occur at a nanoscale level. Recent progress in nanotechnology allows for mimicking of the microenvironment at nanoscale in vitro; electron-beam lithography (EBL) is currently the most promising technique. Although this nanopatterning technique can generate nanostructures of good quality and resolution, it has resulted, thus far, in the production of only simple shapes (e.g., rectangles) over a relatively small area (100 × 100 μm), leaving its potential in biological applications unfulfilled. Here, we used EBL for cell-interaction studies by coating cell-culture-relevant material with electron-conductive indium tin oxide, which formed nanopatterns of complex nanohexagonal structures over a large area (500 × 500 μm). We confirmed the potential of EBL for use in cell-interaction studies by analyzing specific cell responses toward differentially distributed nanohexagons spaced at 1000, 500, and 250 nm. We found that our optimized technique of EBL with HaloTags enabled the investigation of broad changes to a cell-culture-relevant surface and can provide an understanding of cellular signaling mechanisms at a single-molecule level.

• MeSH
• buněčná diferenciace MeSH
• buněčné kultury MeSH
• extracelulární matrix MeSH
• nanostruktury * chemie   MeSH
• nanotechnologie * metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study, a highly sensitive, fast, and selective enzyme-free electrochemical sensor based on the deposition of Ni cavities on conductive glass was proposed for insulin detection. Considering the growing prevalence of diabetes mellitus, an electrochemical sensor for the determination of insulin was proposed for the effective diagnosis of the disease. Colloidal lithography enabled deposition of nanostructured layer (substrate) with homogeneous distribution of Ni cavities on the electrode surface with a large active surface area. The morphology and structure of conductive indium tin oxide glass modified with Ni cavities (Ni-c-ITO) were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The diameter of the resulting cavities was approximately 500 nm, while their depth was calculated at 190 ± 4 nm and 188 ± 18 nm using AFM and SEM, respectively. The insulin assay performance was evaluated by cyclic voltammetry. Ni-c-ITO exhibited excellent analytical characteristics, including high sensitivity (1.032 μA μmol-1 dm3), a low detection limit (156 μmol dm-3), and a wide dynamic range (500 nmol dm-3 to 10 μmol dm-3). Finally, the determination of insulin in buffer with interferents and in real blood serum samples revealed high specificity and demonstrated the practical potential of the method.

• MeSH
• biosenzitivní techniky * metody   MeSH
• elektrochemické techniky metody   MeSH
• elektrody MeSH
• inzulin MeSH
• nanostruktury * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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

Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared on transparent membranes which are very fragile and difficult to manipulate. We present processes for the fabrication of samples with magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for Lorentz transmission electron microscopy and magnetic transmission x-ray microscopy studies. The samples are prepared on silicon nitride membranes and the fabrication consists of a spin coating, UV and electron-beam lithography, the chemical development of the resist, and the evaporation of the magnetic material followed by a lift-off process forming the final magnetic structures. The samples for the Lorentz transmission electron microscopy consist of magnetic nanodiscs prepared in a single lithography step. The samples for the magnetic x-ray transmission microscopy are used for time-resolved magnetization dynamic experiments, and magnetic nanodiscs are placed on a waveguide which is used for the generation of repeatable magnetic field pulses by passing an electric current through the waveguide. The waveguide is created in an extra lithography step.

• MeSH
• magnetismus přístrojové vybavení   MeSH
• nanostruktury chemie   MeSH
• sloučeniny křemíku chemie   MeSH
• transmisní elektronová mikroskopie metody   MeSH
• Publikační typ
• audiovizuální média MeSH
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Konspekt
• Veřejné zdraví a hygiena
• NLK Obory
• onkologie
• environmentální vědy
• chemie, klinická chemie

• MeSH
• fyziologie MeSH
• Publikační typ
• sborníky MeSH

• Konspekt
• Fyziologie člověka a srovnávací fyziologie
• NLK Obory
• dějiny lékařství
• fyziologie

• O autorovi
• Purkyně, Jan Evangelista, 1787-1869 Autorita