Since the outbreak of the COVID-19 pandemic, the use of hand sanitisers has become an inseparable part of our personal hygiene. However, the short-term effect and the need for frequent application are shortcomings that impair the overall protection. Another aspect is that repeated use of some products (typically alcohol-based) may cause skin irritation or eventually more severe health problems. This work proposes spray-drying as a suitable method for the preparation of swellable chitosan carriers, allowing for encapsulation and sustained release of antibacterial chlorhexidine digluconate as a model active substance. After application to hands, micron-sized particles preferentially accommodate space between epidermal ridges, protected against attrition. Thanks to their small size (d < 10 µm), particles are comfortable to carry since they are not recognisable by somatosensory receptors. The performance of formulations with various amounts of chlorhexidine and cross-linker was tested and compared with selected commercial disinfectants available on the Czech market (ethanol gel and alcoholic solution with chlorhexidine) against E. coli and S. epidermidis. The real-life performance was investigated with twelve volunteers performing various activities for up to 2 h. Finally, a replica of the human index finger with accurately captured micro-topology was proposed and compared with volunteers' fingers concerning the total amount of adhered and detached particles.
- MeSH
- chlorhexidin MeSH
- dezinfekční prostředky na mytí rukou * MeSH
- Escherichia coli MeSH
- ethanol MeSH
- lidé MeSH
- pandemie MeSH
- prášky, zásypy, pudry MeSH
- ruka mikrobiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chlorhexidin MeSH
- dezinfekční prostředky na mytí rukou * MeSH
- ethanol MeSH
- prášky, zásypy, pudry MeSH
Pancreatic lipase (PNLIP, EC 3.1.1.3) plays a pivotal role in the digestion of dietary lipids, a metabolic pathway directly related to obesity. One of the effective strategies in obesity treatment is the inhibition of PNLIP, which is possible to be achieved by specific phenolic compounds occurring in high abundance in some plants. In this study, a multidisciplinary approach is presented investigating the PNLIP inhibitory effect of 33 plants belonging in the Asteraceae botanical family. In the first stage of the study, a rapid and cost-efficient PNLIP assay in a 96-microwell plate format was developed and important parameters were optimized, e.g., the enzyme substrate. Upon PNLIP assay optimization, aqueous and dichloromethane Asteraceae plant extracts were tested and a cut-off inhibition level was set to further analyze only the samples with a significant inhibitory effect (inhibitory rate > 40%), using an ultra-high-performance liquid chromatography hybrid quadrupole time-of-flight mass spectrometry (UHPLC-q-TOF-MS) method. Specifically, a metabolomic suspect screening was performed and 69 phenolic compounds were tentatively identified, including phenolic acids, flavonoids, flavonoid-3-O-glycosides, and flavonoid-7-O-glycosides, amongst others. In the case of aqueous extracts, phytochemicals known for inducing PNLIP inhibitory effect, e.g., compounds containing galloyl molecules or caffeoylquinic acids, were monitored in Chrysanthemum morifolium, Grindella camporum and Hieracium pilosella extracts. All in all, the presented approach combines in vitro bioactivity measurements to high-end metabolomics to identify phenolic compounds with potential medicinal and/or dietary applications.
- Klíčová slova
- bioprospecting, enzyme assay, in vitro testing, metabolomics, obesity, phytochemicals, polyphenols, suspect screening, ultra-high-performance liquid chromatography hybrid quadrupole time-of-flight mass spectrometry,
- MeSH
- Asteraceae * chemie MeSH
- chromatografie kapalinová MeSH
- fenoly analýza MeSH
- flavonoidy chemie MeSH
- fytonutrienty analýza MeSH
- glykosidy MeSH
- hmotnostní spektrometrie MeSH
- lipasa MeSH
- lipidy MeSH
- methylenchlorid MeSH
- obezita MeSH
- rostlinné extrakty chemie farmakologie MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fenoly MeSH
- flavonoidy MeSH
- fytonutrienty MeSH
- glykosidy MeSH
- lipasa MeSH
- lipidy MeSH
- methylenchlorid MeSH
- rostlinné extrakty MeSH
Understanding the motility behavior of bacteria in confining microenvironments, in which they search for available physical space and move in response to stimuli, is important for environmental, food industry, and biomedical applications. We studied the motility of five bacterial species with various sizes and flagellar architectures (Vibrio natriegens, Magnetococcus marinus, Pseudomonas putida, Vibrio fischeri, and Escherichia coli) in microfluidic environments presenting various levels of confinement and geometrical complexity, in the absence of external flow and concentration gradients. When the confinement is moderate, such as in quasi-open spaces with only one limiting wall, and in wide channels, the motility behavior of bacteria with complex flagellar architectures approximately follows the hydrodynamics-based predictions developed for simple monotrichous bacteria. Specifically, V. natriegens and V. fischeri moved parallel to the wall and P. putida and E. coli presented a stable movement parallel to the wall but with incidental wall escape events, while M. marinus exhibited frequent flipping between wall accumulator and wall escaper regimes. Conversely, in tighter confining environments, the motility is governed by the steric interactions between bacteria and the surrounding walls. In mesoscale regions, where the impacts of hydrodynamics and steric interactions overlap, these mechanisms can either push bacteria in the same directions in linear channels, leading to smooth bacterial movement, or they could be oppositional (e.g., in mesoscale-sized meandered channels), leading to chaotic movement and subsequent bacterial trapping. The study provides a methodological template for the design of microfluidic devices for single-cell genomic screening, bacterial entrapment for diagnostics, or biocomputation.
- Klíčová slova
- bacterial motility, microfluidic devices, space partitioning, wall accumulator, wall escaper,
- MeSH
- Alphaproteobacteria fyziologie MeSH
- Bacteria růst a vývoj MeSH
- biofilmy MeSH
- biologické modely MeSH
- Escherichia coli fyziologie MeSH
- flagella fyziologie MeSH
- fyziologie bakterií genetika MeSH
- hydrodynamika MeSH
- mikrofluidika metody MeSH
- pohyb fyziologie MeSH
- Pseudomonas putida fyziologie MeSH
- Vibrio fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Garlic is a well-known example of natural self-defence system consisting of an inactive substrate (alliin) and enzyme (alliinase) which, when combined, produce highly antimicrobial allicin. Increase of alliinase stability and its activity are of paramount importance in various applications relying on its use for in-situ synthesis of allicin or its analogues, e.g., pulmonary drug delivery, treatment of superficial injuries, or urease inhibitors in fertilizers. Here, we discuss the effect of temperature, pH, buffers, salts, and additives, i.e. antioxidants, chelating agents, reducing agents and cosolvents, on the stability and the activity of alliinase extracted from garlic. The effects of the storage temperature and relative humidity on the stability of lyophilized alliinase was demonstrated. A combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin's mode of action and develop effective defence mechanism, which could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant (MDR) bacterial strains.
- MeSH
- antibakteriální látky farmakologie MeSH
- Bacteria účinky léků ultrastruktura MeSH
- biokatalýza účinky léků MeSH
- časové faktory MeSH
- česnek enzymologie MeSH
- chemické jevy * MeSH
- disulfidy chemie metabolismus MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny sulfinové chemie metabolismus MeSH
- lyasy štěpící vazby C-S metabolismus MeSH
- lyofilizace MeSH
- mikrobiální testy citlivosti MeSH
- mikrobiální viabilita účinky léků MeSH
- pufry MeSH
- stabilita enzymů účinky léků MeSH
- stereoizomerie MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- allicin MeSH Prohlížeč
- alliin lyase MeSH Prohlížeč
- antibakteriální látky MeSH
- disulfidy MeSH
- kyseliny sulfinové MeSH
- lyasy štěpící vazby C-S MeSH
- pufry MeSH
This work is concerned with the surface modification of fluorescent silica nanoparticles by a monoclonal antibody (M75) and the specific bioadhesion of such particles to surfaces containing the PG domain of carbonic anhydrase IX (CA IX), which is a trans-membrane protein specifically expressed on the surfaces of several tumor cell lines. The adhesion strength of antibody-bearing silica nanoparticles to antigen-bearing surfaces was investigated under laminar flow conditions in a microfluidic cell and compared to the adhesion of unmodified silica nanoparticles and nanoparticles coupled with an unspecific antibody. Adhesion to cancer cells using flow cytometry was also investigated and in all cases the adhesion strength of M75-modified nanoparticles was significantly stronger than for the unmodified or unspecific nanoparticles, up to several orders of magnitude in some cases. The specific modification of nano- and microparticles by an antibody-like protein therefore appears to be a feasible approach for the targeting of tumor cells.
- MeSH
- antigeny nádorové chemie imunologie metabolismus MeSH
- buněčná adheze MeSH
- buňky NIH 3T3 MeSH
- imunokomplex MeSH
- karboanhydrasa IX MeSH
- karboanhydrasy chemie imunologie metabolismus MeSH
- konfokální mikroskopie MeSH
- lidé MeSH
- mikrofluidní analytické techniky MeSH
- monoklonální protilátky chemie imunologie MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nanočástice chemie MeSH
- oxid křemičitý chemie MeSH
- povrchové vlastnosti MeSH
- terciární struktura proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antigeny nádorové MeSH
- CA9 protein, human MeSH Prohlížeč
- imunokomplex MeSH
- karboanhydrasa IX MeSH
- karboanhydrasy MeSH
- M75 monoclonal antibody MeSH Prohlížeč
- monoklonální protilátky MeSH
- oxid křemičitý MeSH
