Smart polymer Dotaz Zobrazit nápovědu
Smart hydrogels are special type of hydrogels that undergo solution-gelation transition in response to alterations in the environment. Solution-gel transformation is brought about through either physical or chemical cross-linking that occur between the hydrogel chains. Various stimulating factors have been identified to be responsible for the change in the physical state of the intelligent hydrogel. The most important triggering factors are the temperature, pH, ions, electrical signalling, magnetic field, glucose, light and others. Each of these stimulating factors can trigger the swelling of the hydrogel through unique mechanism. Many of these triggering factors are characteristics of the biological systems which make the smart polymers quite beneficial for different biomedical applications. Numerous natural and synthetic polymers have been distinguished to act as smart materials. These polymers impressed the scientists to use them in many biomedical and industrial applications such as drug delivery systems, gene therapy applications, tissue engineering and many other applications.
The design of smart surfaces with externally triggerable water/oil wettability and adhesion represents one of the most up-to-date challenges in the field of material science. In this work, the intelligent surface with electrically triggerable wettability and water/oil adhesion is presented. As a basic material background exhibiting electric field (EF) sensitivity, the piezo-responsive polymethylmethacrylate/polyvinylidenefluoride polymer fibers were used. To expand the available range of water/oil contact angles (CAs) and adhesion, the fibers were grafted with hydrophilic or hydrophobic functional groups using diazonium chemistry. The fiber functionality was evaluated using the static CA and wettability hysteresis measurements (increasing/decreasing drop volume and tilting angles), drops adhesion/repellence and graphite self-cleaning test performed with and without the application of EF. It was found that the proposed method enables tuning the surface wettability in the superhydrophobic/superoleophobic-hydrophilic/oleophilic range and changing of surface properties from low adhesive to high adhesive for water and oil. More convincing results were achieved in the case of fiber surface modification by ADT-C8F17, which may result from a rearrangement of the grated -C6H4C8F17 functional group under the application of EF triggering. Moreover, the triggering which can be performed in the extremely fast way (the surface responds to the EF switching on/off in seconds) was found to be fully reversible. Finally, the additional tests indicate the satisfactory stability of created fiber-based coating against the mechanical treatment.
Tento návrh jednoduché metody vizualizace daktyloskopických stop na základě elektrochemické depozice polyfenazinových barviv (polyneutrální červeně a polytoluidinové modři) z neutrálního prostředí, kdy je minimalizováno poškození genetické informace, by mohl usnadnit snímání otisků prstů z nábojnic ve forenzní praxi. Parametry elektrochemických metod cyklické voltametrie a chronoamperometrie (základní elektrolyt, aplikovaný potenciál, doba depozice nebo potenciálový rozsah a počet cyklů) byly postupně optimalizovány, dokud nebyl otisk dostatečně viditelný. Morfologie a struktura modifikovaných povrchů daktyloskopických stop a polyfenazinových filmů byly studovány pomocí skenovací elektronové mikroskopie. Je předpokládán další rozvoj metody a především aplikace metody na vystřelené nábojnice.
A simple fingerprint visualization method based on the electrochemical deposition of polytoluidine blue (PTB) and polyneutral red (PNR) from a neutral environment with the possibility of minimal damage to the genetic information could facilitate fingerprinting from cartridge cases in forensic practice. The parameters of both visualization methods (supporting electrolyte, applied potential, deposition time or potential range, and number of cycles) were optimized until the imprint was sufficiently visible. The morphology and structure of modified fingerprint surfaces and polyphenazine films were studied using scanning electron microscopy. It is assumed that the method will be applied in the future to fired cartridges, which are crucial in forensics.
Here we present a new effective antibacterial material suitable for a coating, e.g., surface treatment of textiles, which is also time and financially undemanding. The most important role is played by hydrophobic carbon quantum dots, as a new type of photosensitizer, produced by carbonization of different carbon precursors, which are incorporated by swelling from solution into various polymer matrices in the form of thin films, in particular polyurethanes, which are currently commercially used for industrial surface treatment of textiles. The role of hydrophobic carbon quantum dots is to work as photosensitizers upon irradiation and produce reactive oxygen species, namely singlet oxygen, which is already known as the most effective radical for elimination different kinds of bacteria on the surface or in close proximity to such modified material. Therefore, we have mainly studied the effect of hydrophobic carbon quantum dots on Staphylococcus aureus and the cytotoxicity tests, which are essential for the safe handling of such material. Also, the production of singlet oxygen by several methods (electron paramagnetic spectroscopy, time-resolved near-infrared spectroscopy), surface structures (atomic force microscopy and contact angle measurement), and the effect of radiation on polymer matrices were studied. The prepared material is easily modulated by end-user requirements.
- MeSH
- antibakteriální látky chemie MeSH
- biofilmy MeSH
- biokompatibilní potahované materiály chemie MeSH
- chytré materiály chemie MeSH
- fotosenzibilizující látky chemie MeSH
- hydrofobní a hydrofilní interakce MeSH
- kvantové tečky chemie MeSH
- myši MeSH
- povrchové vlastnosti MeSH
- reaktivní formy kyslíku metabolismus MeSH
- singletový kyslík chemie MeSH
- Staphylococcus aureus MeSH
- uhlík chemie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Nano-sized carriers are widely studied as suitable candidates for the advanced delivery of various bioactive molecules such as drugs and diagnostics. Herein, the development of long-circulating stimuli-responsive polymer nanoprobes tailored for the fluorescently-guided surgery of solid tumors is reported. Nanoprobes are designed as long-circulating nanosystems preferably accumulated in solid tumors due to the Enhanced permeability and retention effect, so they act as a tumor microenvironment-sensitive activatable diagnostic. This study designs polymer probes differing in the structure of the spacer between the polymer carrier and Cy7 by employing pH-sensitive spacers, oligopeptide spacers susceptible to cathepsin B-catalyzed enzymatic hydrolysis, and non-degradable control spacer. Increased accumulation of the nanoprobes in the tumor tissue coupled with stimuli-sensitive release behavior and subsequent activation of the fluorescent signal upon dye release facilitated favorable tumor-to-background ratio, a key feature for fluorescence-guided surgery. The probes show excellent diagnostic potential for the surgical removal of intraperitoneal metastasis and orthotopic head and neck tumors with very high efficacy and accuracy. In addition, the combination of macroscopic resection followed by fluorescence-guided surgery using developed probes enable the identification and resection of most of the CAL33 intraperitoneal metastases with total tumor burden reduced to 97.2%.
- MeSH
- chytré polymery * MeSH
- fluorescence MeSH
- fluorescenční barviva chemie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorové mikroprostředí MeSH
- nádory hlavy a krku * diagnostické zobrazování chirurgie MeSH
- polymery MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lékové formy s elektronickým prvkem je možné zařadit mezi jedny z nejmodernějších a nejinovativnějších lékových systémů posledních několika dekád. Inkorporace elektronického/digitálního prvku nabízí řadu výhod, jako např. možnost přesného načasování uvolnění léčivé látky v požadované lokaci gastrointestinálního traktu, sběr biometrických dat, či nezpochybnitelný průkaz adherence pacienta k terapii. V současné době je možné pozorovat vývoj oboru do dvou hlavních směrů. Tím prvním je využití těchto systémů ve spojení s řízeným uvolňováním při absorpčních a obecně farmakokinetických studiích nových látek. Druhým směrem je pak digitální monitoring adherence k léčbě. Tento stručný přehled pojednává krátce o historii problematiky, přináší informace o obou zmíněných odvětvích a zmiňuje zásadní zástupce obou skupin a jejich využití.
Delivery systems with an electronic element can be classified as one of the last few decades' most modern and innovative pharmaceutical systems. Incorporating an electronic/digital element offers several advantages, such as the possibility of the precise timing of the drug released in the desired location of the gastrointestinal tract, collection of biometric data, or indisputable proof of the patient's adherence to therapy. Currently, it is possible to observe the development of the field in two main directions. The first one is using these systems in conjunction with the controlled release principle in absorption and general pharmacokinetic studies of new substances. The second direction is digital monitoring of therapy adherence. This brief overview briefly mentions the field's history, brings information about the two main branches, and states the essential systems of both branches and their use.
- MeSH
- chytré materiály MeSH
- komfort pacienta MeSH
- kontaktní čočky * MeSH
- lidé MeSH
- oči MeSH
- oční víčka MeSH
- technologie MeSH
- Check Tag
- lidé MeSH
Polymers with lower critical solution temperature (LCST) are molecularly soluble in their solutions at low temperatures but, when heated above their cloud point temperature, these polymers assemble into supramolecular particles or macroscopic precipitates. These particles or precipitated polymeric depots can be used for diagnostics, targeted drug delivery, controlled drug release from a depot or a combination of diagnostics and therapy (theranostics). Herein, we describe smart polymer systems which contain N-(2,2-difluoroethyl)acrylamide monomer unit (DFEA) and form polymeric nanoparticles upon heating or precipitate after injection to polymeric implants/depots. Due to a high fluorine content and to relaxation properties of this element, these polymers are suitable as tracers for the 19F MRI method, a promising non-invasive diagnostic tool. Moreover, DFEA copolymers can contain monomers that react to additional physicochemical properties, resulting in multiresponsive polymers (pH- or redox-responsive), which can be used for smart drug delivery systems with controlled release of drugs in the target environment.
- MeSH
- dichlorethyleny MeSH
- kontrastní látky * MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- Check Tag
- lidé MeSH
Shape memory alloys (SMA) are materials with specific electric, mechanic and thermal qualities originating in their microscopic structure and as such are used to design so-called Smart structures. In biomedicine, they are used mostly for their shape memory properties during intravasal surgery. The commonly used SMA material for biomedical purposes is Nitinol, a nickel-titanium alloy that exhibits, especially when annealed, among other properties also superelasticity and high resistivity with strain changes. This makes it suitable for usage in strain gauge sensors. In this work, NiTi annealed wires were used to create a strain gauge sensor, which exploits their unique properties. The properties of these sensors were then described using a climatic chamber, stretching device and a set of weights. Those properties were then compared to similar sensors, that are using different principles. The development, that followed, used these sensors in particular biomedical applications.
- MeSH
- automatizované zpracování dat metody přístrojové vybavení MeSH
- biomedicínské technologie MeSH
- biomedicínský výzkum MeSH
- chytré materiály analýza škodlivé účinky terapeutické užití MeSH
- elektrická impedance MeSH
- kvantitativní vztahy mezi strukturou a aktivitou MeSH
- manometrie metody přístrojové vybavení MeSH
- nikl škodlivé účinky terapeutické užití MeSH
- slitiny s tvarovou pamětí * chemie klasifikace škodlivé účinky MeSH
- titan škodlivé účinky terapeutické užití MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
