Q56950965 Dotaz Zobrazit nápovědu
Magnetic nanorobots offer wireless navigation capability in hard-to-reach areas of the human body for targeted therapy and diagnosis. Though in vivo imaging is required for guidance of the magnetic nanorobots toward the target areas, most of the imaging techniques are inadequate to reveal the potential locomotion routes. This work proposes the use of radiopaque magnetic nanorobots along with microcomputed tomography (microCT) for localized in vivo imaging applications. The nanorobots consist of a contrast agent, barium sulfate (BaSO4 ), magnetized by the decoration of magnetite (Fe3 O4 ) particles. The magnetic features lead to actuation under rotating magnetic fields and enable precise navigation in a microfluidic channel used to simulate confined spaces of the body. In this channel, the intrinsic radiopacity of the nanorobots also provides the possibility to reveal the internal structures by X-ray contrast. Furthermore, in vitro analysis indicates nontoxicity of the nanorobots. In vivo experiments demonstrate localization of the nanorobots in a specific part of the gastrointestinal (GI) tract upon the influence of the magnetic field, indicating the efficient control even in the presence of natural peristaltic movements. The nanorobots reported here highlight that smart nanorobotic contrast agents can improve the current imaging-based diagnosis techniques by providing untethered controllability in vivo.
Modern micro/nanorobots can perform multiple tasks for biomedical and environmental applications. Particularly, magnetic microrobots can be completely controlled by a rotating magnetic field and their motion powered and controlled without the use of toxic fuels, which makes them most promising for biomedical application. Moreover, they are able to form swarms, allowing them to perform specific tasks at a larger scale than a single microrobot. In this work, they developed magnetic microrobots composed of halloysite nanotubes as backbone and iron oxide (Fe3 O4 ) nanoparticles as magnetic material allowing magnetic propulsion and covered these with polyethylenimine to load ampicillin and prevent the microrobots from disassembling. These microrobots exhibit multimodal motion as single robots as well as in swarms. In addition, they can transform from tumbling to spinning motion and vice-versa, and when in swarm mode they can change their motion from vortex to ribbon and back again. Finally, the vortex motion mode is used to penetrate and disrupt the extracellular matrix of Staphylococcus aureus biofilm colonized on titanium mesh used for bone restoration, which improves the effect of the antibiotic's activity. Such magnetic microrobots for biofilm removal from medical implants could reduce implant rejection and improve patients' well-being.
- MeSH
- biofilmy * MeSH
- fyzikální jevy MeSH
- lidé MeSH
- magnetické pole MeSH
- pohyb těles MeSH
- titan * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Prostate cancer is the most commonly diagnosed tumor disease in men, and its treatment is still a big challenge in standard oncology therapy. Magnetically actuated microrobots represent the most promising technology in modern nanomedicine, offering the advantage of wireless guidance, effective cell penetration, and non-invasive actuation. Here, new biodegradable magnetically actuated zinc/cystine-based microrobots for in situ treatment of prostate cancer cells are reported. The microrobots are fabricated via metal-ion-mediated self-assembly of the amino acid cystine encapsulating superparamagnetic Fe3 O4 nanoparticles (NPs) during the synthesis, which allows their precise manipulation by a rotating magnetic field. Inside the cells, the typical enzymatic reducing environment favors the disassembly of the aminoacidic chemical structure due to the cleavage of cystine disulfide bonds and disruption of non-covalent interactions with the metal ions, as demonstrated by in vitro experiments with reduced nicotinamide adenine dinucleotide (NADH). In this way, the cystine microrobots served for site-specific delivery of Zn2+ ions responsible for tumor cell killing via a "Trojan horse effect". This work presents a new concept of cell internalization exploiting robotic systems' self-degradation, proposing a step forward in non-invasive cancer therapy.
- MeSH
- cystin * MeSH
- lidé MeSH
- nádory prostaty * MeSH
- zinek MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The development of cancer resistance continues to represent a bottleneck of cancer therapy. It is one of the leading factors preventing drugs to exhibit their full therapeutic potential. Consequently, it reduces the efficacy of anticancer therapy and causes the survival rate of therapy-resistant patients to be far from satisfactory. Here, an emerging strategy for overcoming drug resistance is proposed employing a novel two-dimensional (2D) nanomaterial polysiloxane (PSX). We have reported on the synthesis of PSX nanosheets (PSX NSs) and proved that they have favorable properties for biomedical applications. PSX NSs evinced unprecedented cytocompatibility up to the concentration of 300 μg/mL, while inducing very low level of red blood cell hemolysis and were found to be highly effective for anticancer drug binding. PSX NSs enhanced the efficacy of the anticancer drug doxorubicin (DOX) by around 27.8-43.4% on average and, interestingly, were found to be especially effective in the therapy of drug-resistant tumors, improving the effectiveness of up to 52%. Fluorescence microscopy revealed improved retention of DOX within the drug-resistant cells when bound on PSX NSs. DOX bound on the surface of PSX NSs, i.e., PSX@DOX, improved, in general, the DOX cytotoxicity in vitro. More importantly, PSX@DOX reduced the growth of DOX-resistant tumors in vivo with 3.5 times better average efficiency than the free drug. Altogether, this paper represents an introduction of a new 2D nanomaterial derived from silicane and pioneers its biomedical application. As advances in the field of material synthesis are rapidly progressing, novel 2D nanomaterials with improved properties are being synthesized and await thorough exploration. Our findings further provide a better understanding of the mechanisms involved in the cancer resistance and can promote the development of a precise cancer therapy.
- MeSH
- chemorezistence účinky léků MeSH
- doxorubicin farmakologie terapeutické užití MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory vaječníků farmakoterapie MeSH
- nanostruktury chemie MeSH
- proliferace buněk účinky léků MeSH
- siloxany chemie farmakologie MeSH
- testování materiálů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Three-dimensional (3D) printing technology offers attractive possibilities for many fields. In electrochemistry, 3D printing technology has been used to fabricate customized 3D-printed electrodes as a platform to develop bio/sensing, energy generation and storage devices. Here, we use a 3D-printed graphene/polylactic (PLA) electrode made by additive manufacturing technology and immobilize horseradish peroxidase (HRP) to create a direct electron transfer enzyme-based biosensors for hydrogen peroxide detection. Gold nanoparticles are included in the system to confirm and facilitate heterogeneous electron transfer. This work opens a new direction for the fabrication of third-generation electrochemical biosensors using 3D printing technology, with implications for applications in the environmental and biomedical fields.
There is an assortment of layered transition metal dichalcogenides (TMDs), about 40 reported compounds, each with its unique polymorph and properties. Group 4 TMD, titanium disulfide (TiS2), possess high electronic conductivity and light weight amongst other attractive features. In consideration for electrochemical and thermoelectrical applications, doping is a promising approach to enhance its practicability. The introduction of foreign atoms or compositional variance may improve existing properties or grant access to new ones. Moving away from the more intensively studied and successfully doped group 6 MoS2 and WS2, TiS2 is doped with varying levels of niobium (Nb) via controlled heating of stoichiometric amounts to yield Ti1-xNbxS2 where x = 0.05, 0.1, 0.2. Structural effects are discussed together with two doping parameters, nature and concentration of dopant. Characterisation data reveal retention of 1T-phase polymorph despite formation of TiS3 nanobelts upon doping. Fundamental electrochemical properties such as heterogenous electron transfer rates and its charge transfer resistance are compared amongst the materials of interest. A selective and sensitive 2nd generation electrochemical biosensor is prepared using Ti0.95Nb0.05S2/GOx/GTA since it is the most superior material in glucose detection.
Self-propelled microrobots are seen as the next step of micro- and nanotechnology. The biomedical and environmental applications of these robots in the real world need their motion in the confined environments, such as in veins or spaces between the grains of soil. Here, self-propelled trilayer microrobots have been prepared using electrodeposition techniques, coupling unique properties of green bismuth (Bi) with a layered crystal structure, magnetic nickel (Ni), and a catalytic platinum (Pt) layer. These Bi-based microrobots are investigated as active self-propelled platforms that can load, transfer, and release both doxorubicin (DOX), as a widely used anticancer drug, and arsenic (As) and chromium (Cr), as hazardous heavy metals. The significantly high loading capability for such variable cargoes is due to the high surface area provided by the rhombohedral layered crystal structure of bismuth, as well as the defects introduced through the oxide layer formed on the surface of bismuth. The drug release is based on an ultrafast electroreductive mechanism in which the electron injection into microrobots and consequently into the loaded objects causes an electrostatic repulsion between them and thus an ultrafast release of the loaded cargos. Remarkably, we have presented magnetic control of the Bi-based microrobots inside a microfluidic system equipped with an electrochemical setup as a proof-of-concept to demonstrate (i) heavy metals/DOX loading, (ii) a targeted transport system, (iii) the on-demand release mechanism, and (iv) the recovery of the robots for further usage.
- MeSH
- antitumorózní látky chemie terapeutické užití MeSH
- bismut * chemie toxicita MeSH
- chrom chemie toxicita MeSH
- doxorubicin * chemie MeSH
- lidé MeSH
- nádory * farmakoterapie patologie MeSH
- nanotechnologie trendy MeSH
- platina chemie toxicita MeSH
- těžké kovy chemie toxicita MeSH
- uvolňování léčiv MeSH
- uzavřené prostory MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- abstrakt z konference MeSH
