Antibiotics are antimicrobial substances that can be used for preventive and therapeutic purposes in humans and animals. Their overdose usage has led to uncontrolled release to the environment, contributing significantly to the development of antimicrobial resistance phenomena. Here, enzyme-immobilized self-propelled zinc oxide (ZnO) microrobots are proposed to effectively target and degrade the released antibiotics in water bodies. Specifically, the morphology of the microrobots is tailored via the incorporation of Au during the synthetic process to lead the light-controlled motion into having on/off switching abilities. The microrobots are further modified with laccase enzyme by physical adsorption, and the immobilization process is confirmed by enzymatic activity measurements. Oxytetracycline (OTC) is used as a model of veterinary antibiotics to investigate the enzyme-immobilized microrobots for their removal capacities. The results demonstrate that the presence of laccase on the microrobot surfaces can enhance the removal of antibiotics via oxidation. This concept for immobilizing enzymes on self-propelled light-driven microrobots leads to the effective removal of the released antibiotics from water bodies with an environmentally friendly strategy.

• MeSH
• antibakteriální látky MeSH
• chemické látky znečišťující vodu * MeSH
• lakasa metabolismus   MeSH
• lidé MeSH
• oxid zinečnatý * MeSH
• oxytetracyklin * MeSH
• voda 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

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

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
• bismut * chemie   toxicita   MeSH
• chrom chemie   toxicita   MeSH
• doxorubicin * chemie   MeSH
• lidé MeSH
• nádory * farmakoterapie   patologie   MeSH
• nanotechnologie trendy   MeSH
• platina chemie   toxicita   MeSH
• protinádorové látky chemie   terapeutické užití   MeSH
• těžké kovy chemie   toxicita   MeSH
• uvolňování léčiv MeSH
• uzavřené prostory MeSH
• Check Tag
• lidé MeSH