In the present work, we have studied for the first time the combined effect of both sonication and precipitation pH on the structure of amorphous zirconia gels synthesized from zirconium(IV) propoxide. The techniques of small-angle neutron and X-ray scattering (SANS and SAXS) and low temperature nitrogen adsorption provided the integral data on the changes in the microstructure and mesostructure of these materials caused by ultrasonic (US) treatment. Amorphous ZrO2·xH2O synthesized under ultrasonic treatment was found to possess a very structured surface, characterized by the surface fractal dimension 2.9-3.0, compared to 2.3-2.5 for the non US-assisted synthesis, and it was also found to possess a higher specific surface area, while the sizes of the primary particles remain unchanged.

• Klíčová slova
• Fractals, Mesostructure, Small-angle X-ray scattering, Small-angle neutron scattering, Ultrasonication, Zirconia,
• Publikační typ
• časopisecké články MeSH

Microplastics, which comprise one of the omnipresent threats to human health, are diverse in shape and composition. Their negative impacts on human and ecosystem health provide ample incentive to design and execute strategies to trap and degrade diversely structured microplastics, especially from water. This work demonstrates the fabrication of single-component TiO2 superstructured microrobots to photo-trap and photo-fragment microplastics. In a single reaction, rod-like microrobots diverse in shape and with multiple trapping sites, are fabricated to exploit the asymmetry of the microrobotic system advantageous for propulsion. The microrobots work synergistically to photo-catalytically trap and fragment microplastics in water in a coordinated fashion. Hence, a microrobotic model of "unity in diversity" is demonstrated here for the phototrapping and photofragmentation of microplastics. During light irradiation and subsequent photocatalysis, the surface morphology of microrobots transformed into porous flower-like networks that trap microplastics for subsequent degradation. This reconfigurable microrobotic technology represents a significant step forward in the efforts to degrade microplastics.

• Klíčová slova
• TiO2, micromotors, microplastics, microrobots, surface morphology,
• Publikační typ
• časopisecké články MeSH

PURPOSE: The aim of this study is to show a new mesomicroscopic insight into Letrozole (LTZ) loaded nanocomplexes and their ex vivo characteristics as a drug delivery system. METHODS: The LTZ loaded hybrid chitosan-based carrier was fabricated using a modified ionic crosslinking technique and characterized in more detail. To understand the mechanism of LTZ action encapsulated in the hybrid polymer-lipid carrier, all-atom molecular dynamics simulations were also used. RESULTS: The physicochemical properties of the carrier demonstrated the uniform morphology, but different drug loading ratios. In vitro cytotoxic activity of the optimized carrier demonstrated IC50 of 67.85 ± 0.55 nM against breast cancer cell line. The ex vivo study showed the positive effect of nanocomplex on LTZ permeability 7-10 fold greater than the free drug. The molecular dynamic study also confirmed the prsence of hydrophobic peak of lipids at a distance of 5 Å from the center of mass of LTZ which proved drug entrapment in the core of nanocomplex. CONCLUSIONS: The hybrid nanoparticle increased the cytotoxicity and tissue permeability of LTZ for oral delivery. This study also confirmed the atomic mesostructures and interaction of LTZ in the core of hybrid polymer-lipid nanoparticles.

• Klíčová slova
• PLN, aromatase inhibitor, non-everted sac study, chitosan-lipid nanocomplex, letrozole, molecular dynamics,
• MeSH
• buňky PC12 MeSH
• chitosan chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• krysa rodu Rattus MeSH
• letrozol chemie   MeSH
• lidé MeSH
• lipidy chemie   MeSH
• MFC-7 buňky MeSH
• nádorové buněčné linie MeSH
• nanočástice chemie   MeSH
• nosiče léků chemie   MeSH
• polymery chemie   MeSH
• simulace molekulární dynamiky MeSH
• systémy cílené aplikace léků metody   MeSH
• velikost částic MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chitosan MeSH
• letrozol MeSH
• lipidy MeSH
• nosiče léků MeSH
• polymery MeSH