light-induced-situ-transmission-electron-microscopy-for-observation

Light-Induced <em>In Situ</em> Transmission Electron Microscopy for Observation of the Liquid-Soft Matter Interaction

The current protocol describes the modifications of the transmission electron microscope (TEM) setup for in situ light-induced observations. A glass ...

Wroclaw University of Science and Technology

The novel approach for imaging of antimicrobial photodynamic therapy processes presented in this work is based on transmission electron microscopy methods. With the use of liquid cell, illumination system, and lowered electron dose the successful light-induced in-situ observations on Staphylococcus aureus encapsulated with methylene blue were performed. Results showed that with specified imaging parameters it is possible to conduct reliable research on bacteria in electron microscope despite the unfavorable damaging effect of the highly energetic electron beam used for imaging. This approach differs from the common methods, as it provides direct observations of the processes occurring upon light illumination. The effects obtained with the proposed method are very promising and may serve to answer why different microorganisms respond to the therapy differently.

Light-induced in situ transmission electron microscopy: Novel approach for antimicrobial photodynamic therapy imaging.

Antibacterial photodynamic therapy is a promising treatment for problematic infections caused by bacteria and fungi. Despite its undoubted effectiveness, the ultrastructural mechanism of microbial death remains not fully described and distinct organisms respond to the treatment with different efficacy. For this reason, it was decided to try imaging the process using the in situ transmission electron microscopy method. To conduct an observational experiment, the microscope was significantly modified. Liquid cell methods were used, electron doses and their influence on the sample were estimated, and a fiber-optic sample illuminator was designed and built. The modifications allowed for the light-induced characterization of photosensitizer-bacteria interaction. Microscope modification is a promising platform for further studies of light-induced phenomena in both life and material science.

Fiber-optic sample illuminator design for the observation of light induced phenomena with transmission electron microscopy in situ: Antimicrobial photodynamic therapy.

The efficiency of photomobile polymers (PMP) in the conversion of light into mechanical work plays a fundamental role in achieving cutting-edge innovation in the development of novel applications ranging from energy harvesting to sensor approaches. Because of their photochromic properties, azobenzene monomers have been shown to be an efficient material for the preparation of PMPs with appropriate photoresponsivity. Upon integration of the azobenzene molecules as moieties into a polymer, they act as an engine, allowing fast movements of up to 50 Hz. In this work we show a promising approach for integrating ZnO nanoparticles into a liquid crystalline polymer network. The addition of such nanoparticles allows the trapping of incoming light, which acts as diffusive points in the polymer matrix. We characterized the achieved nanocomposite material in terms of thermomechanical and optical properties and finally demonstrated that the doped PMP was better performing that the undoped PMP film.

Article	Year
Light-induced in situ transmission electron microscopy: Novel approach for antimicrobial photodynamic therapy imaging. Photodiagnosis and photodynamic therapy\| PubMed ID: 34325078	2021
Fiber-optic sample illuminator design for the observation of light induced phenomena with transmission electron microscopy in situ: Antimicrobial photodynamic therapy. Ultramicroscopy\| PubMed ID: 34509894	2021
Photo-Responsivity Improvement of Photo-Mobile Polymers Actuators Based on a Novel LCs/Azobenzene Copolymer and ZnO Nanoparticles Network. Nanomaterials (Basel, Switzerland)\| PubMed ID: 34947671	2021

Olga Kaczmarczyk

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