98%
921
2 minutes
20
Advances in liquid phase transmission electron microscopy (LP-TEM) have enabled the monitoring of polymer dynamics in solution at the nanoscale, but radiolytic damage during LP-TEM imaging limits its routine use in polymer science. This study focuses on understanding, mimicking, and mitigating radiolytic damage observed in functional polymers in LP-TEM. It is quantitatively demonstrated how polymer damage occurs across all conceivable (LP-)TEM environments, and the key characteristics and differences between polymer degradation in water vapor and liquid water are elucidated. Importantly, it is shown that the hydroxyl radical-rich environment in LP-TEM can be approximated by UV light irradiation in the presence of hydrogen peroxide, allowing the use of bulk techniques to probe damage at the polymer chain level. Finally, the protective effects of commonly used hydroxyl radical scavengers are compared, revealing that the effectiveness of graphene's protection is distance-dependent. The work provides detailed methodological guidance and establishes a baseline for polymer degradation in LP-TEM, paving the way for future research on nanoscale tracking of shape transitions and drug encapsulation of polymer assemblies in solution.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11681318 | PMC |
http://dx.doi.org/10.1002/adma.202402987 | DOI Listing |
Sci Rep
May 2025
Laboratory of Biological Sensitizers, Department of Physical Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
To verify whether the recently synthesized nucleoside, 8-(4-Trifluoromethoxy)benzylamino-2'-deoxyadenosine, can sensitize tumorous cells to X-rays, radiolytic and in vitro studies have been conducted. Molecular modeling demonstrated that excess electrons should lead to efficient dissociative electron attachment (DEA) to dA-NHbenzylOCF resulting in a radical product that can potentially damage DNA. The computationally predicted DEA process was confirmed via stationary radiolysis of a dA-NHbenzylOCF water solution followed by LC-MS analysis of the obtained radiolytes.
View Article and Find Full Text PDFJ Phys Chem B
May 2025
Institute of Materials, China Academy of Engineering Physics, Jiangyou 621907, China.
The molecular simulation is an effective approach for investigating the effects of energetic ion irradiation on polymers. However, there is a lack of relevant studies on atomic structural changes and quantitative analysis. This study utilizes an inelastic thermal spike model and reactive molecular dynamics simulations to investigate the damage mechanisms of noble gas ion irradiation in neoprene rubber.
View Article and Find Full Text PDFAntioxidants (Basel)
March 2025
Department of Medical Imaging and Radiation Sciences, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue Nord, Sherbrooke, QC J1H 5N4, Canada.
FLASH radiotherapy is a novel irradiation modality that employs ultra-high mean dose rates exceeding 40-150 Gy/s, far surpassing the typical ~0.03 Gy/s used in conventional radiotherapy. This advanced technology delivers high doses of radiation within milliseconds, effectively targeting tumors while minimizing damage to the surrounding healthy tissues.
View Article and Find Full Text PDFPhys Rev Lett
April 2025
Lawrence Berkeley National Laboratory, National Center for Electron Microscopy, Molecular Foundry, Berkeley, California 94720, USA.
Almost every electron microscopy experiment is fundamentally limited by radiation damage. Nevertheless, little is known about the onset and progression of radiolysis in beam-sensitive materials. Here we apply ambient-temperature scanning nanobeam electron diffraction to record simultaneous dual-space movies of organic and organometallic nanocrystals at sequential stages of beam-induced radiolytic decay.
View Article and Find Full Text PDFIUCrJ
March 2025
Department of Chemistry and Biochemistry, UCLA-DOE Institute for Genomics and Proteomics; STROBE, NSF Science and Technology Center, University of California, Los Angeles, 611 Charles E. Young Dr East, Los Angeles, CA 90095, USA.
High-energy electrons induce sample damage and motion at the nanoscale to fundamentally limit the determination of molecular structures by electron diffraction. Using a fast event-based electron counting (EBEC) detector, we characterize beam-induced, dynamic, molecular crystal lattice reorientations (BIRs). These changes are sufficiently large to bring reciprocal lattice points entirely in or out of intersection with the sphere of reflection, occur as early events in the decay of diffracted signal due to radiolytic damage, and coincide with beam-induced migrations of crystal bend contours within the same fluence regime and at the same illuminated location on a crystal.
View Article and Find Full Text PDF