Adaptive 2D and Pseudo-2D Systems: Molecular, Polymeric, and Colloidal Building Blocks for Tailored Complexity

Two-dimensional and pseudo-2D systems come in various forms. Membranes separating protocells from the environment were necessary for life to occur. Later, compartmentalization allowed for the development of more complex cellular structures. Nowadays, 2D materials (e.g., graphene, molybdenum disulfide) are revolutionizing the smart materials industry. Surface engineering allows for novel functionalities, as only a limited number of bulk materials have the desired surface properties. This is realized via physical treatment (e.g., plasma treatment, rubbing), chemical modifications, thin film deposition (using both chemical and physical methods), doping and formulation of composites, or coating. However, artificial systems are usually static. Nature creates dynamic and responsive structures, which facilitates the formation of complex systems. The challenge of nanotechnology, physical chemistry, and materials science is to develop artificial adaptive systems. Dynamic 2D and pseudo-2D designs are needed for future developments of life-like materials and networked chemical systems in which the sequences of the stimuli would control the consecutive stages of the given process. This is crucial to achieving versatility, improved performance, energy efficiency, and sustainability. Here, we review the advancements in studies on adaptive, responsive, dynamic, and out-of-equilibrium 2D and pseudo-2D systems composed of molecules, polymers, and nano/microparticles.

Corrigendum: 2D-nanomaterials for AKI treatment

[This corrects the article DOI: 10.3389/fbioe.2023.1159989.].

Study of effects of anthracycline drugs on myocardial function in breast cancer patients by quantitative analysis of layer-specific strain via 2D-STI technology

OBJECTIVE

This study aimed to explore the value of layer-specific strain analysis by two-dimensional speckle tracking imaging (2D-STI) in the assessment of myocardial toxicity in breast cancer patients receiving anthracycline chemotherapy.

METHODS

Thirty-four breast cancer patients receiving anthracycline chemotherapy were prospectively enrolled. Conventional echocardiography and 2D-STI were evaluated at baseline after the third and sixth cycles of anthracycline chemotherapy. The strains of different layers of left ventricle (LV) including peak systolic longitudinal strain (endo-LS, mid-LS, epi-LS) and circumferential strain (endo-CS, mid-CS, epi-CS) were measured using EchoPAC analysis software. Peak systolic longitudinal strain (MV-LS, PM-LS, AP-LS), circumferential strain (MV-CS, PM-CS, AP-CS) and radial strain (MV-RS, PM-RS, AP-RS) were measured at mitral valve, papillary muscle and apex levels of LV respectively. Global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and left ventricular twist (LVtw) were also analyzed.

RESULTS

There was no significant difference in the structural and functional parameters of conventional 2D echocardiography in different cycles of anthracycline chemotherapy (P>0.05); layer specific LS and CS in various cycles decreased layer by layer from inside to outside. LS and CS increased from basal segment to apical segment, while RS showed no obvious gradient characteristics; compared with baseline, GLS and LSs (endo-PM, endo-AP, mid-PM, mid-AP and epi-AP) of LV decreased significantly after the third cycle of chemotherapy (P<0.05); LSs (epi-MV and epi-AP) decreased significantly after the sixth cycle of chemotherapy (P<0.05). No significant changes were detected in layer specific CS, RS and LVtw (P>0.05).

CONCLUSION

Layer-specific strain analysis by 2D-STI technology can quantitatively analyze global and regional functions of LV. The myocardial toxicity due to anthracycline chemotherapy can be detected by layer-specific LS of LV in early stage, which is great valuable to guiding clinical early intervention and improving prognosis.

WO3-x Nanoplates Grown on Carbon Nanofibers for an Efficient Electrocatalytic Hydrogen Evolution Reaction

The search for non-noble metal catalysts with high activity for the hydrogen evolution reaction (HER) is crucial for efficient hydrogen production at low cost and on a large scale. Herein, we report a novel WO3-x catalyst synthesized on carbon nanofiber mats (CFMs) by electrospinning and followed by a carbonization process in a tubal furnace. The morphology and composition of the catalysts were tailored via a simple method, and the hybrid catalyst mats were used directly as cathodes to investigate their HER performance. Notably, the as-prepared catalysts exhibit substantially enhanced activity for the HER, demonstrating a small overpotential, a high exchange current density, and a large cathodic current density. The remarkable electrocatalytic performances result from the poor crystallinity of WO3-x, the high electrical conductivity of WO3-x, and the use of electrospun CNFs. The present work outlines a straightforward approach for the synthesis of transition metal oxide (TMO)-based carbon nanofiber mats with promising applications for the HER.

DNA-Assisted Exfoliation of Tungsten Dichalcogenides and Their Antibacterial Effect

This study reports a method for the facile and high-yield exfoliation of WX2 (X = S, Se) by sonication under aqueous conditions using single-stranded DNA (abbreviated as ssDNA) of high molecular weight. The ssDNA provided a high degree of stabilization and prevented reaggregation, and it enhanced the exfoliation efficiency of WX2 nanosheets due to adsorption on the WX2 surface and the electrostatic repulsion of sugars in the ssDNA backbone. The exfoliation yield was higher with ssDNA (80%-90%) than without (2%-4%); the yield with ssDNA was also higher than the value previously reported for aqueous exfoliation (∼10%). Given that two-dimensional nanomaterials have potential health and environmental applications, we investigated antibacterial activity of exfoliated WX2-ssDNA nanosheets, relative to graphene oxide (GO), and found that WSe2-ssDNA nanosheets had higher antibacterial activity against Escherichia coli K-12 MG1655 cells than GO. Our method enables large-scale exfoliation in an aqueous environment in a single step with a short reaction time and under ambient conditions, and it can be used to produce surface-active or catalytic materials that have broad applications in biomedicine and other areas.