Search

Living erythrocyte (red blood cell, RBC) membranes present rich ultrastructural and dynamic details, which require synchronous super‐resolution imaging and single‐molecule tracking to be revealed. Yet, it poses a serious challenge to achieve these dual functions in a single probe, due to the rigid and conflicting photophysical demands of the different techniques. Herein, we rationally developed a far‐red boron dipyrromethene membrane probe with blinking capability and persistent single‐molecule emission, and constructed a microfluidic platform for noninvasive trapping and long‐term imaging of RBCs. By combining them, multi‐dimensional super‐resolution reconstructions and single‐molecule tracking were achieved at the molecular scale on living human RBC membranes in a high‐throughput manner. Our integrated system defines a quantitative method for analyzing RBC membranes under physiological and pathological conditions, improving precision and revealing new perspectives for future disease diagnostics. [ABSTRACT FROM AUTHOR]

Ethylene (ET) is an important gaseous plant hormone. It is highly desirable to develop fluorescent probes for monitoring ethylene in living cells. We report an efficient RhIII‐catalysed coupling of N‐phenoxyacetamides to ethylene in the presence of an alcohol. The newly discovered coupling reaction exhibited a wide scope of N‐phenoxyacetamides and excellent regioselectivity. We successfully developed three fluorophore‐tagged RhIII‐based fluorogenic coumarin‐ethylene probes (CEPs) using this strategy for the selective and quantitative detection of ethylene. CEP‐1 exhibited the highest sensitivity with a limit of detection of ethylene at 52 ppb in air. Furthermore, CEP‐1 was successfully applied for imaging in living CHO‐K1 cells and for monitoring endogenous‐induced changes in ethylene biosynthesis in tobacco and Arabidopsis thaliana plants. These results indicate that CEP‐1 has great potential to illuminate the spatiotemporal regulation of ethylene biosynthesis and ethylene signal transduction in living biological systems. [ABSTRACT FROM AUTHOR]

Ethylene (ET) is an important gaseous plant hormone. It is highly desirable to develop fluorescent probes for monitoring ethylene in living cells. We report an efficient RhIII‐catalysed coupling of N‐phenoxyacetamides to ethylene in the presence of an alcohol. The newly discovered coupling reaction exhibited a wide scope of N‐phenoxyacetamides and excellent regioselectivity. We successfully developed three fluorophore‐tagged RhIII‐based fluorogenic coumarin‐ethylene probes (CEPs) using this strategy for the selective and quantitative detection of ethylene. CEP‐1 exhibited the highest sensitivity with a limit of detection of ethylene at 52 ppb in air. Furthermore, CEP‐1 was successfully applied for imaging in living CHO‐K1 cells and for monitoring endogenous‐induced changes in ethylene biosynthesis in tobacco and Arabidopsis thaliana plants. These results indicate that CEP‐1 has great potential to illuminate the spatiotemporal regulation of ethylene biosynthesis and ethylene signal transduction in living biological systems. [ABSTRACT FROM AUTHOR]

The success of human mesenchymal stem cell (hMSC) therapies is largely dependent on the ability to maintain the multipotency of cells and control their differentiation. External biochemical and biophysical cues can readily trigger hMSCs to spontaneously differentiate, thus resulting in a rapid decrease in the multipotent cell population and compromising their regenerative capacity. Herein, we demonstrate that nonfouling hydrogels composed of pure poly(carboxybetaine) (PCB) enable hMSCs to retain their stem-cell phenotype and multipotency, independent of differentiation-promoting media, cytoskeletal-manipulation agents, and the stiffness of the hydrogel matrix. Moreover, encapsulated hMSCs can be specifically induced to differentiate down osteogenic or adipogenic pathways by controlling the content of fouling moieties in the PCB hydrogel. This study examines the critical role of nonspecific interactions in stem-cell differentiation and highlights the importance of materials chemistry in maintaining stem-cell multipotency and controlling differentiation. [ABSTRACT FROM AUTHOR]