Fluorogen-Activating Human Serum Albumin for Mitochondrial Nanoscale Imaging.

Fluorescence nanoscopy of living cells employs contrast agents to reveal intrinsic correlations between mitochondrial dynamics and functions at the molecular level. However, regular mitochondrial fluorophores usually present poor photostability, low brightness, non-specific inhibitory effects, high phototoxicity, and rapid photobleaching, which have hindered the use of these tools to capture the intricate dynamic features of mitochondria. Herein, we engineered a fluorogen-activating protein (FAP), AmpHecy@HSA, a non-covalent self-assembly of HSA and amphiphilic hemicyanine (AmpHecy) fluorophore, with exceptional cell permeability, long-lasting photostability, high brightness/fluorogenicity, and minimal phototoxicity.

Rational Design and Biological Application of Hybrid Fluorophores.

Fluorophores are considered powerful tools for not only enabling the visualization of cell structures, substructures, and biological processes, but also making for the quantitative and qualitative measurement of various analytes in living systems. However, most fluorophores do not meet the diverse requirements for biological applications in terms of their photophysical and biological properties. Hybridization is an important strategy in molecular engineering that provides fluorophores with complementarity and multifunctionality.

Ultrafast Detection of Monoamine Oxidase A in Live Cells and Clinical Glioma Tissues Using an Affinity Binding-Based Two-Photon Fluorogenic Probe.

Abnormal expression of monoamine oxidase A (MAO-A) has been implicated in the development of human glioma, making MAO-A a promising target for therapy. Therefore, a rapid determination of MAO-A is critical for diagnosis. Through in silico screening of two-photon fluorophores, we discovered that a derivative of N,N-dimethyl-naphthalenamine (pre-mito) can effectively fit into the entrance of the MAO-A cavity.

Intramolecular charge transfer enhancing strategy based MAO-A specific two-photon fluorescent probes for glioma cell/tissue imaging.

MAO-A promotes the proliferation of human glioma cells. Herein, we report a series of MAO-A specific two-photon small molecular fluorescent probes (A1-5) based on an intramolecular charge transfer enhancing strategy. The activity of endogenous MAO-A can be selectively imaged using A3 as a representative probe in different biological samples including human glioma cells/tissues two-photon fluorescence microscopy.

Catalysis-based specific detection and inhibition of tyrosinase and their application.

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting.

Amyloid β-targeted metal complexes for potential applications in Alzheimer's disease.

Alzheimer's disease (AD) is currently an incurable neurodegenerative disorder that affects millions of people around the world. The aggregation of amyloid-β peptides (Aβ), one of the primary pathological hallmarks of AD, plays a key role in the AD pathogenesis. In this regard, Aβ aggregates have been considered as both biomarkers and drug targets for the diagnosis and therapy of AD.