Response strategies and biological applications of organic fluorescent thermometry: cell- and mitochondrion-level detection.

Temperature homeostasis is critical for cells to perform their physiological functions. Among the diverse methods for temperature detection, fluorescent temperature probes stand out as a proven and effective tool, especially for monitoring temperature in cells and suborganelles, with a specific emphasis on mitochondria. The utilization of these probes provides a new opportunity to enhance our understanding of the mechanisms and interconnections underlying various physiological activities related to temperature homeostasis.

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.

A novel coumarin-fluorescein-based fluorescent probe for ultrafast and visual detection of HS in a Parkinson's disease model.

Hydrogen sulfide (HS) has a crucial impact on diverse biological processes and has been shown to be related to various diseases. Many probes have been developed to detect intracellular HS by fluorescent imaging. However, the development of rapid, highly selective and sensitive HS probes remains a challenge.

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.

Design and Synthesis of a Mitochondrial-Targeted JNK Inhibitor and Its Protective Effect on Parkinson's Disease Phenotypes.

C-Jun N-terminal kinase (JNK) is a key mediator involved in a variety of physiological processes. JNK activation is regulated in a complex manner by upstream kinases and phosphatases, and plays an important role in physiological processes such as the immune response and neuronal function. Therefore, JNK has become a therapeutic target for neurodegenerative diseases, ankylosing spondylitis, psoriasis, arthritis and other diseases.

A light-activated magnetic bead strategy utilized in spatio-temporal controllable exosomes isolation.

Tumor-derived exosomes are considered as a key biomarker in the field of liquid biopsy. However, conventional separation techniques such as ultracentrifugation, co-precipitation and column chromatography cannot isolate samples with high throughput, while traditional immunomagnetic separation techniques, due to steric effect of magnetic beads, reducing sensitivity of exosomes optical detection. Herein, we provide a novel and simple nanoplatform for spatiotemporally controlling extraction and elution of exosomes magnetic separation and light-activated cargo release.

Pyrimidine-Based Fluorescent Probe for Monitoring Mitophagy via Detection of Mitochondrial pH Variation.

Impaired mitophagy hinders the clearance of damaged mitochondria, inducing pathological states. Knowledge of this phenomenon is key to diagnosing certain diseases and understanding their pathogenesis. Mitophagy involves an acidization process that could serve as an ideal detection target.

Simultaneous Enhancement of the Long-Wavelength NIR-II Brightness and Photothermal Performance of Semiconducting Polymer Nanoparticles.

Theranostic agents with fluorescence in the second near-infrared (NIR-II) window, especially in its long-wavelength region, and NIR-II-excitable photothermal effect is promising but challenging in tumor diagnosis and therapy. Here, we report a simple but effective strategy to develop semiconducting polymer nanoparticles-based theranostic agents (PBQ NPs) and demonstrate their applications for long-wavelength NIR-II fluorescence imaging beyond 1400 nm and photothermal therapy (PTT) of tumors upon excitation at 1064 nm. Both experimental results and theory calculations show that the brightness and photothermal performance of PBQ NPs can be simultaneously improved by simply increasing the repeating unit number of semiconducting polymers.

Lignin-Incorporated Nanogel Serving As an Antioxidant Biomaterial for Wound Healing.

Oxidative phosphorylation is an important biological process in the body to produce energy, during which oxygen free radicals are generated as byproduct. Excessive oxygen free radicals cause cell death and reduce the rate of tissue regeneration and healing in a wound. Lignin is a natural antioxidant derived from plants, but its biomedical application is restricted because of the uncertain biocompatibility.

Two-photon fluorescent turn-on probes for highly efficient detection and profiling of thiols in live cells and tissues.

Thiols are important units in amino acids such as cysteine and peptides like glutathione. Development of chemical sensors capable of precise detection of thiols is important in cancer diagnosis and therapy. We have developed novel two-photon fluorescent turn-on probes for selective detection of thiols.

A mitochondrion-targeting Mn(ii)-terpyridine complex for two-photon photodynamic therapy.

We developed a mitochondrion-targeting Mn-terpyridine complex (MTP) for two-photon photodynamic therapy. MTP was subjected to two-photon excitation in the NIR region to generate O and hence produce a PDT effect. This use of MTP overcame the drawbacks of traditional PDT agents.

A novel naphthofluorescein-based probe for ultrasensitive point-of-care testing of zinc(II) ions and its bioimaging in living cells and zebrafishes.

The combination of fluorescence method with paper-based diagnostic device is quite suitable in point-of-care testing (POCT). Herein, we designed a novel hybrid fluorescein-based probe ZN-2 and investigated its fluorescent properties thoroughly in the detection of Zn. In comparison with the fluorescein-based probe ZN-1, ZN-2 displayed better sensitivity, long-wavelength and faster response to Zn within 20 min.

A novel pyrimidine based deep-red fluorogenic probe for detecting hydrogen peroxide in Parkinson's disease models.

Parkinson's disease (PD) severely affects life quality of patients and has brought huge economic burden to health system worldwide. Previous studies have shown that the abnormal expression of hydrogen peroxide (HO) in the brain is closely related to the development of neurodegenerative diseases such as PD. Herein, we designed a novel deep-red HO fluorogenic probe PB1 to detect the level of HOin vivo.

Rational design of NIR fluorescence probes for sensitive detection of viscosity in living cells.

Developing near-infrared (NIR) fluorescence probes for detection of intracellular viscosity is still sufficiently challenging. In this work, three kinds of D-A-D type naphthyl and 2,1,3‑benzoxadiazol hybrid NIR dyes functionalized with amino (NY1), N‑methylamino (NY2) and N,N‑dimethylamino (NY3) groups for intracellular micro-viscosity detection were designed and synthesized. All the probes exhibited very weak NIR emission in low viscosity environment and obvious fluorescence enhancement with the increased viscosity.