A Near-Infrared Fluorescent and Photoacoustic Probe for Visualizing Biothiols Dynamics in Tumor and Liver

Pretheranostic agents with extraordinaryNIRF/photoacoustic imaging performanceand photothermal oncotherapy efficacy

Cervical cancer, the most common gynecological malignancy, significantly and adversely affects women's physical health and well-being. Traditional surgical interventions and chemotherapy, while potentially effective, often entail serious side effects that have led to an urgent need for novel therapeutic methods. Photothermal therapy (PTT) has emerged as a promising approach due to its ability to minimize damage to healthy tissue. Connecting a biothiol detection group to PTT-sensitive molecules can improve tumor targeting and further minimize potential side effects. In this study, we developed a near-infrared fluorescence (NIRF)/photoacoustic (PA) dual-mode probe, S-NBD, which demonstrated robust PTT performance. This innovative probe is capable of activating NIRF/PA signals to enable the detection of biothiols with high emission wavelength (838 nm) and large Stokes shift (178 nm), allowing for in vivo monitoring of cancer cells. Additionally, the probe achieved an outstanding photothermal conversion efficiency of 67.1%. The application of laser irradiation (660 nm, 1.0 W/cm2, 5 min) was able to achieve complete tumor ablation without recurrence. In summary, this seminal study presents a pioneering NIRF/PA dual-mode dicyanoisophorone-based probe for biothiol imaging, incorporating features from PTT for the first time. This pioneering approach achieves the dual objectives of improving tumor diagnosis and treatment.

A simple Ag-MoS2 hybrid nanozyme-based sensor array for colorimetric identification of biothiols and cancer cells

The intracellular levels of biothiols are associated with various diseases including cancer, and biothiols are regarded as tumor biomarker. Due to the similarity of the molecular structure of biothiols, the development of simple, rapid, efficient, and sensitive colorimetric sensor arrays holds great promise for clinical cancer diagnosis. Here, we developed a simple Ag-MoS2 hybrid nanozyme-based sensor array for colorimetric identification of biothiols and cancer cells. The novel Ag-MoS2 nanoprobe was synthesized in a simple and efficient way through the in situ self-reduction reaction between MoS2 and noble metal precursor. Benefiting from to the formation of heterogeneous metal structures, the peroxidase (POD)-like catalytic activity of the synthesized Ag-MoS2 hybrid nanocomposites is significantly enhanced compared to MoS2 alone. Moreover, the catalytic activity of Ag-MoS2 nanozyme was correlated with the pH of the reaction solution and the inhibitory effects of the three biothiols on the nanozyme-triggered chromogenic system differed in the specific pH environments. Therefore, each sensing unit of this electronic tongue generated differential colorimetric fingerprints of different biothiols. After principal component analysis (PCA), the developed novel colorimetric sensor array can accurately discriminate biothiols between different types, various concentrations, and different mixture proportions. Further, the sensor array was used for the colorimetric identification of real serum and cellular samples, demonstrating its great potential in tumor diagnostic applications.

Intramolecular Friedel-Crafts Reaction with Trifluoroacetic Acid: Synthesizing Some New Functionalized 9-Aryl/Alkyl Thioxanthenes

In this study, a series of halogen-substituted thioxanthenes were synthesized because the most important and biologically active derivatives of xanthenes are thioxanthenes. In order to obtain new thioxanthene derivatives, first, the starting molecules were synthesized by the appropriate reaction methods in two steps. The intramolecular Friedel-Crafts alkylation (FCA) method was used to convert the prepared three aromatic substituted starting alcohol compounds to their corresponding thioxanthenes by cyclization. For the intramolecular FCA reaction of secondary alcohols, which are the starting compounds (1a-1t), organic Bro̷nsted acids, which require more innovative, easier, and suitable reaction conditions, were used instead of halide reagents with corrosive effects as classical FCA catalysts. Trifluoroacetic acid was determined to be the organocatalyst with the best yield. Therefore, some original 9-aryl/alkyl thioxanthene derivatives (2a-2t) were synthesized using the optimized FCA method. In addition, a new sulfone derivative of thioxanthene 3i was prepared by performing the oxidation reaction with one of the obtained new thioxanthene 2i. Thioxanthenes and their derivatives are important heterocyclic structures that contain pharmacologically valuable sulfur and are used in the treatment of psychotic diseases such as Alzheimer's or schizophrenia, as well as a number of potent biological activities.

Activatable fluorescent probes for early diagnosis and evaluation of liver injury

With the increase in people's living standards, the number of patients suffering from liver injury keeps on increasing. Traditional diagnostic methods can no longer meet the needs of early and accurate diagnosis due to their limitations in application. However, fluorescent probes based on different fluorophores and nanomaterials have been gradually lighting up medical research due to their unique properties, such as high specificity and non-invasiveness. In addition, accurate identification of the different types of liver injury biomarkers can significantly improve the level of early diagnosis. Therefore, this review reviews the fluorescent probes used in the detection of biomarkers of liver injury over recent years and briefly summarizes the corresponding biomarkers of different types of liver injury. Impressively, this review also lists the structures and the response mechanisms of the different probes, and concludes with an outlook, suggesting directions in which improvements can be made. Finally, we hope that this review will contribute to the further development of fluorescent probes for the early diagnosis and assessment of liver injury.

Theoretical investigation on a simple turn on fluorescent probe for detection of biothiols based on coumarin unit

The discovery of a simple and efficient detection method for biothiols would be scientifically significant due to the crucial role of them in various physiological processes. Recently, a simple fluorescent probe, DEMCA-NBSC, based on coumarin fragments, was developed by Ding et al., and provided an efficient way for real-time sensing of biothiols both in vivo and vitro. Theoretical insights to the fluorescence sensing mechanism of the probe were provided in this work. Details of the electron transfer process in the probe under optical excitation and the fluorescent character of the probe were analyzed using a quantum mechanical method. All these theoretical results could inspire the development of a highly convenient and efficient fluorescent probe to sense biothiols both in vivo and vitro.

Enzyme-Instructed Aggregation/Dispersion of Fluorophores for Near-Infrared Fluorescence Imaging In Vivo

Near-infrared (NIR) fluorescence is a noninvasive, highly sensitive, and high-resolution modality with great potential for in vivo imaging. Compared with "Always-On" probes, activatable NIR fluorescent probes with "Turn-Off/On" or "Ratiometric" fluorescent signals at target sites exhibit better signal-to-noise ratio (SNR), wherein enzymes are one of the ideal triggers for probe activation, which play vital roles in a variety of biological processes. In this review, we provide an overview of enzyme-activatable NIR fluorescent probes and concentrate on the design strategies and sensing mechanisms. We focus on the aggregation/dispersion state of fluorophores after the interaction of probes and enzymes and finally discuss the current challenges and provide some perspective ideas for the construction of enzyme-activatable NIR fluorescent probes.