Endogenous H2S-Activated Orthogonal Second Near-Infrared Emissive Nanoprobe for In Situ Ratiometric Fluorescence Imaging of Metformin-Induced Liver Injury

An Activatable Afterglow/MRI Bimodal Nanoprobe with Fast Response to H2 S for In Vivo Imaging of Acute Hepatitis

Accurate detection of hepatic hydrogen sulfide (H₂ S) to monitor H₂ S-related enzymes' activity is critical for acute hepatitis diagnosis, but remains a challenge due to the dynamic and transient nature of H₂ S. Here, we report a H₂ S-activatable near-infrared afterglow/MRI bimodal probe F1-GdNP, which shows an "always-on" MRI signal and "off-on" afterglow signal toward H₂ S. F1-GdNP shows fast response, high sensitivity and specificity toward H₂ S, permitting afterglow imaging of H₂ S and evaluation of cystathionine γ-lyase (CSE)'s activity in living mice. We further employ the high spatial-resolution MRI signal of F1-GdNP to track its delivery and accumulation in liver. Importantly, F1-GdNP offers a high signal-to-background ratio (SBR=86.2±12.0) to sensitively report on the increased hepatic H₂ S level in the acute hepatitis mice via afterglow imaging, which correlated well with the upregulated CSE activity in the liver, showcasing the good potential of F1-GdNP for monitoring of acute hepatitis process in vivo.

Near infrared bioimaging and biosensing with semiconductor and rare-earth nanoparticles: recent developments in multifunctional nanomaterials

Research in novel materials has been extremely active over the past few decades, wherein a major area of interest has been nanoparticles with special optical properties. These structures can overcome some of the intrinsic limitations of contrast agents routinely used in medical practice, while offering additional functionalities. Materials that absorb or scatter near infrared light, to which biological tissues are partially transparent, have attracted significant attention and demonstrated their potential in preclinical research. In this review, we provide an at-a-glance overview of the most recent developments in near infrared nanoparticles that could have far-reaching applications in the life sciences. We focus on materials that offer additional functionalities besides diagnosis based on optical contrast: multiple imaging modalities (multimodal imaging), sensing of physical and chemical cues (multivariate diagnosis), or therapeutic activity (theranostics). Besides presenting relevant case studies for each class of optically active materials, we discuss their design and safety considerations, detailing the potential hurdles that may complicate their clinical translation. While multifunctional nanomaterials have shown promise in preclinical research, the field is still in its infancy; there is plenty of room to maximize its impact in preclinical studies as well as to deliver it to the clinics.

Tumor-activatable biomineralized nanotherapeutics for integrative glucose starvation and sensitized metformin therapy

Metformin is a clinically-approved anti-diabetic drug with emerging antitumor potential, but its antitumor activity is highly susceptible to local glucose abundance. Herein, we construct a nanotherapeutic platform based on biocompatible constituents to sensitize tumor cells for metformin therapy via cooperative glucose starvation. The nanoplatform was synthesized through the spontaneous biomineralization of glucose oxidase (GOx) and metformin in amorphous calcium phosphate nanosubstrate, which was further modified with polyethylene glycol and cRGD ligands. This biomineralized nanosystem could efficiently deliver the therapeutic payloads to tumor cells in a targeted and bioresponsive manner. Here GOx could catalyze the oxidation of glucose into gluconic acid and H₂O₂, thus depleting the glucose in tumor intracellular compartment while accelerating the release of the entrapped therapeutic payloads. The selective glucose deprivation would not only disrupt tumor energy metabolism, but also upregulate the PP2A regulatory subunit B56δ and sensitize tumor cells to the metformin-induced CIP2A inhibition, leading to efficient apoptosis induction via PP2A-GSK3β-MCL-1 axis with negligible side effects. This study may offer new avenues for targeted tumor therapy in the clinical context.

A H2S-Triggered Dual-Modal Second Near-Infrared/Photoacoustic Intelligent Nanoprobe for Highly Specific Imaging of Colorectal Cancer

An endogenous H₂S-triggered intelligent optical nanoprobe combining second near-infrared (NIR-II) fluorescence with photoacoustic (PA) imaging can provide more comprehensive information to further improve the sensitivity and reliability of diagnosis for colorectal tumor, which is rarely explored. Herein, an endogenous H₂S-triggered SiO₂@Ag nanoprobe was designed for in situ dual-modal NIR-II/PA imaging of colorectal cancer. The designed dual-modal nanoprobe can be converted to SiO₂@Ag₂S after in situ biosynthesis via a sulfuration reaction with the over-expressed endogenous H₂S in the colorectal tumor. More importantly, the designed SiO₂@Ag nanoprobe exhibits high sensitivity and specificity for diagnosing colorectal cancer in vivo via dual-modal NIR-II/PA imaging. These results provide a new NIR-II/PA dual-modal imaging strategy for noninvasive intelligent detection of colorectal cancer.

A Small-Molecule Diketopyrrolopyrrole-Based Dye for in vivo NIR-IIa Fluorescence Bioimaging

Organic small-molecule fluorophores with near-infrared IIa (NIR-IIa) emission have great potential in pre-clinical detection and inoperative imaging due to the high-spatial resolution and deep penetration. However, developments of the NIR-IIa fluorophores are still facing considerable challenges. In this work, a series of diketopyrrolopyrrole (DPP)-based fluorophores were designed and synthesized. Subsequently, nanomaterial T25@F127 with significant NIR-IIa emission properties was rationally prepared by encapsulating DPP-based fluorophore T25, and was selected for fluorescence angiography and cerebral vascular microscopic imaging with nearly 800 μm penetrating depth and excellent signal-background ratio of 4.07 and 2.26 (at 250 and 400 μm), respectively. Furthermore, the nanomaterial T25@cRGD with tumor targeting ability can image tiny metastatic tumor on intestine with a small size of 0.3 mm×1.0 mm and high-spatial resolution (SBR=3.84). This study demonstrates that the nanomaterials which encapsulated T25 behave as excellent NIR-IIa fluorescence imaging agents and have a great potential for in vivo biological application.

Real-Time Imaging of Hepatic Inflammation Using Hydrogen Sulfide-Activatable Second Near-Infrared Luminescent Nanoprobes

The sensing and visualized monitoring of hydrogen sulfide (H₂S) in vivo is crucial to understand its physiological and pathological roles in human health and diseases. Common methods for H₂S detection require the destruction of the biosamples and are not suitable to be applied in vivo. In this Communication, we report a "turn-on" second near-infrared (NIR-II) luminescent approach for sensitive, real-time, and in situ H₂S detection, which is based on the absorption competition between the H₂S-responsive chromophores (compound 1) and the NIR-II luminescent lanthanide nanoparticles. Specifically, the luminescence was suppressed by compound 1 due to the competitive absorption of the incident light. In the presence of H₂S, the compound 1 was bleached to recover the luminescence. Thanks to the deep tissue penetration depth and the low absorbance/scattering on biological samples of the NIR-II nanoprobes, the monitoring of the endogenous H₂S in lipopolysaccharide-induced liver inflammation was achieved, which is unattainable by the conventional histopathological and serological approaches.

Variables associated with increased incidence of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes

INTRODUCTION

Type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD) show a rapidly increasing incidence worldwide. Although both diseases often occur in the same patient population, their mutual influence is not fully understood. We therefore aimed at analyzing the impact of T2D on the incidence of NAFLD in a large cohort of outpatients in Germany.

RESEARCH DESIGN AND METHODS

32 201 patients with T2D diagnosed between 2012 and 2018 were identified in the IQVIA Disease Analyzer database. Probability of NAFLD was analyzed using Cox regression models.

RESULTS

The cumulative incidence of NAFLD within the 7-year observation period was 4.3%. The probability of NAFLD was significantly higher among patients with T2D with increased body mass index but not hemoglobin A1c. Prescriptions of sodium-glucose cotransporter-2 inhibitors (HR: 0.54, 95% CI 0.45 to 0.64), glucagon-like peptide-1 receptor antagonists (HR: 0.65, 95% CI 0.52 to 0.81), and insulin (HR: 0.72, 95% CI 0.62 to 0.8) were significantly associated with lower incidence of NAFLD.

CONCLUSION

Our data from a large population-based cohort of patients with T2D identified sociodemographic and therapeutic parameters associated with NAFLD incidence in patients with T2D which should be taken into account for novel therapeutic concepts.