COF-based nanoreactors for click-activated prodrug delivery and precise anti-vascular therapy

Herein, we report a new click-activated prodrug, CA4V, and a bioorthogonal nanoreactor, CA4V/ZIF-90@TzCOF@Apt, which consists of a ZIF-90 core, tetrazine-based covalent organic framework (COF) shells and an aptamer polymer coating. When targeting a tumor, the acid-causing collapse of ZIF-90 initiates a nanoconfined bioorthogonal reaction in defined COF cages, which boosts the click efficiency of CA4V activation and therapeutic effects in vivo.

High-fidelity imaging of lysosomal enzyme through in situ ordered assembly of small molecular fluorescent probes

As an organelle in cells, lysosomes play an important role in the degradation of biological macromolecules and pathogens. To elucidate the function of lysosomes in normal or disease states, recently, various fluorescent probes have been reported for imaging lysosomal analytes. However, because of the particularity of the lysosomal environment, most of the reported lysosomal fluorescent probes suffered from a series of practical issues such as easy diffusion, low detection signal-to-background ratio and false signal. To address these issues, based on an optimized in situ ordered assembly solid-state fluorophore HDPQ, we herein put forward a new strategy for the design of lysosomal enzymes probes. As a proof concept, we synthesized a fluorescent probe HDPQ-GLU for lysosomal enzyme β-glucuronidase (GLU). Experiment results displayed that compared with general lysosomal probe, the novel lysosomal probe not only exhibited excellent anti-pH interference ability and high signal-to-noise ratio in aqueous solution, but also has excellent long-term in situ imaging ability in the living system. Using this probe, we have realized high-fidelity and long-term in situ tracking GLU in lysosomes of living cells and evaluated the dynamic changes of GLU during the growth period of zebrafish. We anticipate that the new strategy based on the novel in situ ordered assembly solid-state fluorophore HDPQ may be a potential platform for developing fluorescent probes for high-fidelity imaging of lysosomal enzymes.

Recent advances in dual-target-activated fluorescent probes for biosensing and bioimaging

Fluorescent probes have been powerful tools for visualizing and quantifying multiple dynamic processes in living cells. However, the currently developed probes are often constructed by conjugation a fluorophore with a recognition moiety and given signal-output after triggering with one singly target interest. Compared with the single-target-activated fluorescent probes mentioned above, the dual-target-activated ones, triggering with one target under stimulus (such as photoirradiation, microenvironment) or another targets, have the advantages of advoiding nonspecific activation and "false positive" results in complicated environments. In recent years, many dual-target-activated fluorescent probes have been developed to detect various biologically relevant species. In view of the importance of a comprehensive understanding of dual-target- activated fluorescent probes, a thorough summary of this topic is urgently needed. However, no comprehensive and critical review on dual target activated fluorescent probes has been published recently. In this review, we focus on the dual-target-activated fluorescent probes and briefly outline their types and current state of development. In each type, the chemical structure, proposed responsive mechanism and application of probes are highlighted. At last, the challenges and prospective opportunities of every type were proposed.

[Data analysis of application and funding of ophthalmology projects funded by National Natural Science Foundation of China from 2010 to 2021]

Objective: To review the application for funding of ophthalmologic projects from the National Natural Science Foundation of China (NSFC) and the current research progress, and to provide reference for the promotion of basic eye research in China. Methods: The NSFC application and funding information of ophthalmology-related projects from 2010 to 2021 were collected as a database for further analysis. The main categories of the analysis included the number of application and funding, the funding ratio, the research directions and the funded organizations. Results: During the 12 years, 13 267 applications were received in the field of ophthalmology, with an increase of 157.21% (1 025/652) in 2021 compared with 2010, and the number of applications for the Youth Foundation grew significantly. There were 2 221 funded projects, with an increase of 81.51% (97/119) in 2021 compared with 2010. After 2017, the number of funded projects was basically around 200 per year, with a funding rate of 16.74%(2 221/13 267). The funding amount was 1 026.9 million yuan in total, with an average of 462 400 yuan. Sun Yat-sen University (1 060 applied and 265 funded projects), Fudan University (759 applied and 186 funded projects), Shanghai Jiaotong University (820 applied and 178 funded projects), Wenzhou Medical University (625 applied and 113 funded projects) and Capital Medical University (538 applied and 95 funded projects) were the top five institutions in terms of the number of application and funding. Conclusions: From 2010 to 2021, the application number of ophthalmology projects increased rapidly, while the number of funded projects increased slowly, and the funding ratio decreased year by year. With the support of NSFC, the basic research of ophthalmology in China has made great progress. However, we still need to find and solve problems to promote the sustainable advance of ophthalmology. (This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on January 21, 2022).

NIRII-HDs: A Versatile Platform for Developing Activatable NIR-II Fluorogenic Probes for Reliable In Vivo Analyte Sensing

Small-molecule-based second near-infrared (NIR-II) activatable fluorescent probes can potentially provide a high target-to-background ratio and deep tissue penetration. However, most of the reported NIR-II activatable small-molecule probes exhibit poor versatility owing to the lack of a general and stable optically tunable group. In this study, we designed NIRII-HDs, a novel dye scaffold optimized for NIR-II probe development. In particular, dye NIRII-HD5 showed the best optical properties such as proper pK_a value, excellent stability, and high NIR-II brightness, which can be beneficial for in vivo imaging with high contrast. To demonstrate the applicability of the NIRII-HD5 dye, we designed three target-activatable NIR-II probes for ROS, thiols, and enzymes. Using these novel probes, we not only realized reliable NIR-II imaging of different diseases in mouse models but also evaluated the redox potential of liver tissue during a liver injury in vivo with high fidelity.

Degradable Magnetic Nanoplatform with Hydroxide Ions Triggered Photoacoustic, MR Imaging, and Photothermal Conversion for Precise Cancer Theranostic

Theranostic agents based on inorganic nanomaterials are still suffered from the nonbiodegradable substances with long-term retention in body and unavoidable biological toxicity, as well as nonspecificity biodistribution with potential damage toward normal tissues. Here, we develop magnetic ions (Fe^III, Fe^II, Gd^III, Mn^II, and Mn^III) coordinated nanoplatform (MICN) with framework structure and modify them with PEG (MICN-PEG). Notably, MICN-PEG demonstrates hydroxide ions (OH^-) triggered the structure collapse along with responsive near-infrared photoacoustic (PA) signal, magnetic resonance imaging (MRI), and photothermal therapy (PTT) performances. Thereby, MICN-PEG is able to remain stable in tumors and exert excellent PA/MRI and PTT effects for multimodal imaging-guided cancer treatment. In contrast, MICN-PEG is gradually collapsed in normal tissues, resulting in the significant improvement of imaging accuracy and treatment specificity. MICN-PEG is gradually cleared after administration, minimizing concerns about the long-term toxicity.

Ratiometric afterglow luminescent nanoplatform enables reliable quantification and molecular imaging

Afterglow luminescence is an internal luminescence pathway that occurs after photo-excitation, holds great promise for non-background molecular imaging in vivo, but suffer from poor quantitative ability owing to luminescent attenuation over time. Moreover, the inert structure and insufficient reactive sites of current afterglow materials make it hard to design activatable afterglow probes for specific detection. Here, we report a ratiometric afterglow luminescent nanoplatform to customize various activatable afterglow probes for reliable quantification and molecular imaging of specific analytes, such as NO, ONOO⁻ or pH. Notably, these afterglow probes can not only address the attenuation of afterglow intensity and eliminate the interference of factors (e.g., laser power, irradiation time, and exposure time), but also significantly improve the imaging reliability in vivo and signal-to-background ratios (~1200-fold), both of which enable more reliable quantitative analysis in biological systems. Moreover, as a proof-of-concept, we successfully design an NO-responsive ratiometric afterglow nanoprobe, RAN1. This nanoprobe can monitor the fluctuations of intratumoral NO, as a biomarker of macrophage polarization, making it possible to real-time dynamically evaluate the degree cancer immunotherapy, which provides a reliable parameter to predict the immunotherapeutic effect.

Afterglow luminescence is promising for non-background molecular imaging in vivo. Here the authors report a ratiometric afterglow luminescent nanoplatform to generate activatable afterglow probes for quantification of specific analytes including NO.

[Analysis of factors associated with the structure of the gut microbial community in HIV/AIDS patients in some areas of Henan province]

Objective: To investigate the related factors associated with the structure of the gut microbial community in HIV infection/AIDS cases (HIV/AIDS) in Henan province. Methods: The convenience sampling method was used to select 122 cases who were receiving Antiviral Treatment (ART) or ART-naive in Henan. Whole blood and stool specimens were collected. Genomic DNA of stool samples was extracted, and the V3-V4 hypervariable regions of the 16S rRNA gene were sequenced using Illumina NovaSeq 6000 high-throughput sequencing system. The analysis was performed mainly at the genus level, and the 30 genera with the highest abundance were selected as a measure of the gut microbial community structure. The correlation between community structure and related factors was analyzed using redundancy analysis and Envfit function. Results: 122 cases were finally completed sequencing and analysis, the average BMI was (23.62±2.78) kg/m² and the average age was (47±13) years. Among them, male accounted for 66.39% (81/122), and heterosexual transmission route constituted the largest ratio, accounting for 51.64% (63/122). 36 cases were treatment naive (29.51%, 36/122). The top five dominant genera of the total population (122 cases) were Prevotella, Roseburia, Megamonas, Bacteroides and Faecalibacterium and the top five dominant genera of the ART population (86 cases) were Prevotella, Megamonas, Bacteroides, Roseburia and Faecalibacterium. The top five dominant genera of the ART-naive population (36 cases) appeared as Prevotella, Faecalibacterium, Roseburia, Bacteroides and Megamonas. In the total population, ART (P<0.001) was the most significant factors of community structure. Other significant factors were: duration of diagnosis (P=0.009), viral load (P=0.022) and anti-HCV (P=0.018). ART was positively correlated with Megamonas and negatively correlated with Prevotella, Roseburia and Faecalibacterium, while the other three factors of duration of diagnosis, viral load and anti-HCV were positively correlated with Prevotella, Roseburia and Faecalibacterium and negatively correlated with Megamonas. In the ART-naive population, duration of diagnosis (P=0.003) were the factors significantly associated with community structure. Duration of diagnosis was positively correlated with Roseburia, Faecalibacterium, Megamonas and Prevotella and negatively correlated with Bacteroides. Conclusion: ART and duration of diagnosis were factors significantly associated with gut microbial community structure and had a significant impact on multiple high-abundance genera.

Calcium released by osteoclastic resorption stimulates autocrine/paracrine activities in local osteogenic cells to promote coupled bone formation

A major cause of osteoporosis is impaired coupled bone formation. Mechanistically, both osteoclast-derived and bone-derived growth factors have been previously implicated. We hypothesize that the release of bone calcium during osteoclastic bone resorption is essential for coupled bone formation. Osteoclastic resorption increases interstitial fluid calcium locally from the normal 1.8 mM up to 5 mM. MC3T3-E1 osteoprogenitors, cultured in a 3.6 mM calcium medium, demonstrated that calcium signaling stimulated osteogenic cell proliferation, differentiation, and migration. Calcium channel knockdown studies implicated calcium channels, Cav1.2, store-operated calcium entry (SOCE), and calcium-sensing receptor (CaSR) in regulating bone cell anabolic activities. MC3T3-E1 cultured in a 3.6 mM calcium medium expressed increased gene expression of Wnt signaling and growth factors platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and bone morphogenic protein-2 (BMP 2). Our coupling model of bone formation, the Receptor activator of nuclear factor-kappa-Β ligand (RANKL) treated mouse calvaria, confirmed the role of calcium signaling in coupled bone formation by exhibiting increased gene expression for osterix and osteocalcin. Critically, dual immunocytochemistry showed that RANKL treatment increased osterix positive cells and increased fluorescence intensity of Cav1.2 and CaSR protein expression per osterix positive cell. The data established that calcium released by osteoclasts contributed to the regulation of coupled bone formation. CRISPR/Cas-9 knockout of Cav1.2 in osteoprogenitors cultured in basal calcium medium caused a >80% decrease in the expression of downstream osteogenic genes, emphasizing the large magnitude of the effect of calcium signaling. Thus, calcium signaling is a major regulator of coupled bone formation.

Spherical nucleic acid reporter-based cascade CRISPR/Cas12a amplifier for stable and sensitive biosensing of circulating tumor DNA

Stable and sensitive ctDNA biosensing in complex biological fluid is highly important but still remains a challenge. Herein, we develop a spherical nucleic acid reporter-based cascade CRISPR/Cas12a amplifier with improved stability and sensitivity (5 orders of magnitude).

Selective detection of ozone in inflamed mice using a novel activatable chemiluminescent probe

We report here an activatable chemiluminescent probe CL-O₃ for the high-contrast imaging of O₃in vivo. CL-O₃ exhibited a high selectivity toward O₃ and was able to evaluate the degree of inflammation in mice by detecting endogenous O₃ levels in acute inflamed mice.

Chemical Design of Activatable Photoacoustic Probes for Precise Biomedical Applications

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

[Synchronous primary bilateral macronodular adrenal hyperplasia with renal cell carcinoma: a case series of three patients]

Three cases of synchronous primary bilateral macronodular adrenal hyperplasia(PBMAH) and renal cell carcinoma (RCC) in the Department of Urology of Peking Union Medical College Hospital were retrospectively reviewed. The clinical features, imaging features, treatment methods and pathological features of these patients were analyzed. It was found that the genetic relationship between synchronous PBMAH and RCC needs further research. And RCC is easy to be misdiagnosed. We should pay high attention to imaging features to find out whether there are lesions in bilateral kidneys when we deal with bilateral adrenal lesions. Laparoscopic approach is recommended for PBMAH and RCC. Total or partial nephrectomy should be performed according the tumor size and location of the renal mass. Patients with PBMAH should be closely followed up after bilateral adrenalectomy to avoid delay in diagnosis or treatment of RCC.

Single-stranded circular DNA theranostics

The past decade has witnessed the blossom of nucleic acid therapeutics and diagnostics (theranostics). Unlike conventional small molecule medicines or protein biologics, nucleic acid theranostics have characteristic features such as the intrinsic ability as “information drugs” to code and execute genetic and theranostic information, ready programmability for nucleic acid engineering, intrinsic stimulatory or regulatory immunomodulation, versatile functionalities, and easy conformational recovery upon thermal or chemical denaturation. Single-stranded circular DNA (circDNA) are a class of single-stranded DNAs (ssDNA) featured with their covalently-closed topology. In addition to the basic advantages of nucleic acids-based materials, such as low cost, biocompatibility, and simplicity of chemical modification, the lack of terminals in circDNA prevents exonuclease degradation, resulting in enhanced biostability relative to the corresponding linear ssDNA. circDNA has been explored for versatile theranostic applications. For instance, circDNA has been extensively studied as templates for bioanalytical signal amplification and the synthesis of nano-/micro-/macro- biomaterials via rolling circle amplification (RCA) and rolling circle transcription (RCT) technologies. circDNA has also been commonly used as the scaffolds for the self-assembly of versatile DNA origami. Finally, circDNA has been implemented as theranostic aptamers, miRNA inhibitors, as well as clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins (CRISPR-Cas) gene editing donors. In this review article, we will discuss the chemistry, characteristic properties, and the theranostic applications of circDNA (excluding double-stranded circular DNA such as plasmids); we will also envision the challenges and opportunities in this research field.

Reversal of Solvatochromism: A New Strategy to Construct Activatable Two-photon Fluorescent Probes for Sensing

Two-photon (TP) imaging with a donor-acceptor (D-A) type fluorophore is an emerging tool for bioimaging and sensing. However, current TP probes suffer from serious solvatochromic quenching in aqueous solution due to their strong intramolecular charge transfer (ICT) in excited states. In this work, based on solvatochromism reversal, we report a novel strategy to develop TP probes for bioimaging. Specifically, compared with the normal two-photon probes that showed a fluorescence off with ICT suppressed, the novel probes exhibited strong fluorescence in the aqueous solution when their ICT was inhibited. This strategy not only provides a new way for the design of high-performance TP probes, but also expands the biological analysis toolbox for use in living systems.

Precisely controlling the cellular internalization of DNA-decorated semiconductor polymer nanoparticles for drug delivery

Precisely controlling the cellular internalization of DNA-decorated semiconductor polymer nanoparticles (SPN-DNA) for drug delivery based on the minimized nonspecific adhesivity to cells.

A novel afterglow nanoreporter for monitoring cancer therapy

Rationale: Immunogenic cell death (ICD)-associated immunogenicity evoked through reactive oxygen species (ROS) is an efficient way to fight against the immune-dysfunctional microenvironment, so as to provoke potent anti-tumor immunity. However, the unknown ROS dose during cancer therapies may induce adverse immune responses (e.g., insufficient ICD, toxicity toward normal tissues or immune system).

Methods: Herein, we developed a pyrido pyrazine - thiophene based semiconducting polymer as novel near-infrared (NIR) organic afterglow nanoparticles for the real-time visualization of self-generated ROS, during photodynamic-mediated immunogenic cell death. Specifically, we introduced the strong “acceptor” (pyrido pyrazine) into thiophene based semiconducting polymer to redshift emission wavelength, and further modulate the “donor” to afford more afterglow reaction sites and reducing ΔEst, so as to enhance luminescence intensity.

Results: The semiconducting polymer-based afterglow nanoparticles exhibit strong afterglow emission with longer-wavelength emission (> 800 nm), compared with the reported organic afterglow nanoparticles (e.g., MEHPPV, PFODBT or Chlorin, < 690 nm), which endows this afterglow nanoparticles with a greatly improvement of signal to noise ratio. Moreover, the photodynamic effect of this afterglow nanoparticles can induce immunogenic cell death of cancer cells and further cause immune responses in mice.

Conclusions: The NIR afterglow signal presents a good relationship with ROS generation, immunogenic cell death and outcome of treatment. Therefore, it was able to provide a non-invasive tool for predicting the degree of ICD that occurs during ROS-mediated cancer therapy and may contribute to precise immunotherapy.