Lanthanide Inorganic Nanoparticles Enhance Semiconducting Polymer Nanoparticles Afterglow Luminescence for In Vivo Afterglow/Magnetic Resonance Imaging

Dual/multimodal imaging strategies are increasingly recognized for their potential to provide comprehensive diagnostic insights in cancer imaging by harnessing complementary data. This study presents an innovative probe that capitalizes on the synergistic benefits of afterglow luminescence and magnetic resonance imaging (MRI), effectively eliminating autofluorescence interference and delivering a superior signal-to-noise ratio. Additionally, it facilitates deep tissue penetration and enables noninvasive imaging. Despite the advantages, only a limited number of probes have demonstrated the capability to simultaneously enhance afterglow luminescence and achieve high-resolution MRI and afterglow imaging. Herein, we introduce a cutting-edge imaging platform based on semiconducting polymer nanoparticles (PFODBT) integrated with NaYF4@NaGdF4 (Y@Gd@PFO-SPNs), which can directly amplify afterglow luminescence and generate MRI and afterglow signals in tumor tissues. The proposed mechanism involves lanthanide nanoparticles producing singlet oxygen (1O2) upon white light irradiation, which subsequently oxidizes PFODBT, thereby intensifying afterglow luminescence. This innovative platform paves the way for the development of high signal-to-background ratio imaging modalities, promising noninvasive diagnostics for cancer.

C-terminal binding protein 2 is a novel tumor suppressor targeting the MYC-IRF4 axis in multiple myeloma

ABSTRACT

Multiple myeloma (MM) cells are addicted to MYC and its direct transactivation targets IRF4 for proliferation and survival. MYC and IRF4 are still considered "undruggable," as most small-molecule inhibitors suffer from low potency, suboptimal pharmacokinetic properties, and undesirable off-target effects. Indirect inhibition of MYC/IRF4 emerges as a therapeutic vulnerability in MM. Here, we uncovered an unappreciated tumor-suppressive role of C-terminal binding protein 2 (CTBP2) in MM via strong inhibition of the MYC-IRF4 axis. In contrast to epithelial cancers, CTBP2 is frequently downregulated in MM, in association with shortened survival, hyperproliferative features, and adverse clinical outcomes. Restoration of CTBP2 exhibited potent antitumor effects against MM in vitro and in vivo, with marked repression of the MYC-IRF4 network genes. Mechanistically, CTBP2 impeded the transcription of MYC and IRF4 by histone H3 lysine 27 deacetylation (H3K27ac) and indirectly via activation of the MYC repressor IFIT3. In addition, activation of the interferon gene signature by CTBP2 suggested its concomitant immunomodulatory role in MM. Epigenetic studies have revealed the contribution of polycomb-mediated silencing and DNA methylation to CTBP2 inactivation in MM. Notably, inhibitors of Enhance of zeste homolog 2, histone deacetylase, and DNA methyltransferase, currently under evaluation in clinical trials, were effective in restoring CTBP2 expression in MM. Our findings indicated that the loss of CTBP2 plays an essential role in myelomagenesis and deciphers an additional mechanistic link to MYC-IRF4 dysregulation in MM. We envision that the identification of novel critical regulators will facilitate the development of selective and effective approaches for treating this MYC/IRF4-addicted malignancy.

Rational Design of NIR-II G-Quadruplex Fluorescent Probes for Accurate In Vivo Tumor Metastasis Imaging

Accurate in vivo imaging of G-quadruplexes (G4) is critical for understanding the emergence and progression of G4-associated diseases like cancer. However, existing in vivo G4 fluorescent probes primarily operate within the near-infrared region (NIR-I), which limits their application accuracy due to the short emission wavelength. The transition to second near-infrared (NIR-II) fluorescent imaging has been of significant interest, as it offers reduced autofluorescence and deeper tissue penetration, thereby facilitating more accurate in vivo imaging. Nonetheless, the advancement of NIR-II G4 probes has been impeded by the absence of effective probe design strategies. Herein, through a "step-by-step" rational design approach, we have successfully developed NIRG-2, the first small-molecule fluorescent probe with NIR-II emission tailored for in vivo G4 detection. Molecular docking calculations reveal that NIRG-2 forms stable hydrogen bonds and strong π-π interactions with G4 structures, which effectively inhibit twisted intramolecular charge transfer (TICT) and, thereby, selectively illuminate G4 structures. Due to its NIR-II emission (940 nm), large Stokes shift (90 nm), and high selectivity, NIRG-2 offers up to 47-fold fluorescence enhancement and a tissue imaging depth of 5 mm for in vivo G4 detection, significantly outperforming existing G4 probes. Utilizing NIRG-2, we have, for the first time, achieved high-contrast visualization of tumor metastasis through lymph nodes and precise tumor resection. Furthermore, NIRG-2 proves to be highly effective and reliable in evaluating surgical and drug treatment efficacy in cancer lymphatic metastasis models. We are optimistic that this study not only provides a crucial molecular tool for an in-depth understanding of G4-related diseases in vivo but also marks a promising strategy for the development of clinical NIR-II G4-activated probes.

"Zero" Intrinsic Fluorescence Sensing-Platforms Enable Ultrasensitive Whole Blood Diagnosis and In Vivo Imaging

Abnormal physiological processes and diseases can lead to content or activity fluctuations of biocomponents in organelles and whole blood. However, precise monitoring of these abnormalities remains extremely challenging due to the insufficient sensitivity and accuracy of available fluorescence probes, which can be attributed to the background fluorescence arising from two sources, 1) biocomponent autofluorescence (BCAF) and 2) probe intrinsic fluorescence (PIF). To overcome these obstacles, we have re-engineered far-red to NIR II rhodol derivatives that possess weak BCAF interference. And a series of "zero" PIF sensing-platforms were created by systematically regulating the open-loop/spirocyclic forms. Leveraging these advancements, we devised various ultra-sensitive NIR indicators, achieving substantial fluorescence boosts (190 to 1300-fold). Among these indicators, 8-LAP demonstrated accurate tracking and quantifying of leucine aminopeptidase (LAP) in whole blood at various stages of tumor metastasis. Furthermore, coupling 8-LAP with an endoplasmic reticulum-targeting element enabled the detection of ERAP1 activity in HCT116 cells with p53 abnormalities. This delicate design of eliminating PIF provides insights into enhancing the sensitivity and accuracy of existing fluorescence probes toward the detection and imaging of biocomponents in abnormal physiological processes and diseases.

CD9 shapes glucocorticoid sensitivity in pediatric B-cell precursor acute lymphoblastic leukemia

Resistance to glucocorticoids (GCs), the common agents for remission induction in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL), poses a significant therapeutic hurdle. Therefore, dissecting the mechanisms shaping GC resistance could lead to new treatment modalities. Here, we showed that CD9- BCP-ALL cells were preferentially resistant to prednisone and dexamethasone over other standard cytotoxic agents. Concordantly, we identified significantly more poor responders to the prednisone prephase among BCP-ALL patients with a CD9- phenotype, especially for those with adverse presenting features including older age, higher white cell count and BCR-ABL1. Furthermore, gain- and loss-of-function experiments dictated a definitive functional linkage between CD9 expression and GC susceptibility, as demonstrated by the reversal and acquisition of relative GC resistance in CD9low and CD9high BCP-ALL cells, respectively. Despite physical binding to the GC receptor NR3C1, CD9 did not alter its expression, phosphorylation or nuclear translocation but potentiated the induction of GC-responsive genes in GCresistant cells. Importantly, the MEK inhibitor trametinib exhibited higher synergy with GCs against CD9- than CD9+ lymphoblasts to reverse drug resistance in vitro and in vivo. Collectively, our results elucidate a previously unrecognized regulatory function of CD9 in GC sensitivity, and inform new strategies for management of children with resistant BCP-ALL.

Enhancing lipid peroxidation via radical chain transfer reaction for MRI guided and effective cancer therapy in mice

Lipid peroxidation (LPO), the process of membrane lipid oxidation, is a potential new form of cell death for cancer treatment. However, the radical chain reaction involved in LPO is comprised of the initiation, propagation (the slowest step), and termination stages, limiting its effectiveness in vivo. To address this limitation, we introduce the radical chain transfer reaction into the LPO process to target the propagation step and overcome the sluggish rate of lipid peroxidation, thereby promoting endogenous lipid peroxidation and enhancing therapeutic outcomes. Firstly, radical chain transfer agent (CTA-1)/Fe nanoparticles (CTA-Fe NPs-1) was synthesized. Notably, CTA-1 convert low activity peroxyl radicals (ROO·) into high activity alkoxyl radicals (RO·), creating the cycle of free radical oxidation and increasing the propagation of lipid peroxidation. Additionally, CTA-1/Fe ions enhance reactive oxygen species (ROS) generation, consume glutathione (GSH), and thereby inactivate GPX-4, promoting the initiation stage and reducing termination of free radical reaction. CTA-Fe NPs-1 induce a higher level of peroxidation of polyunsaturated fatty acids in lipid membranes, leading to highly effective treatment in cancer cells. In addition, CTA-Fe NPs-1 could be enriched in tumors inducing potent tumor inhibition and exhibit activatable T1-MRI contrast of magnetic resonance imaging (MRI). In summary, CTA-Fe NPs-1 can enhance intracellular lipid peroxidation by accelerating initiation, propagation, and inhibiting termination step, promoting the cycle of free radical reaction, resulting in effective anticancer outcomes in tumor-bearing mice.

Chemical Approaches to Optimize the Properties of Organic Fluorophores for Imaging and Sensing

Organic fluorophores are indispensable tools in cells, tissue and in vivo imaging, and have enabled much progress in the wide range of biological and biomedical fields. However, many available dyes suffer from insufficient performances, such as short absorption and emission wavelength, low brightness, poor stability, small Stokes shift, and unsuitable permeability, restricting their application in advanced imaging technology and complex imaging. Over the past two decades, many efforts have been made to improve these performances of fluorophores. Starting with the luminescence principle of fluorophores, this review clarifies the mechanisms of the insufficient performance for traditional fluorophores to a certain extent, systematically summarizes the modified approaches of optimizing properties, highlights the typical applications of the improved fluorophores in imaging and sensing, and indicates existing problems and challenges in this area. This progress not only proves the significance of improving fluorophores properties, but also provide a theoretical guidance for the development of high-performance fluorophores.

Decoding the complexity of on-target integration: characterizing DNA insertions at the CRISPR-Cas9 targeted locus using nanopore sequencing

BACKGROUND

CRISPR-Cas9 technology has advanced in vivo gene therapy for disorders like hemophilia A, notably through the successful targeted incorporation of the F8 gene into the Alb locus in hepatocytes, effectively curing this disorder in mice. However, thoroughly evaluating the safety and specificity of this therapy is essential. Our study introduces a novel methodology to analyze complex insertion sequences at the on-target edited locus, utilizing barcoded long-range PCR, CRISPR RNP-mediated deletion of unedited alleles, magnetic bead-based long amplicon enrichment, and nanopore sequencing.

RESULTS

We identified the expected F8 insertions and various fragment combinations resulting from the in vivo linearization of the double-cut plasmid donor. Notably, our research is the first to document insertions exceeding ten kbp. We also found that a small proportion of these insertions were derived from sources other than donor plasmids, including Cas9-sgRNA plasmids, genomic DNA fragments, and LINE-1 elements.

CONCLUSIONS

Our study presents a robust method for analyzing the complexity of on-target editing, particularly for in vivo long insertions, where donor template integration can be challenging. This work offers a new tool for quality control in gene editing outcomes and underscores the importance of detailed characterization of edited genomic sequences. Our findings have significant implications for enhancing the safety and effectiveness of CRISPR-Cas9 gene therapy in treating various disorders, including hemophilia A.

Discovery of New Isotopes ^{160}Os and ^{156}W: Revealing Enhanced Stability of the N=82 Shell Closure on the Neutron-Deficient Side

Using the fusion-evaporation reaction ^{106}Cd(^{58}Ni,4n)^{160}Os and the gas-filled recoil separator SHANS, two new isotopes _{76}^{160}Os and _{74}^{156}W have been identified. The α decay of ^{160}Os, measured with an α-particle energy of 7080(26) keV and a half-life of 201_{-37}^{+58}  μs, is assigned to originate from the ground state. The daughter nucleus ^{156}W is a β^{+} emitter with a half-life of 291_{-61}^{+86}  ms. The newly measured α-decay data allow us to derive α-decay reduced widths (δ^{2}) for the N=84 isotones up to osmium (Z=76), which are found to decrease with increasing atomic number above Z=68. The reduction of δ^{2} is interpreted as evidence for the strengthening of the N=82 shell closure toward the proton drip line, supported by the increase of the neutron-shell gaps predicted in theoretical models.

The design strategies for CRISPR-based biosensing: Target recognition, signal conversion, and signal amplification

Rapid, sensitive and selective biosensing is highly important for analyzing biological targets and dynamic physiological processes in cells and living organisms. As an emerging tool, clustered regularly interspaced short palindromic repeats (CRISPR) system is featured with excellent complementary-dependent cleavage and efficient trans-cleavage ability. These merits enable CRISPR system to improve the specificity, sensitivity, and speed for molecular detection. Herein, the structures and functions of several CRISPR proteins for biosensing are summarized in depth. Moreover, the strategies of target recognition, signal conversion, and signal amplification for CRISPR-based biosensing were highlighted from the perspective of biosensor design principles. The state-of-art applications and recent advances of CRISPR system are then outlined, with emphasis on their fluorescent, electrochemical, colorimetric, and applications in POCT technology. Finally, the current challenges and future prospects of this frontier research area are discussed.

Light-mediated protein functionalization of photoclickable hydrogel interface for selective cell capture and dot blotting assay

The construction of versatile functional hydrogel interfaces holds promising prospects in biosensing and bioengineering. Herein, we introduced a light-induced protein conjugation strategy for on-demand surface modification of hydrogel interface based on the photoclick cyclization between primary amine and o-nitrobenzyl alcohol. We achieved the on-demand protein conjugation by grafting the molecular plugin, 4-(hydroxymethyl)-3-nitrobenzoic acid (HNBA), onto the hydrogel surface, followed by the mask-aided photoclick reaction with the protein of interest. This method enables the creation of protein patterns on hydrogel interface with a lower limit of pattern width at ∼70 μm. With this method, we demonstrated the surface engineering of epidermal growth factor (EGF) on hydrogel interface for selective capture of EGF receptor-positive cancer cells with an efficiency over 80%. Moreover, we applied the mask-aided photoclick conjugation method for antigen capture and developed a photoclickable hydrogel interface-based dot blotting assay. Due to the high-efficient antigen capture of photoclick conjugation, the photoclickable hydrogel interface-based dot blotting assay shows improved sensitivity for antigen detection with a limit of detection as 0.065 ng. We believed that this light-induced protein conjugation method holds the potential as a robust strategy for the construction of bioactive hydrogel interfaces for various bio-related applications.

Enhancing Human Treg Cell Induction through Engineered Dendritic Cells and Zinc Supplementation

Regulatory T (Treg) cells hold promise for the ultimate cure of immune-mediated diseases. However, how to effectively restore Treg function in patients remains unknown. Previous reports suggest that activated dendritic cells (DCs) de novo synthesize locally high concentrations of 1,25-dihydroxy vitamin D, i.e., the active vitamin D or 1,25(OH)2D by upregulating the expression of 25-hydroxy vitamin D 1α-hydroxylase. Although 1,25(OH)2D has been shown to induce Treg cells, DC-derived 1,25(OH)2D only serves as a checkpoint to ensure well-balanced immune responses. Our animal studies have shown that 1,25(OH)2D requires high concentrations to generate Treg cells, which can cause severe side effects. In addition, our animal studies have also demonstrated that dendritic cells (DCs) overexpressing the 1α-hydroxylase de novo synthesize the effective Treg-inducing 1,25(OH)2D concentrations without causing the primary side effect of hypercalcemia (i.e., high blood calcium levels). This study furthers our previous animal studies and explores the efficacy of the la-hydroxylase-overexpressing DCs in inducing human CD4+FOXP3+regulatory T (Treg) cells. We discovered that the effective Treg-inducing doses of 1,25(OH)2D were within a range. Additionally, our data corroborated that the 1α-hydroxylase-overexpressing DCs synthesized 1,25(OH)2D within this concentration range in vivo, thus facilitating effective Treg cell induction. Moreover, this study demonstrated that 1α-hydroxylase expression levels were pivotal for DCs to induce Treg cells because physiological 25(OH)D levels were sufficient for the engineered but not parental DCs to enhance Treg cell induction. Interestingly, adding non-toxic zinc concentrations significantly augmented the Treg-inducing capacity of the engineered DCs. Our new findings offer a novel therapeutic avenue for immune-mediated human diseases, such as inflammatory bowel disease, type 1 diabetes, and multiple sclerosis, by integrating zinc with the 1α-hydroxylase-overexpressing DCs.

[Effects of preoperative diagnostic hysteroscopy on peritoneal cytology and prognosis in patients with non-endometrioid carcinoma]

Objective: To explore the effects of preoperative hysteroscopic guided biopsy and segmental diagnosis and curettage on the risk of abdominal dissemination and prognosis of non-endometrioid carcinoma. Methods: The clinical and pathological data of 97 patients who underwent surgical treatment and were pathologically confirmed as non-endometrioid carcinoma (including serous carcinoma, clear cell carcinoma, mixed adenocarcinoma, and undifferentiated carcinoma, etc.) from October 2008 to December 2021 in Peking University People's Hospital, were collected for retrospective analysis. According to preoperative diagnostic methods, they were divided into hysteroscopic group (n=44) and non-hysteroscopic group (n=53). The impact of hysteroscopy examination on peritoneal cytology and prognosis was analyzed. Results: (1) There were no statistical differences in age, body mass index, tumor size, pathological characteristics, and treatment methods between the hysteroscopic group and the non-hysteroscopic group (all P>0.05), but the proportion of stage Ⅰ-Ⅱ patients in the hysteroscopic group was significantly higher than that in the non-hysteroscopic group [68% (30/44) vs 47% (25/53); χ2=4.32, P=0.038]. (2) Among 97 patients, 25 (26%, 25/97) of them were cytologically positive for ascites. The hysteroscopic group had a lower positive rate of peritoneal cytology than that in the non-hysteroscopy group, which was significantly different [11% (5/44) vs 38% (20/53); χ2=8.74, P=0.003]. Stratification according to surgical and pathological stages showed that the positive rate of peritoneal cytology in the hysteroscopic group (3%, 1/30) was lower than that in the non-hysteroscopic group (12%, 3/25) in the 55 patients with stage Ⅰ-Ⅱ, and that in the hysteroscopic group (4/14) was also lower than that in the non-hysteroscopic group (61%, 17/28) in the 42 patients with stage Ⅲ-Ⅳ. There were no significant differences (all P>0.05). (3) The 5-year disease-free survival (DFS) rate of the hysteroscopic group and the non-hysteroscopic group were respectively 72.7% and 60.4%, and there was no significant difference between the two groups (P=0.186). After stratification according to staging, the 5-year DFS rate were respectively 90.0% and 72.0% (P=0.051) between the hysteroscopic and non-hysteroscopic groups of patients in stage Ⅰ-Ⅱ, and 35.7% and 50.0% (P=0.218) between the hysteroscopic and non-hysteroscopic groups of patients in stage Ⅲ-Ⅳ, in which there were not statistically significant differences. The 5-year overall survival (OS) rate were respectively 86.4% and 81.1% between the hysteroscopic group and the non-hysteroscopic group, with no significant difference between the two groups (P=0.388). The 5-year OS rate were respectively 93.3% and 96.0% in the hysteroscopic group and non-hysteroscopic group for patients with stage Ⅰ-Ⅱ(P=0.872), and 71.4% and 67.9% in the hysteroscopic group and non-hysteroscopic group in patients with stage Ⅲ-Ⅳ (P=0.999), with no statistical significance. Conclusions: Diagnostic hysteroscopy do not increase the rate of positive peritoneal cytology result at the time of surgery in this cohort, and no significant correlation between preoperative hysteroscopy examination and poor prognosis of non-endometrioid carcinoma is observed. Therefore, preoperative hysteroscopic guided biopsy and segmental diagnosis and curettage in non-endometrioid carcinoma maybe safe.

Superoxide Anion-Mediated Afterglow Mechanism-Based Water-Soluble Zwitterion Dye Achieving Renal-Failure Mice Detection

Afterglow materials-based biological imaging has promising application prospects, due to negligible background. However, currently available afterglow materials mainly include inorganic materials as well as some organic nanoparticles, which are difficult to translate to the clinic, resulting from non-negligible metabolic toxicity and even leakage risk of inorganic heavy metals. Although building small organic molecules could solve such obstacles, organic small molecules with afterglow ability are extremely scarce, especially with a sufficient renal metabolic capacity. To address these issues, herein, we designed water-soluble zwitterion Cy5-NF with renal metabolic capacity and afterglow luminescence, which relied on an intramolecular cascade reaction between superoxide anion (O2•-, instead of 1O2) and Cy5-NF to release afterglow luminescence. Of note, compared with different reference contrast agents, zwitterion Cy5-NF not only had excellent afterglow properties but also had a rapid renal metabolism rate (half-life period, t1/2, around 10 min) and good biocompatibility. Unlike prior afterglow nanosystems possessing a large size, for the first time, zwitterion Cy5-NF has achieved the construction of water-soluble renal metabolic afterglow contrast agents, which showed higher sensitivity and signal-to-background ratio in afterglow imaging than fluorescence imaging for the kidney. Moreover, zwitterion Cy5-NF had a longer kidney retention time in renal-failure mice (t1/2 more than 15 min). More importantly, zwitterion Cy5-NF can be metabolized very quickly even in severe renal-failure mice (t1/2 around 25-30 min), which greatly improved biosecurity. Therefore, we are optimistic that the O2•--mediated afterglow mechanism-based water-soluble zwitterion Cy5-NF is very promising for clinical application, especially rapid detection of kidney failure.

GREPore-seq: A Robust Workflow to Detect Changes After Gene Editing Through Long-range PCR and Nanopore Sequencing

To achieve the enormous potential of gene-editing technology in clinical therapies, one needs to evaluate both the on-target efficiency and unintended editing consequences comprehensively. However, there is a lack of a pipelined, large-scale, and economical workflow for detecting genome editing outcomes, in particular insertion or deletion of a large fragment. Here, we describe an approach for efficient and accurate detection of multiple genetic changes after CRISPR/Cas9 editing by pooled nanopore sequencing of barcoded long-range PCR products. Recognizing the high error rates of Oxford nanopore sequencing, we developed a novel pipeline to capture the barcoded sequences by grepping reads of nanopore amplicon sequencing (GREPore-seq). GREPore-seq can assess nonhomologous end-joining (NHEJ)-mediated double-stranded oligodeoxynucleotide (dsODN) insertions with comparable accuracy to Illumina next-generation sequencing (NGS). GREPore-seq also reveals a full spectrum of homology-directed repair (HDR)-mediated large gene knock-in, correlating well with the fluorescence-activated cell sorting (FACS) analysis results. Of note, we discovered low-level fragmented and full-length plasmid backbone insertion at the CRISPR cutting site. Therefore, we have established a practical workflow to evaluate various genetic changes, including quantifying insertions of short dsODNs, knock-ins of long pieces, plasmid insertions, and large fragment deletions after CRISPR/Cas9-mediated editing. GREPore-seq is freely available at GitHub (https://github.com/lisiang/GREPore-seq) and the National Genomics Data Center (NGDC) BioCode (https://ngdc.cncb.ac.cn/biocode/tools/BT007293).

Superior Fidelity and Distinct Editing Outcomes of SaCas9 Compared with SpCas9 in Genome Editing

A series of clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein 9 (Cas9) systems have been engineered for genome editing. The most widely used Cas9 is SpCas9 from Streptococcus pyogenes and SaCas9 from Staphylococcus aureus. However, a comparison of their detailed gene editing outcomes is still lacking. By characterizing the editing outcomes of 11 sites in human induced pluripotent stem cells (iPSCs) and K562 cells, we found that SaCas9 could edit the genome with greater efficiencies than SpCas9. We also compared the effects of spacer lengths of single-guide RNAs (sgRNAs; 18-21 nt for SpCas9 and 19-23 nt for SaCas9) and found that the optimal spacer lengths were 20 nt and 21 nt for SpCas9 and SaCas9, respectively. However, the optimal spacer length for a particular sgRNA was 18-21 nt for SpCas9 and 21-22 nt for SaCas9. Furthermore, SpCas9 exhibited a more substantial bias than SaCas9 for nonhomologous end-joining (NHEJ) +1 insertion at the fourth nucleotide upstream of the protospacer adjacent motif (PAM), indicating a characteristic of a staggered cut. Accordingly, editing with SaCas9 led to higher efficiencies of NHEJ-mediated double-stranded oligodeoxynucleotide (dsODN) insertion or homology-directed repair (HDR)-mediated adeno-associated virus serotype 6 (AAV6) donor knock-in. Finally, GUIDE-seq analysis revealed that SaCas9 exhibited significantly reduced off-target effects compared with SpCas9. Our work indicates the superior performance of SaCas9 to SpCas9 in transgene integration-based therapeutic gene editing and the necessity to identify the optimal spacer length to achieve desired editing results.

Noninvasive Imaging of Tumor Glycolysis and Chemotherapeutic Resistance via De Novo Design of Molecular Afterglow Scaffold

Chemotherapeutic resistance poses a significant challenge in cancer treatment, resulting in the reduced efficacy of standard chemotherapeutic agents. Abnormal metabolism, particularly increased anaerobic glycolysis, has been identified as a major contributing factor to chemotherapeutic resistance. To address this issue, noninvasive imaging techniques capable of visualizing tumor glycolysis are crucial. However, the currently available methods (such as PET, MRI, and fluorescence) possess limitations in terms of sensitivity, safety, dynamic imaging capability, and autofluorescence. Here, we present the de novo design of a unique afterglow molecular scaffold based on hemicyanine and rhodamine dyes, which holds promise for low-background optical imaging. In contrast to previous designs, this scaffold exhibits responsive "OFF-ON" afterglow signals through spirocyclization, thus enabling simultaneous control of photodynamic effects and luminescence efficacy. This leads to a larger dynamic range, broader detection range, higher signal enhancement ratio, and higher sensitivity. Furthermore, the integration of multiple functionalities simplifies probe design, eliminates the need for spectral overlap, and enhances reliability. Moreover, we have expanded the applications of this afterglow molecular scaffold by developing various probes for different molecular targets. Notably, we developed a water-soluble pH-responsive afterglow nanoprobe for visualizing glycolysis in living mice. This nanoprobe monitors the effects of glycolytic inhibitors or oxidative phosphorylation inhibitors on tumor glycolysis, providing a valuable tool for evaluating the tumor cell sensitivity to these inhibitors. Therefore, the new afterglow molecular scaffold presents a promising approach for understanding tumor metabolism, monitoring chemotherapeutic resistance, and guiding precision medicine in the future.

Engineering of cyanine-based nanoplatform with tunable response toward reactive species for ratiometric NIR-II fluorescent imaging in mice

High-quality second near-infrared (NIR-II) nanoprobes are of great significance for real-time bioimaging and medical diagnosis. Cyanine is an important class of fluorophores to construct activatable probes; however, there are still significant challenges hindering their biological applications, including weak fluorescence in aqueous solution, instability, and insufficient specificity. Herein, an integrated engineering strategy is conducted to develop the cyanine-based activatable NIR-II nanoplatforms with bright, stable emission and high specificity. Specifically, poly(styrene-co-maleic anhydride) (PSMA) is employed to encapsulate NIR-II fluorescent molecules (IR1048) to render the stable and bright NIR-II nanoparticles (PSMA@IR1048 NPs). By charge-modulated strategy, a series of cyanine-fluorophores are loaded on the surface of PSMA@IR1048 NPs and exhibit tunable response toward reactive species. Combing those two strategies, NIR-II ratiometric fluorescent nanoprobes (RNPs, including RNP1, RNP2, and RNP3) are constructed; among them, RNP2 displays hypochlorous acid (HClO) responsive performance and generates a higher NIR-II fluorescent ratio (FL2/FL1) signal. Such nanoprobe can reliably report the pathological HClO level in models of diabetic liver injury and lower limb ischemia-reperfusion (I/R) injury mice. Our study paves an engineering strategy to construct cyanine-based stable, bright, and specific NIR-II probes for bioimaging.

FINDER: A Fluidly Confined CRISPR-Based DNA Reporter on Living Cell Membranes for Rapid and Sensitive Cancer Cell Identification

The accurate, rapid, and sensitive identification of cancer cells in complex physiological environments is significant in biological studies, personalized medicine, and biomedical engineering. Inspired by the naturally confined enzymes on fluid cell membranes, a fluidly confined CRISPR-based DNA reporter (FINDER) was developed on living cell membranes, which was successfully applied for rapid and sensitive cancer cell identification in clinical blood samples. Benefiting from the spatial confinement effect for improved local concentration, and membrane fluidity for higher collision efficiency, the activity of CRISPR-Cas12a was, for the first time, found to be significantly enhanced on living cell membranes. This new phenomenon was then combined with multiple aptamer-based DNA logic gate for cell recognition, thus a FINDER system capable of accurate, rapid and sensitive cancer cell identification was constructed. The FINDER rapidly identified target cells in only 20 min, and achieved over 80 % recognition efficiency with only 0.1 % of target cells presented in clinical blood samples, indicating its potential application in biological studies, personalized medicine, and biomedical engineering.

[Risk factor analysis of lymph node metastasis in endometrial carcinoma combined with molecular types]

Objective: To investigate the relationships between molecular types of the cancer genome atlas (TCGA) of patients with endometrial carcinoma (EC) and lymph node metastasis and other clinicopathological features. Methods: The clinical pathological information of 295 patients with EC who underwent initial inpatient surgical treatment and accepted the detection of the molecular types of TCGA with next-generation sequencing technology at Peking University People's Hospital were collected during April 2016 and May 2022. The TCGA molecular typing of EC was divided into four types: POLE-ultramutated (15 cases), high microsatellite instability (MSI-H; 50 cases), copy-number low (CNL; 175 cases), and copy-number high (CNH; 55 cases). The differences of clinical pathological features among different molecular types and the risk factors of lymph node metastasis were analyzed retrospectively. Results: Among 295 patients with EC, the average age was (56.9±0.6) years. (1) There was a statistically significant difference in lymph node metastasis (0, 8.0%, 10.3% and 25.5%) among the four molecular types (χ2=12.524, P=0.006). There were significant differences in age, stage, pathological type, grade (only endometrioid carcinoma), myometrium invasion, lymphatic vascular space infiltration, and estrogen receptor among the EC patients of four molecular types (all P<0.05). Among them, while in the patients with CNH type, the pathological grade was G3, the pathological type was non-endometrioid carcinoma, and the proportion of myographic infiltration depth ≥1/2 were higher (all P<0.05). (2) Univariate analysis suggested that pathological type, grade, myometrium infiltration depth, cervical interstitial infiltration, lymphatic vascular space infiltration, and progesterone receptor were all factors which significantly influence lymph node metastasis (all P<0.01); multivariate analysis suggested that the lymphatic vascular space infiltration was an independent risk factor for lymph node metastasis (OR=5.884, 95%CI: 1.633-21.211; P=0.007). (3) The factors related to lymph node metastasis were different in patients with different molecular types. In the patients with MSI-H, the non-endometrioid carcinoma of pathological type was independent risk factor for lymph node metastasis (OR=29.010, 95%CI: 2.067-407.173; P=0.012). In the patients with CNL, myometrium infiltration depth≥1/2 (OR=4.995, 95%CI: 1.225-20.376; P=0.025), lymphatic vascular space infiltration (OR=14.577, 95%CI: 3.603-58.968; P<0.001) were the independent risk factors for lymph node metastasis. While in the CNH type patients pathological type of non-endometrioid carcinoma (OR=7.451, 95%CI: 1.127-49.281; P=0.037), cervical interstitial infiltration (OR=22.938, 95%CI: 1.207-436.012; P=0.037), lymphatic vascular space infiltration (OR=9.404, 95%CI: 1.609-54.969; P=0.013), were the independent risk factors for lymph node metastasis. Conclusions: POLE-ultramutated EC patients have the lowest risk of lymph node metastasis, and CNH patients have the highest risk of lymph node metastasis. The risk factors of lymph node metastasis of different molecular types are different. According to preoperative pathological and imaging data, lymph node metastasis is more likely to occur in patients with non-endometrioid carcinoma in MSI-H and CNH type patients, and lymph node metastasis is more likely to occur in patients with myometrium infiltration depth ≥1/2 in CNL type patients.

Enhancing cord blood stem cell-derived NK cell growth and differentiation through hyperosmosis

BACKGROUND

Natural killer (NK) cells hold great promise in treating diverse hematopoietic and solid tumors. Despite their availability from peripheral blood and cord blood, stem cell-derived NK cells offer an 'off-the-shelf' solution. Hematopoietic stem and progenitor cells (HSPCs) derived from cord blood pose no risk to the newborn or mother and are virtually ideal sources for NK cell differentiation.

METHODS

We developed a modified protocol to differentiate HSPCs to NK cells under serum-free conditions using defined factors. The HSPC-derived NK (HSC-NK) cells could be expanded in a K562 feeder cell-dependent manner. Furthermore, using lentivirus transduction, chimeric antigen receptor (CAR)-modified HSPCs could be differentiated into NK cells, leading to the establishment of CAR-NK cells.

RESULTS

The efficiency of NK cell differentiation from HSPCs was increased through the simple modulation of osmotic pressure by the addition of sodium chloride or glucose. Furthermore, the hyperosmosis-primed HSC-NK cells exhibited enhanced proliferation capacity and maintained normal functional characteristics, including transcriptome and antitumor efficacy. The optimized protocol yielded approximately 1.8 million NK cells from a single CD34-positive cell within a 28-day cycle, which signifies more than a ten-fold increase in efficiency relative to the conventional methods. This optimized protocol was also suitable for generating CAR-NK cells with high yields compared to standard conditions.

CONCLUSIONS

The results of this study establish high osmotic pressure as a simple yet powerful adjustment that significantly enhances the efficiency and functionality of HSC-NK cells, including CAR-NK cells. This optimized protocol could lead to cost-effective, high-yield NK cell therapies, potentially revolutionizing cancer immunotherapy strategies.

Oxidative stress biomarker triggered multiplexed tool for auxiliary diagnosis of atherosclerosis

Oxidative stress is integral in the development of atherosclerosis, but knowledge of how oxidative stress affects atherosclerosis remains insufficient. Here, we design a multiplexed diagnostic tool that includes two functions (photoacoustic imaging and urinalysis), for assessing intraplaque and urinary malondialdehyde (MDA), a well-recognized end-product of oxidative stress. Molecular design is conducted to develop the first near-infrared MDA-responsive molecule (MRM). Acid-unlocked ratiometric photoacoustic nanoprobe is designed to report intraplaque MDA, enabling it to reflect plaque burden. Furthermore, MRM is tailored for urinary MDA detection with excellent specificity in a blind study. Moreover, we found a significant difference in urinary MDA between healthy adults and atherosclerotic patients (more than 600 participants). Combining these two functions, such a multiplexed diagnostic tool can dynamically report intraplaque and systemic oxidative stress levels during atherosclerosis progression, pneumonia infection, and drug treatment in atherosclerotic mice, which is promising for the auxiliary diagnosis of atherosclerosis.

Vanin-1-Activated Chemiluminescent Probe: Help to Early Diagnosis of Acute Kidney Injury with High Signal-to-Noise Ratio through Urinalysis

Acute kidney injury (AKI) is a common medical condition with high morbidity and mortality. Although urinalysis provides a noninvasive and convenient diagnostic method for AKI at the molecular level, the low sensitivity of current chemical probes used in urinalysis hinders the time diagnosis of AKI. Herein, we achieved the sensitive and early diagnosis of AKI by the development of a chemiluminescent probe CL-Pa suitable for detection of urinary Vanin-1. Vanin-1 is considered as an early and sensitive biomarker for AKI, while few chemical probes have been applied to for its efficient detection. By virtue of the low autofluorescence interference during urine imaging in the chemiluminescence model, CL-Pa could realize the monitoring of the up-regulated urinary Vanin-1 with a high signal-to-noise ratio (∼588). Importantly, under the help of CL-Pa, the up-regulation of urinary Vanin-1 of cisplatin-induced AKI mice at 12 h post cisplatin injection was detected, which was much earlier than clinical biomarkers (sCr and BUN) and change of kidney histology (48 h post cisplatin injection). Furthermore, using this probe, the fluctuation of urinary Vanin-1 of mice with different degrees of AKI was monitored. This study demonstrated the ability of CL-Pa in sensitively detecting drug-induced AKI through urinalysis and suggested the great potential of CL-Pa for early diagnosis of AKI and evaluate the efficiency of anti-AKI drugs clinically.

Orderly Self-Assembly of Organic Fluorophores for Sensing and Imaging

Fluorescence imaging utilizing traditional organic fluorophores is extensively applied in both cellular and in vivo studies. However, it faces significant obstacles, such as low signal-to-background ratio (SBR) and spurious positive/negative signals, primarily due to the facile diffusion of these fluorophores. To cope with this challenge, orderly self-assembled functionalized organic fluorophores have gained significant attention in the past decades. These fluorophores can create nanoaggregates via a well-ordered self-assembly process, thus prolonging their residency time within cells and in vivo settings. The development of self-assembled-based fluorophores is an emerging field, and as such, in this review, we present a summary of the progress and challenges of self-assembly fluorophores, focusing on their development history, self-assembly mechanisms, and biomedical applications. We hope that the insights provided herein will assist scientists in further developing functionalized organic fluorophores for in situ imaging, sensing, and therapy.

A Semisynthetic Bioluminescence Sensor for Ratiometric Imaging of Metal Ions In Vivo Using DNAzymes Conjugated to An Engineered Nano-Luciferase

DNA-based probes have gained significant attention as versatile tools for biochemical analysis, benefiting from their programmability and biocompatibility. However, most existing DNA-based probes rely on fluorescence as the signal output, which can be problematic due to issues like autofluorescence and scattering when applied in complex biological materials such as living cells or tissues. Herein, we report the development of bioluminescent nucleic acid (bioLUNA) sensors that offer laser excitation-independent and ratiometric imaging of the target in vivo. The system is based on computational modelling and mutagenesis investigations of a genetic fusion between circular permutated Nano-luciferase (NLuc) and HaloTag, enabling the conjugation of the protein with a DNAzyme. In the presence of Zn2+ , the DNAzyme sensor releases the fluorophore-labelled strand, leading to a reduction in bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. Consequently, this process induces ratiometric changes in the bioluminescent signal. We demonstrated that this bioLUNA sensor enabled imaging of both exogenous Zn2+ in vivo and endogenous Zn2+ efflux in normal epithelial prostate and prostate tumors. This work expands the DNAzyme sensors to using bioluminescence and thus has enriched the toolbox of nucleic acid sensors for a broad range of biomedical applications.

Ratiometric Detection of Zn2+ Using DNAzyme-Based Bioluminescence Resonance Energy Transfer Sensors

While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer (BRET)-based protein or small molecule sensors have been developed; however, most of them are not highly selective nor generalizable to different metal ions. Taking advantage of the high selectivity and generalizability of DNAzymes, we report herein DNAzyme-based ratiometric sensors for Zn2+ based on BRET. The 8-17 DNAzyme was labeled with luciferase and Cy3. The proximity between luciferase and Cy3 permiQed BRET when coelenterazine, the substrate for luciferase, was introduced. Adding samples containing Zn2+ resulted in a cleavage of the substrate strand, causing dehybridization of the DNAzyme construct, thus increasing the distance between Cy3 and luciferase and changing the BRET signals. Using these sensors, we detected Zn2+ in serum samples and achieved Zn2+ detection with a smartphone camera. Moreover, since the BRET pair is not the component that determines the selectivity of the sensors, this sensing platform has the potential to be adapted for the detection of other metal ions with other metal-dependent DNAzymes.

Design of a near-infrared fluoro-photoacoustic probe for rapid imaging of carboxylesterase in liver injury

Carboxylesterase (CE) is crucial in metabolizing ester-containing biomolecules and is particularly significant in liver metabolic diseases. Herein, we present the first activatable NIRF/PA dual-mode imaging probe QHD-CE for detection of CE in vitro and in vivo. QHD-CE displays excellent sensitivity and selectivity for CE with a high reaction efficiency (∼90 min). By utilizing QHD-CE, the dynamic changes of CE in drug-induced liver injury and diabetic mice models were monitored.

Rational Design of a Double-Locked Photoacoustic Probe for Precise In Vivo Imaging of Cathepsin B in Atherosclerotic Plaques

Atherosclerotic plaque rupture is a significant cause of acute cardiovascular events such as heart attack and stroke, triggered by the decomposition of fiber caps induced by cysteine cathepsin. However, the accurate measurement of cathepsin B (CTB) activity in plaques is challenging due to the low specificity and insufficient penetration depth of available atherosclerosis-associated cathepsin fluorescent probes, hampering reliable assessment of plaque vulnerability. To address these limitations, we added both lipophilic alkyl chain and hydrophilic CTB substrate to the hemicyanine scaffold to develop a lipid-unlocked CTB responsive probe (L-CRP) that uses lipids and CTB as two keys to unlock photoacoustic (PA) signals for measuring CTB activity in lipophilic environments. Such properties allow L-CRP for the reliable imaging of specific CTB activities in foam cells and atherosclerotic plaques while keeping in silence toward CTB in lipid-deficient environments, such as M1-type macrophages and LPS-induced inflammatory lesions. Moreover, the activatable PA signals of L-CRP exhibit a deeper tissue penetration ability (>1.0 cm) than current CTB probes based on near-infrared fluorescent imaging (∼0.3 cm), suitable for atherosclerosis imaging in living mice. In atherosclerotic mice, L-CRP dynamically reports intraplaque CTB levels, which is well-correlated with the plaque vulnerability characteristics such as fiber cap thickness, macrophage recruitment, and necrotic core size, thus enabling risk stratification of atherosclerotic mice complicated with pneumonia. Moreover, L-CRP successfully identifies atherosclerotic plaques in excised human artery tissues, promising for auxiliary diagnosis of plaque vulnerability in clinical application.

GSH/APE1 Cascade-Activated Nanoplatform for Imaging Therapy Resistance Dynamics and Enzyme-Mediated Adaptive Ferroptosis

Ferroptosis, as a type of programmed cell death process, enables effective damage to various cancer cells. However, we discovered that persistent oxidative stress during ferroptosis can upregulate the apurinic/apyrimidinic endonuclease 1 (APE1) protein that induces therapeutic resistance ("ferroptosis resistance"), resulting in an unsatisfactory treatment outcome. To address APE1-induced therapeutic resistance, we developed a GSH/APE1 cascade activated therapeutic nanoplatform (GAN). Specifically, the GAN is self-assembled by DNA-functionalized ultrasmall iron oxide nanoparticles and further loaded with drug molecules (drug-GAN). GSH-triggered GAN disassembly can "turn on" the catalysis of GAN to induce efficient lipid peroxidation (LPO) for ferroptosis toward the tumor, which could upregulate APE1 expression. Subsequently, upregulated APE1 can further trigger accurate drug release for overcoming ferroptosis resistance and inducing the recovery of near-infrared fluorescence for imaging the dynamics of APE1. Importantly, adaptive drug release can overcome the adverse effects of APE1 upregulation by boosting intracellular ROS yield and increasing DNA damage, to offset APE1's functions of antioxidant and DNA repair, thus leading to adaptive ferroptosis. Moreover, with overexpressed GSH and upregulated APE1 in the tumor as stimuli, the therapeutic specificity of ferroptosis toward the tumor is greatly improved, which minimized nonspecific activation of catalysis and excessive drug release in normal tissues. Furthermore, a switchable MRI contrast from negative to positive is in sync with ferroptosis activation, which is beneficial for monitoring the ferroptosis process. Therefore, this adapted imaging and therapeutic nanoplatform can not only deliver GSH/APE1-activated lipid peroxide mediated adaptive synergistic therapy but also provided a switchable MRI/dual-channel fluorescence signal for monitoring ferroptosis activation, drug release, and therapy resistance dynamics in vivo, leading to high-specificity and high-efficiency adaptive ferroptosis therapy.

A Highly Selective Mn(II)-Specific DNAzyme and Its Application in Intracellular Sensing

Manganese is an essential trace element in the human body that acts as a cofactor in many enzymes and metabolisms. It is important to develop methods to detect Mn²⁺ in living cells. While fluorescent sensors have been very effective in detecting other metal ions, Mn²⁺-specific fluorescent sensors are rarely reported due to nonspecific fluorescence quenching by the paramagnetism of Mn²⁺ and poor selectivity against other metal ions such as Ca²⁺ and Mg²⁺. To address these issues, we herein report in vitro selection of an RNA-cleaving DNAzyme with exceptionally high selectivity for Mn²⁺. Through converting it into a fluorescent sensor using a catalytic beacon approach, Mn²⁺ sensing in immune cells and tumor cells has been achieved. The sensor is also used to monitor degradation of manganese-based nanomaterials such as MnOx in tumor cells. Therefore, this work provides an excellent tool to detect Mn²⁺ in biological systems and monitor the Mn²⁺-involved immune response and antitumor therapy.

[Prognosis analysis of radical or modified radical hysterectomy and simple hysterectomy in patients with stage Ⅱ endometrial cancer]

Objective: To compare the prognosis and perioperative situation of patients with stage Ⅱ endometrial cancer (EC) between radical hysterectomy/modified radical hysterectomy (RH/mRH) and simple hysterectomy (SH). Methods: A total of 47 patients diagnosed EC with stage Ⅱ [International Federation of Gynecology and Obstetrics (FIGO) 2009] by postoperative pathology, from January 2006 to January 2021 in Peking University People's Hospital, were analyzed retrospectively. The patients were (54.4±10.7) years old, and the median follow-up time was 65 months (ranged 9-138 months). They were divided into RH/mRH group (n=14) and SH group (n=33) according to the scope of operation. Then the prognosis of patients between the groups were compared, and the independent prognostic factors of stage Ⅱ EC were explored. Results: (1) The proportions of patients with hypertension in RH/mRH group and SH group were 2/14 and 45% (15/33), the amounts of intraoperative blood loss were (702±392) and (438±298) ml, and the incidence of postoperative complications were 7/14 and 15% (5/33), respectively. There were significant differences (all P<0.05). (2) The median follow-up time of RH/mRH group and SH group were 72 vs 62 months, respectively (P=0.515). According to Kaplan-Meier analysis and log-rank method, the results showed that there were no significant difference in 5-year progression-free survival (PFS) rate (94.3% vs 84.0%; P=0.501), and 5-year overall survival rate (92.3% vs 92.9%; P=0.957) between the two groups. Cox survival analysis indicated that age, pathological type, serum cancer antigen 125 (CA₁₂₅), and estrogen receptor (ER) status were associated with 5-year PFS rate (all P<0.05). But the scope of hysterectomy (RH/mRH and SH) did not affect the 5-year PFS rate of stage Ⅱ EC patients (P=0.508). And level of serum CA₁₂₅ and ER status were independent prognostic factors for 5-year PFS rate (all P<0.05). Conclusions: This study could not find any survival benefit from RH/mRH for stage Ⅱ EC, but increases the incidence of postoperative complications. Therefore, the necessity of extending the scope of hysterectomy is questionable.

A novel ROS-Related chemiluminescent semiconducting polymer nanoplatform for acute pancreatitis early diagnosis and severity assessment

Acute pancreatitis (AP) is a common and potentially life-threatening inflammatory disease of the pancreas. Reactive oxygen species (ROS) play a key role in the occurrence and development of AP. With increasing ROS levels, the degree of oxidative stress and the severity of AP increase. However, diagnosing AP still has many drawbacks, including difficulties with early diagnosis and undesirable sensitivity and accuracy. Herein, we synthesized a semiconducting polymer nanoplatform (SPN) that can emit ROS-correlated chemiluminescence (CL) signals. The CL intensity increased in solution after optimization of the SPN. The biosafety of the SPN was verified in vitro and in vivo. The mechanism and sensitivity of the SPN for AP early diagnosis and severity assessment were evaluated in three groups of mice using CL intensity, serum marker evaluations and hematoxylin and eosin staining assessments. The synthetic SPN can be sensitively combined with different concentrations of ROS to produce different degrees of high-intensity CL in vitro and in vivo. Notably, the SPN shows an excellent correlation between CL intensity and AP severity. This nanoplatform represents a superior method to assess the severity of AP accurately and sensitively according to ROS related chemiluminescence signals. This research overcomes the shortcomings of AP diagnosis in clinical practice and provides a novel method for the clinical diagnosis of pancreatitis in the future.

Organic Afterglow Nanoparticles in Bioapplications

Organic afterglow nanoparticles are unique optical materials that emit light long after cessation of excitation. Due to their advantages of no need for real-time light excitation, avoiding autofluorescence, low imaging background, high signal-to-background ratio, deep tissue penetration, and high sensitivity, afterglow imaging technology has been widely used in cell tracking, biosensing, cancer diagnosis, and cancer therapy, which provides an effective technical method for the acquisition of molecular information with high sensitivity, specificity and real-time at the cellular and living level. In this review, we summarize and illustrate the recent progress of organic afterglow imaging, focusing on the mechanism of organic afterglow materials and their biological application. Furthermore, we also discuss the potential challenges and the further directions of this field.

Enthalpy and entropy synergistic regulation-based programmable DNA motifs for biosensing and information encryption

Deoxyribonucleic acid (DNA) provides a collection of intelligent tools for the development of information cryptography and biosensors. However, most conventional DNA regulation strategies rely solely on enthalpy regulation, which suffers from unpredictable stimuli-responsive performance and unsatisfactory accuracy due to relatively large energy fluctuations. Here, we report an enthalpy and entropy synergistic regulation-based pH-responsive A⁺/C DNA motif for programmable biosensing and information encryption. In the DNA motif, the variation in loop length alters entropic contribution, and the number of A⁺/C bases regulates enthalpy, which is verified through thermodynamic characterizations and analyses. On the basis of this straightforward strategy, the performances, such as pK_a, of the DNA motif can be precisely and predictably tuned. The DNA motifs are finally successfully applied for glucose biosensing and crypto-steganography systems, highlighting their potential in the field of biosensing and information encryption.

Fluidic Spatial-Confinement Scaffold Affords a Multicomponent DNA Reaction with Improved Efficiency and Accelerated Kinetics

Enzyme-free nucleic acid amplification reactions with the capability of signal catalytic amplification have been widely used in biosensors. However, these multicomponent, multistep nucleic acid amplification systems often suffer from low reaction efficiency and kinetics. Herein, inspired by the natural cell membrane system, we utilized the red blood cell membrane as a fluidic spatial-confinement scaffold to construct a novel accelerated reaction platform. By simply modifying with cholesterol, DNA components can be efficiently integrated into the red blood cell membrane through hydrophobic interactions, which greatly increases the local concentration of DNA strands. Moreover, the fluidity of the erythrocyte membrane improves the collision efficiency of DNA components in the amplification system. Based on the increased local concentration and improved collision efficiency, the fluidic spatial-confinement scaffold significantly improved the reaction efficiency and kinetics. Taking catalytic hairpin assembly (CHA) as a model reaction, an RBC-CHA probe based on the erythrocyte membrane platform enables a more sensitive detection of miR-21 with a sensitivity that is 2 orders of magnitude higher than the free CHA probe and a fast reaction rate (about 3.3-fold). The proposed strategy provides a new idea for the construction of a novel spatial-confinement accelerated DNA reaction platform.

Dynamic-Reversible MRI Nanoprobe for Continuous Imaging Redox Homeostasis in Hepatic Ischemia-Reperfusion Injury

Hepatic ischemia-reperfusion (I/R) injury accompanied by oxidative stress is responsible for postoperative liver dysfunction and failure of liver surgery. However, the dynamic non-invasive mapping of redox homeostasis in deep-seated liver during hepatic I/R injury remains a great challenge. Herein, inspired by the intrinsic reversibility of disulfide bond in proteins, a kind of reversible redox-responsive magnetic nanoparticles (RRMNs) is designed for reversible imaging of both oxidant and antioxidant levels (ONOO^-/GSH), based on sulfhydryl coupling/cleaving reaction. We develop a facile strategy to prepare such reversible MRI nanoprobe via one-step surface modification. Owing to the significant change in size during the reversible response, the imaging sensitivity of RRMNs is greatly improved, which enables RRMNs to monitor the tiny change of oxidative stress in liver injury. Notably, such reversible MRI nanoprobe can non-invasively visualize the deep-seated liver tissue slice by slice in living mice. Moreover, this MRI nanoprobe can not only report molecular information about the degree of liver injury but also provide anatomical information about where the pathology occurred. The reversible MRI probe is promising for accurately and facilely monitoring I/R process, accessing injury degree and developing powerful strategy for precise treatment.

Selective in Situ Analysis of Mature microRNAs in Extracellular Vesicles Using a DNA Cage-Based Thermophoretic Assay

Mature microRNAs (miRNAs) in extracellular vesicles (EVs) are involved in different stages of cancer progression, yet it remains challenging to precisely detect mature miRNAs in EVs due to the presence of interfering RNAs (such as longer precursor miRNAs, pre-miRNAs) and the low abundance of tumor-associated miRNAs. By leveraging the size-selective ability of DNA cages and polyethylene glycol (PEG)-enhanced thermophoretic accumulation of EVs, we devised a DNA cage-based thermophoretic assay for highly sensitive, selective, and in situ detection of mature miRNAs in EVs with a low limit of detection (LoD) of 2.05 fM. Our assay can profile EV mature miRNAs directly in serum samples without the interference of pre-miRNAs and the need for ultracentrifugation. A clinical study showed that EV miR-21 or miR-155 had an overall accuracy of 90% for discrimination between breast cancer patients and healthy donors, which outperformed conventional molecular probes detecting both mature miRNAs and pre-miRNAs. We envision that our assay can advance EV miRNA-based diagnosis of cancer.

Designing a Brightness-Restored Rhodamine Derivative by the Ortho-Compensation Effect for Assessing Drug-Induced Acute Kidney Injury

Effective monitoring of essential bioindicators with high-contrast fluorescence imaging is highly crucial to reveal the pathological progression of diseases. However, most reported probes based on asymmetric amino-rhodamine (ARh) derivatives are often limited in practical application due to the low signal-to-noise ratios. Herein, a new fluorophore, 3-methoxy-amino-rhodamine (3-MeOARh), with improved fluorescence quantum yield (0.51 in EtOH) is designed and synthesized by introducing methoxy group in the ortho-position of amino in asymmetric amino-rhodamine. Notably, the good properties of the ortho-compensation effect further effectively enable the construction of an activatable probe with a high signal-to-noise ratio. As a proof of concept, the probe (3-MeOARh-NTR) was successfully synthesized for nitroreductase detection with high selectivity, excellent sensitivity, and good stability. More importantly, the relationship between drug-induced kidney hypoxia and elevated nitroreductase concentration was first uncovered in living tissues through high-contrast imaging. Therefore, the study presents the activatable probe for kidney hypoxia imaging while highlighting the 3-MeOARh structure with a satisfactory signal-to-noise ratio. It is believed that 3-MeOARh can serve as an efficient platform for activatable probe construction to reveal the pathological progression of different diseases.

Zinc-Carnosine Metallodrug Network as Dual Metabolism Inhibitor Overcoming Metabolic Reprogramming for Efficient Cancer Therapy

The targeting of tumor metabolism as a novel strategy for cancer therapy has attracted tremendous attention. Herein, we develop a dual metabolism inhibitor, Zn-carnosine metallodrug network nanoparticles (Zn-Car MNs), which exhibits good Cu-depletion and Cu-responsive drug release, causing potent inhibition of both OXPHOS and glycolysis. Notably, Zn-Car MNs can decrease the activity of cytochrome c oxidase and the content of NAD⁺, so as to reduce ATP production in cancer cells. Thereby, energy deprivation, together with the depolarized mitochondrial membrane potential and increased oxidative stress, results in apoptosis of cancer cells. In result, Zn-Car MNs exerted more efficient metabolism-targeted therapy than the classic copper chelator, tetrathiomolybdate (TM), in both breast cancer (sensitive to copper depletion) and colon cancer (less sensitive to copper depletion) models. The efficacy and therapy of Zn-Car MNs suggest the possibility to overcome the drug resistance caused by metabolic reprogramming in tumors and has potential clinical relevance.

Reprogramming of human peripheral blood mononuclear cells into induced mesenchymal stromal cells using non-integrating vectors

Mesenchymal stromal cells (MSCs) have great value in cell therapies. The MSC therapies have many challenges due to its inconsistent potency and limited quantity. Here, we report a strategy to generate induced MSCs (iMSCs) by directly reprogramming human peripheral blood mononuclear cells (PBMCs) with OCT4, SOX9, MYC, KLF4, and BCL-XL using a nonintegrating episomal vector system. While OCT4 was not required to reprogram PBMCs into iMSCs, omission of OCT4 significantly impaired iMSC functionality. The omission of OCT4 resulted in significantly downregulating MSC lineage specific and mesoderm-regulating genes, including SRPX, COL5A1, SOX4, SALL4, TWIST1. When reprogramming PBMCs in the absence of OCT4, 67 genes were significantly hypermethylated with reduced transcriptional expression. These data indicate that transient expression of OCT4 may serve as a universal reprogramming factor by increasing chromatin accessibility and promoting demethylation. Our findings represent an approach to produce functional MSCs, and aid in identifying putative function associated MSC markers.

In situ orderly self-assembly strategy affording NIR-II-J-aggregates for in vivo imaging and surgical navigation

J-aggregation, an effective strategy to extend wavelength, has been considered as a promising method for constructing NIR-II fluorophores. However, due to weak intermolecular interactions, conventional J-aggregates are easily decomposed into monomers in the biological environment. Although adding external carriers could help conventional J-aggregates stabilize, such methods still suffer from high-concentration dependence and are unsuitable for activatable probes design. Besides, these carriers-assisted nanoparticles are risky of disassembly in lipophilic environment. Herein, by fusing the precipitated dye (HPQ) which has orderly self-assembly structure, onto simple hemi-cyanine conjugated system, we construct a series of activatable, high-stability NIR-II-J-aggregates which overcome conventional J-aggregates carrier's dependence and could in situ self-assembly in vivo. Further, we employ the NIR-II-J-aggregates probe HPQ-Zzh-B to achieve the long-term in situ imaging of tumor and precise tumor resection by NIR-II imaging navigation for reducing lung metastasis. We believe this strategy will advance the development of controllable NIR-II-J-aggregates and precise bioimaging in vivo.

PtSnBi Nanoplates Enable Photoacoustic Imaging-Guided Highly Efficient Photothermal Tumor Ablation

The development of photothermal agents (PTAs) with robust photostability and high photothermal conversion efficiency is of great importance for cancer photothermal therapy. Herein, a novel PTA was created using two-dimensional intermetallic PtSnBi nanoplates (NPs), which demonstrated excellent photostability and biocompatibility with a high photothermal conversion efficiency of ∼61 % after PEGylation. More importantly, PtSnBi NPs could be employed as photoacoustic imaging contrast agents for tumor visualization due to their strong absorbance in the NIR range. In addition, both in vitro and in vivo experiments confirmed that PtSnBi NPs had a good photothermal efficacy under NIR laser irradiation. Therefore, the remarkable therapeutic characteristics of PtSnBi NPs make them a most promising candidate for cancer theranostics.

Virus-like Plasmonic Nanoprobes for Quick Analysis of Antiviral Efficacy and Mutation-Induced Drug Resistance

As the pathogenic viruses and the variants of concern greatly threaten human health and global public safety, the development of convenient and robust strategies enabling rapid analysis of antiviral drug efficacy and mutation-induced resistance is quite important to prevent the spread of human epidemics. Herein, we introduce a simple single-particle detection strategy for quick analysis of anti-infective drugs against SARS-CoV-2 and mutation-induced drug resistance, by using the wild-type and mutant spike protein-functionalized AuNPs as virus-like plasmonic nanoprobes. Both the wild-type and mutant virus-like plasmonic nanoprobes can form core-satellite nanoassemblies with the ACE2@AuNPs, providing the opportunity to detect the drug efficacy and mutation-induced resistance by detecting the changes of nanoassemblies upon drug treatment with dark-field microscopy. As a demonstration, we applied the single-particle detection strategy for quantitative determination of antiviral efficacy and mutation-induced resistance of ceftazidime and rhein. The mutations in the receptor-binding domain of Omicron variant could lead to an increase of EC₅₀ values of ceftazidime and rhein, formerly from 49 and 57 μM against wild-type SARS-CoV-2, to 121 and 340 μM, respectively. The mutation-induced remarkable decline in the inhibitory efficacy of drugs was validated with molecule docking analysis and virus-like plasmonic nanoprobe-based cell-incubation assay. Due to the generality and feasibility of the strategy for the preparation of virus-like plasmonic nanoprobes and single-particle detection, we anticipated that this simple and robust method is promising for the discovery and efficacy evaluation of anti-infective drugs against different pathogenic viruses.

China's adaptive response to climate change through air-conditioning

Studies have shown that the soaring demand for air conditioners in recent years is closely related to the worsening global warming; however, little evidence has been provided for China. This study uses weekly data of 343 Chinese cities to investigate how air conditioner sales respond to climate variability. We detected a U-shaped relationship between air-conditioning and temperature. An additional day with average temperature above 30°C increases weekly sales by 16.2%. Heterogeneity analysis shows that the adoption of air-conditioning is different for south and north China. By combining our estimates with shared socioeconomic pathway scenarios, we project China's mid-century air conditioner sales and the resulting electricity demand. Under the fossil-fueled development scenario, air conditioner sales in the Pearl River Delta would rise by 71% (65.7%-87.6%) in summer. On average, the per capita electricity demand for air-conditioning will surge by 28% (23.2%-35.4%) in China by mid-century.

Fluorophore-based host-guest assembly complexes for imaging and therapy

Recently, supramolecular chemistry with its unique properties has received considerable attention in many fields. Supramolecular fluorescent systems constructed on the basis of macrocyclic hosts are not only effective in overcoming the limitations of imaging and diagnostic reagents, but also in enhancing their performances. This paper summarizes the recent advances in supramolecular fluorescent systems based on host-guest interactions and their application in bioimaging and therapy as well as the challenges and prospects in developing novel supramolecular fluorescent systems.

"Four-In-One" Design of a Hemicyanine-Based Modular Scaffold for High-Contrast Activatable Molecular Afterglow Imaging

Afterglow luminescence (long persistent luminescence) holds great potential for nonbackground molecular imaging. However, current afterglow probes are mainly nanoparticles, and afterglow imaging systems based on organic small molecules are still lacking and have rarely been reported. Moreover, the lack of reactive sites and a universal molecular scaffold makes it difficult to design activatable afterglow probes. To address these issues, this study reports a novel kind of hemicyanine-based molecule scaffolds with stimuli-responsive afterglow luminescence, which is dependent on an intramolecular cascade photoreaction between ¹O₂ and the afterglow molecule to store the photoenergy for delayed luminescence after light cessation. As a proof of concept, three modular activatable molecular afterglow probes (MAPs) with a "four-in-one" molecular design by integrating a stimuli-responsive unit, ¹O₂-generating unit, ¹O₂-capturing unit, and luminescent unit into one probe are customized for quantification and imaging of targets including pH, superoxide anions, and aminopeptidase. Notably, MAPs show higher sensitivity in afterglow imaging than in fluorescence imaging because the responsive unit simultaneously controls the initiation of fluorescence (S₁ to S₀) and ¹O₂ generation (S₁ to T₁). Finally, MAPs are applied for high-contrast afterglow imaging of drug-induced hepatotoxicity, which is poorly evaluated in clinics and drug discovery. By reporting the sequential occurrence of oxidative stress and upregulation of aminopeptidase, such activatable afterglow probes allow noninvasive imaging of hepatotoxicity earlier than the serological and histology manifestation, indicating their promise for early diagnosis of hepatotoxicity.

Tuning the Cellular Uptake and Retention of Rhodamine Dyes by Molecular Engineering for High-Contrast Imaging of Cancer Cells

Probes allowing high-contrast discrimination of cancer cells and effective retention are powerful tools for the early diagnosis and treatment of cancer. However, conventional small-molecule probes often show limited performance in both aspects. Herein, we report an ingenious molecular engineering strategy for tuning the cellular uptake and retention of rhodamine dyes. Introduction of polar aminoethyl leads to the increased brightness and reduced cellular uptake of dyes, and this change can be reversed by amino acetylation. Moreover, these modifications allow cancer cells to take up more dyes than normal cells (16-fold) through active transport. Specifically, we further improve the signal contrast (56-fold) between cancer and normal cells by constructing activatable probes and confirm that the released fluorophore can remain in cancer cells with extended time, enabling long-term and specific tumor imaging.