Advancing Nonsmall Cell Lung Cancer Diagnosis Accuracy via Dual Detection Fluorescent Nanoprobes.

Among the primary threats to human health worldwide, nonsmall cell lung cancer (NSCLC) remains a significant factor and is a leading cause of cancer-related deaths. Due to subtle early symptoms, NSCLC patients are diagnosed at advanced stages, resulting in low survival rates. Herein, novel Au-Se bond nanoprobes (NPs) designed for the specific detection of Calpain-2 (CAPN2) and Human Neutrophil Elastase (HNE), pivotal biomarkers in NSCLC, were developed. The NPs demonstrated exceptional specificity and sensitivity toward CAPN2 and HNE, enabling dual-color fluorescence imaging to distinguish between NSCLC cells and normal lung cells effectively. The NPs' performance was consistent across a wide pH range (6.2 to 8.0), and it exhibited remarkable resistance to biological thiol interference, indicating its robustness in complex physiological environments. These findings suggest the nanoprobe is a promising tool for early NSCLC diagnosis, offering a novel approach for enhancing the accuracy of cancer detection.

Self-Assembly-Based Nanoprobes for the Simultaneous Detection and Downregulation of HSP90α mRNA to Enhance Photothermal Therapy.

Although photothermal therapy (PTT) has been widely applied for tumor treatment, tumor cells thermotolerance still limits PTT efficiency. Since the overexpressed HSP90α in tumor cells further enhances thermotolerance and protects them from PTT damage, a new nanoprobe that can specifically detect and downregulate HSP90α mRNA was developed to enhance the PTT effect. Based on the HSP90α mRNA sequence, the nanoprobe Au-DNA1/DNA2 can specifically bind to HSP90α mRNA for recovering its fluorescence and further inhibit the synthesis of HSP90α to reduce tumor heat tolerance. Moreover, another nanoprobe, Au-DNA3, can self-assemble with the Au-DNA1 nanoprobe after the detection to form Au aggregations to enhance PTT afterward for better efficiency. Simultaneously, such a design improves tissue penetration and tumor retention, thereby reducing the damage to the surrounding normal tissues. Both in vitro and in vivo experiments showed that the nanoprobes have excellent tumor diagnosis and cancer treatment capabilities, which is of great significance for clinical translational applications.

Pt-Se-Bonded Nanoprobe for High-Fidelity Detection of Non-small Cell Lung Cancer and Enhancement of NIR II Photothermal Therapy.

Non-small cell lung cancer (NSCLC) accounts for a high proportion of lung cancer cases globally, but early detection remains challenging, and insufficient oxygen supply at tumor sites leads to suboptimal treatment outcomes. Therefore, the development of core-shell Au@Pt-Se nanoprobes (Au@Pt-Se NPs) with peptide chains linked through Pt-Se bonds was designed and synthesized for NSCLC biomarker protein calcium-activated neutral protease 2 (CAPN2) and photothermal therapy (PTT) enhancement. The NP can be specifically cleaved by CAPN2, resulting in fluorescence recovery to realize the detection. The Pt-Se bonds exhibit excellent resistance to biologically abundant thiols such as glutathione, thus avoiding "false-positive" results and enabling precise detection of NSCLC. Additionally, the platinum (Pt) shell possesses catalase-like properties that catalyze the generation of oxygen from endogenous hydrogen peroxide within the tumor, thereby reducing hypoxia-inducible factor-1α (HIF-1α) levels and alleviating the hypoxic environment at the tumor site. The Au@Pt-Se NPs exhibit strong absorption bands, enabling the possibility of PTT in the near-infrared II region (NIR II). This study presents an effective approach for the early detection of NSCLC while also serving as an oxygen supplier to alleviate the hypoxic environment and enhance NIR II PTT.

Fishing out Methionine-Containing Proteins from Complex Biological Systems Based on a Non-Enzymatic Biochemical Reaction.

Nowadays, it still remains a great challenge to develop a simple, fast, and low-toxic method for identification and separation of proteins from complex biological systems. Herein, a nanocomposite (Fe3O4@Au-Se-peptide) was designed and synthesized to fish out methionine-containing proteins based on a non-enzymatic biochemical reaction, which couples amino groups of lysine with the S-methyl group of methionine in the presence of HOBr. Peptides which contain four lysine residues (Lys-Lys-Lys-Lys-{Se-Cys}) linked to the Fe3O4@Au nanocomposites were used to capture methionine residues efficiently via a S═N cross-linking. The methionine-containing protein was obtained by magnetic separation and released from the Fe3O4@Au-Se-peptide nanocomposites with the influence of H2Se. The HRMS and SDS-PAGE results confirmed the methionine-containing protein could be successfully fished out from a mixture solution. This work provides a useful strategy for recognition and separation of a category of proteins from complex biological systems.

Monitoring the Activation of Caspases-1/3/4 for Describing the Pyroptosis Pathways of Cancer Cells.

Pyroptosis is closely related to inhibiting the occurrence and development of tumors. However, the pyroptosis pathways (PPs) impacted by different stimulants are still unknown. To accurately understand the PP in cancer cells, we designed a multicolor fluorescent nanoprobe (Cas-NP) to monitor the activation of caspases-1/3/4 during pyroptosis. The Cas-NP was prepared by the assembly of three different fluorophores-labeled peptides, specific response to caspases-1/3/4 on Au nanoparticles via the Au-Se bond to in situ monitor caspase-1/3/4 with high selectivity and sensitivity. Moreover, the selenopeptide specific to caspase-4 (Cyanine-5-LEVD-SeH) was synthesized for the first time to overcome the difficulty in commercial synthesis. During the pyroptosis of cancer cells induced by adenosine triphosphate (ATP), only the fluorescence of caspase-1 significantly increases. When the cells are stimulated with lipopolysaccharide (LPS), the fluorescence signals corresponding to caspases-3 and 4 first appear and then the fluorescence of caspase-1 is observed. Furthermore, the inhibitor study indicates that the activated caspase-4 can lead to the activation of caspase-1 after the LPS treatment. We first discovered that caspase-3 is activated during the pyroptosis process stimulated by LPS and further verified the activation sequence of caspases-1/3/4 via visualized fluorescence detection. The study provides an effective tool for understanding complex signaling mechanisms in pyroptosis cells and new ideas to explore useful therapeutic inhibitors based on pyroptosis.

A Mitochondrial-Targeting Near-Infrared Fluorescent Probe for Revealing the Effects of Hydrogen Peroxide And Heavy Metal Ions on Viscosity.

As an important cell organelle, the mitochondrion has special viscosities, while abnormal mitochondrial viscosity is closely related to many diseases. Hydrogen peroxide (H2O2) is an active molecule related to the cell microenvironment, and its influence on mitochondrial viscosity is still not clear, so further investigation is needed. In addition, since excessive accumulation of heavy metal ions would lead to cells' dysfunction, the study of effect of excessive heavy metal ions on mitochondrial viscosity has not been reported. Herein, we designed and synthesized a mitochondrial-targeting near-infrared fluorescent probe (Mito-NV) for real-time in situ imaging and analysis of mitochondrial viscosity. Furthermore, the probe revealed that H2O2 can raise mitochondrial viscosity, while heavy metal ions reduce the viscosity. This work is of great significance for understanding the execution of mitochondrial functions and the occurrence and development of related diseases.

Exploring the binding mechanism of positive allosteric modulators in human metabotropic glutamate receptor 2 using molecular dynamics simulations.

Positive allosteric modulators (PAMs) of human metabotropic glutamate receptor 2 (hmGlu2) are well-known in the treatment of psychiatric disorders for their higher selectivity and lower tolerance risk. A variety of PAMs have been reported over the last decade and two compounds were in Phase II clinical trials for schizophrenia and anxiety. These trials were discontinued on account of the unsatisfactory therapeutic efficacy, but PAMs were explored as novel treatments for addiction and epilepsy. Thus, it is still important to explore novel hmGlu2 PAMs in the near future. Nowadays, the challenges in optimizing drug potency and improving scaffold diversity for PAMs are the noncomprehensive character analyses of multiple scaffolds; the exploration of the binding modes of PAMs in the allosteric binding site have been proposed to reduce this difficulty. However, there has been no comprehensive research about the binding profiles of PAMs in the hmGlu2 receptor. To address this issue, this work explores the binding characters of eight PAMs representing five chemical series by multiple computational methods. As a result, the shared binding modes of the eight studied PAMs interacting with 15 residues in the allosteric binding site were defined. In addition, the reduced hydrophobicity with low electronegativity of R1, increased hydrophobicity with low negative electron density of R2 and the electronegativity of the linker were identified as indicators that regulate the affinity of PAMs. This finding agrees well with the physicochemical properties of reported multiple series PAMs. This comprehensive work sheds additional light on the binding mechanism and physicochemical regularity underlining PAMs affinity and could be further utilized as a structural and energetic blueprint for discovering and assessing novel PAMs for hmGlu2.

Type 2 innate lymphoid cells regulation by regulatory T cells attenuates atherosclerosis.

Regulatory T cells (Tregs) have been shown to attenuate the development and progression of atherosclerosis; however, the exact mechanism is still unclear. In our study, Tregs were adoptively transferred into ApoE-/- mice, and type 2 innate lymphoid cells (ILC2s) were expanded by the IL-2/Jes6-1 complex or depleted by anti-CD90.2 mAb in ApoE-/-Rag1-/- mice to study their effects on atherosclerosis. Then, Tregs were cocultured with ILC2s in vitro to analyze ILC2s number and IL-13 production. In vivo, ApoE-/-Rag1-/- mice were treated with activated Tregs with or without anti-CD90.2 mAb to explore whether Tregs reduced atherosclerosis through ILC2s. Finally, neutralizing antibodies and Transwell assay were used to investigate how Tregs regulate ILC2s. Our results show that both Tregs and ILC2s reduce atherosclerosis lesions and macrophage infiltration. Moreover, Tregs effectively expanded the number of ILC2s and increased their production of IL-13 in vivo and in vitro. Furthermore, the reductions in plaque size and macrophage infiltration by Tregs were partly reversed by anti-CD90.2 mAb. Mechanistically, our data reveal that IL-10, TGF-ß and cell-cell contacts are required for Tregs-ILC2s regulation. These results show that Tregs may play a partial protective role against atherosclerosis by expanding the number of ILC2s and consequently increasing IL-13 production.

A differential study on oxidized/reduced ascorbic acid induced tumor cells' apoptosis under hypoxia.

The anticancer mechanism for reduced/oxidized ascorbic acid (AA/DHA) is of great significance for clinical cancer therapies. A pH controlled fluorescent nanocarrier was designed to targetably deliver AA and DHA into tumor cells for investigating their function in inducing intracellular apoptosis pathways. A fluorescent silicon nanoparticle with polymer coating serves as the pH controlled nanocarrier to deliver AA or DHA into HepG2 and B16-F10 cells for studying their biological functions. The intracellular apoptotic pathway was monitored through the Caspase-3 nanoprobe, while the changes of signal molecules H2O2 and NAD(P)H in the redox homeostasis system were monitored through the corresponding fluorescent probes. Under hypoxic conditions, AA can scavenge H2O2 in tumor cells and promote NAD(P)H accumulation, but DHA promotes the production of both H2O2 and NAD(P)H, indicating that the molecular mechanisms for inducing cancer cells' apoptosis are significantly different. AA leads to reductive stress by promoting the accumulation of NAD(P)H in tumor cells, but DHA enhances oxidative stress by increasing the H2O2 concentration in cells.

Homotypic cell membrane-cloaked biomimetic nanocarrier for the accurate photothermal-chemotherapy treatment of recurrent hepatocellular carcinoma.

BACKGROUND: Tumor recurrence in patients after surgery severely reduces the survival rate of surgical patients. Targeting and killing recurrent tumor cells and tissues is extremely important for the cancer treatment. RESULTS: Herein, we designed a nano-biomimetic photothermal-controlled drug-loading platform HepM-TSL with good targeting ability and immunocompatibility for the treatment of recurrent hepatocellular carcinoma. HepM-TSL can accurately target the recurrent tumor area with the aid of the cloaked homotypic cell membrane and release the chemotherapy drugs in a controlled manner. In vivo results have confirmed that HepM-TSL loaded with drugs and photosensitizer achieves the synergistic treatment of recurrent hepatocellular carcinoma with good therapeutic effect and slight side effects. CONCLUSION: Accordingly, HepM-TSL provides a sound photothermal-chemotherapy synergistic strategy for the treatment of other recurrent cancers besides of recurrent hepatocellular carcinoma.

Divergent Biomimetic Total Syntheses of Ganocins†A-C, Ganocochlearins†C and D, and Cochlearol†T.

A divergent synthetic approach to six Ganoderma meroterpenoids, namely ganocins A-C, ganocochlearins C and D, and cochlearol T, has been developed for the first time. This synthetic route features a two-phase strategy which includes early-stage rapid construction of a common planar tricyclic intermediate followed by highly selective late-stage transformations into various Ganoderma meroterpenoids. Key to the strategy are a bioinspired intramolecular hetero-Diels-Alder reaction and Stahl-type oxidative aromatization, allowing efficient formation of the common tricyclic phenol intermediate. A nucleophilic dearomatization of the phenol unit, combined with a regioselective 1,4-reduction of the resulting dienone, enabled rapid access to ganocins B and C. Additionally, site-selective Mukaiyama hydration, followed by an intramolecular oxa-Michael addition/triflation cascade, served as a key strategic element in the chemical synthesis of ganocin A.

Dicyanoisophorone-Based Near-Infrared-Emission Fluorescent Probe for Detecting NAD(P)H in Living Cells and in Vivo.

NADH and NADPH are ubiquitous coenzymes in all living cells that play vital roles in numerous redox reactions in cellular energy metabolism. To accurately detect the distribution and dynamic changes of NAD(P)H under physiological conditions is essential for understanding their biological functions and pathological roles. In this work, we developed a near-infrared (NIR)-emission fluorescent small-molecule probe (DCI-MQ) composed of a dicyanoisophorone chromophore conjugated to a quinolinium moiety for in vivo NAD(P)H detection. DCI-MQ has the advantages of high water solubility, a rapid response, extraordinary selectivity, great sensitivity (a detection limit of 12 nM), low cytotoxicity, and NIR emission (660 nm) in response to NAD(P)H. Moreover, the probe DCI-MQ was successfully applied for the detection and imaging of endogenous NAD(P)H in both living cells and tumor-bearing mice, which provides an effective tool for the study of NAD(P)H-related physiological and pathological processes.

Unique Topology Analysis by ToposPro for a Metal-Organic Framework with Multiple Coordination Centers.

The reactions of 2-(4-pyridyl) thiazole-4-carboxylic acid (Hptca) and CuCl2·6H2O have led to a novel 3D mixed-valence, four-copper-center, metal-organic framework (MOF) [Cu8Cl2(ptca)10·17H2O] n (1). The topology analysis using ToposPro software package for 1 resulted in three chain-based topology types of sra (42, 63, 8), pcu (412, 63), and dia (66) via choosing corresponding connection atoms as central atoms. The study indicates that connection atoms associated directly with multiple coordination centers are applicable to act as central atoms. This unique topology analysis approach is conceptually different from the current analytical methods which use node atoms as central atoms. In addition, complex 1 exhibits significant selective adsorption of CO2 over N2. This study provides a great example of the topological analysis of MOFs with multiple coordination centers.

Effective Separation of Enantiomers Based on Novel Chiral Hierarchical Porous Metal-Organic Gels.

Metal-organic gel (MOG) matrices with tunable pore sizes ranging from micropore to macropore, derived from microporous metal-organic coordination polymers (PCPs), has attracted great attention for their enhanced pore accessibility compared with the multifunctional PCP materials themselves. The enhanced pore accessibility of chiral MOGs is especially imperative for mass transfer applications, including enantioseparations and purifications. Here, for the first time, a novel hierarchical porous MOG-coated SiO2 , derived from a chiral metal-organic coordination polymer, is employed as chiral stationary phase for effective high-performance liquid chromatography (HPLC) separation of enantiomers. The selected enantiomers with diverse functional groups are all efficiently separated in a few minutes with significantly higher resolution.

Au-Se-Bond-Based Nanoprobe for Imaging MMP-2 in Tumor Cells under a High-Thiol Environment.

The gold nanosensors based on the Au-S bond have been widely applied to biochemical detections. However, signal distortion caused by biothiols has been seldom mentioned and urgently needs to be solved. Herein, we designed a novel but easily assembled gold nanoprobe by coupling a selenol-modified peptide with FITC onto the gold nanoparticle's surface via an Au-Se bond for fluorescence imaging of a tumor marker matrix, metalloproteinases 2 (MMP-2). Compared to the Au-S probes, the Au-Se probes display high thermal stability and a very good anti-interference ability toward glutathione under simulated physiological conditions. More importantly, the Au-Se nanoprobe exhibits a high-fidelity fluorescent signal toward MMP-2, effectively avoiding interference caused by high levels of thiol compounds in vivo. In addition, in vivo experiments further proved that no significant signal intensity change for the tumor cells treated by the Au-Se probes was observed before and after eliminating glutathione. Hence, we believe such Au-Se probes with in vivo glutathione interfering resistance offer new routes and perspectives in biology and medicine in the future.

Cyclic Regulation of the Sulfilimine Bond in Peptides and NC1 Hexamers via the HOBr/H2Se Conjugated System.

The sulfilimine bond (-S═N-), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through hydrogen selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV.

Avoiding Thiol Compound Interference: A Nanoplatform Based on High-Fidelity Au-Se Bonds for Biological Applications.

Gold nanoparticles (Au NPs) assembled through Au-S covalent bonds have been widely used in biomolecule-sensing technologies. However, during the process, detection distortions caused by high levels of thiol compounds can still significantly influence the result and this problem has not really been solved. Based on the higher stability of Au-Se bonds compared to Au-S bonds, we prepared selenol-modified Au NPs as an Au-Se nanoplatform (NPF). Compared with the Au-S NPF, the Au-Se NPF exhibits excellent anti-interference properties in the presence of millimolar levels of glutathione (GSH). Such an Au-Se NPF that can effectively avoid detection distortions caused by high levels of thiols thus offers a new perspective in future nanomaterial design, as well as a novel platform with higher stability and selectivity for the in vivo application of chemical sensing and clinical therapies.

Enhanced Photodynamic Therapy by Reduced Levels of Intracellular Glutathione Obtained By Employing a Nano-MOF with CuII as the Active Center.

In photodynamic therapy (PDT), the level of reactive oxygen species (ROS) produced in the cell directly determines the therapeutic effect. Improvement in ROS concentration can be realized by reducing the glutathione (GSH) level or increasing the amount of photosensitizer. However, excessive amounts photosensitizer may cause side effects. Therefore, the development of photosensitizers that reduce GSH levels through synergistically improving ROS concentration in order to strengthen the efficacy of PDT for tumor is important. We report a nano-metal-organic framework (CuII -metalated nano-MOF {CuL-[AlOH]2 }n (MOF-2, H6 L=mesotetrakis(4-carboxylphenyl)porphyrin)) based on CuII as the active center for PDT. This MOF-2 is readily taken up by breast cancer cells, and high levels of ROS are generated under light irradiation. Meanwhile, intracellular GSH is considerably decreased owing to absorption on MOF-2; this synergistically increases ROS concentration and accelerates apoptosis, thereby enhancing the effect of PDT. Notably, based on the direct adsorption of GSH, MOF-2 showed a comparable effect with the commercial antitumor drug camptothecin in a mouse breast cancer model. This work provides strong evidence for MOF-2 as a promising new PDT candidate and anticancer drug.

A DNA Tetrahedron Nanoprobe with Controlled Distance of Dyes for Multiple Detection in Living Cells and in Vivo.

Multicomponent quantitative detection in living samples is becoming increasingly important; however, the current detection strategy may cause fluorescence self-quenching and reduce the sensitivity of detection. To solve the problem, we develop a DNA tetrahedral nanoprobe to control the dyes distance for simultaneous detection of multiple analytes. Compared to mesoporous silica nanoparticles based nanoprobes, the DNA tetrahedral nanoprobes display enhanced fluorescence intensities due to partially avoiding the fluorescence resonance energy transfer. Confocal fluorescence images show that the nanoprobes are capable of detecting and visualizing pH and O2•- in living cells under a single wavelength excitation. In an inflammation model for mice, the nanoprobes simultaneously image the down-regulation of pH and up-regulation of O2•-. We expect that the current strategy can provide new opportunities in designing probes for multiplexed detection with reduced self-quenching and enhanced sensitivity.

Visualizing Breast Cancer Cell Proliferation and Invasion for Assessing Drug Efficacy with a Fluorescent Nanoprobe.

Hard-to-treat cancers are closely relative to uncontrolled cell proliferation, invasion, and metastasis. Assessing proliferation and invasion properties of tumor cells both in vitro and in vivo is especially important for acquiring reliable information for cancer pathogenesis, drug screening, and therapeutic effect evaluation. Herein, we developed a multicolor fluorescent nanoprobe for simultaneously monitoring breast cancer cells' proliferation marker Ki-67 and invasion marker urokinase plasminogen activator (uPA). After treated with the anticancer drugs tamoxifen and curcumin, the changes in cancer cell proliferation and invasion properties were visually detected and therapeutic effects of corresponding drugs were further assessed in vitro and in vivo. The design of the fluorescent nanoprobe opens up an avenue for investigating unscheduled proliferation, invasion, and metastasis in living cells and in vivo and as such will be a promising tool to screen antitumor drugs and evaluate drug efficiency in an extremely efficient manner.