The abnormal expression of microRNA (miRNA) is closely related to the occurrence and progression of diverse cancers. Accurate diagnosis of early-stage cancers via low-cost Point-of-Care Testing (POCT) remains highly desirable but challenging. Herein, a dual-colorimetric amplification biosensor has been developed for the simultaneous detection of two tumor-associated miRNAs. It enables the sensitive and accurate diagnosis of cancers without the requirement for complex procedures and expensive detection instruments. Specifically, the target miR-10b can initiate the Catalytic Hairpin Assembly (CHA) reaction between gold nanoparticles (GNPs) and magnetic beads (MBs), thereby leading to the coupling of GNPs onto MBs. Meanwhile, miR-21 can activate the Hybridization Chain Reaction (HCR) on MBs. After magnetic separation, the color of the supernatant changes from red to pale, and the G-quadruplex/hemin DNAzyme would form on the MBs sediment, which can further catalyze the colorless ABTS/H2O2 to green. Based on this, the concentrations of miR-10b and miR-21 could be visualized simultaneously. Under optimal conditions, the constructed biosensor demonstrates the feasibility, accuracy, and selectivity towards target miRNAs in both buffer solutions and real serum samples. The proposed strategy may offer a novel path for the precise diagnosis of cancers in POCT.

Constructing in vitro blood-brain barrier (BBB) model provides an innovative approach for studying the pathophysiology of the brain and screening drugs. Although commercial Transwell was the simplest and most widely utilized in vitro model, reasonably mimicking essential characteristics of human BBB and dynamic monitoring BBB function remain a challenge. Herein, inspired by the highly permeable extracellular matrix membrane in human BBB, a novel in vitro BBB model was established by combining functionalized anodic alumina oxide (AAO) membrane with nanochannel electrochemistry (ANE-BBB). Benefiting from the topographical nanostructures and modified cell-adhesive peptide on the AAO surface, a tight endothelial barrier was formed, which can be directly visualized by phase-contrast microscope, and the barrier function can be real time monitored by nanochannel electrochemistry. More importantly, according to the current signal induced by the diffusion of redox species through the nanochannels toward the underlying electrode surface, dynamic evaluation of BBB-crossing behavior and precise screening of brain-targeted nanodrugs can be achieved. The constructed ANE-BBB overcomes the shortcomings of invisible cell culture, low permeability, and inaccurate real-time monitoring of screening drugs in traditional Transwell and provides a reliable tool for the design of nanodrugs to the central nervous system.

The excessive depositions of beta-amyloid (A beta) and abnormal level of reactive oxygen species (ROS) are considered as the important pathogenic factors of Alzheimer's disease (AD). Strategies targeting only one of them have no obvious effects in clinic. In this study, a multifunctional nanocarrier CICe@M-K that crosses the blood-brain barrier (BBB) efficiently was developed for inhibiting A beta aggregation and scavenging ROS synchronously. Antioxidant curcumin (Cur) and photosensitizer IR780 were loaded in mesoporous silica nanomaterials (MSNs). Their surfaces were grafted with cerium oxide nanoparticles (CeO2 NPs) and a short peptide K (CKLVFFAED). Living imaging showed that CICe@M-K was mainly distributed in the brain, liver, and kidneys, indicating CICe@M-K crossed BBB efficiently and accumulated in brain. After the irradiation of 808 nm laser, Cur was continuously released. Both of Cur and the peptide K can recognize and bind to A beta through multiple interaction including pi-pi stacking interaction, hydrophobic interaction, and hydrogen bond, inhibiting A beta aggregation. On the other hand, Cur and CeO2 NPs cooperate to relieve the oxidative stress in the brains by scavenging ROS. In vivo assays showed that the CICe@M-K could diminish A beta depositions, alleviate oxidative stress, and improve cognitive ability of the APP/PS1 AD mouse model, which demonstrated that CICe@M-K is a potential agent for AD treatment.

The immunosuppressive tumor microenvironment (TME) poses tremendous challenges for efficient immunotherapy. Smart nanomedicine is designed to modulate immunosuppressive TMEs based on the combination of dual-enhanced photodynamic therapy (PDT) triggered immunogenic cell death (ICD) and relieved hypoxic microenvironment. Copper(II) metalated metal-organic framework nanosheets (Cu-TCPP(Al)) are the foundation of the nanomedicine, and platinum nanoparticles (Pt NPs) and folate are subsequently introduced onto the Cu-TCPP(Al) surface (Cu-TCPP(Al)-Pt-FA). Upon targeted cellular uptake, intracellular GSH concentration is decreased because of the specific adsorption between GSH and CuII; meanwhile, Pt NPs possess catalase-like activity, which can continuously depose intracellular H2O2 to O2 to alleviate the hypoxic TME. The two factors synergistically improve the ROS concentration for dual-enhanced PDT. The highly toxic ROS can correspondingly cause amplified oxidative stress and then trigger the ICD. The ICD process stimulates antigen-presenting cells and activates the systemic antitumor immune response. Furthermore, the relieved hypoxic TME increases the infiltration of cytotoxic T lymphocytes (CTLs) at the tumor site, which can promote the transformation of the immunosuppressive M2 macrophage to immunoactive M1 phenotype. The easily prepared yet versatile nanomedicine possesses an excellent antitumor effect with the cooperation of dual-enhanced PDT and immunotherapy.

Brain Tumor Theranostics In article number 2203448, Hongping Xia, Songqin Liu, Yafeng Wu, and co-workers prepare dual blood–brain barrier (BBB) targeting biomimetic nanocomplexes (TMPsM) for simultaneous accurate diagnosis and effective treatment of glioma. The biomimetic outer shells endow them with enhanced BBB penetration and ensure the delivery of theranostic agents into brain tumor sites for single intracellular transglutaminase 2-triggered self-assembly aggregation-induced emission imaging and RNAi therapy.

Engineering a versatile nanocomplex integrating effective penetration of the blood-brain barrier (BBB), accurate diagnosis, and boosting therapy has always been an intractable challenge in glioblastoma multiforme (GBM). Herein, biomimetic nanocomplexes (TMPsM) for single intracellular transglutaminase 2 (TG2)-triggered self-assembly imaging and RNAi therapy for GBM are subtly developed. To prove the concept, transferrin receptor (TfR) aptamer-modified brain metastatic tumor cell membrane is prepared as the shell for dual BBB targeting capability and prolonged blood retention time. Upon targeting entering into GBM, hollow MnO2 is decomposed to release KKGKGQQ-tetraphenylethene (Pep-TPE) and siRNA. Owing to TG2 dependence, the non-emissive Pep-TPE would be self-aggregated to induce the emission turn-on in GBM that contain overexpressed TG2. The resulting aggregation-induced emission fluorescence imaging with a high signal-to-noise ratio can achieve the precise localization of the tumor and dynamic detection of TG2 activity, thereby allowing the GBM accurate diagnosis. Notably, the TG2 can be silenced by the released siRNA to cause cell apoptosis and increase chemotherapeutic sensitivity, ultimately realizing excellent antitumor efficacy. In vitro and in vivo results demonstrate that the as-prepared TMPsM indeed possess superior BBB penetration, precise diagnosis, and effective therapy of GBM. The proposed strategy may pioneer a new path for the theranostics of brain tumors.

To achieve an accurate diagnosis and efficient tumor treatment, developing a facile and powerful strategy to build multifunctional nanotheranostics is highly desirable. Benefiting from the distinct characteristics of black phosphorus quantum dots (BPQDs), herein, a versatile nanoprobe (H‐MnO 2 /DOX/BPQDs) is constructed for dual‐modality cancer imaging and synergistic chemo‐phototherapy. The hollow mesoporous MnO 2 (H‐MnO 2 ) nanoparticles are sequentially decorated with a cationic polymer poly (allylamine hydrochloride) (PAH) and an anionic polymer poly (acrylic acid) (PAA). The obtained H‐MnO 2 ‐PAH‐PAA is covalently grafted with BPQDs‐PEG‐NH 2 via a carbodiimide cross‐linking reaction and then loaded with anti‐cancer drug DOX to form final nanoprobe H‐MnO 2 /DOX/BPQDs. Under the tumor microenvironment, H‐MnO 2 /DOX/BPQDs is degraded to release encapsulated functional molecules DOX and BPQDs. DOX acts as the chemotherapy and fluorescence imaging agent, and BPQDs endows the nanoprobe with photodynamic therapy (PDT) and photothermal therapy (PTT) abilities under dual laser irradiation of 630 and 808 nm. H‐MnO 2 offers contrasts for magnetic resonance imaging (MRI) and facilitates conversion of endogenous H 2 O 2 to oxygen, thereby relieving tumor hypoxia and enhancing PDT efficacy. All in vitro and in vivo results demonstrate that the designed nanoprobe displays dual‐modality MRI/FL imaging and synergistic chemotherapy/PDT/PTT, which ultimately enhances the accuracy of cancer diagnosis and therapeutic performance.

Herein, a novel strategy for in situ imaging and real-time monitoring of intracellular tissue transglutaminase (TG2) is presented based on aggregation-induced emission (AIE). It has high sensitivity and specificity, minimal background signal and can also effectively distinguish different cell types (drug-resistant cancer cells, cancer cells and normal cells).

Exosomes are recognized as promising biomarkers for early cancer diagnosis and prognosis owing to a large amount of biological information they carried. But the key is that single type of exosomal biomarker analysis is not sufficient enough for accurate cancer diagnosis and stage monitoring due to the insufficient information and high false positive signal. To address the challenge, here simultaneous in situ detection of different types of exosomal biomarkers (surface proteins: CD81, ephrin type-A receptor 2, and carbohydrate antigen 19-9; miRNAs: miR-451a, miR-21, and miR-10b) is conducted with a 3D microfluidic chip, which works in conjunction with quantum dot (QD) labeling and vesicle fusion technology. After exosomes are efficiently captured by the microfluidic chip, the quantification of multiple exosomal proteins is achieved by using three kinds of QDs with the same excitation and different emission wavelengths, and virus-mimicking fusogenic vesicles encapsulating three exquisitely engineered molecular beacons are introduced for ultrasensitive detection of multiple exosomal miRNAs without requiring RNA extraction. Through comprehensive profiling different types of exosomal biomarkers, the false positive rate is substantially avoided and the accuracy of cancer diagnosis and stage monitoring is improved to approximate to 100%, which are critical to cancer effective treatment and favorable prognosis.

Accurate cancer cell identification and efficient therapy are extremely desirable and challenging in clinics. Here, we reported the first example of DNA tetrahedron nanostructures (DTNSs) to real-time monitor and image three intracellular miRNAs based on the fluorescence "OFF" to "ON" mode, as well as to realize cancer therapy induced by miRNA silencing. DTNSs were self-assembled by seven customized single-stranded nucleic acid chains containing three recognition sequences for target miRNAs. In the three vertexes of DTNSs, fluorophores and quenchers were brought into close proximity, inducing fluorescence quenching. In the presence of target miRNAs, fluorophores and quenchers would be separated, resulting in fluorescence recovery. Owing to the unique tetrahedron-like spatial structure, DTNSs displayed improved resistance to enzymatic digestion and high cellular uptake efficiency, and exhibited the ability to simultaneously monitor three intracellular miRNAs. DTNSs not only effectively distinguished tumor cells from normal cells, but also identified cancer cell subtypes, which avoided false-positive signals and significantly improved the accuracy of cancer diagnosis. Moreover, the DTNSs could also act as an anti-cancer drug; antagomir-21 (one recognition sequence) was detached from DTNSs to silence endogenous miRNA-21 inside cells, which would suppress cancer cell migration and invasion, and finally induce cancer cell apoptosis; the result was demonstrated by experiments in vitro and in vivo. It is anticipated that the development of smart nanoplatforms will open a door for cancer diagnosis and treatment in clinical systems.

DNA tetrahedron nanostructures (DTNSs) were prepared to improve the accuracy of cancer diagnosis through real-time monitoring and imaging three intracellular miRNAs, as well as to realize cancer therapy induced by miRNA silencing.

MicroRNAs (miRNAs) play important roles in the regulation of target gene expression and cell development. Therefore, developing of accurate and visual detection methods for miRNAs is important for early diagnosis of cancer. In this study, we established a visual detection method for miRNA 155 based on DNAzyme amplification strategy in living cells. MnO2 nanosheets were employed to deliver locked DNAzyme and substrate DNA into cells. The gold nanoparticle (AuNP) probe was taken up by cells autonomously. Then, MnO2 nanosheets were reduced to Mn2+ by glutathione in cells and DNA modules were released. MiRNA 155 took away locker DNA by strand displacement reaction to activate the DNAzyme. Then, the DNAzyme cleaved the substrate DNA and released single-stranded DNA named key DNA. Then, Key DNA hybridized with the hairpin DNA, making cy5 far away from AuNP and turning on its fluorescence. One target miRNA led to plenty of released key DNA when lots of substrate DNA was added. Thus, the visual detection of miRNA 155 in living cells would be initiated. Under confocal laser microscopy, the fluorescence was obviously observed in tumor cells but not in normal cells. The method has a linear range from 0.1 to 10 nM and a low detection limit of 44 pM on in vitro detection.

Soybean peroxidase (SBP) is characterized by relatively high heat resistance, wide substrate scope, good stability and broad pH applicability. These advantages led SBP to be used as labeled-antibody for immunoassays. In this work, monoclonal antibody was linked with SBP to beta-HCG (Mab II-SBP) for enzyme-linked immunosorbent assay (ELISA) or chemiluminescence assay to explore its potential as an alternative to the widely used horseradish peroxidase (HRP) based ELISA. The Mab II-SBP was prepared by the sodium periodate oxidation method. The effects of enzyme coupling rate and molar ratio of Mab II to enzyme on assay performance were investigated. The optimum mass concentration ratio of Mab II and SBP was determined to be 1:3. The best coat concentration of the monoclonal antibody to alfa-HCG antibody (Mab I) was 4 mu g/mL. Under optimum conditions, the HCG concentration was determined by the proposed ELISA assay with linear response range from 0.18 to 18 ng/mL and detection limit of 0.07 ng/mL at a signal-to-noise ratio of 3. Both enhancers, 3-(10'-phenothiazinyl) propane-1-sulfonate (SPTZ) and 4-morpholinopyridine (MORPH), amplified chemiluminescence intensity nearly 200-fold in comparison to the SBP-luminol-H2O2 system. The present work demonstrates the feasibility and rationale of SBP-labeling antibodies for ELISA and chemiluminescence assays.

An immunogold chromatographic assay was developed for quantitative determination of human chorionic gonadotropin (HCG) antigen. The monoclonal antibody to beta-HCG antigen (Mab II) conjugated gold nanoparticles (GNPs) were sprayed onto a conjugation pad for specific binding with the target protein to form an immunocomplex. The monoclonal antibody to alfa-HCG antigen (Mab I) was immobilized on the test line (T zone) of the nitrocellulose membrane (NC membrane) to capture the immunocomplex of gold nanoparticle labeled Mab II and HCG protein. Therefore, GNPs would aggregate on the test line of the NC membrane in the presence of HCG, which could be easily distinguished by the naked-eye. As for quantitative detection, the gray value of the red color in the T zone was proportional to the corresponding sample concentration. The gray value versus logarithm concentration curve presented a good linear relationship in the range of 10-600 ng mL(-1). The duration of the assay was within 15 min and no professional large-scale analytical instrument was necessary for quantification. When applied in human serum analysis, the strips could reach the requirements of the clinic tests.