Visualization of the hepatic and renal cell uptake and trafficking of tetrahedral DNA origami in tumour.

DNA nanostructures, known for their programmability, ease of modification, and favourable biocompatibility, have gained widespread application in the biomedical field. Among them, Tetrahedral DNA Origami (TDOs), as a novel DNA nanostructure, possesses well-defined structures, multiple modification sites, and large cavities, making it a promising drug carrier. However, current understanding of TDOs' interactions with biological systems, particularly with target cells and organs, remains unexplored, limiting its further applications in biomedicine. In this work, we prepared TDOs with an average particle size of 40 nm and labelled them with Cy5 fluorescent molecules. Following intravenous injection in mice, the uptake of TDOs by different types of liver and kidney cells was observed. Results indicated that TDOs accumulate in renal tubules and are metabolized by Kupffer cells, epithelial cells, and hepatocytes in the liver. Additionally, in a tumour-bearing mouse model, TDOs passively targeted tumour tissues and exhibited excellent tumour penetration and retention after rapid metabolism in hepatocytes. Our findings provide crucial insights for the development of TDO-based drug delivery systems.

Extended Enrichment for Ultrasensitive Detection of Low-Frequency Mutations by Long Blocker Displacement Amplification.

Detecting low-frequency DNA mutations hotspots cluster is critical for cancer diagnosis but remains challenging. Quantitative PCR (qPCR) is constrained by sensitivity, and allele-specific PCR is restricted by throughput. Here we develop a long blocker displacement amplification (LBDA) coupled with qPCR for ultrasensitive and multiplexed variants detection. By designing long blocker oligos to perfectly match wildtype sequences while mispairing with mutants, long blockers enable 14-44 nt enrichment regions which is 2-fold longer than normal BDA in the experiments. For wild template with a specific nucleotide, LBDA can detect different mutation types down to 0.5 % variant allele frequency (VAF) in one reaction, with median enrichment fold of 1,000 on 21 mutant DNA templates compared to the wild type. We applied LBDA-qPCR to detect KRAS and NRAS mutation hotspots, utilizing a single plex assay capable of covering 81 mutations and tested in synthetic templates and colorectal cancer tissue samples. Moreover, the mutation types were verified through Sanger sequencing, demonstrating concordance with results obtained from next generation sequencing. Overall, LBDA-qPCR provides a simple yet ultrasensitive approach for multiplexed detection of low VAF mutations hotspots, presenting a powerful tool for cancer diagnosis and monitoring.

Effect of M0 macrophage-derived exosome miR-181d-5p targeting BCL-2 to regulate NLRP3/caspase-1/GSDMD pathway on human renal mesangial cells pyroptosis.

BACKGROUND: Lupus nephritis (LN) is a type of autoimmune disease that impacts the kidneys. Exosomes are valuable for in-depth studies of the pathogenesis of LN. This study aimed to explore miR-181d-5p expression levels in M0 macrophage-derived exosomes and their role in human renal mesangial cells (HRMC) pyroptosis through binding to BCL-2. METHODS: Peripheral blood mononuclear cells (PBMCs) were collected from patients with lupus nephritis (LN) and healthy subjects. Monocytes isolated from these samples were induced into M0 macrophages using recombinant human granulocyte colony-stimulating factor (rhG-CSF). In a parallel process, THP-1 cells were induced into M0 macrophages using Phorbol Myristate Acetate (PMA). LPS- and ATP-stimulated HRMC were used to construct a cell pyroptosis model. We then introduced different miR-181d-5p mimic fragments into the M0 macrophages derived from the THP-1 cells. Subsequently, exosomes from these macrophages were co-cultured with HRMC. To evaluate the impact on HRMC, we conducted proliferation and apoptosis assessments using CellCountingKit-8assay and flow cytometry. The effect of exosomal miR-181d-5p on HRMC pyroptosis was assessed using western blot. The miR-181d-5p and BCL-2 targeting relationship was detected using real-time fluorescence quantitative PCR. IL-6, IL-1ß, and TNF-α levels in cell supernatants were detected using ELISA kits. RESULTS: In this study, we observed an increase in miR-181d-5p levels within exosomes secreted from M0 macrophages obtained by induction of monocytes from LN patients. It was found that miR-181d-5p can target binding to BCL-2. Exosomes with elevated levels of miR-181d-5p contributed to a significant increase in miR-181d-5p within HRMC, facilitating its proliferation and inhibiting apoptosis. Furthermore, exosomes expressing high levels of miR-181d-5p were observed to promote an inflammatory response and pyroptosis in HRMC. Notably, these effects were reversed when the levels of miR-181d-5p in the exosomes were reduced. CONCLUSION: Inhibition of miR-181d-5p, derived from M0 macrophage exosomes, effectively suppresses inflammation and pyroptosis in HRMC. This discovery indicates that miR-181d-5p holds the potential as a valuable target in the development of treatments for Lupus Nephritis (LN).

Engineering a pH-responsive polymeric micelle co-loaded with paclitaxel and triptolide for breast cancer therapy.

Breast cancer has overtaken lung cancer as the number one cancer worldwide. Paclitaxel (PTX) is a widely used first-line anti-cancer drug, but it is not very effective in clinical breast cancer therapy. It has been reported that triptolide (TPL) can enhance the anticancer effect of paclitaxel, and better synergistic therapeutic effects are seen with concomitant administration of PTX and TPL. In this study, we developed pH-responsive polymeric micelles for co-delivery of PTX and TPL, which disassembling in acidic tumour microenvironments to target drug release and effectively kill breast cancer cells. Firstly, we synthesized amphiphilic copolymer mPEG2000 -PBAE through Michael addition reaction, confirmed by various characterizations. Polymer micelles loaded with TPL and PTX (TPL/PTX-PMs) were prepared by the thin film dispersion method. The average particle size of TPL/PTX-PMs was 97.29 ± 1.63 nm, with PDI of 0.237 ± 0.003 and Zeta potential of 9.57 ± 0.80 mV, LC% was 6.19 ± 0.21%, EE% was 88.67 ± 3.06%. Carrier material biocompatibility and loaded micelle cytotoxicity were assessed using the CCK-8 method, demonstrating excellent biocompatibility. Under the same drug concentration, TPL/PTX-PMs were the most toxic to tumour cells and had the strongest proliferation inhibitory effect. Cellular uptake assays revealed that TPL/PTX-PMs significantly increased intracellular drug concentration and enhanced antitumor activity. Overall, pH-responsive micellar co-delivery of TPL and PTX is a promising approach for breast cancer therapy.

Focusing on the Abnormal Events of NPC1, NPC2, and NPC1L1 in Pan-Cancer and Further Constructing LUAD and KICH Prediction Models.

Cancer's high incidence and death rate jeopardize human health and life, and it has become a global public health issue. Some members of NPCs have been studied in a few cancers, but comprehensive and prognostic analysis is lacking in most cancers. In this study, we used the Cancer Genome Atlas (TCGA) data genomics and transcriptome technology to examine the differential expression and prognosis of NPCs in 33 cancer samples, as well as to investigate NPCs mutations and their effect on patient prognosis and to evaluate the methylation level of NPCs in cancer. The linked mechanisms and medication resistance were subsequently investigated in order to investigate prospective tumor therapy approaches. The relationships between NPCs and immune infiltration, immune cells, immunological regulatory substances, and immune pathways were also investigated. Finally, the LUAD and KICH prognostic prediction models were built using univariate and multivariate COX regression analysis. Additionally, the mRNA and protein levels of NPCs were also identified.

trans-Cleavage of the CRISPR-Cas12a-aptamer system for one-step antigen detection.

Rapid detection of prostate-specific antigen (PSA) is pivotal for the early screening of prostate cancer (PCa). Here, we devise a one-step, amplification-free fluorescent detection strategy for PSA, employing the trans-cleavage principle of a CRISPR-Cas12a-aptamer system. This method offers a linear range of 0.31-5 ng mL-1 and a detection limit of 0.16 ng mL-1. The high-confidence quantification of PSA is demonstrated through the analysis of real samples, effectively distinguishing between PCa patients and healthy individuals.

Reactive Oxygen Species-Mediated Mitophagy and Cell Apoptosis are Involved in the Toxicity of Aluminum Chloride Exposure in GC-2spd.

Aluminum chloride is an inorganic polymeric coagulant commonly found in daily life and various materials. Although male reproductive toxicity has been associated with AlCl3 exposure, the underlying mechanism remains unclear. This study aimed to examine the impact of AlCl3 exposure on mitophagy and mitochondrial apoptosis in testicular tissue and mouse spermatocytes. Reactive oxygen species (ROS) and ATP levels were measured in GC-2spd after AlCl3 exposure using a multifunctional enzyme labeler. The changes in mitochondrial membrane potential (MMP) and TUNEL were observed through confocal laser microscopy, and the expression of proteins associated with mitophagy and apoptosis was analyzed using Western blot. Our results demonstrated that AlCl3 exposure disrupted mitophagy and increased apoptosis-related protein expression in testicular tissues. In the in vitro experiments, AlCl3 exposure induced ROS production, suppressed cell viability and ATP production, and caused a decrease in MMP, leading to mitophagy and cell apoptosis in GC-2spd cells. Intervention with N-acetylcysteine (NAC) reduced ROS production and partially restored mitochondrial function, thereby reversing the resulting mitophagy and cell apoptosis. Our findings provide evidence that ROS-mediated mitophagy and cell apoptosis play a crucial role in the toxicity of AlCl3 exposure in GC-2spd. These results contribute to the understanding of male reproductive toxicity caused by AlCl3 exposure and offer a foundation for future research in this area.

A sensitive and rapid electrochemical biosensor for sEV-miRNA detection based on domino-type localized catalytic hairpin assembly.

Small extracellular-vesicule-associated microRNA (sEV-miRNA) is an important biomarker for cancer diagnosis. However, rapid and sensitive detection of low-abundance sEV-miRNA in clinical samples is challenging. Herein, a simple electrochemical biosensor that uses a DNA nanowire to localize catalytic hairpin assembly (CHA), also called domino-type localized catalytic hairpin assembly (DT-LCHA), has been proposed for sEV-miRNA1246 detection. The DT-LCHA offers triple amplification, (i). CHA system was localized in DNA nanowire, which shorten the distance between hairpin substrate, inducing the high collision efficiency of H1 and H2 and domino effect. Then, larger numbers of CHAs were triggered, capture probe bind DT-LCHA by exposed c sites. (ii) The DNA nanowire can load large number of electroactive substance RuHex as amplified electrochemical signal tags. (iii) multiple DT-LCHA was carried by the DNA nanowire, only one CHA was triggered, the DNA nanowire was trapped by the capture probe, which greatly improve the detection sensitivity, especially when the target concentration is extremely low. Owing to the triple signal amplification in this strategy, sEV-miRNA at a concentration of as low as 24.55 aM can be detected in 20 min with good specificity. The accuracy of the measurements was also confirmed using reverse transcription quantitative polymerase chain reaction. Furthermore, the platform showed good performance in discriminating healthy donors from patients with early gastric cancer (area under the curve [AUC]: 0.96) and was equally able to discriminate between benign gastric tumors and early cancers (AUC: 0.77). Thus, the platform has substantial potential in biosensing and clinical diagnosis.

Exploring the diagnostic value, prognostic value, and biological functions of NPC gene family members in hepatocellular carcinoma based on a multi-omics analysis.

Liver cancer is a cunning malignancy with a high incidence and mortality rate among cancers worldwide. The NPC gene family members (NPCs: NPC1, NPC2, and NPC1L1) are closely linked to the development of multiple cancers, but their role in liver cancer remains unclear. As a result, we must investigate their functions in liver hepatocellular carcinoma (LIHC). NPCs were significantly differentially expressed between normal and LIHC tissues, with a high mutation frequency in LIHC. The ROC curve analysis revealed that NPC1/NPC2 had high diagnostic and prognostic values in LIHC. NPC1 expression was also found to be negatively correlated with its methylation level. The differentially expressed genes between high and low NPC1 expression groups in LIHC were mainly related to channel activity, transporter complexes, and plasma membrane adhesion molecules. Additionally, NPC1 expression was significantly associated with multiple immune cells and immunization checkpoints. It was hypothesized that a TUG1/SNHG4-miR-148a-3p-NPC1 regulatory axis is associated with hepatocarcinogenesis. Finally, the protein expression of NPC1 in LIHC tissues and paraneoplastic tissues was detected, and NPC1-knockdown HepG2 cells (NPC1KO) inhibited the proliferation, migration, and invasion. This study helped to identify new prognostic markers and potential immunotherapeutic targets for LIHC and revealed the molecular mechanisms underlying NPC1 regulation in LIHC. The NPCs play a key role in the prognosis and diagnosis of LIHC and may be an important indicator for LIHC prognosis and diagnosis; NPC1 might be a potential therapeutic target in LIHC.

An adhesion-based method for rapid and low-cost isolation of circulating tumor cells.

BACKGROUND: Noninvasive monitoring of cancer through circulating tumor cells (CTCs) is hampered long by unsatisfactory CTCs testing techniques. Efficient isolation of CTCs in a rapid and price-favorable way from billions of leukocytes is crucial for testing. METHODS: We developed a new method based on the stronger adhesive power of CTCs versus leukocytes to sensitively isolate CTCs. Using a BSA-coated microplate and low-speed centrifuge, this method could easily separate cancer cells within 20 min at a very low cost. RESULT: The capture ratio can reach 70.7-86.6% in various cancer cell lines (breast/lung/liver/cervical/colorectal cancer) covering different epithelial-mesenchymal transformation (EMT) phenotypes and cell sizes, demonstrating the potential for efficient pan-cancer CTCs detection. Moreover, the label-free process can well preserve cell viability (∼99%) to fit downstream DNA/RNA sequencing. CONCLUSIONS: A novel technique for non-destructive and rapid enrichment of CTCs has been devised. It has enabled the successful isolation of rare tumor cells in the patient blood sample and pleural effusion, highlighting a promising future of this method in clinical translation.

A simple and sensitive electrochemical biosensor for circulating tumor cell determination based on dual-toehold accelerated catalytic hairpin assembly.

Tumor cells in blood circulation (CTCs) are vital biomarkers for noninvasive cancer diagnosis. We developed a simple and sensitive electrochemical biosensor based on dual-toehold accelerated catalytic hairpin assembly (DCHA) to distinguish CTCs from blood cells. In the presence of CTCs, the aptamer probe initiates the DCHA process, which produces amplified electrochemical signals. Compared with conventional catalytic hairpin assembly (CHA), the proposed DCHA showed high sensitivity, which led to a broader working range of 10-1000 cells mL-1 with a limit of detection of 4 cells mL-1. Furthermore, our method exhibited an excellent capability of distinguishing malignant breast cancers from healthy people, with a sensitivity of 97.4%. In summary, we have established an enzyme-free, easy-to-operate, and nondisruptive method for detecting circulating tumor cells in blood circulation based on the DCHA strategy. Its versatility and simplicity will make it more widely used in clinical diagnosis and biomedical research.

DNA framework carriers with asymmetric hydrophobic drug patterns for enhanced cellular cytotoxicity.

We devise a class of amphiphilic drug complexes by programming hydrophobic drug patterns (HDPs) on DNA frameworks. We investigate the effect of HDPs on cellular uptake efficiency and drug potency. We achieve enhanced cytotoxicity against tumor cells by using an asymmetric HDP.

Potential of Miscanthus floridulus associated with endophytic bacterium Bacillus cereus BL4 to remediate cadmium contaminated soil.

Phytoremediation assisted by endophytic bacteria is promising to efficiently remediate cadmium (Cd) contaminated soil. Bacillus cereus BL4, isolated from Miscanthus floridulus growing around a pyrite mine, exhibited high Cd tolerance and plant growth-promoting traits and could improve Cd bioavailability in soil. As a result of the pot experiment, after inoculation with strain BL4, the fresh weight, height, and Cd accumulation of Miscanthus floridulus shoots increased by 19.08-32.26 %, 6.02-16.60 %, and 23.67 %-24.88 %, respectively, and roots increased by 49.38-56.41 %, 22.87-33.93 %, and 28.51 %-42.37 %, respectively. Under Cd stress, the chlorophyll content, photosynthetic rate, and root activity of Miscanthus floridulus increased, while the membrane permeability and malonaldehyde (MDA) content significantly decreased after the inoculation of BL4, which indicated the alleviation of the cytotoxicity of Cd. Accordingly, the glutathione (GSH) content increased, and the activities of antioxidant enzymes presented downward trends after BL4 inoculation. Cd bioavailability in soil increased after BL4 inoculation, accompanied by increases in the activities of soil enzymes (invertase, urease, alkaline phosphatase, dehydrogenase, FDA hydrolase, and catalase) as well as the richness and diversity of soil bacteria. Our findings revealed that strain BL4 might strengthen the phytoremediation of Cd by Miscanthus floridulus through its effects on plant physio-biochemistry and soil microecology, which provided a basis for the relative application to Cd-contaminated soil.

Localized DNA tetrahedrons assisted catalytic hairpin assembly for the rapid and sensitive profiling of small extracellular vesicle-associated microRNAs.

The profiling of small extracellular vesicle-associated microRNAs (sEV-miRNAs) plays a vital role in cancer diagnosis and monitoring. However, detecting sEV-miRNAs with low expression in clinical samples remains challenging. Herein, we propose a novel electrochemical biosensor using localized DNA tetrahedron-assisted catalytic hairpin assembly (LDT-CHA) for sEV-miRNA determination. The LDT-CHA contained localized DNA tetrahedrons with CHA substrates, leveraging an efficient localized reaction to enable sensitive and rapid sEV-miRNA measurement. Based on the LDT-CHA, the proposed platform can quantitatively detect sEV-miRNA down to 25 aM in 30 min with outstanding specificity. For accurate diagnosis of gastric cancer patients, a combination of LDT-CHA and a panel of four sEV-miRNAs (sEV-miR-1246, sEV-miR-21, sEV-miR-183-5P, and sEV-miR-142-5P) was employed in a gastric cancer cohort. Compared with diagnosis with single sEV-miRNA, the proposed platform demonstrated a higher accuracy of 88.3% for early gastric tumor diagnoses with higher efficiency (AUC: 0.883) and great potential for treatment monitoring. Thus, this study provides a promising method for the bioanalysis and determination of the clinical applications of LDT-CHA.

A portable smartphone-based hemoglobin point-of-care testing platform for accurate anemia diagnostics.

Anemia affects over 2 billion people worldwide, with the heaviest burden borne by women and children. At present, anemia is diagnosed by measuring hemoglobin (Hb) levels, which must be done in hospitals or commercial laboratories by skilled operators. In this work, we report a portable, affordable ($3), easy-to-operate (1 min) and accurate smartphone-based Hb analyzer (SHbA) that uses a drop of finger-pricked blood for anemia point-of-care test (POCT) applications. POCT of Hb was achieved using a smartphone ambient light sensor (ALS) to accurately measure the absorbance of colorimetric Hb biochemical analysis reagents in a microcuvette, as well as an Android-based application for results analysis. SHbA validation results agreed well with those reported by a hematology analyzer, and the SHbA has an anemia diagnosis sensitivity of 95.4% and specificity of 96.3% for venous blood (n = 360) and a sensitivity of 96.39% and specificity of 95.58% for fingertip blood (n = 475). In addition, SHbA exhibits excellent performance in the diagnosis and treatment guidance of anemia high-risk populations, including tumor chemotherapy patients (n = 424), pregnant women (n = 214) and thalassemia patients (n = 208). Importantly, volunteer self-testing results (n = 20) indicate that SHbA can be used for home-based anemia diagnosis and monitoring. SHbA has the advantages of high sensitivity and specificity while being cheap and easy to operate, making it widely applicable for the diagnosis and treatment of anemia, especially for high-risk patients in areas with poor medical resources.

Image Analysis of TVCDS in Infertile Patients with Polycystic Ovary Syndrome.

In order to analyze and examine the TVCDS images of infertile patients, this paper conducted an in-depth study based on the symptoms of polycystic ovary syndrome. Through the sample size estimation method, mathematical analysis, and other methods, the image examination of the polycystic ovary in TVCDS was successfully analyzed. 86 cases of infertile patients with PCS were divided into a control group treated with clomiphene alone and an observation group treated with clomiphene combined with TCM periodic therapy, with 43 patients in each group. The therapeutic effects of the two groups were compared and analyzed. Results show that the treatment effective rate and pregnancy success rate of the observation group were 95.35% and 88.37%, respectively, and those of the control group were 83.72% and 76.74%, respectively. The difference between the two groups was statistically significant (P < 0.05). It was understood that the main pathogenesis of polycystic ovary syndrome is the abnormal balance of kidney, qi, and blood meridians. Thus, the balance of kidney-anemone-chong Ren-uprisal is broken and the result is infertility symptoms or irregular menstruation. After a study on TVCDS in infertile patients, it was observed that the levels of progesterone (P) and luteinizing hormone (LH) in patients with irregular menstruation were significantly increased. The increase was higher than that in the control group, with an overall negative rate of 4.00%, compared with 18.00% of the control group, showing a significant difference. It also indicates that TVCDS image examination has a very significant effect on improving menstrual irregularities and reducing the incidence of adverse reactions.

Micro-dynamic process of cadmium removal by microbial induced carbonate precipitation.

Microbially induced carbonate precipitation (MICP) is a technique used extensively to address heavy metal pollution but its micro-dynamic process remains rarely explored. In this study, A novel Cd-tolerant ureolytic bacterium DL-1 (Pseudochrobactrum sp.) was used to study the micro-dynamic process. With conditions optimized by response surface methodology, the removal efficiency of Cd2+ could achieve 99.89%. Three components were separated and characterized in the reaction mixture of Cd2+ removal by MICP. The quantitative-dynamic distribution of Cd2+ in different components was revealed. Five synergistic effects for Cd2+ removal were found, including co-precipitation, adsorption by precipitation, crystal precipitation on the cell surface, intracellular accumulation and extracellular chemisorption. Importantly, during Cd2+ removal by MICP, the phenomenon that crystalline nanoparticles adhere to the cell surface, but without any micrometer-sized precipitation encapsulated bacterial cells was observed. This indicated that the previously studied model of bacterial cells as nucleation sites for metal cation precipitation and crystal growth is oversimplified. Our findings provided valuable insights into the mechanism of heavy metals removal by MICP, and a more straightforward method for studying biomineralization-related dynamic process.

Tetrahedral framework nucleic acids linked CRISPR/Cas13a signal amplification system for rare tumor cell detection.

The sensitive and accurate detection of rare tumor cells provides precise diagnosis and dynamic assessment information in various tumor spectrums. However, rare tumor cells assay is still a challenge due to the exceedingly rare presence in the blood. In this research, we develop a fluorescent approach for the identification of rare tumor cells based on a combination of immunosorbent capture and a three-step signal amplification strategy. First, rare tumor cells are captured by immunoadsorption on 96-well plates. Second, self-synthesized tetrahedral framework nucleic acids (tFNAs) spontaneously anchor into the lipid bilayer of rare tumor cells, resulting in a "one to more" amplification effect. Then, the double-stranded DNA (dsDNA) binds to the vertices of the tFNAs and generates a large amount of target RNA by T7 polymerase, which is the secondary signal amplification. Finally, the target RNA activates the collateral cleavage ability of CRISPR/Cas13a, and the reporter RNA is cleaved for third signal amplification. The detection limit of the proposed method is down to 1 cell mL-1. Furthermore, the tFNAs-Cas13a system is also shown to be capable of detecting rare tumor cells in spiked-in samples and clinical blood samples. This platform enables speedy detection of rare tumor cells with high sensitivity and good specificity, and shows great potential for tumor diagnosis.

DNA Nanowire Guided-Catalyzed Hairpin Assembly Nanoprobe for In Situ Profiling of Circulating Extracellular Vesicle-Associated MicroRNAs.

Extracellular vesicle-associated miRNAs (EV-miRNAs) are emerging as a new type of noninvasive biomarker for disease diagnosis. Their relatively low abundance, however, makes accurate detection challenging. Here, we designed a DNA nanowire guided-catalyzed hairpin assembly (NgCHA) nanoprobe for profiling EV-miRNAs. NgCHA showed high penetrability to EVs, which allowed rapid delivery of the probes into EVs. In the presence of targeted miRNAs within EVs, a fluorescent signal could be generated and amplified by confining the catalytic hairpin assembly system within the nanowires, thus greatly enhancing the analytical sensitivity. We showed that EV-miRNAs from various cell lines could be accurately quantified by NgCHA in situ. By using a four-EV-miRNA panel, this platform can identify patients with breast cancer at an early stage with 95.2% sensitivity and 86.7% specificity. Its applications for risk assessment as well as cancer type prediction were also successfully demonstrated. This platform is sensitive, low-cost, and simple compared with current methods. It may thus serve as a promising tool for the noninvasive diagnosis and monitoring of cancers and other diseases through EV-miRNA profiling.

Unbiased Enrichment of Circulating Tumor Cells Via DNAzyme-Catalyzed Proximal Protein Biotinylation.

Circulating tumor cells (CTCs) are noninvasive biomarkers with great potential for assessing neoplastic diseases. However, the enrichment bias toward heterogeneous CTCs remains to be minimized. Herein, a DNAzyme-catalyzed proximal protein biotinylation (DPPB) strategy is established for unbiased CTCs enrichment, employing DNA-framework-based, aptamer-coupled DNAzymes that bind to the surface marker of CTCs and subsequently biotinylated membrane proteins in situ. The DNA framework enables the construction of multivalent DNAzyme and serves as steric hindrance to avoid undesired interaction between DNAzymes and aptamer, leading to efficient binding and biotinylation. Compared with a biotinylated-aptamer strategy, fivefold lower bias of cell subpopulations was achieved by DPPB before and after capture, which enabled a 4.6-fold performance for CTCs analysis in clinic blood samples. DPPB is envisioned to offer a new solution for CTC-based cancer diagnostics.