Liquid-colloid-solid modular assembly for three-dimensional electrochemical biosensing of small molecules.

Electrochemical biosensors hold promise for advanced analytical applications in modern life analysis due to their miniaturization and cost-effectiveness. Nevertheless, their implementation in complex biological systems necessitates overcoming challenges related to timeliness, sensitivity, and interference resistance. Here, we developed a novel DNA hydrogel three-dimensional electron transporter through liquid-colloid-solid assembly, integrating electronic mediators and employing porous electrode covers with 3D printing technology. Our approach facilitated the fabrication of a high-performance electrochemical sensor for small molecule detection, leveraging target-specific aptamers and catalytic hairpin assembly (CHA) elements within the DNA hydrogel, which exhibited outstanding selectivity, sensitivity, and universality, achieving detection limits of 0.047 nM for kanamycin and 2.67 pM for ATP. Furthermore, this sensor could detect kanamycin in real samples, demonstrating good accuracy and robust anti-interference capabilities in human serum. Our work not only possesses substantial application value in clinical sample analysis but also represents a breakthrough in traditional strategies, thereby contributing to advancements in the application of electrochemical biosensors for life analysis.

Tumor-associated antigen-specific cell imaging based on upconversion luminescence and nucleic acid rolling circle amplification.

Tumor-associated antigen (TAA)-based diagnosis has gained prominence for early tumor screening, treatment monitoring, prognostic assessment, and minimal residual disease detection. However, limitations such as low sensitivity and difficulty in extracting non-specific binding membrane proteins still exist in traditional detection methods. Upconversion luminescence (UCL) exhibits unique physical and chemical properties under wavelength near-infrared light excitation. Rolling circle amplification (RCA) is an efficient DNA amplification technique with amplification factors as high as 105. Therefore, the above two excellent techniques can be employed for highly accurate imaging analysis of tumor cells. Herein, we developed a novel nanoplatform for TAA-specific cell imaging based on UCL and RCA technology. An aptamer-primer complex selectively binds to Mucin 1 (MUC1), one of TAA on cell surface, to trigger RCA reaction, generating a large number of repetitive sequences. These sequences provide lots of binding sites for complementary signal probes, producing UCL from lanthanide-doped upconversion nanoparticles (UCNPs) after releasing quencher group. The experimental results demonstrate the specific attachment of upconversion nanomaterials to cancer cells which express a high level of MUC1, indicating the potential of UCNPs and RCA in tumor imaging.

Urine-derived exosomes and their role in modulating uroepithelial cells to prevent hypospadias.

PURPOSE: Urethral hypospadias, a common congenital malformation in males, is closely linked with disruptions in uroepithelial cell (UEC) processes. Evidence exists reporting that urine-derived exosomes (Urine-Exos) enhance UEC proliferation and regeneration, suggesting a potential role in preventing hypospadias. However, the specific influence of Urine-Exos on urethral hypospadias and the molecular mechanisms involved are not fully understood. This study focuses on investigating the capability of Urine-Exos to mitigate urethral hypospadias and aims to uncover the underlying molecular mechanisms. METHODS: Bioinformatics analysis was performed to identify key gene targets in Urine-Exos potentially involved in hypospadias. Subsequent in vitro and in vivo experiments were conducted to validate the regulatory effects of Urine-Exos on hypospadias. RESULTS: Bioinformatics screening revealed syndecan-1 (SDC1) as a potential pivotal gene for the prevention of hypospadias. In vitro experiments demonstrated that Urine-Exos enhanced the proliferation and migration of UECs by transferring SDC1 and inhibiting cell apoptosis. Notably, Urine-Exos upregulated ß-catenin expression through SDC1 transfer, further promoting UEC proliferation and migration. These findings were confirmed in a congenital hypospadias rat model induced by di(2-ethylhexyl) phthalate (DEHP). CONCLUSION: This study reveals the therapeutic potential of Urine-Exos in hypospadias, mediated by the SDC1/ß-catenin axis. Urine-Exos promote UEC proliferation and migration, thereby inhibiting the progression of hypospadias. These findings offer new insights and potential therapeutic targets for the management of congenital malformations.

Metabolic Glycoengineering-Programmed Nondestructive Capture of Circulating Tumor Cells.

Circulating tumor cells (CTCs) are the "seeds" for malignant tumor metastasis, and they serve as an ideal target for minimally invasive tumor diagnosis. Abnormal glycolysis in tumor cells, characterized by glycometabolism disorder, has been reported as a universal phenomenon observed in various types of tumors. This provides a potential powerful tool for universal CTC capture. However, to the best of our knowledge, no metabolic glycoengineering-based CTC capture strategies have been reported. Here, we proposed a nondestructive CTC capture method based on metabolic glycoengineering and a nanotechnology-based proximity effect, allowing for highly specific, sensitive, and universal CTC capture. To achieve this goal, cells are first labeled with DNA tags through metabolic glycoengineering and then captured through a DNA tetrahedra-functionalized dual-tentacle magnetic nanodevice. Due to the difference in metabolic performance, only tumor cells are labeled with more densely packed DNA tags and captured through enhanced intermolecular interaction mediated by the proximity effect. In summary, we have constructed a versatile platform for nondestructive CTC capture, offering a novel perspective for the application of CTC liquid biopsy in tumor diagnosis and treatment.

Establishment of Digital PCR Method and Reference Material for Adenoviruses 40 and 41.

Coinfection with human adenovirus (HAdV) and SARS-CoV-2 has been associated with acute hepatitis in children with unknown etiology. Similar cases have been reported in many countries, and HAdV 40 and HAdV 41 have been identified. The quantification method is established based on digital PCR (dPCR) for HAdV 40/41, which is more convenient for low-concentration virus detection. The limit of detections of HAdV 40/41 dPCR were 4 and 5 copies/µL. Pseudovirus reference material (RM) that contains the highly conserved HEXON gene was developed and quantified with the dPCR method. The assigned values with expanded uncertainty were (1.43 ± 0.35) × 103 copies/µL for HAdV 40 RM and (1.21 ± 0.28) × 103 copies/µL for HAdV 41 RM. The values could be reproduced on multiple platforms. The dPCR method and pseudovirus RMs contribute to the improved accuracy of HAdV 40/41 detection, which is crucial for clinical diagnosis.

Comprehensive analysis of the RSK gene family in acute myeloid leukemia determines a prognostic signature for the prediction of clinical prognosis and treatment responses.

OBJECTIVE: The prognosis of acute myeloid leukemia (AML) remains poor although the basic and translational research has been highly productive in understanding the genetics and pathopoiesis of AML and a plethora of targeted therapies have been developed. Consequently, it is crucial to deepen the knowledge of molecular pathogenesis underlying AML for the advancement of new treatment options. METHOD: A RSK gene family-related signature was constructed to investigate whether RSK gene family members were useful in predicting the prognosis of AML patients. The relationship between the RSK gene family-related signature and the infiltration of immune cells was further assessed using the CIBERSORT algorithm. The 'oncoPredict' package was used to analyze relationships between the RSK gene family-related signature and the sensitivity to drugs or small molecules. RESULTS: Patients were classified into two groups using the RSK gene family-related signature following the median risk score. Overall survival (OS) was significantly longer in patients with low-risk scores than that in patients with high-risk scores as showed by both training and validation datasets. Moreover, the signature was helpful in predicting 1-year, 3-year, and 5-year OS in training and validation datasets. In addition, it was identified that low-risk patients exhibited greater sensitivity to 20 drugs or small molecules and that high-risk patients had higher sensitivity to 38 drugs or small molecules. CONCLUSION: RSK gene family members, particularly RPS6KA1 and RPS6KA4, may help to predict prognosis for AML patients. Furthermore, RPS6KA1 may serve as a novel drug target for AML.

The Role of Nomogram Based on the Combination of Ultrasound Parameters and Clinical Indicators in the Degree of Pathological Remission of Breast Cancer.

Background: The mortality rate of breast cancer (BC) ranks first among female tumors worldwide and presents a trend of younger age, which poses a great threat to women's health and life. Neoadjuvant chemotherapy (NAC) for breast cancer is defined as the first step of treatment for breast cancer patients without distant metastasis before planned surgical treatment or local treatment with surgery and radiotherapy. According to the current NCCN guidelines, patients with different molecular types of BC should receive neoadjuvant chemotherapy (NAC), which can not only achieve tumor downstaging, increase the chance of surgery, and improve the breast-conserving rate. In addition, it can identify new genetic pathways and drugs related to cancer, improve patient survival rate, and make new progress in breast cancer management. Objective: To explore the role of the nomogram established by the combination of ultrasound parameters and clinical indicators in the degree of pathological remission of breast cancer. Methods: A total of 147 breast cancer patients who received neoadjuvant chemotherapy and elective surgery in the Department of Ultrasound, Nantong Cancer Hospital, from May 2014 to August 2021 were retrospectively included. Postoperative pathological remission was divided into two groups according to Miller-Payne classification: no significant remission group (NMHR group, n = 93) and significant remission group (MHR group, n = 54). Clinical characteristics of patients were recorded and collected. The multivariate logistic regression model was used to screen the information features related to the MHR group, and then, a nomogram model was constructed; ROC curve area, consistency index (C-index, CI), calibration curve, and H-L test were used to evaluate the model. And the decision curve is used to compare the net income of the single model and composite model. Results: Among 147 breast cancer patients, 54 (36.7%) had pathological remission. Multivariate logistic regression showed that ER, reduction/disappearance of strong echo halo, Adler classification after NAC, PR + CR, and morphological changes were independent risk factors for pathological remission (P < 0.05). Based on these factors, the nomogram was constructed and verified. The area under the curve (AUC) and CI were 0.966, the sensitivity and specificity were 96.15% and 92.31%, and the positive predictive value (PPV) and negative predictive value (NPV) were 87.72% and 97.15%, respectively. The mean absolute error of the agreement between the predicted value and the real value is 0.026, and the predicted risk is close to the actual risk. In the range of HRT of about 0.0∼0.9, the net benefit of the composite evaluation model is higher than that of the single model. H-L test results showed that χ 2 = 8.430, P=0.393 > 0.05. Conclusion: The nomogram model established by combining the changes of ultrasound parameters and clinical indicators is a practical and convenient prediction model, which has a certain value in predicting the degree of pathological remission after neoadjuvant chemotherapy.

Recent advances in tumor biomarker detection by lanthanide upconversion nanoparticles.

Early tumor diagnosis could reliably predict the behavior of tumors and significantly reduce their mortality. Due to the response to early cancerous changes at the molecular or cellular level, tumor biomarkers, including small molecules, proteins, nucleic acids, exosomes, and circulating tumor cells, have been employed as powerful tools for early cancer diagnosis. Therefore, exploring new approaches to detect tumor biomarkers has attracted a great deal of research interest. Lanthanide upconversion nanoparticles (UCNPs) provide numerous opportunities for bioanalytical applications. When excited by low-energy near-infrared light, UCNPs exhibit several unique properties, such as large anti-Stoke shifts, sharp emission lines, long luminescence lifetimes, resistance to photobleaching, and the absence of autofluorescence. Based on these excellent properties, UCNPs have demonstrated great sensitivity and selectivity in detecting tumor biomarkers. In this review, an overview of recent advances in tumor biomarker detection using UCNPs has been presented. The key aspects of this review include detection mechanisms, applications in vitro and in vivo, challenges, and perspectives of UCNP-based tumor biomarker detection.

Effect of Fraxetin on Oxidative Damage Caused by Isoproterenol-Induced Myocardial Infarction in Rats.

At present, cardiovascular disorders are the most prominent factors for the high morbidity rate globally. The occurrence of myocardial infarction followed by myocardial ischemia is the important cause of high death rates. Various medical treatments are available, yet the mortality and morbidity rate is high. In the present investigation, the cardioprotective property of fraxetin (Fx) is evaluated in myocardial infarction-induced experimental rats. Fraxetin, a phytochemical known as coumarin isolated from Fraxinus rhynchophylla. Fraxetin has numerous pharmacological activities including antioxidant, apoptosis inhibitor, anti-inflammatory, and antimicrobial agent. The experimental mice were split into 4 groups each comprising six animals. Group I was considered the control group; 0.1% NaCl solution was given as dosage. Group II received only Fx; group III was treated with ISO. Group IV was treated with Fx followed by ISO to induce myocardial infarction. In ISO administrated rats, there were changes in the heart weight, activities of cardiac markers, transmembrane protein activity, antioxidant enzymes, pro-inflammatory proteins, lipid profile, and myocardial structures. Pre-treatment of fraxetin in group IV experimental rats resulted in decreased cardiac weight, diminished level of cardiac markers (cardiac troponin T (cTnT), creatine kinase, creatine kinase-MB, and cardiac troponin I (cTnI)), reduced level of oxidative stress biomarkers (LOOH and TBARS) in the plasma and cardiac tissue, amplified level of enzymes in antioxidant defense system (catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GPx)) in the plasma and heart tissue, and elevated level of ATPase activities. The histopathological studies also revealed the potent activity of fraxetin in protecting the cardiac tissues from inflammation and damage. ISO-administrated experimental rats treated with fraxetin exhibit increased antioxidants activity and decreased free radicals. Our study revealed that the administration of fraxetin significantly reduced the extent of myocardial damage during myocardial infarction in rats caused by isoproterenol. Thus, the results prove the cardioprotective effect of fraxetin in MI-induced rats.

Smartly responsive DNA-miRNA hybrids packaged in exosomes for synergistic enhancement of cancer cell apoptosis.

Endogenous and exogenous tumor-related microRNAs (miRNAs) are considered promising tumor biomarkers and tumor therapeutic agents. In this work, we propose a miRNA self-responsive drug delivery system (miR-SR DDS), which enables the association between endogenous and exogenous miRNAs, so as to achieve a smart responsive and synergistic drug delivery. The miR-SR DDS consists of DNA-miRNA hybrids of let-7a and the complementary DNA of miR-155, which was packaged in exosomes. In response to the overexpressed miR-155 in breast cancer cells, the hybrids disintegrate and release let-7a and the complementary DNA of miR-155 to inhibit the expression of HMGA1 and relieve the inhibition of SOX1, respectively. Under the dual-targeted gene regulation, results show that the growth, migration and invasion of breast cancer cells can be synergistically inhibited through the Wnt/ß-catenin signaling pathway. The concept and successful practice of the miR-SR DDS can be used as a reference for the development of miRNA drugs.

Single-Cell Analysis of Highly Metastatic Circulating Tumor Cells by Combining a Self-Folding Induced Release Reaction with a Cell Capture Microchip.

Nondestructive analysis of the single-cell molecular phenotype of circulating tumor cells (CTCs) is of great significance to the precise diagnosis and treatment of cancer but is also a huge challenge. To address this issue, here, we develop a facile analysis system that integrates CTCs' capture and molecular phenotype analysis. An isothermal nucleic acid amplification technique named self-folding induced release reaction (sFiR), which has high-efficiency signal amplification capabilities and can run under physiological conditions, is first developed to meet the high requirements for sensitivity and nondestructivity. By combining the sFiR with immune recognition and a single cell capture microchip, the molecular phenotype analysis of a single CTC is realized. As a model, nondestructive analysis of junction plakoglobin (JUP), an overexpressed membrane protein that is closely related to the metastasis of CTCs, is successfully achieved. Results reveal that this sFiR-based analysis system can clearly distinguish the expression of JUP in different cancer cell lines and can present quantitative information on the expression of JUP. Furthermore, the captured and analyzed CTCs maintain their basic physiological activity and can be used for drug sensitivity testing. Considering the excellent performance and ease of operation of the system, it can provide technical support for CTC-based cancer liquid biopsy and drug development.

Treatment Patterns and Health Care Costs in Commercially Insured Patients with Follicular Lymphoma.

BACKGROUND: Few studies have estimated the real-world economic burden such as all-cause and follicular lymphoma (FL)-related costs and health care resource utilization (HCRU) in patients with FL. OBJECTIVES: This study evaluated outcomes in patients who were newly initiated with FL indicated regimens by line of therapy with real-world data. METHODS: A retrospective study was conducted among patients with FL from MarketScan® databases between January 1, 2010 and December 31, 2013. Patients were selected if they were ≥18 years old when initiated on a FL indicated therapy, had at least 1 FL-related diagnosis, ≥1 FL commonly prescribed systemic anti-cancer therapy after diagnosis, and did not use any FL indicated regimen in the 24 months prior to the first agent. These patients were followed up at least 48 months and the outcomes, including the distribution of regimens by line of therapy, the treatment duration by line of therapy, all-cause and FL-related costs, and HCRU by line of therapy were evaluated. RESULTS: This study identified 598 patients who initiated FL indicated treatment. The average follow-up time was approximately 5.7 years. Of these patients, 50.2% (n=300) were female, with a mean age of 60.7 years (SD=13.1 years) when initiating their treatment with FL indicated regimens. Overall, 598 (100%) patients received first-line therapy, 180 (43.6%) received second-line therapy, 51 received third-line therapy, 21 received fourth-line therapy, and 10 received fifth-line therapy. Duration of treatment by each line of therapy was 370 days, 392 days, 162 days, 148 days, and 88 days, respectively. The most common first-line regimens received by patients were rituximab (n=201, 33.6%), R-CHOP (combination of rituximab, cyclophosphamide, doxorubicin hydrochloride [hydroxydaunomycin]; n=143, 24.0%), BR (combination of bendamustine and rituximab; n=143, 24.0%), and R-CVP (combination of rituximab, cyclophosphamide, vincristine, and prednisone; n=71, 11.9%). The most common second-line treatment regimens were (N=180): rituximab (n=78, 43.3%) and BR (n=41, 22.8%). Annualized all-cause health care costs per patient ranged from US$97 141 (SD: US$144 730) for first-line to US$424 758 (SD: US$715 028) for fifth-line therapy. CONCLUSIONS: The primary regimens used across treatment lines conform to those recommended by the National Comprehensive Cancer Network clinical practice guidelines. The economic burden for patients with FL is high and grows with subsequent lines of therapy.

A proximity-exponential hybridization chain reaction (PEHCR) and its application for nondestructive analysis of membrane protein-protein interactions on living cells.

Though a variety of methods have been developed for the analysis of membrane protein-protein interactions (PPIs), amplified, dynamic and nondestructive analysis in situ is always a challenge. To address this issue, here we develop a method called proximity-exponential hybridization chain reaction (PEHCR). In our strategy, when two membrane proteins approach due to interaction, they will draw their respective oligonucleotide-labeled antibodies together. The proximity of the oligonucleotides thereafter triggers a well-designed enzyme-free exponential hybridization chain reaction, which can output amplified fluorescence imaging signals. As a model, analysis of EGFR-HER2 interactions under the regulation of different activators and inhibitors is achieved. Owing to the superior signal amplification performance, we are able to clearly observe the membrane PPIs by using a common fluorescence microscope. Furthermore, unlike the existing proximity techniques that require enzymes, our enzyme-free strategy avoids the need to use a specific buffer suitable for enzyme catalysis and can be run directly in cell liquid media to maximize the physiological activity of the cells. So, dynamic analysis of membrane PPIs on living cells is achieved, and the cells, after the analysis, are still alive and are available for other usage. The successful implementation of this work enriches the toolbox for the study of membrane PPIs especially on those heterogeneous cell populations with small amount.

Comprehensive study of the interaction between Puerariae Radix flavonoids and DNA: From theoretical simulation to structural analysis to functional analysis.

Puerariae Radix (PR) is a natural herb whose active ingredient is mainly flavonoids. To explore the interaction between PR flavonoids and DNA not only has important biological implications for understanding the mechanism of action, but also helps develop PR products for the design of appropriate dietary interventions to aid cancer treatment. In this work, we comprehensively studied the interaction between six kinds of PR flavonoids and DNA from four different and progressive levels, including molecular docking, multi-spectral analysis, and functional analysis in vitro and in cell. Results show that the DNA binding affinity of six flavonoids is in an order of quercetin > formononetin > daidzein > puerarin > 4'-methoxy puerarin > puerarin 6″-O-xyloside (POS), in which quercetin can significantly inhibit DNA amplification owing to its strongest binding affinity. The binding between quercetin and DNA is further revealed to be intercalated binding, which can cause conformational changes in DNA, thereby exhibiting an activity of cell cycle arrest and anti-proliferative. This property of quercetin can be utilized for the further development of flavonoids with anticancer activity. In addition to the potential application, this work also provides a platform for the comprehensive study of the interaction between micromolecules and DNA.

Exponential amplification reaction and triplex DNA mediated aggregation of gold nanoparticles for sensitive colorimetric detection of microRNA.

Abnormal expression of specific microRNAs (miRNAs) is associated with the occurrence, development and prognosis of many diseases. In this study, a miRNA detection method based on exponential amplification reaction (EXPAR) and triplex DNA mediated aggregation of gold nanoparticles (AuNPs) was established. Specifically, one class of AuNPs is conjugated with an EXPAR probe, on which there is a complementary sequence of the target miRNA. The EXPAR reaction is triggered and duplex DNA is formed on the surface of AuNPs when the target miRNA exists. Then, single DNA probe on another class of AuNPs interacts with the duplex DNA to form triplex DNA, leading to the aggregation of the two classes of AuNPs, which could be quantified by UV-vis. The proposed method is highly selective and can afford a detection limit of 0.23 fM. Notably, all the ingredients needed for the analysis can pre-add to a tube and only 30 min is needed for the whole detection process. The method is simple, fast and with considerable selectivity and accuracy, so a great potential for this method is expected to meet the need of point-of-care testing of miRNA.

A nanoflow cytometric strategy for sensitive ctDNA detection via magnetic separation and DNA self-assembly.

Circulating tumor DNA (ctDNA) is a tumor-derived fragmented DNA in the bloodstream that is not associated with cells. It has been greatly focused in the recent decade because of its potential clinical utility for liquid biopsies. Development of ctDNA analytical techniques with high sensitivity and cost-efficiency will undoubtedly promote the clinical spread of ctDNA testing. In this paper, we propose a novel flow cytometry-based ctDNA sensing strategy which combines enzyme-free amplification and magnetic separation. The target DNA is capable of triggering a hybridization chain reaction, producing a fluorescent long linear assembly of DNA, which can be further captured by magnetic beads to present fluorescent signals using flow cytometry. In comparison with some conventional methods, our strategy has the advantages of easy operation and cost-efficiency, and thereby shows a promising application in clinical diagnosis. Graphical abstract.

Triplex DNA Nanoswitch for pH-Sensitive Release of Multiple Cancer Drugs.

A DNA-based stimulus-responsive drug delivery system for synergetic cancer therapy has been developed. The system is built on a triplex-DNA nanoswitch capable of precisely responding to pH variations in the range of ∼5.0-7.0. In extracellular neutral pH space, the DNA nanoswitch keeps a linear conformation, immobilizing multiple therapeutics such as small molecules and antisense compounds simultaneously. Following targeted cancer cell uptake via endocytosis, the nanoswitch inside acidic intracellular compartments goes through a conformational change from linear to triplex, leading to smart release of the therapeutic combination. This stimuli-responsive drug delivery system does not rely on artificial responsive materials, making it biocompatible. Furthermore, it enables simultaneous delivery of multiple therapeutics for enhanced efficacy. Using tumor-bearing mouse models, we show efficient gene silencing and significant inhibition of tumor growth upon intravenous administration of the smart nanoswitch, providing opportunities for combinatorial cancer therapy.

Curcumin suppresses wilms' tumor metastasis by inhibiting RECK methylation.

Wilms' tumor (WT) is the most common kidney tumor of children. The transformation suppressor gene RECK, which codes membrane-anchored glycoprotein, frequently downregulates multiple matrix metalloproteinases in tumors. And curcumin, which is a polyphenlic compound separated from turmeric, has antitumor effects on various cancers. However, the correlation of WT, RECK and curcumin is still unrevealed. In this study, we evaluated that the methylation degree of RECK was much higher in WT than in adjacent non-tumor tissues. And RECK methylation was closely associated with tumor metastasis in WT patients. After curcumin treatment, the level of RECK methylation was decreased significantly. And the expression of MMP2 and MMP9 was reduced consequently. Moreover, the proliferation, invasion and migration ability of WT cells were suppressed after curcumin treatment. Meanwhile, the apoptosis rate of WT cells was increased simultaneously. In nude mice model, curcumin restrained ability of tumorigenicity and promoted apoptosis of WT cells. Together, our results suggest that the RECK methylation can serve as a prognostic biomarker of WT. Moreover, curcumin could inhibit RECK methylation, thereby abates the expression of MMPs, and suppresses the tumor progression and metastasis of WT.

Oligoarginine mediated collagen/chitosan gel composite for cutaneous wound healing.

In this study, the collagen/chitosan gel composite supplemented with a cell-penetrating peptide (CPP) (Oligoarginine, R8) was prepared. Then, the physicochemical properties of the new collagen/chitosan/CPPs gel obtained were analyzed and the related characteristics were evaluated by scanning electron microscopy (SEM), fourier transform infrared (FTIR), differential scanning calorimetry (DSC), differential thermal analyzer (DTA). Furthermore, we found that collagen/chitosan/CPPs gel composite was capable of inhibiting Staphylococcus aureus growth and had good ability to heal wounds. The mice test results showed that collagen/chitosan/CPPs gel had the highest healing rate, fastest healing speed in all the treatments. After 14 days, the group treated by collagen/chitosan/CPPs gel showed nearly complete wound surface healing rate of 98 ±â€¯4.71%. In addition, histopathological examination suggested that collagen/chitosan/CPPs could promote cutaneous wound healing through enhancing granulation tissue formation, increasing collagen deposition and promoting angiogenesis in the wound tissue. Meanwhile, no significant cytotoxicity of the gel was observed. In conclusion, the collagen/chitosan/CPPs gel composite which has antibacterial activity renders a high therapeutic efficiency to heal wounds.

Catalytic hairpin assembly-programmed formation of clickable nucleic acids for electrochemical detection of liver cancer related short gene.

DNA amplification usually takes place in an aqueous system to facilitate a highly efficient reaction. Therefore, it is a challenge to connect the DNA amplification with popular dry chemical methods, whose signal outputs usually come from a solid-liquid interface. Here, by linking catalytic hairpin assembly (CHA) with electrochemical biosensors through clickable nucleic acids, we develop a facile method for the detection of liver cancer related short gene MXR7. On one hand, the method maintains the advantages of CHA especially its high efficiency by performing the whole process of CHA in aqueous phase. On the other hand, the method realizes electrochemical detection of MXR7 by transferring a clickable double-helix production of MXR7-triggerd CHA to a dibenzocyclooctyne-functionalized electrode quickly through copper-free click chemistry. In comparison with traditional biotin-streptavidin or hybridization-assisted conjugation, the click chemistry allows quick response in a quarter of an hour, shortening the detection time greatly. In addition, owing to the lower steric hindrance as compared with streptavidin, the signal intensity is strong, making a sensitive detection possible. The detection limit reaches 125 fM, better than previous electrochemical methods. Results also reveal that CHA in solution has much better efficiency than that on interface, allowing two orders of magnitude improvement in detection limit (125 fM vs. 50 pM) with a shorter detection time (135 min vs. 165 min). This work also provides a novel concept to connect aqueous amplification system with interfacial detection method for other bio-analysis.