Exploring the boost of steaming with wine on Ligustri Lucidi Fructus in treating postmenopausal osteoporosis based on superior "multi-component structure" and iron/bone metabolism coregulation.

BACKGROUND: Clinical studies indicated that postmenopausal osteoporosis (PMOP) often accompanied by iron overload risk factor, which exacerbated bone metabolism disorders and accelerated PMOP. Previous research found that multicomponent in Ligustri Lucidi Fructus (FLL) or wine-steamed FLL (WFLL) acted on the common targets of iron overload and PMOP simultaneously, which indicated that FLL and WFLL probably regulated iron/bone metabolism dually. Additionally, WFLL had more superior effect according to the theory of Chinese medicine for thousands of years. PURPOSE: To reveal the "superior multi-component structure (SMCS)" and its molecular mechanisms in parallelly down-regulating iron overload and rescuing bone metabolism by WFLL. DESIGNS AND METHODS: HPLC fingerprinting was established to compare the chemical profiles of FLL and WFLL; Then, the chemical compositions and quality markers of FLL and WFLL were analyzed by UPLC-Orbitrap-MS/MS coupled with OPLS-DA; the dynamic contents of quality markers and the multi-component structure at different wine steaming times (WST) were simultaneously determined by HPLC-DAD. Meanwhile, the dynamic efficacy of FLL at different WST were hunt by systematic zebrafish model. Subsequently, potential mechanism of WFLL in treating PMOP accompanied with iron overload was obtained from network pharmacology (NP) and molecular docking (MD). Finally, zebrafish and ovariectomy rat model were carried out to validate this potential mechanism. RESULTS: HPLC fingerprints similarity of 15 batches in FLL and WFLL were among 0.9-1.0. 126 compositions were identified, including 58 iridoids, 25 terpenes, 30 phenylethanoids, 7 flavonoids and 6 others. 20 quality markers associated with WFLL was revealed, and the ratio of phenylethanols: Iridoids: Triterpenes (P/I/T) was converted from 1: 15: 4.5 to 1: 0.8: 0.9 during steaming (0 - 24 h) calculated by the quantification of 11 quality markers; the bone mineralization and motor performance of zebrafish larvae indicated that the optimum efficacy of WFLL at 12 h (p < 0.05) in which the SMCS of P/I/T was converted to 1: 4: 1.8. NP discovered that BMP-Smad pathway is one of the potential mechanisms of FLL in anti PMOP and then regulated bone formation and iron overload simultaneously. MD revealed that 17 active ingredients and 10 core targets genes could spontaneously bind with appropriate affinity. Rats model verified that FLL and WFLL significantly reversed PMOP, based on the improvement in bone formation indexes (ALP, OPG, OGN), iron metabolism indicators (hepcidin, ferritin), bone microstructure (BMD, BV/TV, Tb. Th, Tb. N); Moreover, WFLL significant enhanced reversal effect in anti-PMOP compared to FLL (p < 0.05). FLL and WFLL increased genes and proteins expression (Hep, BMP-6, p-Smad1/5, Smad4) related to BMP-Smad pathway compared with model group, and WFLL was more superior than FLL (p< 0.05). CONCLUSION: The SMCS of FLL was optimized by wine-steam, WFLL represented a dual effect in downregulating iron overload and promoting bone formation, and the BMP-Smad pathway is one of the potential molecular mechanisms.

Investigation of the Functional Requirements and Influencing Factors of Self-management App Use in Patients with Diabetes Mellitus.

Objective: Diabetes self-management apps can provide convenient and personalized health information and reduce glycosylated haemoglobin, weight, the occurrence of severe hypoglycaemia and disease burden. This study aims to describe the attitudes towards and needs of self-management apps among diabetic patients in China. Methods: A self-administered cross-sectional survey was offered to patients in Changzhou from March to December 2021. Participants were included if they were≥ 18 years old, had the ability to read and write, and completed the questionnaire independently. Responses were summarized using descriptive statistics. Multiple logistic regression analysis was used to identify factors associated with attitudes towards the use of self-management apps. Results: We surveyed 615 diabetes patients and found that 60% of the patients were willing to use self-management applications. The scores indicating importance of functional needs were sequentially ordered as follows: contact and interaction with medical practitioners (4.16), reminder to assess blood glucose levels (4.07), alert indicating abnormal blood glucose levels (4.06), medication reminder (3.93), documentation of intake per meal (3.91), calculation of carbohydrate intake (3.85), graphic presentation of blood glucose levels (3.84), setting of personal goals (3.82), reminder to exercise (3.80), and providing diabetes knowledge (3.77). Factors influencing the usage of mobile applications included age (OR:0.956, 95%CI:0.935-0.977, P < .01), employed (OR:2.822, 95%CI:1.373-5.802, P < .05), medical insurance (OR:2.084, 95%CI:1.073-4.047, P < .05) and the eHealth Literacy Scale score (OR:1.128, 95%CI:1.088-1.169, P < .01). The main reason for unwillingness to use self-management applications was a lack of experience using it. Conclusions: The functional needs of patients using diabetes self-management apps include contacting and interacting with medical staff, recording and alarming blood glucose, reminding medicine, recording and calculating intake, providing graphic representation of blood glucose, setting health goals, recording exercise and sending diabetes knowledge. Age, employed, medical insurance and the eHealth Literacy Scale score were the factors influencing willingness to use self-management applications. The main reason for reluctance to use self-management applications was lack of experience.

θ-Nanopipette for Single-Cell Resistive-Pulse Profiling of DNA Repair Proteins Accompanied by Drug Evaluation.

Single-cell analysis of the DNA repair protein is important but remains unachieved. Exploration of nanopipettte technologies in single-cell electroanalysis has recently seen rapid growth, while the θ-nanopipette represents an emerging technological frontier with its potential largely veiled. Here a θ-nanopipette is first applied for single-cell resistive-pulse sensing (RPS) of the important DNA repair protein O6-alkylguanine DNA alkyltransferase (hAGT). The removal of alkyl mutations by hAGT could restore the damaged aptamer linking with a structural DNA carrier, allowing the selective binding of the aptamer to thrombin with precisely matched size to produce distinct RPS signals when passing through the orifice. Kinetic analysis of hAGT repair was studied. Meanwhile, the device shows the simultaneous on-demand infusion of inhibitors to inactivate the hAGT activity, indicative of its potential in drug screening for enhanced chemotherapy. This work provides a new paradigm for θ-nanopipette-based single-cell RPS of a DNA repair protein accompanied by drug evaluation.

Silicon solar cell-enabled organic photoelectrochemical transistor optoelectronics.

Organic electrochemical transistors (OECTs) have been increasingly explored for innovative electronic devices. However, they inherently demand two power suppliers, which is unfavorable for the utilization of portable and wearable systems with strict energy requirements. Herein, by assembling a monocrystalline silicon solar cell into the OECT circuit with light as fuel, we demonstrated the possibility of a self-powered and light-modulated operation of organic photoelectrochemical transistor (OPECT) optoelectronics. Exemplified by poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based depletion-mode and accumulation-mode OECTs, different light-addressable configurations were constructed, and the corresponding characteristics were systematically studied and compared. Different device behaviors with distinct characteristics could be achieved with the appropriate usage of light stimulation. Toward applications, optologics were designed with various parameters depending on the incident irradiance. Light-controlled OPECT unipolar inverters were further demonstrated and optimized with respect to the power source and resistance. This work features new OPECT optoelectronics combined with proper flexible substrates and solar cells for potential applications in portable and wearable devices. Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s40843-022-2295-8.

Appraisal of treatment outcomes in integrative medicine using metabonomics: Taking non-alcoholic fatty liver disease with spleen deficiency syndrome as an example.

OBJECTIVE: Appraisal of treatment outcomes in integrative medicine is a challenge due to a gap between the concepts of Western medicine (WM) disease and traditional Chinese medicine (TCM) syndrome. This study presents an approach for the appraisal of integrative medicine that is based on targeted metabolomics. We use non-alcoholic fatty liver disease with spleen deficiency syndrome as a test case. METHODS: A patient-reported outcome (PRO) scale was developed based on literature review, Delphi consensus survey, and reliability and validity test, to quantitatively evaluate spleen deficiency syndrome. Then, a metabonomic foundation for the treatment of non-alcoholic fatty liver disease with spleen deficiency syndrome was identified via a longitudinal interventional trial and targeted metabolomics. Finally, an integrated appraisal model was established by identifying metabolites that responded in the treatment of WM disease and TCM syndrome as positive outcomes and using other aspects of the metabonomic foundation as independent variables. RESULTS: Ten symptoms and signs were included in the spleen deficiency PRO scale. The internal reliability, content validity, discriminative validity and structural validity of the scale were all qualified. Based on treatment responses to treatments for WM disease (homeostasis model assessment of insulin resistance) or TCM syndrome (spleen deficiency PRO scale score) from a previous randomized controlled trial, two cohorts comprised of 30 participants each were established for targeted metabolomics detection. Twenty-five metabolites were found to be involved in successful treatment outcomes to both WM and TCM, following quantitative comparison and multivariate analysis. Finally, the model of the integrated appraisal system was exploratively established using binary logistic regression; it included 9 core metabolites and had the prediction probability of 83.3%. CONCLUSION: This study presented a new and comprehensive research route for integrative appraisal of treatment outcomes for WM disease and TCM syndrome. Critical research techniques used in this research included the development of a TCM syndrome assessment tool, a longitudinal interventional trial with verified TCM treatment, identification of homogeneous metabolites, and statistical modeling.

Lingguizhugan Decoction, a Chinese herbal formula, improves insulin resistance in overweight/obese subjects with non-alcoholic fatty liver disease: a translational approach.

Lingguizhugan Decoction (LGZG) has been investigated in basic studies, with satisfactory effects on insulin resistance in non-alcoholic fatty liver disease (NAFLD). This translational approach aimed to explore the effect and underlying mechanism of LGZG in clinical setting. A randomized, double-blinded, placebo-controlled trial was performed. A total of 243 eligible participants with NAFLD were equally allocated to receive LGZG (two groups: standard dose and low dose) or placebo for 12 weeks on the basis of lifestyle modifications. The primary efficacy variable was homeostasis model assessment of insulin resistance (HOMA-IR). Analyses were performed in two populations in accordance with body mass index (BMI; overweight/obese, BMI ⩾ 24 kg/m2; lean, BMI < 24 kg/m2). For overweight/obese participants, low-dose LGZG significantly decreased their HOMA-IR level compared with placebo (-0.19 (1.47) versus 0.08 (1.99), P = 0.038). For lean subjects, neither dose of LGZG showed a superior effect compared with placebo. Methylated DNA immunoprecipitation sequencing and real-time qPCR found that the DNA N6-methyladenine modification levels of protein phosphatase 1 regulatory subunit 3A (PPP1R3A) and autophagy related 3 (ATG3) significantly increased after LGZG intervention in overweight/obese population. Low-dose LGZG effectively improved insulin resistance in overweight/obese subjects with NAFLD. The underlying mechanism may be related to the regulation of DNA N6-methyladenine modification of PPP1R3A and ATG3. Lean subjects may not be a targeted population for LGZG.

Effects of traditional Chinese medicine collaborative model (TCMCM) combined with adjuvant chemotherapy on IIIb and IIIc gastric cancer: a protocol for a randomized controlled trial.

BACKGROUND: Metastasis and/or recurrence can decrease the survival time of gastric cancer patients undergoing radical operation. Among them, those with stage IIIb and IIIc are especially at a high risk of metastasis and recurrence. The traditional Chinese medicine collaborative model (TCMCM) has been used in the treatment of cancer; however, its effects have not been systematically evaluated. This study is designed to evaluate whether TCMCM can decrease adverse effects after chemotherapy and reduce the recurrence and metastasis of stage IIIb and IIIc gastric cancer. METHODS/DESIGN: This prospective, multicenter, randomized, open-label trial will recruit 260 patients with stage IIIb and IIIc gastric cancer who undergo radical surgery for D2 lymphadenectomy. The patients will be randomly assigned to receive usual adjuvant chemotherapy and TCMCM (intervention group) in a 1:1 ratio. Patients in the intervention group will receive an oral traditional Chinese formula, auricular acupressure, and acupoint therapy. All participants will receive usual adjuvant chemotherapy. The primary outcome is a 3-year disease-free survival rate. Secondary outcomes include quality of life, side effects caused by chemotherapy, and safety-related measures. Assessments will be performed during the screening period, at 4 and 8 cycles after adjuvant chemotherapy, and 9, 12, 18, 24, 30, and 36 months after randomization. Adverse events will be recorded. In addition, biological samples will be collected for mechanism analysis. DISCUSSION: This will be the first clinical trial to evaluate the effects of TCMCM on disease-free survival (DFS) and quality of life in patients with stage IIIb and IIIc gastric cancer. Our results may be used to standardize TCMCM. We will also perform a larger-scale clinical trial in the future. TRIAL REGISTRATION: ClinicalTrials.gov NCT03607656 . Registered on 1 July 2018. The final protocol version is V1.1.

A plasmon-enhanced theranostic nanoplatform for synergistic chemo-phototherapy of hypoxic tumors in the NIR-II window.

Development of simple and effective synergistic therapy by combination of different therapeutic modalities within one single nanostructure is of great importance for cancer treatment. In this study, by integrating the anticancer drug DOX and plasmonic bimetal heterostructures into zeolitic imidazolate framework-8 (ZIF-8), a stimuli-responsive multifunctional nanoplatform, DOX-Pt-tipped Au@ZIF-8, has been successfully fabricated. Pt nanocrystals with catalase-like activity were selectively grown on the ends of the Au nanorods to form Pt-tipped Au NR heterostructures. Under single 1064 nm laser irradiation, compared with Au NRs and Pt-covered Au NRs, the Pt-tipped Au nanorods exhibit outstanding photothermal and photodynamic properties owing to more efficient plasmon-induced electron-hole separation. The heat generated by laser irradiation can enhance the catalytic activity of Pt and improve the O2 level to relieve tumor hypoxia. Meanwhile, the strong absorption in the NIR-II region and high-Z elements (Au, Pt) of the DOX-Pt-tipped Au@ZIF-8 provide the possibility for photothermal (PT) and computed tomography (CT) imaging. Both in vitro and in vivo experimental results illustrated that the DOX-Pt-tipped Au@ZIF-8 exhibits remarkably synergistic plasmon-enhanced chemo-phototherapy (PTT/PDT) and successfully inhibited tumor growth. Taken together, this work contributes to designing a rational theranostic nanoplatform for PT/CT imaging-guided synergistic chemo-phototherapy under single laser activation.

Traditional Chinese medicine Lingguizhugan decoction treating non-alcoholic fatty liver disease with spleen-yang deficiency pattern: Study protocol for a multicenter randomized controlled trial.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease characterized by excessive fat accumulation in the liver. One of the underlying pathophysiological mechanisms is insulin resistance (IR). Traditional Chinese medicine (TCM) has showed potential benefits in the management of NAFLD. Lingguizhugan decoction (LGZG) is a representative Chinese herbal formula; however, there is still no rigorous clinical trial supporting its application. METHODS/DESIGN: This study will be a three-arm, dose-optimization, randomized, double-blinded, placebo-controlled clinical trial. A total of 243 patients with NAFLD will be recruited and randomly assigned to the standard dose LGZG (SLGD) group, low dose LGZG (LLGD) group, or the placebo group based on a ratio of 1:1:1. The treatment period will be 12 weeks and the follow-up period will last 4 weeks. The primary outcome will be the proportions of participants with at least a 1-unit decrease of HOMA-IR from baseline to 12 weeks. Secondary outcomes will include the changes of body weight, body mass index, liver function, blood lipid metabolism, blood glucose metabolism, inflammatory responses, liver-kidney echo ratio by ultrasound, and various scales. Biological samples will also be collected for future researches on mechanism exploration. DISCUSSION: This study will provide initial evidence regarding the efficacy and safety of LGZG in the treatment of NAFLD with spleen-yang deficiency pattern and promote its application in community healthcare centers. In addition, potential mechanisms will be explored based on studies of oral and gut microbiota. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800014364. Registered on 1 January 2018. The final protocol version was V3.0.

Ling-gui-zhu-gan decoction alleviates hepatic steatosis through SOCS2 modification by N6-methyladenosine.

BACKGROUND: The ling-gui-zhu-gan (LGZG) decoction is a classic formula in traditional chinese medicine (TCM) and is widely used in clinical settings. Recently, the LGZG decoction was demonstrated to have an effect in alleviating hepatic steatosis induced by a high-fat diet (HFD). However, the mechanisms underlying this therapeutic effect remain unclear. The present study was designed to evaluate the effect and explore possible mechanisms of action of the LGZG decoction in nonalcoholic fatty liver disease (NAFLD). METHODS: Liver tissue and blood samples were harvested. Liver steatosis, triglyceride (TG), liver total cholesterol (TC), liver low-density lipoprotein (LDL), serum almandine aminotransferase (ALT), aspartate aminotransferase (AST), and free fatty acid (FFA) were assayed. N6-methyladenosine (m6A) levels were estimated using an m6A RNA methylation quantification kit and immunohistochemistry. The m6A methylome was detected through methylated RNA immunoprecipitation sequencing (MeRIP-seq), followed by data analysis. The expression levels of differentially methylated genes (DMGs) were determined using real-time polymerase chain reaction and western blotting. RESULTS: The LGZG decoction significantly alleviated hepatic steatosis and reduced m6A levels. MeRIP-seq revealed the coding sequence (CDS) domain to be the most critical modification site for m6A methylation, and the molecular functions of DMGs predominantly included insulin-like growth factor receptor binding and fatty acid metabolism and degradation. Further, LGZG treatment could reduce the m6A methylation levels of suppressor of cytokine signaling 2 (SOCS2), along with the expression of SOCS2 at mRNA and protein levels. CONCLUSIONS: The LGZG decoction is an effective formula for treating NAFLD, and the possible mechanisms underlying its action could be related to N6-methyladenosine modification-medicated SOCS2.

Gan-Jiang-Ling-Zhu decoction alleviates hepatic steatosis in rats by the miR-138-5p/CPT1B axis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a commonly-encountered chronic liver disease which lacks verified pharmacological interventions. Gan-Jiang-Ling-Zhu decoction (GJLZ) is a classic formula utilized in clinical practice. In this study, we aimed to evaluate the therapeutic effect of GJLZ in NAFLD and explore the possible underlying mechanisms. METHODS: Twenty-four rats were randomly divided into three groups: normal group, fed with chow diet for 8 weeks; model group, fed with high fat diet for 8 weeks; and GJLZ group, initially fed HFD for 4 weeks, and then administered the GJLZ decoction for 4 weeks by oral gavage while continuously feeding HFD. Rats were sacrificed after the intervention, and liver tissues and blood samples were harvested. Liver steatosis was detected by HE and Oil Red O staining. Body weight and liver index were analyzed. Liver triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL), serum almandine aminotransferase (ALT), aspartate aminotransferase (AST), and nonesterified fatty acid (NEFA) were assayed using commercial kits. Differentially expressed genes were identified by RNA-sequencing and verified using real-time PCR (RT-PCR) and western blotting. Whole miRNAs were detected by RNA-sequence analysis, and mRNA-targeted miRNAs were verified by RT-PCR. The miRNA-mRNA regulation pattern was confirmed using the dual-luciferase reporter assay. RESULTS: Treatment with GJLZ significantly improved hepatic steatosis and inflammation, reduced liver index and liver TG content, and also significantly reduced serum ALT and AST levels. Based on the results of RNA-sequence analysis, five differentially expressed genes (DEGs) in the peroxisome proliferator-activated receptor (PPAR) signaling pathway were recognized. RT-PCR confirmed that carnitine palmitoyltransferase 1b (CPT1B) expression was significantly regulated by GJLZ treatment. GJLZ decoction intervention also increased significantly hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) expression. Next, miRNA profiling and screening were performed based on CPT1B alteration. Rno-miR-138-5p likely responded to GJLZ intervention, and rno-miR-138-5p inhibitor increased CPT1B expression while rno-miR-138-5p mimic reduced CPT1B expression. When CPT1B mutated, miR-138-5p mimic and inhibitor could not regulate the luciferase activity of CPT1B. CONCLUSIONS: GJLZ is an effective formula for NAFLD management, and its possible mechanism of action involves the regulation of CPT1B expression via rno-miR-138-5p.

Engineering of ATP-Powered Photosensitizer for Targeted Recycling Activatable Imaging of MicroRNA and Controllable Cascade Amplification Photodynamic Therapy.

Owing to the low abundance of microRNAs (miRNAs) in living tumor cells, the development of intracellular cancer-relevant miRNA stimuli-activatable photosensitizers (PSs) for accurate imaging and efficient photodynamic therapy (PDT) of tumors in vivo is extremely challenging. Herein, we engineered a tumor targeting and intracellular trace miRNA-activatable nanophotosensitizer Y-motif/FA@HyNP on the basis of an endogenous ATP-powered strand-displacement cascade amplification strategy, which was prepared by assembly of a quencher BHQ2-labeled Y-motif DNA structure (containing ATP-binding aptamer and target miRNA-binding complementary sequence) on the surface of folate (FA) and amine-functionalized hybrid micellar nanoparticles. We showed that the fluorescence emissions at both 555 and 627 nm were effectively inhibited due to BHQ2 in Y-motif/FA@HyNPs, leading to negligible PDT efficacy. Once Y-motif/FA@HyNPs were selectively internalized into tumor cells via FA-receptor-mediated endocytosis, the intracellular trace target miRNA initiated the dissociation of the BHQ2-terminated sequences from Y-motif/FA@HyNPs by means of abundant endogenous ATP-powered strand-displacement reactions, causing remarkable fluorescence enhancement and cascade amplification PDT. The activated dual-color fluorescence emissions at 555 and 627 nm were feasible to achieve real-time, highly sensitive, and specific imaging of trace target miRNA in living tumor cells. With the guidance of excellent imaging in living mice, Y-motif/FA@HyNPs exhibited the precise and efficient PDT of tumors as well as insignificant side effects in vivo. This work revealed the great potential of using an integration of receptor-mediated cell uptake and target-triggered recycling cascade amplification strategy to design early cancer-relevant stimuli-activatable PSs for both fluorescence imaging and PDT ablation of tumors in vivo, which could effectively facilitate the timeliness and precision of early cancer diagnosis and therapy.

Cu Nanoclusters-Encapsulated Liposomes: Toward Sensitive Liposomal Photoelectrochemical Immunoassay.

Herein we report the strategy of liposome-mediated Cu2+-induced exciton trapping upon CdS quantum dots (QDs) for amplified photoelectrochemical (PEC) bioanalysis application. Specifically, the Cu nanoclusters (NCs)-encapsulated liposomes were first fabricated and then processed with antibodies bound to their external surfaces. After the sandwich immunocomplexing, the confined liposomal labels were subjected to sequential lysis treatments for the release of Cu NCs and numerous Cu2+ ions, which were then directed to interact with the CdS QDs electrode. The interaction of Cu2+ ions with CdS QDs could generate CuxS and form the trapping sites to block the photocurrent generation. Since the photocurrent inhibition is closely related with the Cu NCs-loaded liposomal labels, a novel and general "signal-off" PEC immunoassay could thus be tailored with high sensitivity. Meanwhile, a complementary "signal-on" fluorescent detection could be accomplished by measuring the fluorescence intensity originated from the Cu NCs. This work features the first use of Cu NCs in PEC bioanalysis and also the first NCs-loaded liposomal PEC bioanalysis. More importantly, by using other specific ions/reagents-semiconductors interactions, this protocol could serve as a common basis for the general development of a new class of liposome-mediated PEC bioanalysis.

Nanochannels Photoelectrochemical Biosensor.

Nanochannels have brought new opportunities for biosensor development. Herein, we present the novel concept of a nanochannels photoelectrochemical (PEC) biosensor based on the integration of a unique CuxO-nanopyramid-islands (NPIs) photocathode, an anodic aluminum oxide (AAO) membrane, and alkaline phosphatase (ALP) catalytic chemistry. The CuxO-NPIs photocathode possesses good performance, and further assembly with AAO yields a designed architecture composed of vertically aligned, highly ordered nanoarrays on top of the CuxO-NPIs film. After biocatalytic precipitation (BCP) was stimulated within the channels, the biosensor was used for the successful detection of ALP activity. This study has not only provided a novel paradigm for an unconventional nanochannels PEC biosensor, which can be used for general bioanalytical purposes, but also indicated that the new concept of nanochannel-semiconductor heterostructures is a step toward innovative biomedical applications.

A nanochannel array based device for determination of the isoelectric point of confined proteins.

A nanochannel array based nanodevice can mimic the biological environments and thus unveil the natural properties, conformation and recognition information of biomolecules such as proteins and DNA in confined spaces. Here we report that porous anodic alumina (PAA) of a highly parallel nanochannel array covalently modified with proteins significantly modulates the transport of a negatively charged probe of ferricyanide due to the electrostatic interactions between the probes and modified nanochannel inner surface. Results show that such electrostatic interaction exists in a wide range of ionic strength from 1 mM to 100 mM in 20 nm nanochannels modified with proteins (hemoglobin, bovine serum albumin, and goat anti-rabbit IgG secondary antibody). In addition, the maximal steady-state flux of the charged probe through the modified nanochannel array is directly related to the ionic strength which determines the electric double layer thickness and solution pH which modulates the nanochannel surface charge. Thus, the modulated mass transport of the probe by solution pH can be used to study the charge properties of the immobilized proteins in nanochannel confined conditions, leading us to obtain the isoelectric point (pI) of the proteins confined in nanochannels. The determined pI values of two known proteins of hemoglobin and bovine serum albumin are close to the ones of the same proteins covalently modified on a 3-mercaptopropionic acid self-assembled monolayer/gold electrode. In addition, the pI of an unknown protein of goat anti-rabbit IgG secondary antibody confined in nanochannels was determined to be 6.3. Finally, the confinement effect of nanochannels on the charge properties of immobilized proteins has been discussed.

A nanochannel array-based electrochemical device for quantitative label-free DNA analysis.

A strategy for label-free oligonucleotide (DNA) analysis has been proposed by measuring the DNA-morpholino hybridization hindered diffusion flux of probe ions Fe(CN)(6)(3-) through nanochannels of a porous anodic alumina (PAA) membrane. The flux of Fe(CN)(6)(3-) passing through the PAA nanochannels is recorded using an Au film electrochemical detector sputtered at the end of the nanochannels. Hybridization of the end-tethered morpholino in the nanochannel with DNA forms a negatively charged DNA-morpholino complex, which hinders the diffusion of Fe(CN)(6)(3-) through the nanochannels and results in a decreased flux. This flux is strongly dependent on ionic strength, nanochannel aperture, and target DNA concentration, which indicates a synergetic effect of steric and electrostatic repulsion effects in the confined nanochannels. Further comparison of the probe flux with different charge passing through the nanochannels confirms that the electrostatic effect between the probe ions and DNA dominates the hindered diffusion process. Under optimal conditions, the present nanochannel array-based DNA biosensor gives a detection limit of 0.1 nM.