查找使用阿拉丁产品的科研文献

A novel sandwich-type electrochemical aptasensor for sensitive detection of kanamycin based on GR–PANI and PAMAM–Au nanocomposites

Wei Xu,Yu Wang,Su Liu,Jinghua Yu,Hongzhi Wang,Jiadong Huang

In this work, we report a novel sandwich-type electrochemical aptasensor for sensitive and selective detection of antibiotic kanamycin. This aptasensor was constructed by assembling graphene–polyaniline (GR–PANI) and polyamidoamine dendrimer–Au nanoparticle (PAMAM–Au) nanocomposites on the surfaces of a glass carbon electrode, which as electrode materials exhibited excellent charge-transport property and loading capacity of biomolecules. Followed by the sandwich-type specific identification, kanamycin detection was realized by outputting a redox current from electro-reduction reaction of H2O2 catalyzed by HRP. It was demonstrated that the developed strategy had a wide linear response range from 5 × 10−6 to 4 × 10−2 μg mL−1 and a low detection limit of 4.6 × 10−6 μg mL−1. Additionally, this aptasensor had the advantages in its low cost, high sensitivity, and superb specificity. Thus, it might provide a useful tool for kanamycin determination and related food safety analysis and clinical diagnosis.

An electrochemical paracetamol sensor based on layer-by-layer covalent attachment of MWCNTs and a G4.0 PAMAM modified GCE

Yanjun Zhang,Xiuhui Liu,Lin Li,Zhipan Guo,Zhonghua Xue,Xiaoquan Lu

An electrochemical sensor for the detection of paracetamol (PAT) was reported employing multiwalled carbon nanotubes (MWCNTs) and the fourth generation poly(amidoamine) dendrimers (G4.0 PAMAM). The strategy of this work lies on the formation of a stable covalent linkage between carboxylated MWCNTs and amine terminated G4.0 PAMAM via covalent layer-by-layer (LbL) self-assembly, which provides larger surface areas for efficient adsorption of PAT. The constructed electrode was characterized first by Fourier transform infrared spectroscopy and scanning electron microscopy, and then the electrochemical behavior of PAT on the (MWCNTs–G4.0)6/GCE was investigated in detail by cyclic voltammetry, electrochemical impedance spectroscopy and chronocoulometry. Under optimal conditions, the experimental results demonstrated that the constructed sensor exhibited excellent catalytic activity toward PAT, and a wide linear range from 3.0 × 10−7 to 2.0 × 10−4 M was obtained with a limit of detection (LOD) of 1.0 × 10−7 M (S/N = 3). Moreover, it could also be applied to the determination of PAT in commercial tablets and human serum, and the satisfactory results confirm the applicability of this sensor in practical analysis.

Selective recognition of salicylic acid employing new fluorescent imprinted membrane functionalized with poly(amidoamine) (PAMAM)-encapsulated Eu(TTA)3phen

Minjia Meng,Mengqi Bai,Zulin Da,Yanhua Cui,Bingrong Li,Jianming Pan

Selective fluorescent molecularly imprinted membrane (FMIM) for salicylic acid (SA) was successfully prepared by phase inversion technique with SA as template molecule, chitosan (CHI) as functional polymer , and Eu(TTA) 3 phen/PAMAM composed of Eu(TTA) 3 phen and the dendrimer (PAMAM) as the fluorophore, which was characterized by SEM, AFM, and XPS techniques. The introduction of the hydrophilic Eu(TTA) 3 phen/PAMAM into FMIM was able to improve the flux and the adsorption capacity of SA with good fluorescent stability. Among the FMIM, the FMIM2 prepared with 2.0% Eu(TTA) 3 phen/PAMAM in the cast membrane fluid was the optimal fluorescent imprinted membrane for selective detection of SA, which displayed a relatively wider linear range and lower limit of detection (LOD) (24 mg L −1 ). The imprinted FMIM2 could selectively detect the SA from complicated samples without obvious interference from analogues compared to the non-imprinted FNIM2. Moreover, the FMIM had promising recycling performance. It can be potentially used as an alternative imprinted membrane for selective detection and separation of trace SA in water.

Construction of an ultrasensitive non-enzymatic sensor to investigate the dynamic process of superoxide anion release from living cells

Hongwei Wei,Tianyi Shang,Tiaodi Wu,Guoan Liu,Lan Ding,Xiuhui Liu

In this work, a novel non-enzymatic superoxide anion (O 2 • − ) sensor was constructed based on Ag nanoparticles (NPs) / poly (amidoamine) (PAMAM) dendrimers and used to investigate the dynamic process of O 2 • − release from living cells. The AgNPs/PAMAM nanohybrids were characterized by transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode exhibited excellent catalytic activity toward the reaction of O 2 • − with a super low detection limit (LOD) of 2.530 × 10 –13   M (S/N = 3) and wide linear range of 8 orders of magnitude. It could fulfill the requirement of real-time measurement O 2 • − released from living cells. Furthermore, zymosan was chosen as the stimulant to induce O 2 • − generation from cancer cells (rat adrenal medulla pheochromocytoma cell (PC12)). The electrochemical experiment results indicated that the levels of intracellular O 2 • − depended on the amount of Zymosan. A large amount of O 2 • − generated in the living cells by added heavy stimulant could damage cells seriously. More importantly, a vitro simulation experiment confirmed the role of superoxide dismutase (SOD) for the first time because it could maintain the O 2 • − concentration at a normal physiological range. These findings are of great significance for evaluating the metabolic processes of O 2 • − in the biological system, and this work has the tremendous potential application in clinical diagnostics to assess oxidative stress .

Preparation of Fe3O4 magnetic nanomaterials for the enrichment of phosvitin phosphopeptides

Shuze Ren,Songming Li,Mahmoud Abou-Elsoud,Rui Cui,Xing Fu,Xi Huang

Phosvitin phosphopeptides (PPP) have a high ability to chelate mineral ions and promote calcium absorption. In this study, The Fe 3 O 4 nanospheres were first synthesized by hydrothermal method, then the three magnetic nanoparticles (Fe 3 O 4 @PDA@PMAA@PAMAM, Fe 3 O 4 @PDA@Ce 4+ , and Fe 3 O 4 @PDA@TiO 2 ) were obtained by layer modification on their surfaces, respectively. The magnetic nanoparticles were characterized by TEM, XRD, VSM, and Zeta potential. TEM analysis revealed that the nanoparticles were spherical and regular in shape. XRD diffraction analysis showed that the modified nanoparticles have a complete crystal structure. Meanwhile, PAMAM, Ce 4+ , TiO 2 , and other groups have been successfully modified on the nanoparticles. VSM hysteresis regression line results revealed that the magnetic nanoparticles are superparamagnetic. The three kinds of magnetic nanoparticles still maintained excellent enrichment performance after five times of repeated use. Fe 3 O 4 @PDA@TiO 2 has the best enrichment performance (167 mg g −1 ). The N/P ratio of the enriched PPP decreased from 1.36 to 0.98, which also showed that it had excellent PPP enrichment performance. Therefore, the modified magnetic nanoparticles could be an optimal PPP enrichment and purification material.

The influence of modified molecular (D/L-serine) chirality on the theragnostics of PAMAM-based nanomedicine for acute kidney injury

Lulu Kong,Di Fan,Lin Zhou,Shaohua Wei

Acute kidney injury (AKI) is a severe clinical disease with extremely high morbidity and mortality. It is challenging to find a simple method for early detection of AKI and monitoring the treatment results. Renal tubular damage and inflammation are early events in AKI. Renal tubular damage is conducive to the accumulation of small-sized nanoparticles in the kidney, and inflammation is related to the excessive production of H2O2. Recent studies proved that chiral molecule modification of nanomaterials is a powerful strategy to regulate their biodistribution. Thus, L-serine and D-serine modified poly(amidoamine) (PAMAM) dendrimers were synthesized and used as fluorescent probe (NPSH) carriers to obtain L-SPH and D-SPH, respectively. D-SPH has a strong accumulation capability in the kidney of AKI mice. Then, the H2O2 fluorescent probe can detect the excessively produced H2O2 to generate fluorescence to diagnose AKI. Subsequently, the anti-inflammatory drug manganese pentacarbonyl bromide (CORM) was loaded in D-SPH to obtain D-SPHC with AKI theragnostic functions. Simultaneously, the D-SPHC fluorescence signal intensity change during the treatment can be used to monitor the recovery process. This study is the first report of chiral materials used in the diagnosis and treatment of AKI.

Novel water-soluble and pH-responsive anticancer drug nanocarriers: Doxorubicin–PAMAM dendrimer conjugates attached to superparamagnetic iron oxide nanoparticles (IONPs)

Yulei Chang,Xinlei Meng,Yili Zhao,Kun Li,Bao Zhao,Ming Zhu,Yapeng Li,Xuesi Chen,Jingyuan Wang

PH-responsive drug release system based on the conjugates of PAMAM dendrimers–doxorubicin (PAMAM–DOX) and superparamagnetic iron oxide (Fe 3 O 4 ) nanoparticles (IONPs) has been constructed and characterized. The IONPs were stabilized by mPEG-G2.5 PAMAM dendrimers. The anticancer drug DOX was conjugated to the dendrimer segments of amino-stabilized IONPs using hydrazine as the linker via hydrazone bonds, which is acid cleavable and can be used as an ideal pH-responsive drug release system. The drug release profiles of DOX–PAMAM dendrimer conjugates were studied at pH 5.0 and 7.4. The results showed that the hydrolytic release profile can be obtained only at the condition of lysosomal pH (pH   =   5.0), and IONPs participated in carrying DOX to the tumor by the Enhanced Permeability and Retention (EPR) effect. These novel DOX-conjugated IONPs have the potential to enhance the effect of MRI contrast and cancer therapy in the course of delivering anticancer drugs to their target sites. Although the dendrimer–DOX-coated IONPs do not have any targeting ligands attached on their surface, they are potentially useful for cancer diagnosis in vivo.

Synthesis and characterization of a PAMAM dendrimer nanocarrier functionalized by HA for targeted gene delivery systems and evaluation in vitro

Haimei Hu,Han Wang,Shuanghong Liang,Xiaoling Li,Dan Wang

In vitro and in vivo evaluation of stimuli-responsive vesicle from PEGylated hyperbranched PAMAM-doxorubicin conjugate for gastric cancer therapy

Jinshan Nie,Yang Wang,Wei Wang

Gastric Cancer is one of the major leading causes of death by cancer worldwide, but the chemotherapeutics, one of the preferred approaches, bring about extensive side effects when systemically injected. In our work, doxorubicin-loaded pH and redox responsive hyperbranched poly(amidoamine)( h- PAMAM)-based vesicle was prepared to enhance anti-tumor efficacy of chemotherapeutic compounds. The doxorubicin (DOX) molecules were attached to PEGylated h- PAMAM by acid sensitive cis -aconityl linkage to form pH sensitive conjugate (PPCD), which self-assembled in THF into micelles . The resulted micelles were then crosslinked by disulfide bonds and transferred from THF into water to form vesicles, which could be disassembled into small-sized conjugates under the redox condition. The drug release profiles showed that the PPCD vesicle presented stimuli-triggered drug release in acidic and reducing environment, and lower DOX leakage under neutral condition. The in vitro cell assay reflected the rapid DOX release and significant tumor-cytotoxic effect of the PPCD vesicle. The in vivo anticancer activity and systematic toxicity studies showed that the PPCD vesicles had lower tissue toxicity with good antitumor effect. In brief, h- PAMAM-based PPCD vesicle provides a safe and effective drug delivery system for the therapy of gastric cancer.

Enhanced Photoelectrochemical Method for Sensitive Detection of Protein Kinase A Activity Using TiO2/g-C3N4, PAMAM Dendrimer, and Alkaline Phosphatase

Xue Li,Lusheng Zhu,Yunlei Zhou,Huanshun Yin,Shiyun Ai

A novel photoelectrochemical (PEC) assay is developed for sensitive detection of protein kinase A (PKA) activity based on PKA-catalyzed phosphorylation reaction in solution and signal amplification strategy triggered by PAMAM dendrimer and alkaline phosphatase (ALP). In this strategy, it is noteworthy at this point that PKA phosphorylation was achieved in solution instead of on the surface of the electrode, which has advantages of the good contact in reactants and simple experimental procedure. For immobilizing the phosphorylated peptide (P-peptide) on electrode surface, graphite-like carbon nitride (g-C3N4) and titanium dioxide (TiO2) complex is synthesized and characterized, which plays a significant role for TiO2 conjugating phosphate groups and g-C3N4 providing PEC signal. Subsequently, PAMAM dendrimer and ALP can be captured on P-peptide and TiO2/g-C3N4 modified ITO electrode via interaction between the -COOH groups on the surface of PAMAM dendrimer and the -NH2 groups of peptide and ALP, which can lead to the increase of ALP amount on the modified electrode surface assisted with the PAMAM dendrimer. As a result, the amount of ALP catalyzes of L-ascorbic acid 2-phosphate trisodium salt (AAP) to produce electron donor of ascorbic acid (AA), resulting in an increased photocurrent. The proposed detection assay displays high selectivity and low detection limit of 0.048 U/mL (S/N = 3) for PKA activity. This biosensor can also be applied for the evaluation of PKA inhibition and PKA activity assay in cell samples. Therefore, the fabricated PEC biosensor is potentionally well in PKA activity detection and inhibitor screening.

Construction of PAMAM-based Nanocomplex Conjugated with Pt(IV)-complex and Lauric Acid Exerting Both Anti-tumor and Antibacterial Effects

Xin You-Tao,Wang Lu-Yao,Chang Huan-Huan,Ma Fei-He,Sun Ming-Lei,Chen Li,Gao Hui

Oxaliplatin is the common chemotherapy drug for the treatment of colorectal cancer (CRC), however, the harmful Fusobacterium nucleatum ( Fn ) that existed in the CRC tumor tissues leads to extreme drug resistance to oxaliplatin, which reduces the anticancer efficiency. Here we fabricated a new dendrimer-based nanocomplex with anti-tumor and antibacterial dual-functions through conjugating Pt(IV)-complex and lauric acid (LA) to the dendritic carrier PAMAM (G=3). The synthesized PAMAM-Pt-LA nanoparticle was further coated with hyaluronic acid (HA) on its surface through electrostatically interaction in order to enhance biocompatibility and tumor targeting. The biocompatibility, anti-tumor activity and antibacterial activity of PAMAM-Pt-LA@HA nanocomplex were evaluated in vitro. The results showed that the PAMAM-Pt-LA@HA nanocomplex ehxibited a good biocompatibility, high anti-colorectal cancer activity and high anti- Fn activity. This dual-functional nanocomplex provides a new method to develop anticancer nanomedicines that will be more therapeutically efficacious and less toxic than oxaliplatin for the treatment of CRC.

Efficient Gene Delivery Based on Guanidyl-Nucleic Acid Molecular Interactions

Dongli Wang,Jie Song,Jing Wang,Zhiyi Zhang,Qing Shen,Jun Wang,Haiyan Guo,Ruifeng Wang,Cao Xie,Weiyue Lu,Min Liu

Low transfection efficacy of non-viral gene vectors restricts their applications. In this paper, N 1 ,N 3 -dicarbamimidoyl-5-methylisophthalamide (BGG) is designed as a functional group, in which two guanidyls are located at the meta positions of an aryl ring. BGG is conjugated with PAMAM G5 (G5-BGG) and G5-BGG/DNA complex is dispersed into a polyvinyl alcohol (PVA) hydrogel for local injection. Molecular docking, NMR, IR and Isothermal titration calorimetry (ITC) experiments demonstrate that G5-BGG has multiple molecular interactions with nucleic acids, which yield high binding affinity toward nucleic acids. Interestingly, the in vitro transfection efficiency and serum stability of G5-BGG are significantly improved when the BGG modification ratio is just one. The integrated G5-BGG/DNA complex is released from a PVA hydrogel sustainably, crosses the cell membrane and escapes from endosome/lysosome. After local injection only once, these features of the G5-BGG/DNA-loaded PVA hydrogel are found to improve antitumor efficiency in vivo, and antitumor efficiency is significantly better than PEI 25K. The results confirm that BGG is a potential group for developing non-viral gene vectors with high transfection efficacy.