ABSTRACT
This work reports novel chitosan functionalized graphene oxide (GO) nanocomposites combined fluorescence imaging and therapeutic functions in one agent, which can serve as a promising alternative to alleviate related diseases caused hyperinflammation. Briefly, GO was designed to be conjugated with chitosan, fluorescein-labeled peptide, toll-like receptor 4 antibody and hydroxycamptothecin/aloe emodin. We have demonstrated that such nanocomposites could effectively achieve active targeted delivery of pro-apoptotic and anti-inflammatory drugs into inflammatory cells and cause cells apoptosis by acid-responsive drug release. Moreover, confocal fluorescence imaging confirms that the drug-induced inflammatory cells apoptosis could be visualized the light-up fluorescence of fluorescein activated by caspase-3. Meanwhile, inflammatory-related biomarkers have down-regulated after the nanocomposites' treatment in both vitro and vivo experiments consistent with the results in histological sections. In summary, the bifunctional nanocomposites that possess anti-inflammation and fluorescence imaging could serve as a promising therapeutic agent for reducing hyperinflammation caused by numerous diseases.
Subject(s)
Anti-Inflammatory Agents/therapeutic use , Apoptosis/physiology , Drug Carriers/chemistry , Inflammation/drug therapy , Nanocomposites/chemistry , Animals , Anti-Inflammatory Agents/chemistry , Antibodies/immunology , Camptothecin/analogs & derivatives , Camptothecin/chemistry , Camptothecin/therapeutic use , Cattle , Cell Line , Chitosan/chemistry , Drug Liberation , Emodin/chemistry , Emodin/therapeutic use , Fluorescent Dyes/chemistry , Graphite/chemistry , Humans , Lipopolysaccharides , Mammary Glands, Human/drug effects , Mammary Glands, Human/pathology , Mastitis/chemically induced , Mastitis/drug therapy , Mastitis/pathology , Mice , Toll-Like Receptor 4/immunologyABSTRACT
A label-free electrochemical strategy is proposed combining equivalent substitution effect with AuNPs-assisted signal amplification. According to the differences of S1 protein in various infectious bronchitis virus (IBV) strains, a target DNA sequence that can specifically recognize H120 RNA forming a DNA-RNA hybridized double-strand structure has been designed. Then, the residual single-stranded target DNA is hydrolyzed by S1 nuclease. Therefore, the content of target DNA becomes equal to the content of virus RNA. After equivalent coronavirus, the target DNA is separated from DNA-RNA hybridized double strand by heating, which can partly hybridize with probe 2 modified on the electrode surface and probe 1 on AuNPs' surface. Thus, AuNPs are pulled to the surface of the electrode and the abundant DNA on AuNPs' surface could adsorb a large amount of hexaammineruthenium (III) chloride (RuHex) molecules, which produce a remarkably amplified electrochemical response. The voltammetric signal of RuHex with a peak near - 0.28 V vs. Ag/AgCl is used as the signal output. The proposed method shows a detection range of 1.56e-9 to 1.56e-6 µM with the detection limit of 2.96e-10 µM for IBV H120 strain selective quantification detection, exhibiting good accuracy, stability, and simplicity, which shows a great potential for IBV detection in vaccine research and avian infectious bronchitis diagnosis. Graphical abstract.
Subject(s)
Biosensing Techniques/methods , Coronavirus Infections/virology , Coronavirus/isolation & purification , Electrochemical Techniques/methods , Infectious bronchitis virus/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Animals , Biosensing Techniques/standards , Capsid Proteins/genetics , Chickens , Coronavirus/genetics , DNA Probes , Gold , In Situ Hybridization , Infectious bronchitis virus/genetics , Limit of Detection , Metal Nanoparticles/chemistry , RNA, Viral/genetics , RNA, Viral/isolation & purification , Species SpecificityABSTRACT
An aptamer based assay is presented for the determination of the antibiotics oxytetracycline (OTC) and kanamycin (KAN). Magnetic beads were applied for separation, and gold nanoparticles (AuNPs) for signal amplification. DNA aptamers against OTC and KAN were firstly designed. After specific recognition events, the aptamer sequences were released from the surface of magnetic beads and the remaining DNA probes captured horseradish peroxidase (HRP) modified AuNPs. Subsequently, 3,3',5,5'-tetramethylbenzidine and o-phenylenediamine are catalytically oxidized by HRP, and the generated colorimetric responses can reflect the concentrations of OTC (at 370 nm) and KAN (at 450 nm), respectively. Experimental results demonstrate that the method is highly sensitive with the detection limit as low as 1 ag mL-1 for OTC and KAN. An extremely wide linear range (over 11 orders of magnitude) is achieved. The high selectivity is attributed to the high affinity between aptamer and the substrate. The results of real sample tests also verify that the method is promising for antibiotics analysis in the applications of food monitoring and clinical diagnosis. Graphical abstract Schematic presentation of a colorimetric assay for antibiotics based on aptamer-modified magnetic beads and horseradish peroxidase modified gold nanoparticles. Colorimetric responses result from the enzymatic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD), respectively.
