RESUMEN
Electroactive hydrogel scaffolds are fabricated by the 3D-printing technique using composites of 30% Pluronic F127 and aniline tetramer-grafted-polyethylenimine (AT-PEI) copolymers with various contents from 2.5% to 10%. The synthesized AT-PEI copolymers can self-assemble into nanoparticles with the diameter of ≈50 nm and display excellent electroactivity due to AT conjugation. The copolymers are then homogeneously distributed into 30% Pluronic F127 solution by virtue of the thermosensitivity of F127, denoted as F/AT-PEI composites. Macroscopic photographs of latticed scaffolds elucidate their excellent printability of F/AT-PEI hydrogels for the 3D-printing technique. The conductivities of the printed F/AT-PEI scaffolds are all higher than 2.0 × 10-3 S cm-1 , which are significantly improved compared with that of F127 scaffold with only 0.94 × 10-3 S cm-1 . Thus, the F/AT-PEI scaffolds can be considered as candidates for application in electrical stimulation of tissue regeneration such as repair of muscle and cardiac nerve tissue.
Asunto(s)
Compuestos de Anilina/química , Hidrogeles/química , Hidrogeles/síntesis química , Poloxámero/química , Polietileneimina/química , Impresión Tridimensional , Conductividad Eléctrica , Nanopartículas/química , Tamaño de la Partícula , Poloxámero/síntesis química , Polietileneimina/síntesis química , Propiedades de SuperficieRESUMEN
Electrode materials play a vital role in the development of electrochemical immunosensors (EIs), particularly of label-free EIs. In this study, composites containing reduced graphene oxide with silver nanoparticles (rGO/Ag NPs) were synthesized using binary reductants, i.e. hydrazine hydrate and sodium citrate. Due to the fact that graphene oxide (GO) was fully restored to rGO, and rGO stacking was effectively inhibited by insertion of small Ag NPs between the graphene sheets, the electrical conductivity of rGO/Ag NPs composites was significantly improved compared to rGO alone, with an enhancement factor of 346% at 40wt% of rGO. Moreover, the conducting path between rGO and Ag NPs formed because the structural defects in rGO were effectively repaired by decoration with Ag NPs. Subsequently, based on a screen-printed three-electrode system, a label-free EI for detecting prostate-specific antigen (PSA) was constructed using rGO/Ag NPs composites as a support material. The fabricated EIs demonstrated a wide linear response range (1.0-1000ng/ml), low detection limit (0.01ng/ml) and excellent specificity, reproducibility and stability. Thus, the proposed EIs based on rGO/Ag NPs composites can be easily extended for the ultrasensitive detection of different protein biomarkers.
Asunto(s)
Técnicas Electroquímicas/métodos , Grafito/química , Inmunoensayo/métodos , Nanocompuestos/química , Antígeno Prostático Específico/sangre , Plata/química , Anticuerpos Inmovilizados/química , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/instrumentación , Electrodos , Diseño de Equipo , Humanos , Inmunoensayo/instrumentación , Límite de Detección , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Modelos Moleculares , Nanocompuestos/ultraestructura , Óxidos/química , Reproducibilidad de los ResultadosRESUMEN
Objective: To investigate the chemical constituents of effective part of Oroxylum indicum which related to lowering LDLC action. Methods: The compounds were isolated with chromatography methods such as silica gel,polyamide and Sephadex LH-20. The structures were identified by physiochemical properties and spectral analysis. Results: 14 compounds were isolated from 95% alcohol extract and elucidated as ß-sitosterol( 1), hexadecanoic acid( 2), oroxin A( 3), oroxin B( 4), chrysin( 5), quercetin( 6),quercetin-3-Orutinoside( 7),5,4'-dihydroxy-3,6,7-trimethoxyflavone( 8), diosmetin( 9), geniposide( 10),isoorientin( 11), quercitroside( 12), apigenin( 13) and gallicacid( 14). Conclusion: Compounds 2,7 ~ 12 and 14 are reported from this plants for the first time.
Asunto(s)
LDL-Colesterol/análisis , Apigenina , Disacáridos , Flavonas , Flavonoides , Luteolina , Plantas Medicinales , SitoesterolesRESUMEN
Both recent studies and our calculation suggest that the physicochemical properties of launched drugs changed continuously over the past decades. Besides shifting of commonly used properties, the average biological relevance (BR) and similarity to natural products (NPs) of launched drugs decreased, reflecting the fact that current drug discovery deviated away from NPs. To change the current situation characterized by high investment but low productivity in drug discovery, efforts should be made to improve the BR of the screening library and hunt drugs more effectively in the biologically relevant chemical space. Additionally, a multiple dimensional molecular descriptor, named the biologically relevant spectrum (BRS) was proposed for quantitative structure-activity relationships (QSAR) study or screening library preparation. Prediction models for 43 biological activity categories were developed with BRS and support vector machine (SVM). In most cases, the overall prediction accuracies were around 95% and the Matthew's correlation coefficients (MCC) were over 0.8. Thirty-seven out of 48 drug-activity associations were successfully predicted for drugs that launched from 2006 to 2012, which were not included in the training data set. A web-server named BioRel ( http://ibi.hzau.edu.cn/biorel ) was developed to provide services including BR, BRS calculation, activity class, and pharmacokinetic property prediction.