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The identification of biofilm growth footprints influencing on the biofilm detachment and breakup can advance research into how biofilms form. Thus, a gravity-driven ceramic membrane bioreactor (GDCMBR) was used to investigate the growth, detachment and breakup of biofilm using rainwater pretreated by electrocoagulation under 70-days continuous operation. The in-situ ultrasonic time-domain reflectometry (UTDR) technique was applied to non-invasively determine the biofilm thickness. Initially, the biofilm was slowly thickening, but it would collapse and became thinner after accumulating to a certain level, and then it thickened again in a later period, following a cyclic pattern of 'thickening - collapsing - thickening'. This is because the biofilm growth is related with the accumulation of flocs, however, excessive floc formation results in the biofilm being overweight till reaching the thickness limit and thus collapsing. Subsequently, the biofilm gradually thickens again due to the floc production and continuous deposition. Although the biofilm was dynamically changing, the water quality of treatment of the biofilm always remained stable. Ammonia nitrogen and total phosphorus have been almost completely removed, while CODMn removal efficiency was around 25%. And total bacteria amount in the membrane concentrate was obviously higher than that in the influent with the greater microbial activity, demonstrating the remarkable enrichment effect on bacteria. The understanding of biofilm growth characteristic and footprint identification enables us to develop rational approaches to control biofilm structure for efficient GDCMBR performance and operation lifespan.
Assuntos
Biofilmes , Reatores Biológicos , Cerâmica , Purificação da Água/métodos , Chuva , Membranas Artificiais , FósforoRESUMO
Behavioural variation is essential for animals to adapt to different social and environmental conditions. The Kinship Theory of Intragenomic Conflict (KTIC) predicts that parent-specific alleles can support different behavioural strategies to maximize allele fitness. Previous studies, including in honey bees (Apis mellifera), supported predictions of the KTIC for parent-specific alleles to promote selfish behaviour. Here, we test the KTIC prediction that for altruism-promoting genes (i.e. those that promote behaviours that support the reproductive fitness of kin), the allele with the higher altruism optimum should be selected to be expressed while the other is silenced. In honey bee colonies, workers act altruistically when tending to the queen by performing a 'retinue' behaviour, distributing the queen's mandibular pheromone (QMP) throughout the hive. Workers exposed to QMP do not activate their ovaries, ensuring they care for the queen's brood instead of competing to lay unfertilized eggs. Due to the haplodiploid genetics of honey bees, the KTIC predicts that response to QMP is favoured by the maternal genome. We report evidence for parent-of-origin effects on the retinue response behaviour, ovarian development and gene expression in brains of worker honey bees exposed to QMP, consistent with the KTIC. Additionally, we show enrichment for genes with parent-of-origin expression bias within gene regulatory networks associated with variation in bees' response to QMP. Our study demonstrates that intragenomic conflict can shape diverse social behaviours and influence expression patterns of single genes as well as gene networks.
RESUMO
As a prognostic biomarker for breast cancer, human epidermal growth factor receptor 2 (HER-2) is of crucial diagnostic value. Here, a label-free electrochemical aptasensor was established for the ultrasensitive detection of HER-2 using a modified electrode of Bi-Sb alloy materials (Bi-Sb AMs). The performance of the aptasensor was enhanced greatly due to the introduction of Bi-Sb alloy materials (Bi-Sb AMs) with high conductivity. Furthermore, by integrating the aptasensor with the Sensit Smart U-disk electrochemical analyzer, the point-of-care testing (POCT) for HER-2 was realized. Under the optimal experimental parameters, the POCT analyzer showed a wide linear response from 0.01 pg mL-1 to 100 ng mL-1, with a low detection limit (LOD) of 5.96 fg mL-1 for the detection of HER-2. The presented POCT analyzer exhibited good specificity, stability, and reproducibility. Benefiting from the simple operation and rapid testing, the developed analyzer will have potential application in the prognostic diagnosis and treatment of breast cancer.
Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Humanos , Técnicas Eletroquímicas , Ligas , Reprodutibilidade dos Testes , Limite de Detecção , OuroRESUMO
We have previously shown that microRNAs (miRNAs) in nipple discharge are potential diagnostic biomarkers. In particular, exosomes are present in nipple discharge. Herein, we sought to elucidate the protective role of exosomes on miRNAs in nipple discharge and investigate the stability of miRNAs encapsulated in exosomes under degradative conditions. A novel TTMAAlPc-RNA complex method was used to measure the RNase concentration in colostrum and nipple discharge. Quantitative real-time polymerase chain reaction was performed to test the stability of exogenous synthetic miRNAs (cel-lin-4-5p and cel-miR-2-3p) and endogenous miRNAs (hsa-miR-4732-5p, hsa-miR-3646, hsa-miR-4484, and kshv-miR-K12-5-5p). RNase was present and functional in colostrum and nipple discharge. Endogenous miRNAs were more stably expressed compared to exogenous miRNAs at room temperature and 4°C. Triton X-100 (1%, 30 min) destroyed the exosomal membrane, causing RNA degradation in colostrum but not in nipple discharge. Therefore, we confirmed that exosomes in colostrum and nipple discharge could protect miRNAs from degradation by RNase. Exosomes in nipple discharge may be more resistant to Triton X-100 lysis compared to those in the colostrum. Exosomal miRNAs in nipple discharge in breast cancer are stable under degradative conditions. Differential Triton X-100 sensitivity of exosomes of nipple discharge and colostrum warrants further investigation.
Assuntos
Neoplasias da Mama , MicroRNAs , Derrame Papilar , Humanos , Feminino , Neoplasias da Mama/diagnóstico , Octoxinol , MicroRNAs/genética , Derrame Papilar/metabolismo , RibonucleasesRESUMO
This study compared the ameliorating effects of L-borneol, natural borneol, and synthetic borneol on the injury of different brain regions in the rat model of acute phase of cerebral ischemia/reperfusion(I/R) for the first time, which provides a reference for guiding the rational application of borneol in the early treatment of ischemic stroke and has important academic and application values. Healthy specific pathogen-free(SPF)-grade SD male rats were randomly assigned into 13 groups: a sham-operation group, a model group, a Tween model group, a positive drug(nimodipine) group, and high-, medium-, and low-dose(0.2, 0.1, and 0.05 g·kg~(-1), respectively) groups of L-borneol, natural borneol, and synthetic borneol according to body weight. After 3 days of pre-administration, the rat model of I/R was established by suture-occluded method and confirmed by laser speckle imaging. The corresponding agents in different groups were then administered for 1 day. The body temperature was monitored regularly before pre-administration, days 1, 2, and 3 of pre-administration, 2 h after model awakening, and 1 d after model establishment. Neurological function was evaluated based on Zea-Longa score and modified neurological severity score(mNSS) 2 h and next day after awakening. The rats were anesthetized 30 min after the last administration, and blood was collected from the abdominal aorta. Enzyme-linked immunoassay assay(ELISA) was employed to determine the serum levels of tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6), IL-4, and transforming growth factor-beta1(TGF-ß1). The brain tissues were stained with triphenyltetrazolium chloride(TTC) for the calculation of cerebral infarction rate, and hematoxylin-eosin(HE) staining was used for observing and semi-quantitatively evaluating the pathological damage in different brain regions. Immunohistochemistry was employed to detect the expression of ionized calcium binding adapter molecule 1(IBA1) in microglia. q-PCR was carried out to determine the mRNA levels of iNOS and arginase 1(Arg1), markers of polarization phenotype M1 and M2 in microglia. Compared with the sham-operation group, the model group and the Tween model group showed significantly elevated body temperature, Zea-Longa score, mNSS, and cerebral infarction rate, severely damaged cortex, hippocampus, and striatum, increased serum levels of IL-6 and TNF-α, and decreased serum levels of IL-4 and TGF-ß1. The three borneol products had a tendency to reduce the body temperature of rats 1 day after modeling. Synthetic borneol at the doses of 0.2 and 0.05 g·kg~(-1), as well as L-borneol of 0.1 g·kg~(-1), significantly reduced Zea-Longa score and mNSS. The three borneol products at the dose of 0.2 g·kg~(-1) significantly reduced the cerebral infarction rate. L-borneol at the doses of 0.2 and 0.1 g·kg~(-1) and natural borneol at the dose of 0.1 g·kg~(-1) significantly reduced the pathological damage of the cortex. L-borneol and natural borneol at the dose of 0.1 g·kg~(-1) attenuated the pathological damage of hippocampus, and 0.2 g·kg~(-1) L-borneol attenuated the damage of striatum. The 0.2 g·kg~(-1) L-borneol and the three doses of natural borneol and synthetic borneol significantly reduced the serum level of TNF-α, and the 0.1 g·kg~(-1) synthetic borneol reduced the level of IL-6. L-borneol and synthetic borneol at the dose of 0.2 g·kg~(-1) significantly inhibited the activation of cortical microglia, and 0.2 g·kg~(-1) L-borneol up-regulated the expression of Arg1 and down-regulated the expression level of iNOS. In conclusion, the three borneol products may alleviate inflammation to ameliorate the pathological damage of brain regions of rats in the acute phase of I/R by inhibiting the activation of microglia and promoting the polarization of microglia from M1 type to M2 type. The protective effect on brain followed a trend of L-borneol > synthetic borneol > natural borneol. We suggest L-borneol the first choice for the treatment of I/R in the acute phase.
Assuntos
Isquemia Encefálica , Traumatismo por Reperfusão , Ratos , Masculino , Animais , Fator de Crescimento Transformador beta1/metabolismo , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Interleucina-4/metabolismo , Polissorbatos , Encéfalo , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Infarto Cerebral , ReperfusãoRESUMO
BACKGROUND: Cationic polymers are outstanding representatives of the most efficient small interfering RNA (siRNA) vectors. Low cytotoxicity and siRNA protecting effect can be obtained with these cationic polymers via a variety of structural modifications. Nevertheless, the gap between their efficiency and the requirement for therapeutic processes is still noticeable. METHODS: A cationic polymer vector was synthesized via the copolymerization of N-(1,3-dihydroxy propan-2-yl)methacrylamide (DHPMA) and N-(3-aminopropyl)methacrylamide (APMA). RESULTS: APMA provides amine functionality that allows the conjugation of guanidine and methionine groups. Attributed to the hydroxy groups of DHPMA, the synthesized guanidine and methionine grafted DHPMA-b-APMA block copolymer (mDG) is water soluble and has good biocompatibility. The obtained mDG has high zeta potential, narrow molecular weight distribution, better membrane-penetrating ability, high transfection efficiency, tumor cell targeting ability and high stability. CONCLUSIONS: The synthesized polymer vector can deliver siRNA molecules into tumor cells and then reverse drug resistance by down regulation of P-glycoprotein mRNA expression.
Assuntos
Acrilamidas/química , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/farmacocinética , Metionina/farmacologia , Polímeros/química , RNA Interferente Pequeno/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP , Acrilamidas/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Metionina/química , TransfecçãoRESUMO
High reactive oxygen species (ROS) levels in tumor microenvironment (TME) impair both immunogenic cell death (ICD) efficacy and T cell activity. Furthermore, tumor escapes immunosurveillance via programmed death-1/programmed death ligand-1 (PD-L1) signal, and the insufficient intracellular hydrogen peroxide weakens ferroptosis efficacy. To tackle the above issues, a glutathione (GSH)/ROS/pH triple-responsive prodrug nanomedicine that encapsulates Fe2O3 nanoparticle via electrostatic interaction is constructed for magnetic resonance imaging (MRI)-guided multi-mode theranostics with chemotherapy/ferroptosis/immunotherapy. The diselenide bond consumes ROS in TME to increase T cells and ICD efficacy, the cleavage of which facilitates PD-L1 antagonist D peptide release to block immune checkpoint. After intracellular internalization, Fe2O3 nanoparticle is released in the acidic endosome for MRI simultaneously with lipid peroxides generation for tumor ferroptosis. Doxorubicin is cleaved from polymers in the condition of high intracellular GSH level accompanied by tumor ICD, which simultaneously potentiates ferroptosis by NADPH oxidase mediated H2O2 self-generation. In vivo results indicate that the nanoplatform strengthens tumor ICD, induces cytotoxic T lymphocytes proliferation, inhibits 4T1 tumor regression and metastasis, and prolongs survival median. In all, a new strategy is proposed in strengthening ICD and T cells activity cascade with ferroptosis as well as immune checkpoint blockade for effective tumor immunotherapy.
Assuntos
Ferroptose , Peróxido de Hidrogênio , Imunoterapia , Pró-Fármacos , Espécies Reativas de Oxigênio , Peróxido de Hidrogênio/química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Ferroptose/efeitos dos fármacos , Animais , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Imunoterapia/métodos , Microambiente Tumoral/efeitos dos fármacos , Humanos , Imageamento por Ressonância Magnética/métodos , Polímeros/química , Linhagem Celular Tumoral , Doxorrubicina/química , Doxorrubicina/farmacologia , Nanopartículas/química , Camundongos Endogâmicos BALB C , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Feminino , Glutationa/metabolismo , Glutationa/química , Nanomedicina Teranóstica/métodosRESUMO
OBJECTIVE: Oxidative stress is a hallmark in the pathogenesis of Parkinson disease (PD), which involves the selective loss of nigral dopaminergic neurons in PD. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is well known for its powerful antioxidant property and a wide range of other biological effects. In this study, we investigated the protective effect of resveratrol derived from Rhizoma Et Radix Polygoni Cuspidati and its liposomal form on the nigral cells of PD rats induced by unilateral microinjection of 6-hydroxy dopamine in the striatum. The results showed that after 14 days gavage of resveratrol and resveratrol liposome respectively (20 mg x kg(-1) WB per day), the abnormal rotational behavior of PD rats were deceased evidently, the numbers of total nigral cells, total nigral neurons and TH immuno-positive neurons were more than that of PD rats without given resveratrol or resveratrol liposome, simultaneously, the number of apoptotic nigral cells were decreased obviously. The results also showed that resveratrol and resveratrol liposome could decrease the total ROS activity, increase the total antioxidant capability of the nigral tissues. All the data indicated that resveratrol liposome performed stronger effects than resveratrol except for behavioral improvement. Our study confirmed that resveratrol derived from Rhizoma Et Radix Polygoni Cuspidati and its liposomal form could inhibit the loss of dopaminergic neurons of PD rats, the underlying mechanism may be attributed to their radical scavenging effect and antioxidant property. Due to presumably increased bioavailability, resveratrol liposome possesses the stronger therapeutic effect and may become a better clinical agent for the treatment of PD than free resveratrol.
Assuntos
Lipossomos/farmacologia , Neurônios/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologia , Estilbenos/farmacologia , Substância Negra/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Comportamento/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Substância Negra/metabolismo , Substância Negra/patologiaRESUMO
Photothermal therapy (PTT) has attracted wide attention due to its noninvasiveness and its thermal ablation ability. As photothermal agents are crucial factor in PTT, those with the characteristics of biocompatibility, non-toxicity and high photothermal stability have attracted great interest. In this work, new indocyanine green (IR-820) was utilized as a photothermal agent and near-infrared (NIR) fluorescence imaging nanoprobe. To improve the biocompatibility, poly(styrene-co-maleic anhydride) (PSMA) was utilized to encapsulate the IR-820 molecules to form novel IR-820@PSMA nanoparticles (NPs). Then, the optical and thermal properties of IR-820@PSMA NPs were studied in detail. The IR-820@PSMA NPs showed excellent photothermal stability and biocompatibility. The cellular uptaking ability of the IR-820@PSMA NPs was further confirmed in HeLa cells by the NIR fluorescent confocal microscopic imaging technique. The IR-820@PSMA NPs assisted PTT of living HeLa cells was conducted under 793 nm laser excitation, and a high PTT efficiency of 73.3% was obtained.
Assuntos
Nanopartículas , Neoplasias do Colo do Útero , Feminino , Células HeLa , Humanos , Verde de Indocianina/análogos & derivados , Fototerapia , Terapia Fototérmica , Polímeros , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/terapiaRESUMO
Transferrin (Trf) is a new type of active drug targeting carrier and disease biomarker that regulates the balance of iron ions in human body. The recognition and isolation of Trf is of great significance for disease diagnosis and treatment. Thus, a new type of magnetic dual affinity epitope molecularly imprinted polymer coated on Fe3O4 nanoparticles (Fe3O4@DEMIP) was successfully prepared for specific recognition of Trf. C-terminal nonapeptide and Trf glycan were selected as bi-epitope templates for metal chelation and boron affinity immobilization, respectively. 4-vinylphenylboric acid (4-VP), N-isopropyl acrylamide (NIPAM) and zinc acrylic were used as functional monomers. Results showed that Fe3O4@DEMIP exhibited excellent specific recognition ability adsorption capacity toward Trf, with an adsorption of 43.96 mg g-1 (RSD = 3.28%) and a more satisfactory imprinting factor (about 6.60) than that of other reported imprinting methods. In addition, Fe3O4@DEMIP displayed pH, temperature and magnetic sensitivity properties to realize temperature and pH-controlled recognition and release of target proteins and magnetic rapid separation. Furthermore, the Fe3O4@DEMIP coupled with high-performance liquid chromatography (HPLC) analysis was successfully used for specific recognition of Trf in biosamples. This study provides a reliable protocol for preparing metal chelation and boron affinity dual affinity bi-epitope molecularly imprinted polymers for synergistic and efficient recognition of biomacromolecules in the complex biological systems.
Assuntos
Impressão Molecular , Polímeros , Adsorção , Epitopos , Humanos , TransferrinaRESUMO
Paclitaxel (PTX) is a powerful anticancer natural product, with its separation and purification having been widely studied. In this work, new molecular imprinted polymers (MIPs) using deep eutectic solvents (DESs) with different molar ratios were prepared as functional monomers. These were then used as adsorbents in solid phase extraction (SPE) for the separation of PTX from its structural analogs. The polymers were characterized by energy disperive X-rays (EDX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and fourier transform infrared spectroscopy (FT-IR). The results suggested that the formative regular DES-MIPs had an even pore-size distribution and a large specific surface area. The dynamic adsorption and static adsorption showed that the DES-MIPs had excellent adsorption performance, with a maximum adsorption capacity and optimum adsorption time of 87.08â¯mg/g and 180â¯min, respectively. The selective adsorption experiments showed that the material had outstanding selectivity, and the maximum selectivity factor was 6.20. For stability, after six consecutive adsorption and desorption cycles, the DES-MIPs maintained the perfect stability and reusability. Furthermore, the fabricated SPE column was successfully utilized for extracting and eluting PTX. This study provides a reliable protocol for the separation and purification PTX from its structural analogs and the DES-MIPs materials have excellent potential application value in pharmaceutical industry.
Assuntos
Impressão Molecular , Adsorção , Polímeros Molecularmente Impressos , Paclitaxel , Extração em Fase Sólida , Solventes , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Biocompatible magnetic molecularly imprinted polymers (BMMIPs) were prepared with Zein for the first time, and were used to enrich tetracycline compounds selectively. Innovative combination of BMMIPs and electrochemistry to obtain lower detection line to satisfy industrial detection demands. Using Zein as the crosslinking agent, the polymers were synthesized on the surface of Fe3O4 particles. The scanning electron microscope, transmission electron microscope and X-ray diffraction technologies were used to characterize BMMIPs. Through optimization, BMMIPs attained large adsorption capacity (236.40 mg/g) with fast kinetics (40 min) and followed the Langmuir isotherm and pseudo-second-order kinetic models. BMMIPs had good recognition ability, the selective factors of oxytetracycline, chlortetracycline, doxycycline were 4.78, 4.23, and 3.39, respectively. Excellent linearity was attained in the range of 0.025-500 µg/mL, with low detection limits and low quantitation limits of 0.025 and 0.083 µg/mL. According to our exploring, BMMIPs was ideal materials for enrichment of tetracycline in complex biological samples.
Assuntos
Materiais Biocompatíveis/química , Contaminação de Alimentos/análise , Leite/química , Impressão Molecular/métodos , Tetraciclinas/análise , Adsorção , Animais , Antibacterianos/análise , Antibacterianos/química , Antibacterianos/isolamento & purificação , Técnicas Eletroquímicas , Análise de Alimentos/métodos , Limite de Detecção , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Polímeros/química , Tetraciclina/análise , Tetraciclina/química , Tetraciclina/isolamento & purificação , Tetraciclinas/química , Tetraciclinas/isolamento & purificação , Difração de Raios X , Zeína/químicaRESUMO
Reversible addition-fragmentation chain transfer (RAFT) polymerization integrates the advantages of radical polymerization and living polymerization. This work presents the preparation of methionine functionalized biocompatible block copolymers via RAFT polymerization. Firstly, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-aminopropyl)methacrylamide (BNHEMA-b-APMA, BA) was synthesized via RAFT polymerization using 4,4'-azobis(4-cyanovaleric acid) (ACVA) as an initiating agent and 4-cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent. Subsequently, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-guanidinopropyl)methacrylamide (methionine grafted BNHEMA-b-GPMA, mBG) was prepared by modifying amine groups in APMA with methionine and guanidine groups. Three kinds of block polymers, mBG1, mBG2, and mBG3, were synthesized for comparison. A ninhydrin reaction was used to quantify the APMA content; mBG1, mBG2, and mBG3 had 21%, 37%, and 52% of APMA, respectively. Gel permeation chromatography (GPC) results showed that BA copolymers possess molecular weights of 16,200 (BA1), 20,900(BA2), and 27,200(BA3) g/mol. The plasmid DNA (pDNA) complexing ability of the obtained block copolymer gene carriers was also investigated. The charge ratios (N/P) were 8, 16, and 4 when pDNA was complexed completely with mBG1, mBG2, mBG3, respectively. When the N/P ratio of mBG/pDNA polyplexes was higher than 1, the Zeta potential of mBG was positive. At an N/P ratio between 16 and 32, the average particle size of mBG/pDNA polyplexes was between 100-200 nm. Overall, this work illustrates a simple and convenient protocol for the block copolymer carrier synthesis.
Assuntos
DNA/genética , Metionina/uso terapêutico , Plasmídeos/metabolismo , Polímeros/química , Metionina/farmacologia , Polimerização , TransfecçãoRESUMO
In this study, a novel sandwiched electrochemiluminescence (ECL) immunosensor for the detection of carcinoembryonic antigen (CEA) was developed. The nanocomposite of polydopamine and Ag nanoparticles (PDA-AgNPs) was prepared by the redox reaction between Ag+ and dopamine. This nanocomposite not only provided an effective matrix for the immobilization of primary antibody (Ab1) but also enhanced the conductivity of the electrode. Carbon quantum dots (CQDs) were immobilized on the poly(ethylenimine) functionalized graphene oxide (PEI-GO) through amido-bond. Then Au nanoparticles were decorated on the CQDs modified PEI-GO matrix, and the resulted complex AuNPs/CQDs-PEI-GO was introduced to link secondary antibody (Ab2). The CQDs can be connected to the electrode surface through the combination of CEA with Ab1 and Ab2, and then the amplified electrochemiluminescence signal of CQDs was obtained with the synergistic effect of AgNPs, polydopamine, AuNPs and PEI-GO. Under the optimal conditions, the ECL intensity was proportional to the logarithm value of CEA concentration in the linear range from 5pgmL-1 to 500ngmL-1 with a detection limit of 1.67pgmL-1 for CEA detection. The immunosensor was applied for the CEA detection in real samples with satisfactory results. The proposed ECL immunosensor showed good performance with high sensitivity, specificity, reproducibility, stability and will be potential in clinical detection.
Assuntos
Anticorpos Imobilizados/química , Carbono/química , Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Indóis/química , Nanocompostos/química , Polímeros/química , Pontos Quânticos/química , Técnicas Biossensoriais/métodos , Ouro/química , Grafite/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanocompostos/ultraestrutura , Polietilenoimina/química , Reprodutibilidade dos Testes , Prata/químicaRESUMO
OBJECTIVE: Oxidative stress which is an important factor in the pathogenesis of Parkinson's disease (PD) leads to the selective loss of nigral dopaminergic neurons in PD. Resveratrol is a well known antioxidant that exerts extensive pharmacological effects. This study aimed to investigate the protective effect of resveratrol derived from Polygonum cuspidatum and its liposomal form on nigral cells of PD rats. METHODS: A rat PD model was established by unilateral microinjection of 6-hydroxy dopamine in the striatum. Then, P. cuspidatum and its liposomal form were intragastrically administered once daily for 2 consecutive weeks. The behaviors, tyrosine hydroxylase positive cells, apoptotic cells, ROS level and total antioxidant capacity were determined. RESULTS: Our results showed after 14 days of oral treatment with resveratrol or resveratrol liposome (20 mg/kg per day), the abnormal rotational behavior, the loss and apoptosis of nigral cells, and the levels of total reactive oxygen species were markedly decreased and the total antioxidant capability of nigral tissues significantly improved. Furthermore, resveratrol liposome showed more profound effects than free resveratrol. CONCLUSION: Resveratrol derived from P. cuspidatum and its liposomal form could protect the dopaminergic neurons in PD rats, to which their radical scavenging ability and antioxidant properties may attribute. Presumably due to the increased bioavailability, resveratrol liposome exerts more potent protection and may become a promising agent for the treatment of PD than free resveratrol.
Assuntos
Modelos Animais de Doenças , Fallopia japonica , Fármacos Neuroprotetores/administração & dosagem , Estilbenos/administração & dosagem , Substância Negra/citologia , Substância Negra/efeitos dos fármacos , Animais , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/isolamento & purificação , Lipossomos , Masculino , Fármacos Neuroprotetores/isolamento & purificação , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar , Resveratrol , Estilbenos/isolamento & purificação , Substância Negra/metabolismoRESUMO
Chromophoric dissolved organic matter (CDOM) represents one of the primary light-absorbing species in natural waters and plays a critical in determining the aquatic light field. CDOM shows a featureless absorption spectrum that increases exponentially with decreasing wavelength, which limits the penetration of biologically damaging UV-B radiation (wavelength from 280 to 320 nm) in the water column, thus shielding aquatic organisms. CDOM absorption measurements and their relationship with dissolved organic carbon (DOC), and fluorescence are presented in typical macrophyte and algae lake zone of Lake Taihu based on a field investigation in April in 2004 and lab analysis. Absorption spectral of CDOM was measured from 240 to 800 nm using a Shimadzu UV-2401PC UV-Vis recording spectrophotometer. Fluorescence with an excitation wavelength of 355 nm, an emission wavelength of 450 nm is measured using a Shimadzu 5301 spectrofluorometer. Concentrations of DOC ranged from 6.3 to 17.2 mg/L with an average of 9.08 +/- 2.66 mg/L. CDOM absorption coefficients at 280 nm and 355 nm were in the range of 11.2 - 32.6 m(-1) (average 17.46m(-1) +/- 5.75 m(-1) and 2.4 - 8.3 m(-1) (average 4.17m(-1) +/- 1.47 m(-l)), respectively. The values of the DOC-specific absorption coefficient at 355 nm ranged from 0.31 to 0.64 L x (mg x m)-1. Fluorescence emission at 450 nm, excited at 355 nm, had a mean value of 1.32nm(-1) +/- 0.84 nm(-1). A significant lake zone difference is found in DOC concentration, CDOM absorption coefficient and fluorescence, but not in DOC-specific absorption coefficient and spectral slope coefficient. This regional distribution pattern is in agreement with the location of sources of yellow substance: highest concentrations close to river mouth under the influence of river inflow, lower values in East Lake Taihu. The values of algae lake zone are obvious larger than those of macrophyte lake zone. In Meiliang Bay, CDOM absorption, DOC concentration and fluorescence tend to decreasing from inside to mouth of the Bay. The results show a good correlation between CDOM absorption and DOC coefficients during 280 - 500 nm short wavelength intervals. The R-square coefficient between CDOM absorption and DOC concentration decreases with the increase of wavelength from 280 to 500 nm. The significant linear regression correlations between fluorescence, DOC concentration and absorption coefficients were found at 355 nm. The exponential slope coefficients ranged from 13.0 to 16.4 microm(-1) with a mean value 14.37microm(-1) +/- 0.73microm(-1), 17.3microm(-1) - 20.3microm(-1) with a mean value 19.17microm(-1) +/- 0.84microm(-1) and 12.0microm(-1) - 15.8microm(-1) with a mean value 13.38microm(-1) +/- 0.82microm(-1) over the 280 - 500 nm, 280 - 360 nm and 360 - 440 nm intervals.