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1.
Small ; : e2400238, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38385800

RESUMO

The performance of Stimulated Emission Depletion (STED) microscopy depends critically on the fluorescent probe. Ultrasmall Au nanoclusters (Au NCs) exhibit large Stokes shift, and good stimulated emission response, which are potentially useful for STED imaging. However, Au NCs are polydispersed in size, sensitive to the surrounding environment, and difficult to control surface functional group stoichiometry, which results in reduced density and high heterogeneity in the labeling of biological structures. Here, this limitation is overcome by developing a method to encapsulate ultrasmall Au NCs with DNA cages, which yielded monodispersed, and monofunctionalized Au NCs that are long-term stable. Moreover, the DNA-caging also greatly improved the fluorescence quantum yield and photostability of Au NCs. In STED imaging, the DNA-caged Au NCs yielded ≈40 nm spatial resolution and are able to resolve microtubule line shapes with good labeling density and homogeneity. In contrast, without caging, the Au NCs-DNA conjugates only achieved ≈55 nm resolution and yielded spotted, poorly resolved microtubule structures, due to the presence of aggregates. Overall, a method is developed to achieve precise surface functionalization and greatly improve the monodispersity, stability, as well as optical properties of Au NCs, providing a promising class of fluorescent probes for STED imaging.

2.
Sci Rep ; 14(1): 1059, 2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38212473

RESUMO

The pathogenesis of allergic asthma is similar to that of allergic rhinitis, with inflammation cells producing and releasing inflammatory mediators and cytokines closely related to CCR3.Based on the theory of "one airway, one disease", the use of CCR3 monoclonal antibody may have a similar effect on allergic rhinitis. However, there are few studies on CCR3 monoclonal antibody in allergic rhinitis. Therefore, the aim of this study was to investigate the effective concentration of CCR3 monoclonal antibody, to compare the effects of different methods of administration, and to examine the lung condition of allergic mice to investigate whether antibody treatment protects the lungs. In this study, we constructed a mouse model of allergic rhinitis and intraperitoneally injected different doses of CCR3 monoclonal antibody (5, 10, and 20 uL/mg) to observe its therapeutic effect: observing changes in tissue morphology of nasal mucosa, infiltration of inflammation, and using ELISA to detect changes in relevant inflammatory mediators and cytokines, studying the role of CCR3 mAb in inhibiting CCR3-related actions on the nasal mucosa of allergic rhinitis mice. Furthermore, In addition, the therapeutic effects of intraperitoneal injection (i.p.) and intranasal administration (i.n.) were studied on the basis of effective concentrations.


Assuntos
Rinite Alérgica , Camundongos , Animais , Mucosa Nasal/patologia , Citocinas/uso terapêutico , Modelos Animais de Doenças , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Inflamação/patologia , Mediadores da Inflamação , Camundongos Endogâmicos BALB C , Ovalbumina
3.
Anal Chem ; 96(2): 866-875, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38164718

RESUMO

Despite extensive efforts, point-of-care testing (POCT) of protein markers with high sensitivity and specificity and at a low cost remains challenging. In this work, we developed an aptamer-CRISPR/Cas12a-regulated liquid crystal sensor (ALICS), which achieved ultrasensitive protein detection using a smartphone-coupled portable device. Specifically, a DNA probe that contained an aptamer sequence for the protein target and an activation sequence for the Cas12a-crRNA complex was prefixed on a substrate and was released in the presence of target. The activation sequence of the DNA probe then bound to the Cas12a-crRNA complex to activate the collateral cleavage reaction, producing a bright-to-dark optical change in a DNA-functionalized liquid crystal interface. The optical image was captured by a smartphone for quantification of the target concentration. For the two model proteins, SARS-CoV-2 nucleocapsid protein (N protein) and carcino-embryonic antigen (CEA), ALICS achieved detection limits of 0.4 and 20 pg/mL, respectively, which are higher than the typical sensitivity of the SARS-CoV-2 test and the clinical CEA test. In the clinical sample tests, ALICS also exhibited superior performances compared to those of the commercial ELISA and lateral flow test kits. Overall, ALICS represents an ultrasensitive and cost-effective platform for POCT, showing a great potential for pathogen detection and disease monitoring under resource-limited conditions.


Assuntos
Técnicas Biossensoriais , Cristais Líquidos , Sistemas Automatizados de Assistência Junto ao Leito , Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , Oligonucleotídeos , Sondas de DNA
4.
J Nat Prod ; 86(9): 2162-2170, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37615114

RESUMO

Six new isoquinoline alkaloids, including aporphine alkaloids (2, 3, 9, and 10), a benzylisoquinoline alkaloid (13), and a protoberberine alkaloid (17), were isolated from the roots of Fissistigma polyanthum, along with a new furanone (20) and 13 known isoquinoline alkaloids (1, 4-8, 11, 12, 14-16, 18, and 19). The structures of the new compounds were elucidated by the analysis of spectroscopic data. Compounds 1 and 2 are rare oxalyl-fused dehydroaporphine alkaloids. Compound 12 presented the most potent dual-target activities on AChE inhibition and Aß aggregation inhibition, while compounds 13 and 19 simultaneously exhibited discernible AChE and BChE inhibitions with antioxidant activities. The activity results indicate that F. polyanthum alkaloids have a potential of inhibition and prevention of Alzheimer's disease mainly through both ChEs and ß-amyloid pathways in addition to antioxidant activity.


Assuntos
Alcaloides , Annonaceae , Benzilisoquinolinas , Estrutura Molecular , Alcaloides/farmacologia , Alcaloides/química , Isoquinolinas/farmacologia , Isoquinolinas/química
5.
Adv Healthc Mater ; 12(23): e2300490, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37053081

RESUMO

Nanoenzymes have been widely explored for chemodynamic therapy (CDT) in cancer treatment. However, poor catalytic efficiency of nanoenzymes, especially in the tumor microenvironment with insufficient H2 O2 and mild acidity, limits the effect of CDT. Herein, a new ultrathin RuCu nanosheet (NS) based nanoenzyme which has a large specific surface area and abundant channels and defects is developed. The RuCu NSs show superb catalytic efficiency for the oxidation of peroxidase substrate H2 O2 at a wide range of pH and their catalytic efficiency (kcat /Km = 177.2 m-1  s-1 ) is about 14.9 times higher than that of the single-atom catalyst FeN3 P. Besides being an efficient nanozyme as peroxidase, the RuCu NSs possess other two enzyme activities, not only disproportionating superoxide anion to produce H2 O2 but also consuming glutathione to keep a high concentration of H2 O2 in the tumor microenvironment for Fenton reaction. With these advantages, the RuCu NSs exhibit good performance to kill cancer cells and inhibit tumor growth in mice, demonstrating a promising potential as new CDT reagent.


Assuntos
Neoplasias , Peroxidase , Animais , Camundongos , Peroxidases , Catálise , Glutationa , Superóxidos , Microambiente Tumoral , Peróxido de Hidrogênio , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico
6.
Asia Pac J Clin Oncol ; 19(2): e60-e70, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35404506

RESUMO

BACKGROUND: Characteristic symptoms and signs are often absent in patients with hepatocellular carcinoma (HCC). As a result, many patients are not diagnosed until their tumors have grown to large (> 5cm) or huge sizes (> 10cm). Liver resection has traditionally been reserved for patients with small HCC, but more recently it is being used for patients with large and huge tumors. The aim of this study was to determine risk predictors of recurrence, patterns of recurrence, and survival rates for large and huge HCC patients who underwent curative liver resection. MATERIALS AND METHODS: We retrospectively identified a subgroup of patients who underwent liver resection for HCC with diameters 5 cm or larger. Overall survival (OS) and recurrence-free survival (RFS) rates were calculated using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to investigate potential risk factors for recurrence and death. RESULTS: Among 897 patients, the median follow-up was 48 (range, 5-140) months. The 1-, 3-, and 5-year RFS rates were 51.6%, 36.1%, and 30.1%, respectively, and OS rates were 80.2%, 55.4%, and 47.7%, respectively. Significant independent predictors of recurrence were preoperative satellite nodule (HR = 2.25; 95% CI, 1.17-4.31; p = .02), preoperative AFP levels above 400 ng/ml (HR = 1.23; 95% CI, 1.04-1.45; p = .01), resection margins of 1 cm or less (HR = 1.21; 95% CI, 1.00-1.46; p = .047), cirrhosis (HR = 2.64; 95% CI, 2.13-3.28; p < .001), and microvascular invasion (HR = 1.71; 95% CI, 1.45-2.20; p < .001). All of these except narrow resection margin were also independent risk factors of OS. CONCLUSIONS: Hepatic resection for patients with large and huge HCC without hepatic vascular invasion, extrahepatic metastases, or severe chronic liver disease results in acceptable long-term outcomes.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Prognóstico , Recidiva Local de Neoplasia/patologia
7.
Anal Chem ; 95(2): 1132-1139, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36533834

RESUMO

Extracellular vesicles (EVs) have emerged as a potential biomarker in liquid biopsy. However, cancer heterogeneity poses significant challenge to precise molecular diagnosis based on single-parameter input. Hence, strategies for analyzing multiple inputs with molecular computing were developed with the aim of improving diagnostic accuracy in liquid biopsy. In the present study, based on the surface of aptamer-encoded EVs, three toe-hold extended DNA aptamers served as specific inputs to perform AND-logic-gating to distinguish between healthy and cancerous EVs. In addition, this strategy has been successfully employed to analyze circulating EVs in clinical samples from colorectal cancer patients and healthy donors. The developed method has a promising future in the analysis of multiplex EV membrane proteins and the identification of early cancer.


Assuntos
Aptâmeros de Nucleotídeos , Neoplasias Colorretais , Vesículas Extracelulares , Humanos , Biomarcadores Tumorais/metabolismo , Vesículas Extracelulares/metabolismo , Biópsia Líquida/métodos , Aptâmeros de Nucleotídeos/metabolismo , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/metabolismo
8.
Nat Biomed Eng ; 6(8): 979-991, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35986185

RESUMO

Sensitive and specific blood-based assays for the detection of pulmonary and extrapulmonary tuberculosis would reduce mortality associated with missed diagnoses, particularly in children. Here we report a nanoparticle-enhanced immunoassay read by dark-field microscopy that detects two Mycobacterium tuberculosis virulence factors (the glycolipid lipoarabinomannan and its carrier protein) on the surface of circulating extracellular vesicles. In a cohort study of 147 hospitalized and severely immunosuppressed children living with HIV, the assay detected 58 of the 78 (74%) cases of paediatric tuberculosis, 48 of the 66 (73%) cases that were missed by microbiological assays, and 8 out of 10 (80%) cases undiagnosed during the study. It also distinguished tuberculosis from latent-tuberculosis infections in non-human primates. We adapted the assay to make it portable and operable by a smartphone. With further development, the assay may facilitate the detection of tuberculosis at the point of care, particularly in resource-limited settings.


Assuntos
Vesículas Extracelulares , Mycobacterium tuberculosis , Tuberculose , Animais , Estudos de Coortes , Humanos , Tuberculose/diagnóstico , Fatores de Virulência
9.
Front Pharmacol ; 13: 917384, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35734398

RESUMO

Background: The RESORCE trial reported that regorafenib was effective as the second-line treatment for patients with hepatocellular carcinoma (HCC) after progression on sorafenib. Real-world data are needed to assess clinical outcomes and adverse events in the setting of daily practice. Objective: We aimed to evaluate the efficacy and safety of regorafenib after disease progression with sorafenib in Chinese patients with advanced HCC. Patients and Methods: A total of 41 patients with advanced HCC who did not respond to sorafenib and followed a regorafenib regimen were enrolled in this retrospective study. Overall survival (OS), progression-free survival (PFS), radiological responses, and adverse events (AEs) were evaluated. Survival curves were compared by using the log-rank test and constructed with the Kaplan-Meier method. Results: The median PFS with regorafenib was 6.6 months (range: 5.0-8.2 months), and the median OS with regorafenib was not reached. The 1-year OS rate of regorafenib was 66.4%. The median OS of sequential sorafenib to regorafenib treatment was 35.3 months [95% confidence interval (CI), 24.3-46.3], and the 2-year OS rate of sequential sorafenib to regorafenib treatment was 74.4%. The most common AEs of regorafenib treatment were elevated aspartate aminotransferase [17/41 patients (41.5%)], elevated alanine aminotransferase [16/41 patients (39%)] and hand-foot syndrome [14/41 patients (34.1%)]. Conclusion: Regorafenib appears to be safe and clinically effective in patients with advanced HCC who progressed on first-line sorafenib.

10.
Nanoscale ; 14(21): 7856-7863, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35583119

RESUMO

Multidrug resistance (MDR) has become one of the most intractable problems in clinics as it would cause failure in chemotherapy. In this study, we demonstrated that a nanoscale self-assembled nanomedicine, which almost consisted of a pure chemo-drug, could efficiently overcome MDR. Celastrol (CST) was directly assembled into a discrete nanomedicine by precipitation, and then CST nanoparticles (CNPs) inhibited drug efflux pumps by activating HSF-1 expression and promoting HSF-1 translocation into nucleus to suppress the Pgp expression. The more drug accumulated in cells could activate apoptosis signals simultaneously and realize drug resistance reversal. CNPs significantly increased the level of ROS to regulate ERK/JNK signaling, which would further induce resistant cell apoptosis. The tandem apoptosis strategy used the same concentration of CST but achieved a higher antitumor effect. Overall, our study provides a new translational and alternative strategy using conventional natural products to overcome MDR with high efficacy.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Triterpenos Pentacíclicos/farmacologia , Triterpenos Pentacíclicos/uso terapêutico
11.
Colloids Surf B Biointerfaces ; 213: 112424, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35227993

RESUMO

Antibiotic bone cement filling technology has been widely used in the treatment of infectious bone defects for decades. However, the current treatment requires multiple complicated procedures, which would lead to pain and financial burden for patients. Repairing bone defects and control infection at the same time is the pain spot of orthopaedic area. In this study, we develop a composite scaffold that aiming at effectively repair infectious bone defects simultaneously. Vancomycin hydrochloride(Van) /Poly(lactic-co-glycolic) acid(PLGA) microspheres prepared by double emulsion method were successfully loaded into ß-tricalcium phosphate scaffold through electrostatic and physical crosslinking. Full characterization, including mechanical properties, biocompatibility, in vitro release profile and antibacterial properties of the composite scaffolds(CPSFs) were performed. The rabbit osteomyelitis model based on big hole and small hole methods was established. Pharmacodynamics study, including the local bacteriostatic and osteogenic ability were evaluated by X-ray, Micro-CT and histopathology at 4 months after surgery. These findings indicate that a reliable rabbit model of local bone defect infection successfully established by big hole approach. The CPSFs with significant histocompatibility and biocompatibility could sustained release vancomycin for extended duration. It exhibited great application potential in clinical aim at the indication of local infectious bone defects.


Assuntos
Fosfatos de Cálcio , Osteogênese , Animais , Regeneração Óssea , Fosfatos de Cálcio/farmacologia , Humanos , Microesferas , Dor , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Tecidos Suporte , Vancomicina/farmacologia
12.
Animals (Basel) ; 10(9)2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32947771

RESUMO

Avian pathogenic Escherichia coli (APEC) is the leading cause of systemic infections in poultry worldwide and has a hidden threat to public health. Escherichia coli type three secretion system 2 (ETT2), similar to the Salmonella pathogenicity island SPI1, is widely distributed in APEC and associated with virulence. The function of YqeI, which is one of the hypothetical transcriptional regulators locating at the ETT2 locus of APEC, is unknown. In this study, we successfully obtained the mutant strain AE81ΔyqeI of the wild type strain AE81 and performed the transcriptional profiling assays. Additionally, the transcriptional sequencing results revealed that YqeI influenced localization, locomotion and biological adhesion and so on. The transmission electron microscope observation showed that the wild type strain AE81 possessed long curved flagella, whereas the mutant strain AE81ΔyqeI hardly had any. The strain AE81ΔyqeI exhibited lower motility than AE81 after culturing the dilute bacterial suspension on a semisolid medium. It was also found that the survival ability of AE81ΔyqeI weakened significantly when AE81ΔyqeI was cultured with 0%, 10%, 20%, 30%, 40% and 50% SPF serum in PBS, and AE81ΔyqeI had decreased adherence to DF-1 cells compared with AE81 in the bacterial adhesion assay. The bacterial colonization assay indicated that the virulence of AE81ΔyqeI was reduced in the heart, liver, spleen, and lung. These results confirmed that the transcription regulator YqeI is involved in APEC's pathogenicity, and this study provides clues for future research.

13.
Nanoscale ; 11(11): 4743-4750, 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30604821

RESUMO

Gadolinium-metallofullerenols (Gd@C82(OH)22) are a promising agent for cancer therapy and have shown beneficial effects in regulating the tumor microenvironment with low toxicity. However, the underlying mechanism by which Gd@C82(OH)22 interacts with fibroblasts remains unclear. In order to explore the critical role that activated fibroblasts play in tumorigenesis and fibrosis, we investigated the regulatory effect of Gd@C82(OH)22 in fibroblast activation and oncogenic transformation, and found that the PDGFR-α is an essential molecule in modulating the morphology and functional changes in fibroblasts after Gd@C82(OH)22 treatment. Apart from increasing the PDGFR-α protein level, Gd@C82(OH)22 nanoparticles also significantly increased the protein level of Rab5, which is required for regulating PDGFR-α endosomal recycling. The Rab5-mediated recycling of PDGFR-α maybe attributed to the Gd@C82(OH)22 regulated inhibition of fibroblast activation. Overall, our work demonstrated that Gd@C82(OH)22 nanoparticles can attenuate the PDGF-stimulated phosphorylation of PDGFR-α in fibroblasts and suppress the fibroblast activation by interrupting endosomal recycling. These findings may be contributed to the collagen accumulation for encaging cancer.


Assuntos
Antineoplásicos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fulerenos/química , Gadolínio/química , Nanopartículas Metálicas/química , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Antineoplásicos/química , Forma Celular/efeitos dos fármacos , Endossomos/metabolismo , Fibroblastos/citologia , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Células NIH 3T3 , Fosforilação/efeitos dos fármacos , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Transdução de Sinais/efeitos dos fármacos , Proteínas rab5 de Ligação ao GTP/metabolismo
14.
ACS Appl Mater Interfaces ; 11(3): 2647-2654, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29707939

RESUMO

Graphdiyne (GDY) is a novel two-dimensional (2D) carbon allotrope with sp-hybridized carbon atoms and hexagonal rings. Because of its unique structure and electronic property, GDY was reported as a promising candidate applied in energy storage, catalysis, biosensing and so on. However, using GDY as a platform to immobilize metal ion or enzyme was still not reported. Here, we presented a GDY-based composite with dual-enzyme activity by immobilizing ferrous ion and glucose oxidase onto GDY sheet. GDY showed great adsorption capacity and maintained the high catalytic activity of ferrous ion. The ferrous ion preferred to adsorb in between the neighboring two C-C triple bonds of GDY with lower adsorption energy (-5.64 eV) if compared to graphene (-1.69 eV). Meanwhile, GDY exhibited the ability of adsorbing glucose oxidase while did not obviously influence the structure and catalytic activity of the enzyme. The as-prepared composite was successfully used in one-step blood glucose detection. This work provides a new insight on ion and enzyme immobilization by 2D material.


Assuntos
Técnicas Biossensoriais , Enzimas Imobilizadas/química , Glucose Oxidase/química , Glucose/isolamento & purificação , Carbono/química , Glucose/química , Grafite/química , Humanos , Ferro/química
15.
Nanoscale ; 10(26): 12639-12649, 2018 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-29943786

RESUMO

A key challenge of chemotherapy in clinical treatments is multidrug resistance (MDR), which mainly arises from drug efflux-induced tumor cell survival. Thus, it is necessary to provide biocompatible chemotherapeutics to improve drug accumulation in MDR cells. Herein, two clinical small molecular drugs, celastrol (CST) and doxorubicin (DOX), were self-assembled into carrier-free and biocompatible nanoparticles (CST/DOX NPs) via a simple and green precipitation method for synergistic combination chemotherapy to overcome DOX resistance. These spherical CST/DOX NPs can improve the water-solubility of CST, reduce the dosage of DOX, and therefore significantly enhance cellular drug accumulation by activating heat shock factor 1 (HSF-1) and inhibiting NF-κB to depress P-gp expression, which results in apoptosis and autophagy of DOX resistant cells through the ROS/JNK signaling pathway. Finally, synergistic combination chemotherapy was attained in both MCF-7/MDR cells and 3D multicellular tumor spheroids. Thus, CST/DOX NPs provide an alternative for overcoming drug resistance in future clinical applications.


Assuntos
Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Nanopartículas , Triterpenos/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Apoptose , Autofagia , Linhagem Celular Tumoral , Fatores de Transcrição de Choque Térmico/metabolismo , Humanos , Células MCF-7 , NF-kappa B/metabolismo , Triterpenos Pentacíclicos , Transdução de Sinais
16.
J Biomed Nanotechnol ; 14(1): 179-189, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29463375

RESUMO

The incidence of many diseases is closely related to air pollution. Suspended particulate matter of different sizes represents a major source of environmental pollution. Fine particles, especially ultrafine particles smaller than 2.5 µm, might be more harmful to human health because of their extremely small size, which enables them to penetrate human lungs and bronchi and makes them difficult to filter out. Therefore, the fatal risks associated with PM call for the development of air purification materials with high efficiency and low resistance. In this study, poly(lactic-co-glycolic acid) and polycaprolactone were used to prepare nanofibrous membranes suitable for the efficient capture of particulate matter formed in haze-fog episodes, especially particles smaller than 0.5 µm. The present nanofibrous membranes exhibit superior filtration efficiency for particulate matter, with a much lower pressure drop compared to typical commercial microfiber air filters. Thanks to the combination of small pore size, high porosity, and robust mechanical properties, the poly(lactic-co-glycolic acid)/polycaprolactone (6:4) composite membrane exhibits a high filtration efficiency of 97.81% and a low pressure drop of 181 Pa. These favorable features, combined with the easy availability and biocompatibility of the component materials, highlight the promising potential of the present nanofibrous membranes for the development of personal wearable air purifiers.


Assuntos
Ácido Láctico , Nanofibras , Poliésteres , Ácido Poliglicólico , Filtros de Ar , Glicóis , Humanos , Teste de Materiais , Tamanho da Partícula , Material Particulado , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Dispositivos Eletrônicos Vestíveis
17.
Sci Bull (Beijing) ; 63(2): 92-100, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36658930

RESUMO

Doxorubicin (DOX) is widely used in cancer therapy. However, its application is sometimes limited by its adverse cardiotoxicity and delivery pathways. In our study, we prepared a topical implantable delivery device for controlled drug release and site-specific treatment. The core region consisted of poly (lactic co-glycolic acid) and poly-caprolactone, whereas the shell region was composed of cross-linked gelatin. DOX was enclosed in the core region of a core-shell nanofiber obtained by electrospinning. This implantable delivery device was implanted on the top of the melanoma in a mouse model, which had shown a DOX-controlled release profile with sustained and sufficient local concentration against melanoma growth in mice with negligible side effects. Compared with the traditional intravenous administration, the implantable device allows precisely localized treatment and therefore can reduce the dose, decrease the injection frequency, and ensure antitumor efficacy associated with lower side effects to normal tissues. Using a coaxial electrospinning process, it is promising to deliver different hydrophobic or hydrophilic drugs for direct tumor site-specific therapy without large systemic doses and minimized systemic toxicity.

18.
Bioconjug Chem ; 28(8): 2125-2134, 2017 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-28686433

RESUMO

DNA polymerases are known to recognize preferably d-nucleotides over l-nucleotides during DNA synthesis. Here, we report that several general DNA polymerases catalyze polymerization reactions of nucleotides directed by the DNA template containing an l-thymidine (l-T). The results display that the 5'-3' primer extension of natural nucleotides get to the end at chiral modification site with Taq and Phanta Max DNA polymerases, but the primer extension proceeds to the end of the template catalyzed by Deep Vent (exo-), Vent (exo-), and Therminator DNA polymerases. Furthermore, templating l-nucleoside displays a lag in the deoxyribonucleotide triphosphate (dNTP) incorporation rates relative to natural template by kinetics analysis, and polymerase chain reactions were inhibited with the DNA template containing two or three consecutive l-Ts. Most interestingly, no single base mutation or mismatch mixture corresponding to the location of l-T in the template was found, which is physiologically significant because they provide a theoretical basis on the involvement of DNA polymerase in the effective repair of l-T that may lead to cytotoxicity.


Assuntos
Reparo do DNA , DNA Polimerase Dirigida por DNA/metabolismo , DNA/química , DNA/metabolismo , Desoxirribonucleotídeos/metabolismo , Timidina/metabolismo , Pareamento de Bases , Sequência de Bases , DNA/biossíntese , DNA/genética , Replicação do DNA , Cinética , Estereoisomerismo
19.
Sci Rep ; 7(1): 2994, 2017 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-28592826

RESUMO

D-amino acid oxidases (DAAO) are stereospecific enzymes which are generally almost inactive towards L-enantiomer in neutral solution when L-, D-amino acids are supplied as substrates. In this paper, the D-amino acid oxidase can catalytic oxidize L-amino acids by modulating pH of aqueous solution. With L-Pro as substrate, the catalytic rate (k cat) and the affinity (K m) of DAAO were 6.71 s-1 and 33 mM at pH 8.0, respectively, suggesting that optimal pH condition enhanced the activity of DAAO towards L-Pro. Similar results were obtained when L-Ala (pH 9.8), L-Arg (pH 6.5), L-Phe (pH 9.0), L-Thr (pH 9.4), and L-Val (pH 8.5) were catalyzed by DAAO at various pH values. The racemization of the L-amino acids was not found by capillary electrophoresis analysis during oxidation, and quantification analysis of L-amino acids before and after catalytic reaction was performed, which confirmed that the modulation of enantioselectivity of DAAO resulted from the oxidation of L-amino acids rather than D-amino acids by changing pH. A mechanistic model was proposed to explain enhanced activity of DAAO towards L-amino acids under optimal pH condition.


Assuntos
D-Aminoácido Oxidase/metabolismo , Concentração de Íons de Hidrogênio , Especificidade por Substrato/efeitos dos fármacos , Cinética , Soluções
20.
FASEB J ; 31(4): 1494-1507, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28003341

RESUMO

Chicoric acid (CA), a natural phenolic acid extracted from chicory and the echinacea (purple coneflower) plant (Echinacea purpurea), has been regarded as a nutraceutical that has powerful antioxidant and antiobesity activities. We investigated the inhibitory effects of CA on systemic inflammation-induced neuroinflammation, amyloidogenesis, and cognitive impairment. C57BL/6J mice were treated with 0.05% CA in the drinking water for 45 d. The mice were then treated by intraperitoneal injection of lipopolysaccharide (LPS). It was found that CA prevented LPS-induced memory impairment and neuronal loss through behavioral tests and histological examination. Furthermore, amyloidogenesis in the CNS was detected. The results showed that CA prevented LPS-induced increases in amyloid ß (1-42 specific) (Aß1-42) accumulation, levels of amyloid precursor protein, and neuronal ß-secretase 1 (BACE1), as well as the equilibrium cholinergic system in mouse brain. Moreover, CA down-regulated LPS-induced glial overactivation by inhibiting the MAPK and NF-κB pathway. Consequently, CA reduced the levels of NF-κB transcriptionally regulated inflammatory mediators and cytokines such as iNOS, cyclooxygenase-2 (COX-2), IL-1ß, and TNF-α in both mouse brain and BV2 microglial cells. These results demonstrated that CA alleviated memory impairment and amyloidogenesis triggered by LPS through suppressing NF-κB transcriptional pathway, suggesting that CA might be a plausible therapeutic intervention for neuroinflammation-related diseases such as Alzheimer disease.-Liu, Q., Chen, Y., Shen, C., Xiao, Y., Wang, Y., Liu, Z., Liu, X. Chicoric acid supplementation prevents systemic inflammation-induced memory impairment and amyloidogenesis via inhibition of NF-κB.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Amiloidose/tratamento farmacológico , Ácidos Cafeicos/farmacologia , Transtornos da Memória/tratamento farmacológico , NF-kappa B/metabolismo , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/metabolismo , Succinatos/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Amiloidose/etiologia , Amiloidose/prevenção & controle , Animais , Ácido Aspártico Endopeptidases/metabolismo , Ácidos Cafeicos/uso terapêutico , Linhagem Celular , Ciclo-Oxigenase 2/metabolismo , Interleucina-1beta/metabolismo , Lipopolissacarídeos/toxicidade , Transtornos da Memória/etiologia , Transtornos da Memória/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Óxido Nítrico Sintase Tipo II/metabolismo , Succinatos/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo
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