Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 573
Filtrar
1.
Photodiagnosis Photodyn Ther ; : 102181, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429100

RESUMO

BACKGROUND: 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is not only the first-line treatment for actinic keratosis (AK), but also demonstrated to improve photoaging during AK field treatment. However, its long-term improvement effect on photoaging remains elusive. OBJECTIVE: To evaluate the long-term improvement effect of ALA-PDT on photoaging. METHODS: The data of 10 patients with AK who received field-directed ALA-PDT on one side of the face and lesion-directed ALA-PDT on the other side were retrospectively reviewed. Their clinical photographs were evaluated with Global scores of photoaging (GSP) assessment independently by two dermatologists at baseline and 1 month, 6 months and 24 months after ALA-PDT. RESULTS: GSP evaluation was performed after 24 months of follow-up. Improvements in the fine line and mottled pigmentation were observed (p < 0.05). All the 10 patients achieved complete response of AK lesions and had no relapse during the 24-month follow-up period. LIMITATION: A small sample size. CONCLUSION: Photoaging can be effectively alleviated in the long-term follow-up after ALA-PDT treatment for AK. The present study may inspire new treatment strategies for photoaging.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33447913

RESUMO

At present, it has been noticed that some patients recovered from COVID-19 present a recurrent positive RNA test of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) after being discharged from hospitals. The purpose of the current study was to characterize the clinical features of re-hospitalized patients with recurrent SARS-CoV-2 positive results. From January 12 to April 1 of 2020, our retrospective study was conducted in China. The exposure history, baseline data, laboratory findings, therapeutic schedule, and clinical endpoints of the patients were collected. All the patients were followed until April 10, 2020. Among all COVID-19 patients included in the current study, there were 14 re-hospitalized patients due to recurrent positive tests of SARS-CoV-2 RNA. Fever (11 [78.6%]), cough (10 [71.4%]), and fatigue (7 [50.0%]) were the most common symptoms on the patient's first admission, and less symptoms were found on their second admission. The average duration from the onset of symptoms to admission to hospital was found to be 8.4 days for the first admission and 2.6 days for the second admission (P = 0.002). The average time from the detection of RNA (+) to hospitalization was 1.9 days for the first admission and 2.6 days for the second admission (P = 0.479), and the average time from RNA (+) to RNA (-) was 11.1 days for the first admission and 6.3 days for the second admission (P = 0.030). Moreover, the total time in hospital was 18.6 days for the first admission and 8.0 days for the second admission (P = 0.000). It may be necessary to increase the isolation observation time and RT-PCR tests should be timely performed on multiple samples as soon as possible.

3.
Chem Commun (Camb) ; 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33443497

RESUMO

This work provides a novel strategy of optimal utilization of fluoroethylene carbonate to generate a uniform and compact solid electrolyte interface film, enhancing the cycle life of potassium ion batteries. With K foil being treated with fluoroethylene carbonate prior to use, enhanced cycling performance up to 1200 hours was achieved. Combining in situ electrochemical impedance spectroscopy with the distribution of relaxation time analysis and XPS analysis, the solubility of KF in the electrolyte is proposed as a crucial factor to determine the quality of a solid electrolyte interface. Our work contributes to understanding the role and manipulating the usage of the fluoroethylene carbonate additive in potassium ion batteries.

4.
J Cell Physiol ; 236(1): 6-14, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32506425

RESUMO

Endometriosis refers to a benign chronic gynecological disorder, and is defined as the ectopic growth of endometrium in pelvic cavity. Endometriosis affects about 10% of reproductive-aged women. Unfortunately, the pathogenesis of endometriosis remains obscure, and the disease witnesses a lack of effective therapy approaches. Therefore, more research needs to be performed to throw light on endometriosis, its pathogenesis, and therapy. Long noncoding RNAs (lncRNAs), which are defined as functional cellular RNA longer than 200 nucleotides, have been implicated in many chronic disorders. It has been suggested that lncRNAs are closely related to the endometriosis process. Nevertheless, the molecular mechanisms by which lncRNAs associate with endometriosis should be elucidated more detailed. In our brief review, we first exhibit the aberrant lncRNAs expression in endometriosis. Then, we talk about the molecular mechanisms underlying lncRNAs in endometriosis. Finally, we also present the potential of lncRNAs as biomarkers for endometriosis.

6.
Ecotoxicol Environ Saf ; 207: 111143, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32942098

RESUMO

The wide use of graphene oxide (GO) has raised increasing concerns about the potential risks to environmental and human health. Recent studies have shown the vital role of gut microbiome in various pathological status or even exogenous exposure, but more detailed understanding about the effects of possible gut microbiome alterations under GO exposure on reproductive toxicology evaluations in pregnant mammals remained elusive. Here we found that orally administrated GO daily during gestational day (GD) 7-16 caused dose-dependent pregnant complications of mice on the endpoint (GD19), including decreased weight of dam and live fetus, high rate of resorbed embryos and dead fetus, and skeletal development retardation. Meanwhile in placenta tissues of pregnant mice exposed to GO at dose over 10 mg/kg, the expression levels of tight junctions (Claudin1 and Occludin) and vascular endothelial growth factor (VEGFA) decreased approximately by 30%-80%, meaning impaired placenta barrier. According to the data of fecal 16s RNA sequencing in 40 mg/kg dose group and the control group, gut microbiome showed dramatically decreased α- and ß-diversity, and upregulated Firmicutes/Bacteroidetes ratio owing to GO exposure. What's more, significantly differentiated abundance of Euryarchaeota is expected to be a special biomarker for failed pregnancy caused by GO. Notably, the result of Spearman correlation analysis suggested that there was a strong link (correlation coefficient>0.6) between perturbed gut microbiome with both abnormally expressed factors of placenta barrier and adverse pregnant outcomes. In summary, the damages of GO exposure to placenta barrier and pregnancy were dose-dependent. And GO exposure was responsible for gut microbiome dysbiosis in mice with pregnant complications. These findings could provide referable evidence to evaluate reproductive risk of GO to mammals.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Grafite/toxicidade , Placenta/fisiologia , Animais , Bacteroidetes , Disbiose , Fezes , Feminino , Feto , Firmicutes , Humanos , Camundongos , Ocludina/metabolismo , Placenta/metabolismo , Gravidez , Fator A de Crescimento do Endotélio Vascular/metabolismo
7.
Water Res ; 188: 116540, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33126006

RESUMO

Response of microbial interactions to environmental perturbations has been a central issue in wastewater treatment system. However, the interactions among anammox microbial community under salt perturbation is still unclear. Here, we used random matrix theory (RMT)-based network analysis to investigate the dynamics of networks under elevated salinity in an anammox system. Results showed that high salinity (20 and 30 g/L NaCl) inhibited anammox performance. Salinity led to closer and more complex networks for the overall network and subnetwork of Planctomycetes and Proteobacteria, especially under low salinity (5 g/L NaCl), which could serve as a strategy to survive under salt perturbation. Planctomycetes, most dominant phylum and playing crucial roles in anammox, possessed higher proportion of competitive relationships (64.3%) under 30 g/L NaCl. OTU 109 (closely related to Ignavibacterium), the only network hub detected in the anammox system, also had larger amount of competitive relationships (27.3%) than the control (0%) under 30 g/L NaCl. Similar result was found for the most abundant keystone bacteria Candidatus Kuenenia. These increasing competitions at different taxa level could be responsible for the deterioration of nitrogen removal. Besides, all the network topological features tended to reach the values of the original network, which showed the network of microbial community could gradually adapt to the elevated salinity. Microbial network analysis adds a different dimension for our understanding of the response in microbial community to elevated salinity.


Assuntos
Microbiota , Salinidade , Reatores Biológicos , Nitrogênio , Oxirredução
8.
J Hazard Mater ; 402: 123563, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32745876

RESUMO

Ingestion of nanoparticles may cause various damages to human body. However, how such ingestion by pregnant mother influences fetal development is not known because, presumably, ingested nanoparticles have to cross multiple biological barriers (such as intestinal and placental) to reach fetus. To answer this crucial question, here we investigated how a relatively biocompatible zirconia nanoparticles (ZrO2 NPs, 16 nm) were translocated to fetal brains in three exposure models of pregnant mice: Model 1, oral exposure of nanoparticles before maternal blood-placental barrier (BPB) was fully developed; Model 2, exposures after BPB was developed, but before fetal blood-brain-barrier (BBB) was fully developed; Model 3, exposures after both maternal BPB and fetal BBB were fully developed. Our experimental results showed that translocation of ZrO2 NPs into fetal brains was 55 % higher in Model 2 and 96 % higher in Model 1 compared with that in Model 3 after nanoparticles (50 mg/kg) were orally exposed to pregnant mice. Therefore, nanoparticles are able to cross multiple biological barriers and nanotoxicity to fetus is highly dependent on stages of pregnancy and fetal development or the maturity of multiple biological barriers. Oral exposures to nanoparticles during pregnancy are dangerous to fetal brain development, especially in early pregnancy.

9.
Ying Yong Sheng Tai Xue Bao ; 31(9): 2963-2976, 2020 Sep 15.
Artigo em Chinês | MEDLINE | ID: mdl-33345497

RESUMO

Based on field experiments in 2017-2019, we examined the characteristics, yield effect and regulatory mechanism of light energy utilization in alfalfa/gramineous forage grass intercropping. With monoculture of alfalfa, forage triticale (C3 plant), and forage maize (C4 plant) as control, we measured the yield effect, the effect of light energy utilization factor on yield formation, the characteristic difference and mechanism of light energy utilization under alfalfa/triticale and alfalfa/maize intercropping patterns. Results showed that land equivalent ratios of both intercropping patterns were all greater than 1, indicating that land utilization ratio and yield benefit of the two intercropping patterns were higher than that of monoculture, among which alfalfa/triticale intercropping pattern was the most promising one. The contribution of light energy utilization factors to yield was following an order of leaf area index (1.531) > net photosynthetic rate (0.882) > intercellular CO2 concentration (0.282) > transpiration rate (-0.229) > canopy opening (-0.291) > PAR interception rate (-0.681) > stomatal conductance (-0.751). Among them, leaf area index was not only one of the important indices to characterize photosynthetic capacity, but also an important component factor of forage crop yield aiming at harvesting nutrients. Therefore, among all factors of photosynthetic characteristics, net photosynthetic rate was the main factor affecting yield. The net photosynthetic rate of alfalfa, triticale and maize under intercropping showed the same pattern, and being different from that of monoculture. The main ways for intercropping to increase net photosynthetic rate included: triticale and maize increased net photosynthetic rate and yield by enhancing the carboxylation fixation capacity of CO2 and the utilization capacity of strong light, while alfalfa could improve its net photosynthetic rate and promote growth under low light, by increasing the content of chlorophyll b in functional leaves, changing chlorophyll composition and enhancing the collection and transmission of light energy.


Assuntos
Agricultura , Medicago sativa , Fotossíntese , Folhas de Planta , Poaceae , Zea mays
11.
Chem Commun (Camb) ; 56(100): 15655-15658, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33355559

RESUMO

The effects of all-hydrocarbon cross-linking on the cell-penetrating properties of Tat were systematically investigated. These stapled cell-penetrating peptides were designed to exhibit a cationic secondary amphipathic profile. We found that the hydrophobicity and helical conformation of these hydrocarbon staple peptides correlate well with their cellular uptake efficiency. Our results also revealed that higher affinity to heparan sulfate of the rigid stapled Tat peptides correlated well with the higher cellular uptake compared with non-stapled Tat peptides with flexible charge display. Notably, the stapled Tat peptides showed increased endosomal escape, high proteolytic stability, and low cytotoxicity. Therefore, they present a potent system for the intracellular transport of bioactive cargos.

12.
Zhongguo Fei Ai Za Zhi ; 23(12): 1049-1058, 2020 Dec 20.
Artigo em Chinês | MEDLINE | ID: mdl-33357311

RESUMO

BACKGROUND: Pulmonary sclerosing pneumocytoma (PSP) is rare benign lung tumor which usually develops in middle-aged women without typical clinical and imaging findings. PSP consists of two basic cell types (surface cubic epithelial cells and round mesenchymal cells) and four histological types (hemorrhagic, sclerotic, solid and papillary). It grows slowly, but it can metastasize to distant organs. The pathology before surgery is easily misdiagnosed. This study aims to improve clinicians' understanding of PSP by discussing the clinical characteristics of the disease. METHODS: This represents a retrospective study of thirty-five patients diagnosed with pulmonary sclerosing pneumocytoma by pathological examination from January 2011 to December 2019. RESULTS: A total of 35 patients in this study, 12 cases were male and 23 cases were female, the average age is 51 years old. 7 cases were discovered accidentally by physical examination or routine chest computed tomography (CT), and 28 cases were found due to symptoms such as cough, sputum, hemoptysis and chest pain. The imaging changes is mainly featured with isolated or clear circular or round-like single nodule and lump in the lungs. In this group, 12 cases underwent percutaneous lung biopsy, only 7 cases were diagnosed with PSP. A total of 28 patients underwent surgery, 24 cases underwent rapid frozen pathological biopsy, only 5 cases diagnosed with PSP. Postoperative pathological examination results shows that 1 case was diagnosed with keratotic squamous cell carcinoma with partial PSP, and the rest were diagnosed with PSP. The surgical and non-surgical patients were followed up for 1 to 8 years after discharge, and the overall recovery was good. The patients were no recurrence and metastasis on chest CT review. CONCLUSIONS: PSP is a clinically rare benign lung tumor, which is more common in middle-aged women. The clinical manifestations and imaging features are lack of significance. Percutaneous lung puncture pathological examination and intraoperative rapid frozen pathological sections often leads to misdiagnosis. Final diagnosis relies on postoperative pathological work-up for most cases.

13.
Cardiol Res Pract ; 2020: 3946913, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33204525

RESUMO

Objectives: To investigate the metabolic profile in patients with aortic stenosis (AS) after transcatheter aortic valve replacement (TAVR) and explore the potential biomarkers to predict prognosis after TAVR based on metabolomics. Methods and Results: Fifty-nine consecutive AS patients were prospectively recruited. Blood samples from the ascending aorta, coronary sinus, and peripheral vein at before and after TAVR were collected, respectively. Liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry were performed to analyze the metabolic profile before and after TAVR. Influential metabolites were identified by integrating the univariate test, multivariate analysis, and weighted gene coexpression network analysis (WGCNA) algorithm. PLS-DA analysis revealed a significant extremely early (within 30 minutes after TAVR) alterations of metabolites in the ascending aorta, coronary sinus, and peripheral vein. The early (within 7 days after TAVR) changed metabolites in the peripheral vein were involved in purine metabolism, primary bile acid biosynthesis, glycerolipid metabolism, amino sugar and nucleotide sugar metabolism, one carbon pool by folate and alanine, and the aspartate and glutamate metabolism pathway. We used volcano plots to find that the cardiac-specific changed metabolites were enriched to the sphingolipid metabolism pathway after TAVR. Besides, WGCNA algorithm was performed to reveal that arginine and proline metabolites could reflect left ventricle regression to some extent. Conclusion: This is the first study to reveal systemic and cardiac metabolites changed significantly in patients with AS after TAVR. Some altered metabolites involved in the arginine and proline metabolism pathway in the peripheral vein could predict left ventricle regression, which merited further study.

14.
Nat Commun ; 11(1): 5927, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230181

RESUMO

Mitochondrial acyl-coenzyme A species are emerging as important sources of protein modification and damage. Succinyl-CoA ligase (SCL) deficiency causes a mitochondrial encephalomyopathy of unknown pathomechanism. Here, we show that succinyl-CoA accumulates in cells derived from patients with recessive mutations in the tricarboxylic acid cycle (TCA) gene succinyl-CoA ligase subunit-ß (SUCLA2), causing global protein hyper-succinylation. Using mass spectrometry, we quantify nearly 1,000 protein succinylation sites on 366 proteins from patient-derived fibroblasts and myotubes. Interestingly, hyper-succinylated proteins are distributed across cellular compartments, and many are known targets of the (NAD+)-dependent desuccinylase SIRT5. To test the contribution of hyper-succinylation to disease progression, we develop a zebrafish model of the SCL deficiency and find that SIRT5 gain-of-function reduces global protein succinylation and improves survival. Thus, increased succinyl-CoA levels contribute to the pathology of SCL deficiency through post-translational modifications.

15.
Insect Sci ; 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33205532

RESUMO

Insect growth and development are precisely controlled by hormone homeostasis. The prothoracicotropic hormone (PTTH) receptor, Torso, is a member of the receptor tyrosine kinase family in insects. Activation of Torso by PTTH triggers biosynthesis and release of the steroid hormone in the prothoracic gland (PG). Although numbers of genes functioning in steroid hormone synthesis and metabolism have been identified in insects, the PTTH transduction pathway via its receptor Torso is poorly understood. In the current study, we describe a loss-of-function analysis of Torso in the silkworm, Bombyx mori, by targeted gene disruption using the transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/RNA-guided Cas9 nucleases) system. Depletion of B. mori Torso (BmTorso) did not eventually affect larval ecdysis and metamorphosis processes. Instead, BmTorso deficiency resulted in significant extension of developing time during larval and pupal stages with increased pupa and cocoon sizes. The ecdysteriod titers in the hemolymph of BmTorso mutants sharpy declined. Transcriptional levels of genes involved in ecdysone biosynthesis and ecdysteroid signaling pathways were significantly reduced in BmTorso-deficient animals. Additionally, RNA-Seq analysis revealed that genes involved in the longevity pathway and protein processing in the endoplasmic reticulum pathway were affected after BmTorso deletion. These results indicate that Torso is critical for maintaining steroid hormone homeostasis in insects.

16.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(5): 834-841, 2020 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-33140607

RESUMO

The aim of the study is to identify the effects and underlying mechanisms of visfatin on inflammation and necroptosis in vascular endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with visfatin or pretreated with Polyinosinic acid (LOX-1 inhibitor). By using the Western blot, RT-PCR, immunocytochemistry, enzyme-linked immunosorbent assay (ELISA), MTT and flow cytometry technique, the occurrence of inflammation and necroptosis in HUVECs were evaluated. Our results showed that 100 ng/mL visfatin significantly increased the mRNA and protein expression of monocyte chemotactic protein 1 (MCP-1) and LOX-1 after 24 hours' treatment in HUVECs. However, pretreatment with Polyinosinic acid could significantly reduce the expression of MCP-1 compared with visfatin group. Additionally, 100 ng/mL visfatin could induce the production of necrotic features and increase the mRNA expression of BMF (one of the markers of necroptosis), while pretreating with Polyinosinic acid markedly downregulated the mRNA expression of BMF gene and promoted the cell proliferation. These results indicate that visfatin might induce inflammation and necroptosis via LOX-1 in HUVECs, suggesting that visfatin plays a central role in the development of atherosclerosis.

17.
Small ; : e2006366, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230931

RESUMO

Sodium-ion batteries (SIBs) have been considered as one of the most promising secondary battery techniques for large-scale energy storage applications. However, developing appropriate electrode materials that can satisfy the demands of long-term cycling and high energy/power capabilities remains a challenge. Herein, a fluorine modulation strategy is reported that can trigger highly active exposed crystal facets in anatase TiO2- x Fx , while simultaneously inducing improved electron transfer and Na+ diffusion via lattice regulation. When tested in SIBs, the optimized fluorine doped TiO2- x Fx nanocrystals exhibit a high reversible capacity of 275 mA h g-1 at 0.05 A g-1 , outstanding rate capability (delivering 129 mA h g-1 at 10 A g-1 ), and remarkable cycling stability with 91% capacity retained after 6000 cycles at 2 A g-1 . Importantly, the optimized TiO2- x Fx nanocrystals are dominated by pseudocapacitive Na+ storage, which can be attributed to the fluorine induced surface and lattice regulation, enabling ultrafast electrode kinetics.

18.
J Nat Prod ; 83(11): 3372-3380, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33180497

RESUMO

The effects of l-tryptophan supplementation on secondary metabolite production in the marine-derived fungus Fusarium sp. L1 were investigated by culturing the fungus in GPY medium with and without the amino acid. HPLC analysis of the products showed distinct metabolite profiles between the two cultures. The 1H NMR spectrum of the EtOAc extract of the culture supplemented with l-tryptophan displayed a series of characteristic aromatic proton signals (δH 6.50-8.50) and NH signals (δH 10.50-11.50) that were not observed in those from cultures not supplemented with l-tryptophan. Subsequently, 23 distinct indole alkaloids, including six new compounds, fusaindoterpenes A and B (1 and 2), fusariumindoles A-C (3-5), and (±)-isoalternatine A (6), together with 17 known compounds, were obtained from this culture. Fusaindoterpene A (1) contains a 6/9/6/6/5 heterocyclic system. Their chemical structures were determined by analysis of HRMS, NMR spectroscopy, optical rotation calculation, ECD calculation, and single-crystal X-ray diffraction data. Compounds 2, 9, and 15 displayed inhibitory activity against the Zika virus (ZIKV) in a standard plaque assay with EC50 values of 7.5, 4.2, and 5.0 µM, respectively, while not showing significant cell cytotoxicity against the A549 adenocarcinomic human alveolar basal epithelial cell line.

19.
BMC Res Notes ; 13(1): 506, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33187555

RESUMO

OBJECTIVES: A pneumonia associated with 2019 novel coronavirus (2019-nCoV, subsequently named SARS-CoV2) emerged worldwide since December, 2019. We aimed to describe the epidemiological characteristics of 2019 coronavirus disease (COVID-19) in Shaanxi province of China. RESULTS: 1. Among the 245 patients, 132 (53.9%) were males and 113 (46.1%) were females. The average age was 46.15 ± 16.43 years, ranging from 3 to 89 years. 2. For the clinical type, 1.63% (4/245) patients were mild type, 84.90% (208/245) were moderate type, 7.76% (19/245) were severe type, 5.31% (13/245) were critical type and only 0.41% (1/245) was asymptomatic. 3. Of the 245 patients, 116 (47.35%) were input case, 114 (46.53%) were non-input case, and 15 (6.12%) were unknown exposure. 4. 48.57% (119/245) cases were family cluster, involving 42 families. The most common pattern of COVID-19 family cluster was between husband and wife or between parents and children.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Quarentena , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Análise por Conglomerados , Infecções por Coronavirus/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/epidemiologia , Estudos Retrospectivos , Fatores Sexuais , Adulto Jovem
20.
Curr Drug Deliv ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33234104

RESUMO

BACKGROUND: In the field of antibacterial, nanomaterials are favored by researchers because of their unique advantages. Medicinal plants, especially traditional Chinese medicine, are considered to be an important source of new chemicals with potential therapeutic effects, as well as an important source for the discovery of new antibiotics. MRSA is endangering people's lives as a kind of multidrug-resistant Staphylococcus aureus which are resistant to tetracycline, amoxicillin, norfloxacin and other first-line antibiotics. It is a hotspot to find good anti-drug-resistant bacteriae, nature-originated nanomaterials with good biocompatibility. OBJECTIVE: We reported the formation of phytochemical nanoparticles (NPs) by the self-assembly of berberine (BBR) and 3,4,5-methoxycinnamic acid (3,4,5-TCA) from Chinese herb medicine, which had good antibacterial activity against MRSA. METHOD AND RESULTS: We found that NPs had good antibacterial activity against MRSA; especially, its antibacterial activity was better than first-line amoxicillin, norfloxacin and its self-assembling precursors on MRSA. When the concentration reached 0.1 µmol/mL, the inhibition rate of NPs reached 94.62%, which was higher than that of BBR and the other two antibiotics (p < 0.001). It was observed by field-emission scanning electron microscopy (FESEM) that NPs could directly adhere to the bacterial surface, which might be an important aspect of the antibacterial activity of NPs. Meanwhile, we further analyzed that the self-assembly was formed by hydrogen bonds and π-π stacking through ultraviolet-visible (UV-vis), fourier transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic spectrum (1 H NMR), and powder X-ray diffraction (pXRD). NPs' morphology was observed by FESEM and TEM. The particles size and surface charge were characterized by dynamic light scattering (DLS); and the surface charge was -31.6 mv, which proved that the synthesized NPs were stable. CONCLUSION: We successfully constructed a naturally self-assembled nanoparticle, originating from traditional Chinese medicine, which had good antibacterial activity for MRSA. It is a promising way to obtain natural nanoparticles from medicinal plants and apply them to antibacterial therapy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA