Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Langmuir ; 40(16): 8533-8541, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38606693

ABSTRACT

Indium sulfide with a two-dimensional layered structure offers a platform for catalyzing water oxidation by a photoelectrochemical process. However, the limited hole holders hinder the weak intrinsic catalytic activity. Here, the nonmetallic phosphorus atom is coordinated to In2.77S4/In(OH)3 through a bridge-bonded sulfur atom. By substituting the S position by the P dopant, the work function (surface potential) is regulated from 445 to 210 mV, and the lower surface potential is shown to be beneficial for holding the photogenerated holes. In2.77S4/In(OH)3/P introduces a built-in electric field under the difference of Fermi energy, and the direction is from the bulk to the surface. This band structure results in upward band bending at the interface of In2.77S4/In(OH)3 and P-doped sites, which is identified by density functional theory calculations (∼0.8 eV work function difference). In2.77S4/In(OH)3/P stands out with the highest oxidation efficiency (ηoxi = 70%) and charge separation efficiency (ηsep = 69%). Importantly, it delivers a remarkable water oxidation photocurrent density of 2.51 mA cm-2 under one sun of illumination.

2.
Front Biosci (Landmark Ed) ; 28(12): 343, 2023 12 26.
Article in English | MEDLINE | ID: mdl-38179754

ABSTRACT

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease that affects axial joints such as the spine. Early diagnosis is essential to improve treatment outcomes. The purpose of this study is to uncover underlying genetic diagnostic features of AS. METHODS: We downloaded gene expression data from the Gene Expression Omnibus (GEO) database for three studies of groups of healthy and AS samples. After preprocessing and normalizing the data, we employed linear models to identify significant differentially expressed genes (DEGs) and further integrated the differential genes to acquire reliable differential transcriptional markers. Gene functional enrichment analysis was conducted to obtain enriched pathways and regulatory gene interactions were extracted from pathways to further elucidate pathway networks. Seventy-three reliably differentially expressed genes (DEGs) were integrated by differential analysis. Utilizing the regulatory relationships of the 21 Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway genes that were enriched in the analysis, a regulatory network of 622 genes was constructed and its topological properties were further analyzed. RESULTS: Functional enrichment analysis found 73 DEGs that were strongly associated with immune pathways like Th17, Th1 and Th2 cell differentiation. Using KEGG combined with DEGs, six hub genes (KLRD1, HLA-DRB3, HLA-DRB5, IL2Rß, CD247, and CXCL10) were suggested from the network. Of these, the IL2Rß gene was significantly differentially expressed compared with the normal control. CONCLUSION: IL2Rß (Interleukin-2 receptor beta) is strongly associated with the onset and progression of autoimmune joint diseases, and may be used as a potential biomarker of AS. This study offers new characteristics that can help in the diagnosis and individualized therapy of AS.


Subject(s)
Gene Regulatory Networks , Spondylitis, Ankylosing , Humans , Gene Expression Profiling , Spondylitis, Ankylosing/diagnosis , Spondylitis, Ankylosing/genetics , Biomarkers , Oligonucleotide Array Sequence Analysis , Computational Biology
3.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(10): 1085-1091, 2022 Oct 15.
Article in Chinese | MEDLINE | ID: mdl-36305107

ABSTRACT

OBJECTIVES: To study the clinical features and prognosis of children and their family members with family clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection under the admission mode of parent-child ward. METHODS: A retrospective analysis was performed on the medical data of 190 children and 190 family members with SARS-CoV-2 Omicron variant infection who were admitted to Shanghai Sixth People's Hospital, the designated hospital for coronavirus disease 2019 (COVID-19), April 8 to May 10, 2022. RESULTS: Both the child and adult groups were mainly mild COVID-19, and the proportion of mild cases in the child group was higher than that in the adult group (P<0.05). Respiratory symptoms were the main clinical manifestations in both groups. Compared with the adult group, the child group had higher incidence rates of fever, abdominal pain, diarrhea, and wheezing (P<0.05) and lower incidence rates of nasal obstruction, runny nose, cough, dry throat, throat itching, and throat pain (P<0.05). Compared with the child group, the adult group had higher rates of use of Chinese patent drugs, traditional Chinese medicine decoction, recombinant interferon spray, cough-relieving and phlegm-eliminating drugs, and nirmatrelvir/ritonavir tablets (P<0.05). Compared with the adult group, the child group had a lower vaccination rate of SARS-CoV-2 vaccine (30.5% vs 71.1%, P<0.001) and a shorter duration of positive SARS-CoV-2 nucleic acid (P<0.05). The patients with mild COVID-19 had a shorter duration of positive SARS-CoV-2 nucleic acid than those with common COVID-19 in both groups (P<0.05). The patients with underlying diseases had a longer duration of positive SARS-CoV-2 nucleic acid than those without such diseases in both groups (P<0.05). CONCLUSIONS: Both children and adults with family clusters of SARS-CoV-2 Omicron variant infection manifest mainly mild COVID-19. Despite lower vaccination rate of SARS-CoV-2 vaccine in children, they have rapid disease recovery, with a shorter duration of positive SARS-CoV-2 nucleic acid than adults, under the admission mode of parent-child ward.


Subject(s)
COVID-19 , Nucleic Acids , Adult , Humans , COVID-19/epidemiology , SARS-CoV-2 , Cough , Retrospective Studies , COVID-19 Vaccines , China/epidemiology , Family
4.
Front Neurosci ; 16: 944688, 2022.
Article in English | MEDLINE | ID: mdl-36090270

ABSTRACT

Objective: This study aims to compare the characteristics of dysphagia among different lesion sites and explore the possible risk factors that are relevant to penetration and aspiration after stroke. Materials and methods: Data on patients with post-stroke dysphagia were collected. Major measures of the videofluoroscopic swallowing study included pharyngeal transit duration (PTD), pharyngeal response duration (PRD), soft palate elevation duration (SED), stage transition duration (STD), hyoid bone anterior-horizontal displacement (HAD), hyoid bone superior-horizontal displacement (HSD), upper esophageal sphincter opening (UESO), Pharyngeal Residual Grade (PRG), and Penetration Aspiration Scale (PAS). Included patients were divided into supratentorial (deep or lobar intracerebral) and infratentorial stroke groups. The Kruskal-Wallis test, Spearman's correlation analysis, and multivariate logistic regression analyses were used to test the difference and the correlation between those measures. Time-to-event endpoints (oral feeding) were analyzed by the Kaplan-Meier method. Results: A total of 75 patients were included in this study. Significant differences were demonstrated in PTD, PRD, SED, STD, HAD, HSD, UESO, PAS, and PRG between supratentorial and infratentorial stroke groups (p < 0.05). The PRG score of the lobar intracerebral subgroup was significantly higher (p < 0.05) than that of the deep intracerebral and lobar + deep intracerebral stroke subgroups, while HSD was significantly shorter (p < 0.01). Spearman's correlation analysis revealed that PAS was related to PTD, PRG, HAD, and UESO (p < 0.05). Multivariate logistic regression analysis demonstrated that HAD and PRG may be risk factors for penetration and aspiration (p < 0.05). Kaplan-Meier survival plot showed that there was a significant difference in time to oral feeding between supratentorial and infratentorial stroke groups (p < 0.01). Conclusion: Infratentorial stroke may lead to worse swallowing function as compared with supratentorial stroke, and lobar intracerebral stroke may be worse than deep intracerebral stroke. Suitable preventive measures may be considered for patients with higher PRG scores and shorter HSD to avoid penetration and aspiration.

5.
Brain Sci ; 12(6)2022 Jun 19.
Article in English | MEDLINE | ID: mdl-35741687

ABSTRACT

Objective: To investigate the relationship between post-stroke cognitive impairment (PSCI) and severe post-stroke dysphagia (PSD) and explore the risk factors related to PSCI combined with severe PSD. Methods: Data from patients were collated from the rehabilitation-specific disease database. The Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Videofluoroscopy Swallowing Study (VFSS), Penetration-aspiration Scale (PAS), and Functional Oral Intake Scale (FOIS) were used to evaluate cognitive and swallowing functions. Differences between groups were determined by the Pearson chi-square test (χ2) or Fisher exact test. PAS and FOIS data were analyzed with the use of the Wilcoxon rank-sum or Kruskal−Wallis test in the prespecified subgroup analysis. Risk factors were investigated by multivariate logistic regression. Results: A total of 1555 patients were identified with PSCI. The results indicated that patients with PSCI had a higher incidence rate of severe PSD as compared to patients without PSCI (p < 0.001). Patients with severe PSCI were more likely to clinically manifest oral phase dysfunction (p = 0.024), while mild PSCI patients mainly manifested pharyngeal phase dysfunction (p < 0.001). There was a significant difference in FOIS score changes between subgroups during the hospitalization period (severe PSCI vs. moderate PSCI and severe PSCI vs. mild PSCI) (all p < 0.001). In addition, multivariate logistic regression revealed pneumonia (p < 0.001), tracheotomy (p < 0.001), and dysarthria (p = 0.006) were related to PSCI, combined with severe PSD. Conclusion: PSCI may be related to severe PSD. Patients with severe PSCI were more likely to manifest oral phase dysfunction, while mild PSCI manifested pharyngeal phase dysfunction. Pneumonia, tracheotomy, and dysarthria were risk factors related to PSCI combined with severe PSD.

6.
Biomed Chromatogr ; 36(9): e5429, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35712886

ABSTRACT

Cyclocarya paliurus (CP) extracts have been shown to lower sugar and lipid levels in blood, but the material basis is not clear. We analyzed CP aqueous extracts using high-performance liquid chromatography "fingerprinting", checked their pharmacological parameters using virtual screening, and undertook molecular docking and molecular dynamics simulations. Also, the inhibitory effects of CP components upon α-glucosidase in vitro were evaluated. Fingerprinting and virtual screening showed that the aqueous extract of CP contained the active components protocatechuic acid, chlorogenic acid, caffeic acid and rutin, which were safe and had no side effects in vivo. Molecular docking and molecular dynamics simulations showed that chlorogenic acid and rutin might have a potent inhibitory effect on α-glucosidase. An enzyme-activity assay in vitro showed that the half-maximal inhibitory values of chlorogenic acid and rutin were 398.9 and 351.8 µg/ml, respectively. Chlorogenic acid and rutin had an inhibitory effect on α-glucosidase. Cyclocarya paliurus could be developed as a natural α-glucosidase inhibitor.


Subject(s)
Juglandaceae , alpha-Glucosidases , Chlorogenic Acid/pharmacology , Chromatography, High Pressure Liquid , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Juglandaceae/chemistry , Juglandaceae/metabolism , Molecular Docking Simulation , Molecular Dynamics Simulation , Plant Extracts/chemistry , Plant Extracts/pharmacology , Rutin , alpha-Glucosidases/metabolism
7.
Front Neurosci ; 16: 845737, 2022.
Article in English | MEDLINE | ID: mdl-35573312

ABSTRACT

Objective: The objectives of the study were to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for poststroke dysphagia (PSD) and explore the optimal stimulation parameters. Method: The databases of Medline, Embase, Web of Science, and Cochrane Library were searched from the establishment to June 2021. All randomized controlled trials about rTMS treatment for PSD were enrolled. Dysphagia Grade (DG) and Penetration Aspiration Scale (PAS) were applied as the major dysphagia severity rating scales to evaluate the outcomes. Results: A total of 12 clinical randomized controlled studies were included in our study. The summary effect size indicated that rTMS had a positive effect on PSD (SMD = -0.67, p < 0.001). The subgroup analysis for treatment duration and different stroke stages showed significant differences (treatment duration >5 days: SMD = -0.80, p < 0.001; subacute phase after stroke: SMD = -0.60, p < 0.001). Furthermore, no significant differences were observed among the other stimulation parameter subgroups (including stimulation frequency, location, and a single stimulation time) (p > 0.05). Conclusion: rTMS is beneficial to the recovery of PSD patients, while an intervention of more than 5 days and in the subacute phase after stroke might bring new strategies and rational therapeutics to the treatment of PSD. Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022299469.

8.
Neural Regen Res ; 17(1): 163-169, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34100452

ABSTRACT

Studies have shown that downregulation of nuclear-enriched autosomal transcript 1 (Neat1) may adversely affect the recovery of nerve function and the increased loss of hippocampal neurons in mice. Whether Neat1 has protective or inhibitory effects on neuronal cell apoptosis after secondary brain injury remains unclear. Therefore, the effects of Neat1 on neuronal apoptosis were observed. C57BL/6 primary neurons were obtained from the cortices of newborn mice and cultured in vitro, and an oxygen and glucose deprivation cell model was established to simulate the secondary brain injury that occurs after traumatic brain injury in vitro. The level of Neat1 expression in neuronal cells was regulated by constructing a recombinant adenovirus to infect neurons, and the effects of Neat1 expression on neuronal apoptosis after oxygen and glucose deprivation were observed. The experiment was divided into four groups: the control group, without any treatment, received normal culture; the oxygen and glucose deprivation group were subjected to the oxygen and glucose deprivation model protocol; the Neat1 overexpression and Neat1 downregulation groups were treated with Neat1 expression intervention techniques and were subjected to the in oxygen and glucose deprivation protocol. The protein expression levels of neurons p53-induced death domain protein 1 (PIDD1, a pro-apoptotic protein), caspase-2 (an apoptotic priming protein), cytochrome C (a pro-apoptotic protein), and cleaved caspase-3 (an apoptotic executive protein) were measured in each group using the western blot assay. To observe changes in the intracellular distribution of cytochrome C, the expression levels of cytochrome C in the cytoplasm and mitochondria of neurons from each group were detected by western blot assay. Differences in the cell viability and apoptosis rate between groups were detected by cell-counting kit 8 assay and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, respectively. The results showed that the apoptosis rate, PIDD1, caspase-2, and cleaved caspase-3 expression levels significantly decreased, and cell viability significantly improved in the Neat1 overexpression group compared with the oxygen and glucose deprivation group; however, Neat1 downregulation reversed these changes. Compared with the Neat1 downregulation group, the cytosolic cytochrome C level in the Neat1 overexpression group significantly decreased, and the mitochondrial cytochrome C level significantly increased. These data indicate that Neat1 upregulation can reduce the release of cytochrome C from the mitochondria to the cytoplasm by inhibiting the PIDD1-caspase-2 pathway, reducing the activation of caspase-3, and preventing neuronal apoptosis after oxygen and glucose deprivation, which might reduce secondary brain injury after traumatic brain injury. All experiments were approved by the Animal Ethics Committee of the First Affiliated Hospital of Chongqing Medical University, China, on December 19, 2020 (approval No. 2020-895).

9.
J Food Biochem ; 45(5): e13707, 2021 05.
Article in English | MEDLINE | ID: mdl-33760271

ABSTRACT

Liupao tea, a drink homologous to medicine and food. It can treat dysentery, relieve heat, remove dampness, and regulate the intestines and stomach. The objective of this study is to explore the material basis and mechanism of Liupao tea intervention in COVID-19 and to provide a new prevention and treatment programme for COVID-19. We used high performance liquid chromatography to analyze the extract of Liupao tea and establish its fingerprint. The main index components of the fingerprint were determined using SARS-COV-2 3-chymotrypsin-like protease (3CLpro ), and an in vitro drug screening model based on fluorescence resonance energy transfer was used to evaluate its inhibitory activity in vitro. The fingerprint results showed that the alcohol extract of Liupao tea contained gallic acid, epigallocatechin gallate (EGCG), caffeine, epicatechin gallate, rutin, and ellagic acid. The molecular docking binding energies of the six index components of SARS-CoV-2 3Clpro were all less than -5.0 kJ/mol and showed strong binding affinity. The results of in vitro activity showed that the IC50 of EGCG was 8.84 µmol/L, which could inhibit SARS-CoV-2 3Clpro to a certain extent. This study unleashed that EGCG has a certain inhibitory effect on SARS-CoV-2 3CLpro , and Liupao tea has a certain significance as a tea drink for the prevention of COVID-19. PRACTICAL APPLICATIONS: The objective of this study was to explore the material basis and mechanism of Liupao tea intervention in COVID-19 and to provide a new prevention and treatment programme for COVID-19. The molecular docking binding energies of the six index components of Liupao tea with SARS-CoV-2 3CLpro were all less than -5.0 kJ/mol, among them, the enzyme activity experiment shows that EGCG has a certain inhibitory effect on SARS-CoV-2 3CLpro , it can be used as a potential SARS-CoV-2 3CLpro inhibitor. We predicted that the understandings gained in the current research may evidence that Liupao tea has a certain significance as a tea drink for the prevention of COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Chromatography, High Pressure Liquid , Humans , Molecular Docking Simulation , Tea
10.
Nat Prod Res ; 35(12): 2090-2094, 2021 Jun.
Article in English | MEDLINE | ID: mdl-31411045

ABSTRACT

Antifungalmycin N2 (3-methyl-3,5-amino-4-vinyl-2-pyrone, C6H7O2N) was a novel metabolite produced from Streptomyces sp. strain N2, and the present study aimed to evaluate its antibacterial and cytotoxic properties. By using Oxford cup method, the obtained results revealed that antifungalmycin N2 exhibited a significant antibacterial activity against the pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, and Micrococcus kristinae, especially the Gram-positive S. aureus. Meanwhile, the MTT assay showed that antifungalmycin N2 could exert a marked inhibitory action on tumor cell lines, such as the cell lines of BEL-7402 (human hepatocellular carcinoma), Hela (human cervical carcinoma), HCT116 (human colon cancer), and SW620 (human colon cancer). And the IC50 values antifungalmycin N2 against the above cell lines ranged from 11.23 to 15.37 µg/mL. In conclusion, the antibacterial and cytotoxic activities suggested that the novel antifungalmycin N2 was a promising active structure to be developed as new drug for treating infectious diseases and cancers.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Streptomyces/chemistry , Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Drug Discovery , Drug Evaluation, Preclinical , Escherichia coli/drug effects , Humans , Microbial Sensitivity Tests , Micrococcaceae/drug effects , Staphylococcus aureus/drug effects
11.
J Zhejiang Univ Sci B ; 21(4): 341, 2020 04.
Article in English | MEDLINE | ID: mdl-32253843

ABSTRACT

Erratum to: J Zhejiang Univ-Sci B (Biomed & Biotechnol) 2019 2019 20(10):816-827. https://doi.org/10.1631/jzus.B1900071. The original version of this article unfortunately contained a mistake. In p.823, Figs. 8c and 8d were in-correct, and the obvious pathological changes were mistakenly placed in the picture. The correct versions should be as follows.

12.
J Zhejiang Univ Sci B ; 20(10): 816-827, 2019.
Article in English | MEDLINE | ID: mdl-31489801

ABSTRACT

Catalpol is the main active ingredient of an extract from Radix rehmanniae, which in a previous study showed a protective effect against various types of tissue injury. However, a protective effect of catalpol on uterine inflammation has not been reported. In this study, to investigate the protective mechanism of catalpol on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and mouse endometritis, in vitro and in vivo inflammation models were established. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blot (WB), and immunofluorescence techniques. The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, and IL-6, and chemokines such as C-X-C motif chemokine ligand 8 (CXCL8) and CXCL5, both in bEECs and in uterine tissue. From the experimental results of WB, qRT-PCR, and immunofluorescence, the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group. The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase (MPO) activity. The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.


Subject(s)
Endometritis/drug therapy , Inflammation/prevention & control , Iridoid Glucosides/pharmacology , NF-kappa B/physiology , Signal Transduction/drug effects , Toll-Like Receptor 4/physiology , Animals , Cattle , Chemokines/genetics , Cytokines/genetics , Epithelial Cells/drug effects , Female , Iridoid Glucosides/therapeutic use , Lipopolysaccharides/pharmacology , Mice
13.
Oncol Lett ; 18(3): 2771-2776, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31452755

ABSTRACT

Cervical cancer is one of the leading causes of cancer-associated mortality among females; however, the underlying molecular mechanisms of its carcinogenesis remain largely unclear. Previous comprehensive genomic studies have revealed prevalent estrogen receptor 1 (ESR1) mutations in breast cancer, which are rare in certain other types of cancer. To the best of our knowledge, it is unknown whether ESR1 mutations also exist in cervical cancer. Considering the evidence that cervical cancer shares certain genetic aberrations with breast cancer, and that the progression of both breast and cervical cancers can be affected by estrogen, it is possible that cervical cancer may also harbor ESR1 mutations. In the present study, a total of 260 Chinese cervical cancer samples with distinct subtypes were tested for the presence of ESR1 mutations. A total of three heterozygous missense ESR1 mutations, p.K303R (c.908A>G), p.T311M (c.932C>T) and p.Y537C (c.1610A>G), were identified in 3/207 (1.4%) cervical squamous cell carcinoma samples, which were absent in 27 adenosquamous carcinomas and 26 adenocarcinomas samples. Of the three individuals with an ESR1mutation, 1 patient was also diagnosed with ovarian endometriosis and the other 2 patients were diagnosed with a uterine fibroid. A bioinformatics analysis suggested that these ESR1 mutations may be pathogenic by promoting the development of cervical cancer. Furthermore, a previous comprehensive study confirmed that individuals with cervical squamous cell carcinoma possessed ESR1 mutations. These combined studies indicate that ESR1 mutations may participate in the carcinogenesis of cervical squamous cell carcinoma, albeit at a low frequency. In conclusion, the present study identified three potentially pathogenic ESR1 mutations in Chinese cervical squamous cell carcinoma samples, but not in other subtypes.

14.
Colloids Surf B Biointerfaces ; 183: 110443, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31445358

ABSTRACT

The development of intelligent oral drug delivery carrier aiming at efficiently bring insulin to intestine is of great significance for diabetes mellitus therapy. In the present study, a series of amphiphilic pH-sensitive block copolymer poly(methyl methacrylate-co-methacrylicacid)-b-poly(2-amino ethyl methacrylate) [P(MMA-co-MAA)-b-PAEMA] was synthesized via activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and further self-assembled into pH-responsive cationic polymeric micelles (PCPMs) for oral insulin delivery. The structure and molecular weight were confirmed by proton nuclear magnetic resonance (1H-NMR), Fourier transforming infrared spectrum (FT-IR) and gel permeation chromatography (GPC), respectively. The critical micelle concentration (CMC) values of these copolymers were measured by fluorescent probe method at pH 1.2 (8-15 µg/mL) and pH 7.4 (22-42 µg/mL), respectively, demonstrating high stability at acidic environment. A decrease in the particle size of PCPMs was associated with an increased pH at beginning, which reached around 200 nm at neutral pH, while the particle size increased obviously with pH increase, indicating the pH-sensitivity of PCPMs. The insulin was entrapped into the core of PCPMs (Ins-loaded PCPMs) with high loading efficiency via diafiltration method. The in vitro experiments show Ins-loaded PCPMs have low toxicity and exhibit pH-triggered release profile with remitted initial burst release. The results indicate that the PCPMs self-assembled from P(MMA-co-MAA)-b-PAEMA may be potential carriers for efficient oral delivery of insulin with controlled release property.


Subject(s)
Drug Delivery Systems/methods , Insulin/administration & dosage , Micelles , Polymers/chemistry , Administration, Oral , Caco-2 Cells , Cell Survival/drug effects , Drug Carriers/chemistry , Humans , Hydrogen-Ion Concentration , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/chemistry , Insulin/chemistry , Molecular Structure , Particle Size , Polymers/chemical synthesis , Proton Magnetic Resonance Spectroscopy , Spectroscopy, Fourier Transform Infrared
15.
Colloids Surf B Biointerfaces ; 151: 280-286, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-28038414

ABSTRACT

The pH-sensitive nanoparticles are selected as the potentially promising oral protein and peptide drug carriers due to their excellent performance. With the poly (lactic-co-glycolic acid)/hydroxypropyl methylcellulose phthalate (PLGA/HP55) nanoparticle as a model nanoparticle, the structure-property relationship of nanoparticles with different conditions is investigated by dissipative particle dynamics (DPD) simulations in our work. In the oral drug delivery system, the poly (lactic-co-glycolic acid) (PLGA) is hydrophobic polymer, hydroxypropyl methylcellulose phthalate (HP55) is pH-sensitive enteric polymer which used to protect the nanoparticles through the stomach and polyvinyl alcohol (PVA) is hydrophilic polymer as the stabilizer. It can be seen from DPD simulations that all polymer molecules form spherical core-shell nanoparticles with stabilizer PVA molecules adsorbed on the outer surface of the PLGA/HP55 matrix at certain compositions. The DPD simulation study can provide microscopic insight into the formation and morphological changes of pH-sensitive nanoparticles which is useful for the design of new materials for high-efficacy oral drug delivery.


Subject(s)
Drug Carriers/chemistry , Lactic Acid/chemistry , Methylcellulose/analogs & derivatives , Nanoparticles/chemistry , Polyglycolic Acid/chemistry , Administration, Oral , Computer Simulation , Humans , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Methylcellulose/chemistry , Nanomedicine/methods , Particle Size , Polylactic Acid-Polyglycolic Acid Copolymer , Temperature , Water/chemistry
16.
Zhongguo Zhong Yao Za Zhi ; 41(20): 3792-3797, 2016 Oct.
Article in Chinese | MEDLINE | ID: mdl-28929657

ABSTRACT

This study is to determine five naphthaquinones (acetylshikonin, ß-acetoxyisovalerylalkannin, isobutylshikonin, ß,ß'-dimethylacrylalkannin,α-methyl-n-butylshikonin) by quantitative analysis of multi-components with a single marker (QAMS). ß,ß'-Dimethylacrylalkannin was selected as the internal reference substance, and the relative correlation factors (RCFs) of acetylshikonin, ß-acetoxyisovalerylalkannin, isobutylshikonin and α-methyl-n-butylshikonin were calculated. Then the ruggedness of relative correction factors was tested on different instruments and columns. Meanwhile, 16 batches of Arnebia euchroma were analyzed by external standard method (ESM) and QAMS, respectively. The peaks were identifited by LC-MS. The ruggedness of relative correction factors was good. And the analytical results calculated by ESM and QAMS showed no difference. The quantitative method established was feasible and suitable for the quality evaluation of A. euchroma.


Subject(s)
Boraginaceae/chemistry , Drugs, Chinese Herbal/analysis , Naphthoquinones/analysis , Chromatography, High Pressure Liquid
17.
ACS Appl Mater Interfaces ; 7(46): 25592-600, 2015 Nov 25.
Article in English | MEDLINE | ID: mdl-26539742

ABSTRACT

The microstructures of doxorubicin-loaded micelles prepared from block polymers His(x)Lys10 (x = 0, 5, 10) conjugated with docosahexaenoic acid (DHA) are investigated under different pH conditions, using dissipative particle dynamics (DPD) simulations. The conformation of micelles and the DOX distributions in micelles were obviously influenced by pH values and the length of the histidine segment. At pH >6.0, the micelles self-assembled from the polymers were dense and compact. The drugs were entrapped well within the micellar core. The particle size increases as the histidine length increases. With the decrease of pH value to be lower than 6.0, there was no distinct difference for the micelles self-assembled from the polymer without histidine residues. However, the micelles prepared from the polymers with histidine residues shows a structural transformation from dense to swollen conformation, leading to an increased particle size from 10.3 to 14.5 DPD units for DHD-His10Lys10 micelles. This structural transformation of micelles can accelerate the DOX release from micelles under lower pH conditions. The in vitro drug release from micelles is accelerated by the decrease of pH value from 7.4 (physiological environment) to 5.0 (lysosomal environment). The integration of simulation and experiments might be a valuable method for the optimization and design of biomaterials for drug delivery with desired properties.


Subject(s)
Computer Simulation , Drug Delivery Systems , Micelles , Delayed-Action Preparations , Docosahexaenoic Acids/chemistry , Doxorubicin/pharmacology , Drug Liberation , Hydrogen-Ion Concentration , Kinetics , Peptides/chemistry , Polymers/chemistry , Water/chemistry
18.
Colloids Surf B Biointerfaces ; 136: 536-44, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26454543

ABSTRACT

In this work, the formation of polymeric micelles as drug delivery vehicles in an aqueous environment is investigated by dissipative particle dynamics (DPD) simulations. Doxorubicin (DOX) is selected as the model drug, whereas docosahexaenoic acid (DHA) conjugated His10Lys10 (DHA-His10Lys10) as the drug carrier. It is shown from DPD simulation that drug molecules and DHA-His10Lys10 molecules could aggregate and form micelles under a defined composition recipe; drug molecules are homogeneously distributed inside the carrier matrix, on whose surface the stabilizer lysine segments are absorbed. Under different compositions of drug and water, aggregate morphologies of polymeric micelles are observed as spherical, columnar, and lamellar structures. We finally proposed the formation mechanism of drug loaded polymeric micelles and apply it in practice by analyzing the simulated phenomena. All the results can effectively guide the experimental preparation of drug delivery system with desired properties or explore a novel polymeric micelle with high performance.


Subject(s)
Micelles , Polymers , Docosahexaenoic Acids/administration & dosage , Doxorubicin/administration & dosage
19.
J Nanosci Nanotechnol ; 15(4): 3295-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-26353581

ABSTRACT

A Gd27.5La27.5Al20Co20Fe5 bulk metallic glass (BMG) was synthesized by replacing 50% of the Gd element with the relatively cheap La element. The BMG has a rather high glass forming ability and the predicted critical diameter is about 7 mm by the differential scanning calorimetry (DSC) measurements. The BMG exhibits a medium range of refrigerant capacity (RC). The replacement of Gd with La leads to a slight reduction of the corresponding refrigerant efficiency of the alloy. However, the high value of magnetic entropy changes (-ΔS(m)peak) and low cost still indicates that the Gd27.5La27.5Al20Co20Fe5 BMG can be regarded as a good magnetic refrigerant candidate.

20.
Anal Sci ; 30(2): 257-62, 2014.
Article in English | MEDLINE | ID: mdl-24521913

ABSTRACT

An inorganic-organic silica material (SBA-15-1), prepared by immobilization of the naphthalimide derivative within the channels of the mesoporous silica material SBA-15, is characterized by several spectroscopic methods. SBA-15-1 can be used as a chemical sensor for detecting and removing Hg(2+) in a heterogeneous system. The fluorescence enhancement of SBA-15-1 was attributed to the formation of a complex between SBA-15-1 and Hg(2+) by a 1:1 complex ratio with the photo-induced electron transfer (PET) being forbidden. The sensor can be applied to the quantification of Hg(2+) with a linear range covering from 1.0 × 10(-7) to 1.0 × 10(-5) M under the neutral condition. Most importantly, the fluorescence changes of the sensor are remarkably specific for Hg(2+) in the presence of other metal ions. Moreover, the response of the sensor toward Hg(2+) is fast and chemically reversible. In addition, the sensor has been used for the determination of Hg(2+) in environmental samples with satisfactory results.

SELECTION OF CITATIONS
SEARCH DETAIL
...