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1.
Environ Sci Pollut Res Int ; 31(19): 28507-28524, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38558341

ABSTRACT

Exploring the impact of complex urban morphology on the urban heat island (UHI) effect is essential for sustainable environmental management and enhancing human well-being. This study explored the combined cooling effect of street canyon geometry and the surrounding built environment using a CatBoost model and the Shapley method. The findings indicated that in streets with low building height and density, a high proportion of sky and vegetation and a flatter skyline are conductive to mitigate UHI effect. In streets with high building height and density, a lower proportion of sky and vegetation, and a well-proportioned skyline, can effectively mitigate UHI effect. Regardless of the building density and height around the street, street trees are the optimal choice for greening construction and improvement of large and medium-sized cities in China, given their high controllability and the current urban stock background. Therefore, reasonable control and allocation of street trees can effectively adjust the street canyon geometry, providing suitable cooling strategies for streets with different surrounding built environments. This study proposed a method to mitigate the UHI effect through street canyon geometry, which can be extended to other high-density urban thermal environment studies and guide policymakers on street construction and urban design.


Subject(s)
Built Environment , Cities , China , City Planning , Humans
2.
Food Res Int ; 178: 113962, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38309913

ABSTRACT

This study was focused on a novel approach of creating perturbations under high pressure (HP) meta-stable Ice Ⅰ to Ice Ⅲ phase transition and its bactericidal effects. Experiments were carried out under subzero high pressure processing conditions using Escherichia coli suspended in milk, and the microbial inactivation before and after the meta-stable state regulation was compared. The phase transition position of unperturbed milk was 302 MPa/-37.5 °C. The volume change resulting from the phase transition was employed as the perturbation mechanism. Glucose (5 %, 20 %) and sodium chloride solutions (5 %, 20 %) were used as regulatory sources. Glucose solutions accelerated the phase change of the milk better than the sodium chloride solution and resulted in an optimum phase transition position of milk at 243 MPa/-30.6 °C. The induced perturbations accelerated meta-stable transformation and enhanced the microbial destruction. At 330 MPa/3s, compared to the unfrozen samples, the lethality of E. coli in the frozen-regulated samples significantly increased by 1.79 log. The relationship between the E. coli inactivation within the phase change pressure range and the pressure was not continuous, but a segmented one, both before and after meta-stable state regulation. A higher level of E. coli destruction was accomplished by a 5 min pressure-holding of frozen samples at 220 MPa and 280 MPa as compared to the one-pulse and two-pulses treatments without holding time. The maximum lethality of 6.73 log was achieved at 280 MPa/5 min in the frozen-regulated application.


Subject(s)
Escherichia coli , Ice , Animals , Colony Count, Microbial , Milk , Sodium Chloride , Anti-Bacterial Agents , Glucose
3.
Food Res Int ; 169: 112837, 2023 07.
Article in English | MEDLINE | ID: mdl-37254411

ABSTRACT

In this study, the distribution of ice Ⅰ - ice III phase transition positions and its influencing factors on various fruit juices and food model solutions under high pressure (HP) were investigated. In addition, the effect of perturbation on induction of phase change in metastable apple juice was also explored. The phase transition positions of fruit juice samples deviated far from the theoretical value (210 MPa/ -21 °C), with pressure in range of 268 âˆ¼ 305 MPa and temperature between -31.09 °C and -37.21 °C, with the most extreme phase transition position of 305 MPa/ -37.21 °C for apple juice. The phase change position was affected by the type of solution but not by the concentration of solutions. The cooling media namely, sodium chloride (5%, 20%) and glucose solution (5%, 20%) were used as perturbation sources to stimulate the metastable apple juice by using instantaneous volume reduction during the ice Ⅰ - ice III phase transition. They successfully promoted the phase transition of apple juice, where 20% sodium chloride solution significantly (p < 0.05) reduced the phase change pressure of apple juice to 239 MPa. The perturbation effect was influenced by the type and concentration of the perturbation source, the composition of the cavity area and the softness of the sample container.


Subject(s)
Ice , Malus , Ice/analysis , Temperature , Sodium Chloride , Food Preservation , Food
4.
Foods ; 11(22)2022 Nov 18.
Article in English | MEDLINE | ID: mdl-36429290

ABSTRACT

BACKGROUND: Traditional thermal processing is a widely used method to ensure food safety. However, thermal processing leads to a significant decline in food quality, especially in the case of fruits and vegetables. To overcome this drawback, researchers are extensively exploring alternative non-thermal High-Pressure Processing (HPP) technology to ensure microbial safety and retaining the sensory and nutritional quality of food. However, HPP is unable to inactivate the spores of some pathogenic bacteria; thus, HPP in conjunction with moderate- and low-temperature is employed for inactivating the spores of harmful microorganisms. Scope and approach: In this paper, the inactivation effect of high-pressure and high-pressure thermal processing (HPTP) on harmful microorganisms in different food systems, along with the bactericidal kinetics model followed by HPP in certain food samples, have been reviewed. In addition, the effects of different factors such as microorganism species and growth stage, process parameters and pressurization mode, and food composition on microbial inactivation under the combined high-pressure and moderate/low-temperature treatment were discussed. KEY FINDINGS AND CONCLUSIONS: The establishment of a reliable bactericidal kinetic model and accurate prediction of microbial inactivation will be helpful for industrial design, development, and optimization of safe HPP and HPTP treatment conditions.

5.
Foods ; 11(13)2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35804658

ABSTRACT

In this study, a self-cooling laboratory system was used for pressure−shift freezing (PSF), and the effects of pressure−shift freezing (PSF) at 150 MPa on the quality of largemouth bass (Micropterus salmoides) during frozen storage at −30 °C were evaluated and compared with those of conventional air freezing (CAF) and liquid immersion freezing (LIF). The evaluated thawing loss and cooking loss of PSF were significantly lower than those of CAF and LIF during the whole frozen storage period. The thawing loss, L* value, b* value and TBARS of the frozen fish increased during the storage. After 28 days storage, the TBARS values of LIF and CAF were 0.54 and 0.65, respectively, significantly higher (p < 0.05) than the 0.25 observed for PSF. The pH of the samples showed a decreasing trend at first but then increased during the storage, and the CAF had the fastest increasing trend. Based on Raman spectra, the secondary structure of the protein in the PSF-treated samples was considered more stable. The α-helix content of the protein in the unfrozen sample was 59.3 ± 7.22, which decreased after 28 days of frozen storage for PSF, LIF and CAF to 48.5 ± 3.43, 39.1 ± 2.35 and 33.4 ± 4.21, respectively. The results showed that the quality of largemouth bass treated with PSF was better than LIT and CAF during the frozen storage.

6.
Foods ; 11(8)2022 Apr 08.
Article in English | MEDLINE | ID: mdl-35454669

ABSTRACT

It was demonstrated that the inactivation of high pressure (HP) treatment on Escherichia coli survival in sterile physiological saline (SPS) was influenced by the treatment conditions: unfrozen, frozen-thawed and fully frozen (phase transition). In order to probe the enhanced phase transition microbial destruction, vibration effects of phase transition position were created and discussed. Test samples were placed in HP chamber for treatment (150/240/330 MPa, no holding time) at room temperature and a special cooling device was used to maintain the phase transition conditions. Results showed that the phase transition from ice I to ice III of frozen SPS could be realized based on the cooling of a 20% sodium chloride solution. HP treatment under fully frozen conditions produced the best lethal effect compared to unfrozen and freeze-thaw samples. Vibration tests were carried out by using model solutions and apple juice to explore the behavior of phase transition. A synchronous and advance phase transition of internal apple juice was realized, respectively, by using pure water and 5% sodium chloride solution as external vibration sources, and the advance phase transitions of external pure water were realized by using 5% sodium chloride solution and 5% glucose solution as internal vibration sources.

7.
Food Res Int ; 151: 110857, 2022 01.
Article in English | MEDLINE | ID: mdl-34980393

ABSTRACT

Self-cooling phase-transition units were built and tested to successfully carryout pressure shift freezing, high pressure thawing and subzero temperature microbial destruction kinetics. The design of these equipment has been progressively improved over the years as highlighted in this paper. Phase transition data on grape & apple juices, and sodium chloride (20%) & glucose solutions (20%) in Ice I were gathered and modeled using Simon-like and polynomial equations. Factors influencing the Ice I and water to Ice III phase transition position were evaluated, and found to be mainly affected by the solute in the aqueous solution. For pressure shifting freezing and pressure assisting freezing to Ice III, water and 20% sodium chloride solution were successfully employed and verified as cooling media for creating the temperature change pathway of potato and carrot. Using sodium chloride solution (20%) as the cooling medium, the phase transition pathway of apple juice and grape juice under high pressure for the phase transition of Ice I and metastable water to Ice III was established. This could be used in kinetic studies. The developed cooling unit concepts can use in any commercial high pressure equipment for subzero temperature treatment of foods without externally supplied cooling.


Subject(s)
Ice , Laboratories , Freezing , Kinetics , Temperature
8.
J Musculoskelet Neuronal Interact ; 20(3): 429-436, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32877980

ABSTRACT

OBJECTIVE: To investigate the expression of micro ribonucleic acid (miR)-214 in the bone tissue and blood of patients with fragility fracture. METHODS: The expression of miR-214 was detected via quantitative reverse transcription-polymerase chain reaction. The effect of miR-214 on proliferation and apoptosis of osteoblasts were detected via methyl thiazolyl tetrazolium assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. RESULTS: The expression of miR-214 in the bone tissue and blood of patients with fragility fracture significantly declined. miR-214 could promote the proliferation of osteoblasts and inhibited the apoptosis of osteoblasts. miR-214 is involved in fracture healing through inhibiting Sox4 and promoting phosphorylation of PI3K/AKT pathway. The expression of BSP in cells treated with miR-214 mimics was significantly increased to 2.5-fold (p=0.0168), while the expression of BSP in cells treated with miR-214 AMO was significantly decreased, reduced to 0.3 times (p=0.0397). The expression of BMP2 in cells treated with miR-214 mimics was significantly increased to 2.5-fold (p=0.003), while the expression of BMP2 was significantly decreased in cells treated with miR-214 AMO, reduced to 0.3 times (p=0.0002). miR-214 can regulate the expression of Sox2, PI3K and AKT proteins. CONCLUSION: MiR-214 regulates the proliferation, apoptosis, bone formation of osteoblasts and participate in the fracture healing process by inhibiting the expression of Sox4, which provided new ideas for clinical treatment of fracture healing.


Subject(s)
Fracture Healing/physiology , Gene Expression Regulation/physiology , MicroRNAs/metabolism , Osteoporotic Fractures/metabolism , SOXC Transcription Factors/biosynthesis , Adult , Aged , Aged, 80 and over , Apoptosis/physiology , Cell Proliferation/physiology , Cells, Cultured , Female , Humans , Male , Middle Aged , Osteoblasts/metabolism , Osteogenesis/physiology
9.
Article in English | MEDLINE | ID: mdl-32024309

ABSTRACT

The LACE index and HOSPITAL score models are the two most commonly used prediction models identifying patients at high risk of readmission with limited information for home care patients. This study compares the effectiveness of these two models in predicting 30-day readmission following acute hospitalization of such patients in Taiwan. A cohort of 57 home care patients were enrolled and followed-up for one year. We compared calibration, discrimination (area under the receiver operating curve, AUC), and net reclassification improvement (NRI) to identify patients at risk of 30-day readmission for both models. Moreover, the cost-effectiveness of the models was evaluated using microsimulation analysis. A total of 22 readmissions occurred after 87 acute hospitalizations during the study period (readmission rate = 25.2%). While the LACE score had poor discrimination (AUC = 0.598, 95% confidence interval (CI) = 0.488-0.702), the HOSPITAL score achieved helpful discrimination (AUC = 0.691, 95% CI = 0.582-0.785). Moreover, the HOSPITAL score had improved the risk prediction in 38.3% of the patients, compared with the LACE index (NRI = 0.383, 95% CI = 0.068-0.697, p = 0.017). Both prediction models effectively reduced readmission rates compared to an attending physician's model (readmission rate reduction: LACE, 39.2%; HOSPITAL, 43.4%; physician, 10.1%; p < 0.001). The HOSPITAL score provides a better prediction of readmission and has potential as a risk management tool for home care patients.


Subject(s)
Home Care Services/statistics & numerical data , Models, Theoretical , Patient Readmission/statistics & numerical data , Aged , Aged, 80 and over , Cost-Benefit Analysis , Female , Hospitals , Humans , Male , Risk Management , Taiwan
10.
Onco Targets Ther ; 12: 5135-5142, 2019.
Article in English | MEDLINE | ID: mdl-31303766

ABSTRACT

Background: Extensive-disease small-cell lung cancer (ED-SCLC) has been known to be rapid progression and relapse, despite highly sensitive to chemotherapy. Amrubicin (AMR), a third-generation synthetic anthracycline, was accepted as a feasible alternative compared with the standard first-line chemotherapy for previously untreated ED-SCLC. While, the efficacies of these amrubicin-based regimens are unsatisfactory. Aim: Our meta-analysis was performed to assess the efficacy and toxicity of first-line therapy comparing AMR and chemotherapy in patients with ED-SCLC. Methods: Electronic databases were searched for eligible trials updated on November 2018. Randomized-controlled trials assessing the efficacy and safety of AMR in ED-SCLC were included, of which the interested results were objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs). Results: A total of 6 randomized controlled trials were included in this analysis. There are no significant differences in OS (OR=1.03, 95% CI=0.66-1.60, P=0.91), PFS (OR=1.2, 95% CI=10.77-1.88, P=0.41) or ORR (OR=1.31, 95% CI=0.90-1.92, P=0.16) with AMR (OR=0.90, 95% CI=0.76-1.05, P=0.17). The most common treatment-related AEs in the AMR group are leukopenia (OR=3.13, 95% CI=1.22-7.99, P=0.02) and neutropenia (OR=3.25, 95% CI=1.38-7.65, P=0.007). Fatigue, anemia, nausea, vomiting, diarrhea the difference between the two groups had no statistical significance. Conclusion: The results of our analysis indicated that AMR therapy demonstrated non-inferiority to the standard first-line chemotherapy for previously untreated ED-SCLC. Whether it can be accepted as an alternative regimen to the standard first-line chemotherapy is still warranted.

11.
Biophys Chem ; 245: 1-5, 2019 02.
Article in English | MEDLINE | ID: mdl-30500608

ABSTRACT

In the last decade, following fluorescent dyes and protein tags, pH sensitive false fluorescent neurotransmitters (FFN) were introduced and were valuable for labeling secretory vesicles and monitoring exocytosis at living cells. In particular, the synthetic analog of neurotransmitters FFN102 was shown to be an electroactive probe. Here, we show that FFN102 is suitable to be used as a bioanalytic probe at the widely used PC12 cell model. FFN102 was uptaken in the secretory vesicles of PC12 cells, partially replacing the endogenous dopamine stored in these vesicles. The different oxidation potentials of dopamine and FFN102 allowed to determine that ca. 12% of dopamine was replaced by FFN102. Moreover, the FFN102 was found to be over released through the initial fusion pore suggesting that it was mostly uptaken in fast diffusion compartment of the vesicles.


Subject(s)
Dopamine/metabolism , Fluorescent Dyes/metabolism , Neurotransmitter Agents/metabolism , Secretory Vesicles/metabolism , Animals , Cell Compartmentation , Electrochemical Techniques/methods , Electrodes , Exocytosis , PC12 Cells , Rats
12.
Sci Rep ; 8(1): 15843, 2018 10 26.
Article in English | MEDLINE | ID: mdl-30367096

ABSTRACT

The recent emergence of Zika virus (ZIKV) has been concentrated in the Caribbean, Southeastern United States, and South- and Central America; resulting in travel-based cases being reported around the globe. As multi-disciplinary collaborations are combatting the ZIKV outbreak, the need to validate the sequence of existing strains has become apparent. Here, we report high-quality sequence data for multiple ZIKV strains made publicly available through the National Institutes of Health- (NIH) funded biorepository, BEI Resources (www.beiresources.org). Next-generation sequencing, 3' rapid amplification of cDNA ends (RACE), and viral genome annotation pipelines generated GenBank sequence records for 16 BEI Resources strains. Minor variants, consensus mutations, and consensus insertions/deletions were identified within the viral stocks using next-generation sequencing (NGS) and consensus changes were confirmed with Sanger sequencing. Bioinformatics analyses of the sequencing results confirm that the virus stocks available to the scientific research community through BEI Resources adequately represent the viral population diversity of ZIKV.


Subject(s)
Genetic Variation , Genome, Viral , Zika Virus/genetics , Databases, Nucleic Acid , High-Throughput Nucleotide Sequencing , Humans , Phylogeny , RNA, Viral/chemistry , RNA, Viral/genetics , Recombination, Genetic , Whole Genome Sequencing , Zika Virus/classification , Zika Virus Infection/virology
13.
PLoS Negl Trop Dis ; 12(7): e0006670, 2018 07.
Article in English | MEDLINE | ID: mdl-30059496

ABSTRACT

Chikungunya virus (CHIKV) has been detected sporadically since the 1950s and includes three distinct co-circulating genotypes. In late 2013, the Asian genotype of CHIKV was responsible for the Caribbean outbreak (CO) that rapidly became an epidemic throughout the Americas. There is a limited understanding of the molecular evolution of CHIKV in the Americas during this epidemic. We sequenced 185 complete CHIKV genomes collected mainly from Nicaragua in Central America and Florida in the United States during the 2014-2015 Caribbean/Americas epidemic. Our comprehensive phylogenetic analyses estimated the epidemic history of the Asian genotype and the recent Caribbean outbreak (CO) clade, revealed considerable genetic diversity within the CO clade, and described different epidemiological dynamics of CHIKV in the Americas. Specifically, we identified multiple introductions in both Nicaragua and Florida, with rapid local spread of viruses in Nicaragua but limited autochthonous transmission in Florida in the US. Our phylogenetic analysis also showed phylogeographic clustering of the CO clade. In addition, we identified the significant amino acid substitutions that were observed across the entire Asian genotype during its evolution and examined amino acid changes that were specific to the CO clade. Deep sequencing analysis identified specific minor variants present in clinical specimens below-consensus levels. Finally, we investigated the association between viral phylogeny and geographic/clinical metadata in Nicaragua. To date, this study represents the largest single collection of CHIKV complete genomes during the Caribbean/Americas epidemic and significantly expands our understanding of the emergence and evolution of CHIKV CO clade in the Americas.


Subject(s)
Chikungunya Fever/virology , Chikungunya virus/isolation & purification , Adolescent , Asia/epidemiology , Chikungunya Fever/epidemiology , Chikungunya virus/classification , Chikungunya virus/genetics , Chikungunya virus/physiology , Child , Child, Preschool , Epidemics , Female , Genetic Variation , Genome, Viral , Genotype , Humans , Male , Nicaragua/epidemiology , Phylogeny , Travel , United States/epidemiology , Young Adult
14.
Biophys Chem ; 235: 48-55, 2018 04.
Article in English | MEDLINE | ID: mdl-29477767

ABSTRACT

Applications of the Fluorescent False Neurotransmitter FFN102, an analog of biogenic neurotransmitters and a suitable probe for coupled amperometry and TIRFM (total internal reflexion fluorescence microscopy) investigations of exocytotic secretion, were considered here. The electroactivity of FFN102 was shown to very likely arise from the oxidation of its phenolic group through a CE (Chemical-Electrochemical) mechanism. Evidences that the aminoethyl group of FFN102 is the key recognition element by BON N13 cells were also provided. Amperometric measurements were then performed at the single cell level with carbon fiber electrode (CFE) or Indium Tin Oxide (ITO) surfaces. It proved the disparity of kinetic and quantitative parameters of FFN102-stained cells acquired either at cell top and bottom. Moreover, coupled analyses of FFN102 loaded vesicles allowed us to classify three types of optical signals that probably arise from secretion releases thanks to their concomitant detection with an electrochemical spike. Finally, preliminary benefits from the coupling involving FFN102 were reported in terms of origins of overlapped amperometric spikes or assignment of fluorescence extinctions to real exocytotic events.


Subject(s)
Electrochemical Techniques , Exocytosis/physiology , Fluorescence , Neurotransmitter Agents/chemistry , Cell Line, Tumor , Humans , Microscopy, Fluorescence , Molecular Structure
15.
Genome Announc ; 6(4)2018 Jan 25.
Article in English | MEDLINE | ID: mdl-29371358

ABSTRACT

We report 26 complete genomes of Zika virus (ZIKV) isolated after passaging the Zika virus strain FLR in mosquito (C6/36) and mammalian (Vero) cell lines. The consensus ZIKV genomes we recovered show greater than 99% nucleotide identify with each other and with the FLR strain used as input.

16.
Biosens Bioelectron ; 85: 891-896, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27311114

ABSTRACT

MicroRNA-21 (miR-21) is a promising diagnostic biomarker for breast cancer screening and disease progression, thus the method for the sensitive and selective detection of miR-21 is vital to its clinical diagnosis. Herein, we develop a novel method to quantify miR-21 levels as low as attomolar sensitivity by a target-triggered triple isothermal cascade amplification (3TICA) strategy. An ingenious unimolecular DNA template with three functional parts has been designed: 5'-fragment as the miR-21 recognition unit, middle fragment as the miR-21 analogue amplification unit, and 3'-fragment as the 8-17 DNAzyme production unit. Triggered by miR-21 and accompanied by polymerase-nicking enzyme cascade, new miR-21 analogues autonomously generated for the successive re-triggering and cleavage process. Simultaneously, the 8-17 DNAzyme-contained sequence could be exponentially released and activated for the second cyclic cleavage toward a specific ribonucleotide (rA)-contained substrate, inducing a remarkably amplified generation of HRP-mimicking DNAzyme in the presence of hemin. Finally, the amperometric technique was used to record the catalytic reduction current of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. The increase in the steady-state current was proportional with the increase of the miR-21 concentration from 1 aM to 100 pM. An ultra-low detection limit of 0.5 aM with an excellent selectivity for even discriminating differences between 1-base mismatched target and miR-21 was achieved. This simple and cost-effective 3TICA strategy is promising for the detection of any short oligonucleotides, simply by altering the target recognition unit in the template sequence.


Subject(s)
Biosensing Techniques/methods , Breast Neoplasms/blood , MicroRNAs/blood , Benzidines/chemistry , Breast/pathology , Breast Neoplasms/diagnosis , DNA, Catalytic/chemistry , Electrochemical Techniques/methods , Female , Humans , Hydrogen Peroxide/chemistry , Limit of Detection , MicroRNAs/analysis , Nucleic Acid Amplification Techniques/methods
17.
J Biomed Nanotechnol ; 10(4): 615-21, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24734513

ABSTRACT

An isothermal, highly sensitive and specific assay for the detection of hsa-miR-21 with the integration of QDs tagging and rolling circle amplification was offered. In addition, a dual channel strategy for miRNA detection was proposed: anodic stripping voltammetry (ASV) and fluorescent method were both performed for the final Cd2+ signal readout. The designed strategy exhibited good specificity to hsa-miR-21 and presented comparable detection results by detection methods.


Subject(s)
Biosensing Techniques/instrumentation , Conductometry/instrumentation , MicroRNAs/analysis , MicroRNAs/genetics , Nucleic Acid Amplification Techniques/methods , Quantum Dots , Spectrometry, Fluorescence/instrumentation , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Sensitivity and Specificity
18.
Mater Sci Eng C Mater Biol Appl ; 35: 300-6, 2014 Feb 01.
Article in English | MEDLINE | ID: mdl-24411381

ABSTRACT

In this study, a hybrid photopolymeric bioadhesive system consisting of urethane methacrylated dextran (Dex-U) and 3, 4-Dihydroxyphenyl-l-alanine (DOPA) modified three-arm poly (ethylene glycol) s (PEG-DOPAs) was designed. The process of photopolymerization was detected by Photo-Differential Scanning Calorimetry (Photo-DSC). The adhesion strength was evaluated by the lap shear tests. The surface tension of the solutions, burst pressures and the cytotoxicity assays were also investigated. The addition of PEG-DOPAs significantly improved the properties of Dex-U especially in the field of adhesion strength and burst pressure. And materials variation could be tailored to match the demands for tissue repair. Compared to the Dex-U systems, the maximum adhesion strength of the copolymeric system increased from 2.7±0.1 MPa to 4.0±0.6 MPa. Owing to its strong adhesion strength, rapid curing rate and good biocompatibility, such photocrosslinkable hydrogelsa could be applied to the areas of bioadhesive.


Subject(s)
Biomimetic Materials/chemical synthesis , Dextrans/chemistry , Polyethylene Glycols/chemistry , Tissue Adhesives/chemical synthesis , Adhesiveness/radiation effects , Cross-Linking Reagents/chemical synthesis , Cross-Linking Reagents/radiation effects , Dextrans/radiation effects , Hardness/radiation effects , Light , Materials Testing , Photochemistry/methods , Polyethylene Glycols/radiation effects , Tissue Adhesives/radiation effects
19.
J Biomed Nanotechnol ; 9(7): 1155-63, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23909129

ABSTRACT

A pH-triggered drug delivery system that can specially target to folate-receptors-overexpressing cancer cells was designed based on newly developed polydopamine capsules and folic acid. The polycapsules bioconjugates possess capabilities of high drug loading, enhanced folate-receptor-mediated cell uptake, and sustained drug release by intracellular pH changes. It was also found that the sustained release of drugs significantly increased reactive oxygen species (ROS) level in targeted cells. The efficient cell-specific endocytosis and intracellular pH-responsive controlled drug delivery of the capsules is promising for future in vivo therapeutic applications.


Subject(s)
Delayed-Action Preparations/administration & dosage , Folate Receptors, GPI-Anchored/metabolism , Folic Acid/pharmacokinetics , Indoles/chemistry , Nanocapsules/therapeutic use , Polymers/chemistry , Contrast Media , Delayed-Action Preparations/chemistry , HeLa Cells , Humans , Hydrogen-Ion Concentration , Materials Testing , Microscopy, Fluorescence/methods , Molecular Imaging/methods , Nanocapsules/chemistry
20.
Anal Chem ; 85(11): 5609-16, 2013 Jun 04.
Article in English | MEDLINE | ID: mdl-23621478

ABSTRACT

The variable susceptibility to the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment observed in various types of leukemia cells is related to the difference in the expression levels of death receptors, DR4 and DR5, on the cell surfaces. Quantifying the DR4/DR5 expression status on leukemia cell surfaces is of vital importance to the development of diagnostic tools to guide death receptor-based leukemia treatment. Taking the full advantages of novel nanobiotechnology, we have developed a robust electrochemical cytosensing approach toward ultrasensitive detection of leukemia cells with detection limit as low as ~40 cells and quantitative evaluation of DR4/DR5 expression on leukemia cell surfaces. The optimization of electron transfer and cell capture processes at specifically tailored nanobiointerfaces and the incorporation of multiple functions into rationally designed nanoprobes provide unique opportunities of integrating high specificity and signal amplification on one electrochemical cytosensor. The high sensitivity and selectivity of this electrochemical cytosensing approach also allows us to evaluate the dynamic alteration of DR4/DR5 expression on the surfaces of living cells in response to drug treatments. Using the TRAIL-resistant HL-60 cells and TRAIL-sensitive Jurkat cells as model cells, we have further verified that the TRAIL susceptibility of various types of leukemia cells is directly correlated to the surface expression levels of DR4/DR5. This versatile electrochemical cytosensing platform is believed to be of great clinical value for the early diagnosis of human leukemia and the evaluation of therapeutic effects on leukemia patients after radiation therapy or drug treatment.


Subject(s)
Biosensing Techniques/methods , Electrochemical Techniques/methods , Gold/chemistry , Leukemia/diagnosis , Metal Nanoparticles/chemistry , Receptors, Death Domain/metabolism , Antioxidants/pharmacology , Carbon/chemistry , Electrodes , Ferric Compounds/metabolism , Flow Cytometry , HL-60 Cells , Horseradish Peroxidase/metabolism , Humans , Immunoassay , Leukemia/drug therapy , Leukemia/metabolism , Melatonin/pharmacology , Nitrogen/chemistry , Receptors, Cell Surface/immunology , Receptors, Cell Surface/metabolism , Receptors, Death Domain/immunology , TNF-Related Apoptosis-Inducing Ligand/metabolism
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