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1.
Mediators Inflamm ; 2024: 4465592, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707705

RESUMO

Objective: This study aims to evaluate the impact and predictive value of the preoperative NPRI on short-term complications and long-term prognosis in patients undergoing laparoscopic radical surgery for colorectal cCancer (CRC). Methods: A total of 302 eligible CRC patients were included, assessing five inflammation-and nutrition-related markers and various clinical features for their predictive impact on postoperative outcomes. Emphasis was on the novel indicator NPRI to elucidate its prognostic and predictive value for perioperative risks. Results: Multivariate logistic regression analysis identified a history of abdominal surgery, prolonged surgical duration, CEA levels ≥5 ng/mL, and NPRI ≥ 3.94 × 10-2 as independent risk factors for postoperative complications in CRC patients. The Clavien--Dindo complication grading system highlighted the close association between preoperative NPRI and both common and severe complications. Multivariate analysis also identified a history of abdominal surgery, tumor diameter ≥5 cm, poorly differentiated or undifferentiated tumors, and NPRI ≥ 2.87 × 10-2 as independent risk factors for shortened overall survival (OS). Additionally, a history of abdominal surgery, tumor maximum diameter ≥5 cm, tumor differentiation as poor/undifferentiated, NPRI ≥ 2.87 × 10-2, and TNM Stage III were determined as independent risk factors for shortened disease-free survival (DFS). Survival curve results showed significantly higher 5-year OS and DFS in the low NPRI group compared to the high NPRI group. The incorporation of NPRI into nomograms for OS and DFS, validated through calibration and decision curve analyses, attested to the excellent accuracy and practicality of these models. Conclusion: Preoperative NPRI independently predicts short-term complications and long-term prognosis in patients undergoing laparoscopic colorectal cancer surgery, enhancing predictive accuracy when incorporated into nomograms for patient survival.


Assuntos
Neoplasias Colorretais , Laparoscopia , Neutrófilos , Complicações Pós-Operatórias , Pré-Albumina , Humanos , Neoplasias Colorretais/cirurgia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Prognóstico , Pré-Albumina/metabolismo , Fatores de Risco , Intervalo Livre de Doença , Adulto , Análise Multivariada , Modelos Logísticos
2.
Environ Pollut ; 353: 124150, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38735466

RESUMO

In the environment, soil colloids are widespread and possess a significant adsorption capacity. This makes them capable of transporting different pollutants, presenting a potential risk to human and ecological well-being. This study aimed to examine the adsorption and co-migration characteristics of benzo(a)pyrene (BaP) and soil colloids in areas contaminated with organic substances, utilizing both static and dynamic batch experiments. In the static adsorption experiments, it was observed that the adsorption of BaP onto soil colloids followed the pseudo-second-order kinetic model (R2 = 0.966), and the adsorption isotherm conformed to the Langmuir model (R2 = 0.995). The BaP and soil colloids primarily formed bonds through π-π interactions and hydrogen bonds. The dynamic experimental outcomes revealed that elevating colloids concentration contributed to increased BaP mobility. Specifically, when the concentration of soil colloids in influent was 500 mg L-1, the mobility of BaP was 23.2 % compared to that without colloids of 13.4 %. Meanwhile, the lowering influent pH value contributed to increased BaP mobility. Specifically, when the influent pH value was 4.0, the mobility of BaP was 30.1 %. The BaP's mobility gradually declined as the initial concentration of BaP in polluted soil increased. Specifically, when the initial concentration of BaP in polluted soil was 5.27 mg kg-1, the mobility of BaP was 39.1 %. This study provides a support for controlling BaP pollution in soil and groundwater.

3.
Crit Rev Oncol Hematol ; 198: 104356, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38641134

RESUMO

Cholangiocarcinoma (CCA) is the second most common hepatobiliary malignancy after hepatocellular carcinoma. Due to the poor treatment effect and high mortality rate of CCA, it is of great significance to explore new therapeutic targets. Ferroptosis is a type of cell death caused by iron-dependent cell oxidative injury, which is closely related to the occurrence and development of numerous diseases. Novel ideas for the prevention and treatment of related diseases have been provided by ferroptosis, which has become a focus of research in recent years. This review introduces the underlying mechanisms related to ferroptosis, as well as a research update for ferroptosis in the occurrence and development of CCA. The clinical value of ferroptosis-related regulatory mechanisms in CCA will be elucidated.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Ferroptose , Humanos , Colangiocarcinoma/patologia , Colangiocarcinoma/terapia , Colangiocarcinoma/metabolismo , Colangiocarcinoma/etiologia , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/terapia , Neoplasias dos Ductos Biliares/etiologia , Animais
4.
Chem Rev ; 124(9): 5505-5616, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38626459

RESUMO

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas , Polímeros , Polímeros/química , Nanopartículas/química , Humanos , Animais , Portadores de Fármacos/química , Neoplasias/tratamento farmacológico
5.
Appl Opt ; 62(34): 9057-9065, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38108742

RESUMO

To improve the accuracy of saliency detection in challenging scenes such as small objects, multiple objects, and blur, we propose a light field saliency detection method via two-way focal stack fusion. The first way extracts latent depth features by calculating the transmittance of the focal stack to avoid the interference of out-of-focus regions. The second way analyzes the focused distribution and calculates the background probability of the slice, which can distinguish the foreground from the background. Extracting the potential cues of the focal stack through the two different ways can improve saliency detection in complex scenes. Finally, a multi-layer cellular automaton optimizer is utilized to incorporate compactness, focus, center prior, and depth features to obtain the final salient result. Comparison and ablation experiments are performed to verify the effectiveness of the proposed method. Experimental results prove that the proposed method demonstrates effectiveness in challenging scenarios and outperforms the state-of-the-art methods. They also verify that the depth and focus cues of the focal stack can enhance the performance of previous methods.

6.
BMC Gastroenterol ; 23(1): 422, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38036949

RESUMO

BACKGROUND: The prognosis of patients with extrahepatic cholangiocarcinoma (ECCA) must be determined with precision. However, the usual TNM staging system has the drawback of ignoring age, adjuvant therapy, and gender and lacks the ability to more correctly predict patient prognosis. Therefore, we determine the risk factors of survival for patients with advanced ECCA patients and developed brand-new nomograms to forecast patients with advanced ECCA's overall survival (OS) and cancer-specific survival (CSS). METHOD: From the Epidemiology and End Results (SEER) database, patients with advanced ECCA were chosen and randomly assigned in a ratio of 6:4 to the training and validation subgroups. The cumulative incidence function (CIF) difference between groups was confirmed by applying Gray's and Fine test and competing risk analyses. Next, the cancer-specific survival (CSS) and overall survival (OS) nomograms for advanced ECCA were developed and validated. RESULTS: In accordance with the selection criteria, 403 patients with advanced ECCA were acquired from the SEER database and then split at random into two groups: a training group (n = 241) and a validation group (n = 162). The 1-, 2-, and 3-year cancer-specific mortality rates were 58.7, 74.2, and 78.0%, respectively, while the matching mortality rates for the competition were 10.0, 13.8, and 15.0%. Nomograms were generated for estimating OS and CSS, and they were assessed using the ROC curve and the C-index. The calibration curves showed that there was a fair amount of agreement between the expected and actual probabilities of OS and CSS. Additionally, greater areas under the ROC curve were seen in the newly developed nomograms for OS and CSS when compared to the 7th AJCC staging system. The advanced ECCA patients were divided into groupings with an elevated risk and those with a low risk and the Kaplan-Meier method was used for the survival analysis, which showed that survival time was shorter in the high-risk group than in the low-risk group. CONCLUSION: The proposed nomograms have good predictive ability. The nomograms may can help doctors determine the prognosis of patients with advanced ECCA as well as provide more precise treatment plans for them.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Humanos , Prognóstico , Nomogramas , Ductos Biliares Intra-Hepáticos , Estadiamento de Neoplasias
7.
Biomacromolecules ; 24(11): 4958-4969, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37709729

RESUMO

Polymer nanoparticles have generated significant interest as delivery systems for therapeutic cargo. Self-immolative polymers (SIPs) are an interesting category of materials for delivery applications, as the characteristic property of end-to-end depolymerization allows for the disintegration of the delivery system, facilitating a more effective release of the cargo and clearance from the body after use. In this work, nanoparticles based on a pH-responsive polymer poly(ethylene glycol)-b-(2-diisopropyl)amino ethyl methacrylate) and a self-immolative polymer poly[N,N-(diisopropylamino)ethyl glyoxylamide-r-N,N-(dibutylamino)ethyl glyoxylamide] (P(DPAEGAm-r-DBAEGAm)) were developed. Four particles were synthesized based on P(DPAEGAm-r-DBAEGAm) polymers with varied diisopropylamino to dibutylamino ratios of 4:1, 2:1, 2:3, and 0:1, termed 4:1, 2:1, 2:3, and 0:1 PGAm particles. The pH of particle disassembly was tuned from pH 7.0 to pH 5.0 by adjusting the ratio of diisopropylamino to dibutylamino substituents on the pendant tertiary amine. The P(DPAEGAm-r-DBAEGAm) polymers were observed to depolymerize (60-80%) below the particle disassembly pH after ∼2 h, compared to <10% at pH 7.4 and maintained reasonable stability at pH 7.4 (20-50% depolymerization) after 1 week. While all particles exhibited the ability to load a peptide cargo, only the 4:1 PGAm particles had higher endosomal escape efficiency (∼4%) compared to the 2:3 or 0:1 PGAm particles (<1%). The 4:1 PGAm particle is a promising candidate for further optimization as an intracellular drug delivery system with rapid and precisely controlled degradation.


Assuntos
Nanopartículas , Polímeros , Polímeros/química , Sistemas de Liberação de Medicamentos , Polietilenoglicóis/química , Nanopartículas/química , Concentração de Íons de Hidrogênio
8.
Entropy (Basel) ; 25(9)2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37761635

RESUMO

An abundance of features in the light field has been demonstrated to be useful for saliency detection in complex scenes. However, bottom-up saliency detection models are limited in their ability to explore light field features. In this paper, we propose a light field saliency detection method that focuses on depth-induced saliency, which can more deeply explore the interactions between different cues. First, we localize a rough saliency region based on the compactness of color and depth. Then, the relationships among depth, focus, and salient objects are carefully investigated, and the focus cue of the focal stack is used to highlight the foreground objects. Meanwhile, the depth cue is utilized to refine the coarse salient objects. Furthermore, considering the consistency of color smoothing and depth space, an optimization model referred to as color and depth-induced cellular automata is improved to increase the accuracy of saliency maps. Finally, to avoid interference of redundant information, the mean absolute error is chosen as the indicator of the filter to obtain the best results. The experimental results on three public light field datasets show that the proposed method performs favorably against the state-of-the-art conventional light field saliency detection approaches and even light field saliency detection approaches based on deep learning.

9.
Water Sci Technol ; 87(6): 1423-1437, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37001157

RESUMO

Volume capture ratio of annual rainfall (VCRAR) is the key parameter of low-impact development (LID) facilities design, which is significantly affected by the rainfall event division method. However, there is no universal agreement on how to determine an optimal division method to achieve it. A modified minimum inter-event time (MIT) method based on MATLAB software was proposed to find an optimal MIT value. The result showed that the optimal MIT value in Beijing is 200 min based on the daily rainfall data from 1987 to 2016, and the annual average rainfall events were 34.2 with an average rainfall depth of 13.7 mm. Taking bioretention facilities as an example, the errors of design VCRAR under different MIT values were compared based on a Stormwater Management Model (SWMM). The results showed that when design VCRAR was ≤50, 55-60, 60-75, 75-80 and >80%, the optimal MIT value for LID facilities design was 60, 120, 200, 360 and 1,440 min, respectively. Therefore, the optimal MIT should be flexibly selected with the changing of design VCRAR, to ensure that LID facilities meet the design goals.


Assuntos
Chuva , Movimentos da Água , Hidrologia , Pequim
10.
J Environ Manage ; 325(Pt B): 116484, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283172

RESUMO

Thermal pollution from stormwater runoff has been the focus of many studies in recent years due to its potential harm to aquatic microorganisms. However, there were few studies on the thermal pollution caused by stormwater runoff from various types of urban pavement surfaces. A lab-scale experiment was conducted to compare the thermal load of stormwater runoff from impermeable and permeable pavements and the influencing factors were investigated. The experimental findings demonstrated that the rainfall return period and initial temperature of various pavement surfaces significantly impacted the thermal load. The stormwater runoff absorbed more heat as the initial temperature, and rainfall return period increased. The difference of the thermal load of stormwater runoff between permeable brick pavement (PBP) and the impermeable asphalt pavement (IAP) increased from 305.26 to 436.70 kJ/m2, when the initial surface temperature rose from 35 to 47 °C. The average runoff temperature decreased by 1.39-1.90 °C for PBP compared to the IAP, with an increase in surface temperature from 35 to 47 °C. Under the various initial surface temperatures, the mean temperature of the infiltration effluent from the PBP was 3.12-4.20 °C lower than the average temperature of stormwater runoff from the surface layer. Therefore, a PBP can effectively alleviate thermal pollution from stormwater runoff and safeguard the receiving waters' quality.


Assuntos
Chuva , Movimentos da Água , Qualidade da Água , Hidrocarbonetos/análise , Monitoramento Ambiental
11.
Int Immunopharmacol ; 110: 109025, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35853280

RESUMO

BACKGROUND: Recent studies have shown that microRNAs (miRNAs) are aberrantly expressed in patients with Crohn's disease (CD). This suggests that the aberrant expression of miRNAs may contribute to the development of CD. Currently, the specific miRNAs involved in CD development have not been clearly identified. Therefore, we aimed to identify CD-associated miRNAs and explore their functions. METHODS: miRNA microarray analysis was performed to screen for differentially expressed miRNAs in colon tissues from normal controls (NC) and CD patients. The identified miRNAs were validated using quantitative real-time PCR (qPCR). The therapeutic roles of miR-20a-5p mimics via the delivery of poly(lactic-co-glycolic acid) microspheres (PLGA MSs) were further investigated in IL-10-/- mice with spontaneous chronic colitis that were used as a model of CD. The target genes of miR-20a-5p and the associated signaling pathways were identified through bioinformatic analysis and experimental verification of the interactions between the targets predicted by the algorithms and dysregulated mRNAs. RESULTS: The analysis showed that miR-20a-5p was the most significantly downregulated miRNA in patients with CD. Treatment with PLGA MSs carrying miR-20a-5p significantly ameliorated the colitis, decreased mucosal inflammation, and improved epithelial barrier function. Bioinformatic analysis and experimental studies showed that miR-20a-5p inhibition enhanced Th17 differentiation and improved intestinal epithelial barrier function by targeting STAT3. CONCLUSIONS: Downregulation of miR-20a-5p improved the intestinal epithelial barrier function and prevented CD development through the STAT3/IL-17 signaling pathway. Therefore, the delivery of miR-20a-5p by PLGA MSs may serve as a potential therapeutic strategy for CD treatment.


Assuntos
Colite , Doença de Crohn , MicroRNAs , Animais , Colite/induzido quimicamente , Colite/genética , Colite/terapia , Doença de Crohn/genética , Doença de Crohn/metabolismo , Doença de Crohn/terapia , Regulação para Baixo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Microesferas
12.
Angew Chem Int Ed Engl ; 61(33): e202206647, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35718884

RESUMO

While the addition of C1-Lewis base enolates to carbonyls and related structures are well established, the related addition to thiocarbonyls compounds are unknown. Herein, we report a reaction cascade in which a C1-pyridinium enolate undergos addition to dithioesters, trithiocarbonates and xanthates. The reaction provides access to a range of dihydrothiophenes and dihydrothiopyrans (28-examples). Mechanistic investigations, including isolation of intermediates, electronic correlation, and kinetic isotope effect studies support the viability of an activated acid intermediate giving rise to the C1-pyridinium enolate which undergoes turnover limiting cyclization. Subsequent formation of a ß-thiolactone regenerates the catalyst with loss of carbon oxysulfide providing the observed products.

13.
Am J Cancer Res ; 12(2): 907-921, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35261811

RESUMO

This study aimed to investigate outcomes and recurrence patterns after hepatectomy for hepatocellular carcinoma (HCC) patients with different China Liver Cancer staging (CNLC), and then analyze the risk factors of different recurrence patterns. A total of 731 HCC patients undergoing curative resection were reviewed from 6 independent institutions. Data on preoperative and clinicopathological parameters, operation and tumor recurrence information, recurrence management and long-term outcomes were analyzed. Our results showed that 1-, 3-, and 5-year OS rate for Ia was 96.6%, 88.5%, and 77.4%, while 1-, 3-, and 5-year of Ib was 84.2%, 65.5%, and 51.3%, respectively. Compared to Ia, the patients in IIa and IIb staging had poorer 1-, 3-, and 5-year OS and DFS. Furthermore, the 1-, 3-, and 5-year OS rate in IIIa was 59.3%, 37.3%, and 27.7%, while the 1-, 3-, and 5-year OS of IIIb was 25.6%, 12.8%, and 0%, respectively. The mostly site of recurrence after liver surgery was intrahepatic recurrence (CNLC Ia: 89.4%; Ib: 65.9%; IIa: 68.9%; IIb: 91.7%; IIIa: 63.8%). However, the CNLC IIIb patients have higher percentage of extrahepatic recurrence (56.5%). The main recurrence pattern of time course was late recurrence in CNLC Ia patients (61.1%). However, the rate of early recurrence in Ib, IIa, IIb, IIIa, IIIb patients was 69.0%, 62.2%, 62.5%, 78.3% and 95.7% respectively. In conclusion, the outcomes and recurrence patterns of HCC patients after resection vary with different CNLC staging, which defined the prognosis of patients with HCC after resection. The HCC patients with CNLC IIIa can also benefit from liver resection. The CNLC staging could be considered in forming management strategies, treatment choice and surveillance for HCC patients.

14.
Macromol Biosci ; 22(5): e2100445, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35182032

RESUMO

pH-responsive nanoparticles have generated significant interest for use as drug delivery systems due to their potential for inducible release at low pH. The pH variation from the bloodstream (pH 7.4) to intracellular compartments of cells called endosomes/lysosomes (pH < 5.0) has been of particular interest. However, one of the limitations with nanoparticle delivery systems is the inability to migrate out of these compartments to the cytosol or other organelles, via a process termed endosomal escape. Previous studies have postulated that pH-responsive nanoparticles can facilitate endosomal escape through a range of mechanisms including membrane interaction, pH-induced swelling, and the proton-sponge effect. In this study, a series of pH-swellable nanoparticles (85-100 nm) are designed and their impact on biological interactions, particularly endosomal escape, are investigated. The particles exhibit tunable pH-induced swelling (from 120% to 200%) and have good buffering capacity. The cellular association is studied using flow cytometry and endosomal escape is determined using a calcein leakage assay. Interestingly, no endosomal escape with all nanoparticle formulations is found, which suggests there are limitations with both the proton-sponge effect and pH-induced swelling mechanism as the primary methods for inducing endosomal escape.


Assuntos
Nanopartículas , Prótons , Sistemas de Liberação de Medicamentos , Endossomos , Concentração de Íons de Hidrogênio
15.
Biomacromolecules ; 23(1): 174-181, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34898168

RESUMO

We rationally designed a monomer that when polymerized formed a well-defined nonionic polymer [poly(2-(methacryloyloxy) ethylureido glycinamide), PMEGA] by reversible addition fragmentation chain transfer with a flat and tunable upper critical solution temperature (UCST) in water. The monomer was made in one pot from commercially available compounds and with ease of purification. Strong hydrogen-bonding side groups on the polymer produced sharp coil-to-globule transitions upon cooling below its UCST. Ideal random copolymers produced with butyl methacrylate also showed flat UCST profiles, in which the UCST increased with a greater butyl methacrylate copolymer composition from 7 to 65 °C. In the presence of NaCl, the UCST decreased linearly with NaCl concentration due to the "salting-in" effect, and it was found that the slopes from the linear decrease of UCST were nearly identical for all copolymer compositions. This new polymer and its copolymers support the hypothesis that strong hydrogen bonding between the side groups allowed the flat UCST to be readily tuned with a high level of predictability. We postulate that this polymer system may provide wide biological applicability similar to that found for the well-used flat lower critical solution temperature (LCST) of poly(N-isopropylacrylamide).


Assuntos
Polímeros , Água , Micelas , Polimerização , Temperatura
17.
Water Sci Technol ; 84(9): 2214-2227, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34810306

RESUMO

The permeable brick pavement system (PBPs) is one of a widely used low impact development (LID) measures to alleviate runoff volume and pollution caused by urbanization. The performance of PBPs on decreasing runoff volume is decided by its permeability, and it was general described by hydraulic conductivity based on Darcy's law. But there is large error when using hydraulic conductivity to describe the infiltration of PBPs, and which infiltration process is not following Darcy's law, so it is important to find more accurate infiltration models to describe the infiltration of PBPs. The Horton, Philip, Green-Ampt, and Kostiakov infiltration models were selected to find an optimal model to investigate infiltration performance of PBPs via a laboratory-scale experiment, and the maximum absolute error (MAE), Bias, and coefficient of determination (R2) were selected to evaluate the models' errors via fitting with experiment data. The results showed that the fitting accuracy of Kostiakov, Philip, and Green-Ampt models was significantly affected by the monitoring area and hydraulic gradients. Meanwhile, Horton model fitted well (MAE = 0.25-0.32 cm/h, Bias = 0.07-0.11 cm/h, and R2 = 0.98-0.99) with the experiment data, and the parameters of the Horton model often can be achieved by monitoring, such as the maximum infiltration rate and the stable infiltration rate. Therefore, the Horton model is an optimal model to describe the infiltration performance of PBPs, which can also be adopted to evaluate hydrological characterization of PBPs.


Assuntos
Chuva , Movimentos da Água , Hidrologia , Laboratórios
18.
Biomacromolecules ; 22(9): 3892-3900, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34410113

RESUMO

Self-immolative polymers have significant potential for applications such as drug or gene delivery. However, to realize this potential, such materials need to be customized to respond to specific variations in biological conditions. In this work, we investigated the design of new star-shaped self-immolative poly(ethyl glyoxylate)s (PEtGs) and their incorporation into responsive nanoparticles. PEtGs are a subclass of stimulus-responsive self-immolative polymers, which can be combined with different stimuli-responsive functionalities. Two different tetrathiol initiators were used for the polymerization in combination with a variety of potential pH-responsive end-caps, yielding a library of star PEtG polymers which were responsive to pH. Characterization of the depolymerization behavior of the polymers showed that the depolymerization rate was controlled by the end caps rather than the architecture of the polymer. A selection of the star polymers were modified with amines to allow introduction of charge-shifting properties. It was shown that pH-responsive nanoparticles could be prepared from these modified polymers and they demonstrated pH-dependent particle disruption. The pH responsiveness of these particles was studied by dynamic light scattering and 1H nuclear magnetic resonance spectroscopy.


Assuntos
Nanopartículas , Preparações Farmacêuticas , Glioxilatos , Concentração de Íons de Hidrogênio , Polimerização , Polímeros
19.
Commun Biol ; 3(1): 228, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385384

RESUMO

The toxic kernel cake of Jatropha curcas (KCakeJ) is an emerging health and environmental concern. Although phorbol esters are widely recognized as the major toxin of KCakeJ, convincing evidence is absent. Here, we show that rather than phorbol esters an isomeric mixture of 11-hydroxy-9E-octadecenoic acid, 12-hydroxy-10E-octadecenoic acid and 12-hydroxy-10Z-octadecenoic acid (hydroxy-octadecenoic acids, molecular formula C18H34O3) is the major toxic component. The toxicities of hydroxy-octadecenoic acids on experimental animals, e.g. acute lethality, causing inflammation, pulmonary hemorrhage and thrombi, allergies, diarrhea and abortion, are consistent with those on human/animals caused by Jatropha seed and/or KCakeJ. The hydroxyl group and the double bond are essential for hydroxy-octadecenoic acids' toxicity. The main pathway of the toxicity mechanism includes down-regulating UCP3 gene expression, promoting ROS production, thus activating CD62P expression (platelet activation) and mast cell degranulation. The identification of the major toxin of KCakeJ lays a foundation for establishing an environmentally friendly Jatropha biofuel industry.


Assuntos
Jatropha/toxicidade , Ácidos Oleicos/química , Ésteres de Forbol/química , Sementes/química , Animais , Carpas , Carpa Dourada , Cobaias , Humanos , Jatropha/química , Células MCF-7 , Camundongos , Ratos , Ratos Sprague-Dawley , Sementes/toxicidade
20.
Angew Chem Int Ed Engl ; 58(38): 13370-13374, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31328857

RESUMO

While the enantioselective Rauhut-Currier reaction is established with bis(enone) substrates, it is yet to be reported with less electrophilic bis(enoate) substrates. By exploiting high-nucleophilicity N-heterocyclic carbenes, it is possible to achieve Rauhut-Currier reactions with these substrates. The reaction is demonstrated with a range of intramolecular reactions (20 examples) and six esterification/RC reaction cascades, which all proceed with high enantioselectivity (most >93:7 er).

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