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1.
Int J Nanomedicine ; 14: 6339-6356, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496690

RESUMO

Objective: The rational combination of immunotherapy with standard chemotherapy shows synergistic clinical activities in cancer treatment. In the present study, an oral powder formulation of pemetrexed (PMX) was developed to enhance intestinal membrane permeability and investigate its application in metronomic chemotherapy in combination with immunotherapy. Methods: PMX was ionically complexed with a bile acid derivative (Nα-deoxycholyl-l-lysyl-methylester; DCK) as a permeation enhancer and mixed with dispersing agents, such as poloxamer 188 (P188) and Labrasol, to form an amorphous oral powder formulation of PMX/DCK (PMX/DCK-OP). Results: The apparent permeability (Papp) of PMX/DCK-OP across a Caco-2 cell monolayer was 2.46- and 8.26-fold greater than that of PMX/DCK and free PMX, respectively, which may have been due to the specific interaction of DCK with bile acid transporters, as well as the alteration of membrane fluidity due to Labrasol and P188. Furthermore, inhibition of bile acid transporters by actinomycin D in Caco-2 cell monolayers decreased the Papp of PMX/DCK-OP by 75.4%, suggesting a predominant role of bile acid transporters in the intestinal absorption of PMX/DCK-OP. In addition, caveola/lipid raft-dependent endocytosis, macropinocytosis, passive diffusion, and paracellular transport mechanisms significantly influenced the permeation of PMX/DCK-OP through the intestinal membrane. Therefore, the oral bioavailability of PMX/DCK-OP in rats was 19.8%±6.93%, which was 294% higher than that of oral PMX. Moreover, an in vivo anticancer efficacy study in B16F10 cell-bearing mice treated with a combination of oral PMX/DCK-OP and intraperitoneal anti-PD1 exhibited significant suppression of tumor growth, and the tumor volume was maximally inhibited by 2.03- and 3.16-fold compared to the oral PMX/DCK-OP and control groups, respectively. Conclusion: These findings indicated the therapeutic potential of a combination of low-dose oral chemotherapy and immunotherapy for synergistic anticancer efficacy.


Assuntos
Ácido Desoxicólico/química , Composição de Medicamentos , Intestinos/efeitos dos fármacos , Pemetrexede/farmacologia , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Disponibilidade Biológica , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Proliferação de Células/efeitos dos fármacos , Ácido Quenodesoxicólico/análogos & derivados , Ácido Quenodesoxicólico/química , Humanos , Íons , Lisina/análogos & derivados , Lisina/química , Camundongos Endogâmicos BALB C , Pemetrexede/administração & dosagem , Pemetrexede/sangue , Pemetrexede/farmacocinética , Permeabilidade , Ratos Sprague-Dawley
2.
Carbohydr Polym ; 219: 143-154, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151511

RESUMO

In recent years, the utilization of polysaccharides as targeted drug carriers has attracted considerable attention. Herein, Angelica sinensis polysaccharide (ASP), a plant polysaccharide with good biocompatibility, excellent aqueous solubility and intrinsic liver-targeted capability, was modified with hydrophobic group (deoxycholic acid) to fabricate amphiphilic conjugate (ASP-DOCA). Self-assembled nanoparticles were successfully developed for hepatoma-targeted delivery of therapeutic drug doxorubicin (DOX). The DOX loaded nanoparticles (DOX/ASP-DOCA NPs) were spherical in shape with a particle size of 228 nm and negatively charged around -17 mV. DOX was released from nanoparticles in a sustainable and pH-dependent manner. In vitro cellular uptake revealed that DOX/ASP-DOCA NPs were internalized into HepG2 cells through asialoglycoprotein receptor (ASGPR)-mediated endocytosis, resulting in a higher anti-proliferation effect than DOX-loaded dextran derivative DOX/DEX-DOCA NPs. Additionally, DOX/ASP-DOCA NPs showed higher inhibition on the growth of HepG2 multicellular spheroids (MCs) than DOX/DEX-DOCA NPs. In vivo imaging demonstrated that ASP-DOCA NPs specifically targeted HepG2 tumors via ASGPR, improving the accumulation of DOX/ASP-DOCA NPs in tumors and generating superior antitumor activity compared with free DOX and DOX/DEX-DOCA NPs. Taken together, ASP-DOCA NPs possess potential applications in drug delivery systems targeting liver cancer.


Assuntos
Angelica sinensis/metabolismo , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Nanoconjugados/uso terapêutico , Nanopartículas/uso terapêutico , Polissacarídeos/uso terapêutico , Animais , Receptor de Asialoglicoproteína/metabolismo , Ácido Desoxicólico/química , Células HeLa , Células Hep G2 , Humanos , Camundongos , Nanopartículas/ultraestrutura , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
3.
Int J Nanomedicine ; 14: 3679-3689, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239660

RESUMO

Background and purpose: Conventional topical ophthalmic aqueous solutions and suspensions are often associated with low bioavailability and high administration frequency, pulsatile dose and poor exposure to certain ocular parts. The aim of this study was to develop an ophthalmic nanoparticles loaded gel, for delivering prednisolone acetate (PA), to increase dosing accuracy, bioavailability, and accordingly, efficiency of PA in treating inflammatory ocular diseases. Methods: A novel formulation of self-assembled nanoparticles was prepared by the complexation of chitosan (CS) and, the counter-ion, sodium deoxycholate (SD), loaded with the poorly-water-soluble PA. Particle size, zeta potential, encapsulation efficiency (EE) and drug loading content (LC) of prepared nanoparticles were assessed. Moreover, the nanoparticles were characterized using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Drug release and eye anti-inflammatory potential of the prepared novel formulation was investigated. Results: Mean particle size of the nanoparticles have dropped from 976 nm ±43 (PDI 1.285) to 480 nm ±28 (PDI 1.396) when the ratio of CS-SD was decreased. The incorporation of 0.1-0.3% of polyvinyl alcohol (PVA), in the preparation stages, resulted in smaller nanoparticles: 462 nm ±19 (PDI 0.942) and 321 nm ±22 (PDI 0.454) respectively. DSC and FTIR results demonstrated the interaction between CS and SD, however, no interactions were detected between PA and CS or SD. Drug release of PA as received, in simulated tears fluid (pH 7.4), showed a twofold increase (reaching an average of 98.6% in 24 hours) when incorporated into an optimized nanoparticle gel formulation (1:5 CS-SD). Conclusion: The anti-inflammatory effect of PA nanoparticles loaded gel on female guinea pig eyes was significantly superior to that of the micronized drug loaded gel (P < 0.05).


Assuntos
Anti-Inflamatórios/farmacologia , Quitosana/química , Ácido Desoxicólico/química , Olho/efeitos dos fármacos , Olho/patologia , Nanopartículas/química , Prednisolona/análogos & derivados , Animais , Varredura Diferencial de Calorimetria , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Feminino , Cobaias , Inflamação/patologia , Nanopartículas/ultraestrutura , Tamanho da Partícula , Prednisolona/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Int J Nanomedicine ; 14: 4123-4131, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239671

RESUMO

Purpose: The objective of this work was to formulate a delivery system of pDNA encoded p53 gene-loaded chitosan-sodium deoxycholate (CS-DS) nanoparticles, and to evaluate their influence on in vitro cytotoxicity and transfection efficiency of p53 gene. Methods: The prepared pDNA-loaded CS-DS nanoparticles were evaluated for morphology, particle size, zeta potential, entrapment efficiency %, in vitro release, in vitro cytotoxicity, and transfection efficiency. Results: The mean particle size ranged from from 96.5 ± 11.31 to 405 ± 46.39 nm. All nanoparticles had good positive zeta potential values. Entrapment efficiency % ranged from 38.25 ± 3.25 to 94.89 ± 5.67. The agarose gel electrophoresis confirmed the strong binding between plasmid and CS. The in vitro pDNA release from nanoparticles exhibited an initial burst effect followed by a sustained drug release over a period of 6 days. In vitro cytotoxicity against human Caco-2 cells showed low cell cytotoxicity of plain CS-DS nanoparticles, while pDNA-loaded CS-DS nanoparticles showed a cytotoxic effect with increasing nanoparticles' concentration. Gene transfection, analyzed by PCR and ELISA, showed a direct correlation between gene expression and concentration of pDNA. The highest expression of the gene was achieved with pDNA concentration of 9 µg/mL with 5.7 times increase compared to naked pDNA of the same concentration. Conclusion: The obtained results were very encouraging and offer an alternative approach to enhancing the transfection efficiency of genetic material-loaded chitosan-based delivery systems.


Assuntos
Quitosana/química , DNA/genética , Ácido Desoxicólico/química , Nanopartículas/química , Plasmídeos/metabolismo , Transfecção , Proteína Supressora de Tumor p53/genética , Células CACO-2 , Morte Celular , Liberação Controlada de Fármacos , Humanos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Eletricidade Estática
5.
Eur J Med Chem ; 178: 458-467, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202993

RESUMO

The liver X receptors (LXRs) of the nuclear receptor family are promising therapeutic targets of multiple diseases like lipid disorders, chronic inflammation, as well as different human cancers. To date, no LXR agonists or antagonists can be used in clinics, emphasizing the importance for discovering new LXR modulators. Fragment-based lead discovery (FBLD) is powerful for designing new scaffolds and new mechanistic drugs, but fragment screening has not been applied to LXRs yet, which might be due to the lack of a specific fragment screening method against the dynamic and hydrophobic ligand binding domain (LBD) of LXRs. Herein, a series of fluorescent tracers were designed, synthesized and tested. The tracer based on hyodeoxycholic acid exhibited a good capability for competitively detecting the ligand binding of LXRß using a fluorescence polarization approach. Then, 1074 fragments were screened against the LBD of LXRß (LXRß-LBD), resulting in 27 binding hits. These fragment hits were further tested using the co-activator recruitment assay and reporter gene assay, and efforts in X-ray crystallography fortunately solved a co-crystal structure of LXRß-LBD with the fragment F3 (tert-butyl-7-amino-3,4-dihydroisoquinoline-2(1H)-carboxylate). The fluorescence-based fragment screening tool and the newly identified LXRß binding fragments provide the basis for developing novel LXRß modulators.


Assuntos
Ácido Desoxicólico/farmacologia , Polarização de Fluorescência , Corantes Fluorescentes/farmacologia , Receptores X do Fígado/antagonistas & inibidores , Cristalografia por Raios X , Ácido Desoxicólico/síntese química , Ácido Desoxicólico/química , Relação Dose-Resposta a Droga , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Humanos , Receptores X do Fígado/metabolismo , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade
6.
Colloids Surf B Biointerfaces ; 179: 519-526, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31075678

RESUMO

Quercetin (QCT) has important functions such as antioxidant, anti-inflammatory and anticancer. However, its applications in food and in drug are restricted owing to its poor water solubility. In this work, a novel amphiphilic wall-material chitosan was synthesized via grafting of chitosan with deoxycholic acid (DA) as hydrophobic group and modified N-acetyl-L-cysteine (NAC) as hydrophilic group. Amphiphilic chitosan was self-assembled to load QCT as nanomicelles by a low-cost and inorganic solvent procedure. Both the encapsulation efficiencies (EE) and drug-loading rates (DL) increased when increasing the grafting rate of DA. There was a bursting release of QCT for the QCT-loaded nanomicelles (CS-DA-NAC-QNMs) from 0 to 8 h, and then the release rate decreased gradually. After releasing for 72 h, the final cumulative release percentages were more than 40%. All the QCT-loaded nanomicelles samples showed good hemocompatibility, and their water solubility and biocompatibility increased evidently. What's more, they exhibited an obvious inhibition rate of A549 cells.


Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos , Micelas , Nanopartículas/química , Quercetina/farmacologia , Tensoativos/química , Células A549 , Animais , Morte Celular/efeitos dos fármacos , Ácido Desoxicólico/química , Liberação Controlada de Fármacos , Humanos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Coelhos , Solubilidade , Eletricidade Estática , Ultrassom
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 216: 190-201, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-30901704

RESUMO

Spectral-fluorescent properties of polymethine dye probes anionic 3,3'-di(sulfopropyl)-4,5,4',5'-dibenzo-9-ethylthiacarbocyanine-betaine (DEC) and cationic 3,3',9-trimethylthiacarbocyanine iodide (Cyan 2) in the presence of biological surfactants, bile salts sodium cholate (NaC), sodium deoxycholate (NaDC) and sodium taurocholate (NaTC), as well as sodium dodecyl sulfate (SDS), have been studied in a wide range of surfactant concentrations. When a surfactant is introduced into a solution of DEC, changes of the spectral-fluorescent properties are observed due to decomposition of dye dimers into cis-monomers and cis-trans conversion of the resulting monomers. In the presence of SDS, both processes occur in parallel, caused by noncovalent interaction of dye monomers with micelles, and mainly occur near the critical micelle concentration (CMC). In contrast, upon the introduction of increasing concentrations of bile salts, decomposition of dye dimers into the monomers begins at lower concentrations than cis-trans conversion. The former process is almost completed at concentrations close to CMC of secondary micelles (CMC2), while the latter process occurs even at concentrations of bile salts much higher than CMC2. Hence, DEC can serve as a probe that permits estimating the value of CMC2 and is indicative of reorganization of secondary micelles upon an increase in bile salt concentration. Aggregation of DEC and Cyan 2 on bile salts is also observed. Since it is observed at relatively low concentrations of bile salts (

Assuntos
Carbocianinas/metabolismo , Ácido Desoxicólico/metabolismo , Indóis/metabolismo , Colato de Sódio/metabolismo , Tensoativos/metabolismo , Ácido Taurocólico/metabolismo , Betaína/análogos & derivados , Betaína/metabolismo , Carbocianinas/química , Ácido Desoxicólico/química , Dimerização , Indóis/química , Micelas , Colato de Sódio/química , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/metabolismo , Espectrometria de Fluorescência , Tensoativos/química , Ácido Taurocólico/química
8.
Molecules ; 24(6)2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30917485

RESUMO

Camptothecin (CPT) shows potent anticancer activity through inhibition of topoisomerase I. However, its water insolubility and severe toxicity limit its clinical application. Coupling with bile acid moieties is a promising method for liver-targeted drug delivery, which takes advantage of the bile acid receptors on hepatocytes. In this study, we evaluated the potential liver targeting and stability of a deoxycholic acid-CPT conjugate (G2). The competitive inhibition of antitumor activity experiment based on bile acid transporters was performed using the MTT method. The effects of deoxycholic acid on uptake of G2 and CPT were assessed in 2D and 3D HepG2 cell models. The stability of G2 and CPT was evaluated in vitro (in simulated gastric fluid, simulated intestinal fluid, and fresh rat plasma). Finally, biodistribution of G2 and CPT was investigated in Kunming mice following oral administration. The results showed that deoxycholic acid pretreatment could significantly reduce the antitumor activity and cellular uptake of G2 in HepG2 cells, but had no distinct effects on CPT. Meanwhile, G2 exhibited better stability compared with CPT. More importantly, biodistribution study in mice demonstrated that the liver targeting index of G2 increased 1.67-fold than that of CPT. Overall, the study suggests that conjugation with deoxycholic acid is a feasible method to achieve liver targeting delivery of CPT.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/administração & dosagem , Ácido Desoxicólico/química , Fígado/química , Administração Oral , Animais , Camptotecina/química , Camptotecina/farmacocinética , Proliferação de Células/efeitos dos fármacos , Ácido Desoxicólico/administração & dosagem , Estabilidade de Medicamentos , Células Hep G2 , Humanos , Camundongos , Modelos Biológicos , Ratos , Solubilidade , Distribuição Tecidual
9.
Biomed Chromatogr ; 33(7): e4515, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30811616

RESUMO

The extent of human intestinal absorption (HIA) for a drug is considered to be an important pharmacokinetic parameter which must be determined for orally administered drugs. Traditional experimental methods relied upon animal testing and are renowned for being time consuming and expensive as well as being ethically unfavourable. As a result, the development of alternative methods to evaluate a drug's pharmacokinetics is crucial. Micellar liquid chromatography is considered to be one of these methods that can replace the use of animals in the prediction of HIA. In this study, the combination of an aminopropyl column with the biosurfactant sodium deoxycholate bile salt was used in the experimental determination of micelle-water partition coefficients (log Pmw ) for a group of compounds. Multiple linear regression was then used for the prediction of HIA using the experimentally determined log Pmw along with other molecular descriptors, leading to the construction of a model equation of R2 = 85% and a prediction power represented by R2 Pred. = 72%. The use of micellar liquid chromatography with an aminopropyl column in combination with sodium deoxycholate was found to be a good method for the prediction of human intestinal absorption, providing data for a far wider range of compounds compared with previous studies.


Assuntos
Cromatografia Líquida/métodos , Absorção Intestinal/fisiologia , Modelos Biológicos , Ácido Desoxicólico/análise , Ácido Desoxicólico/química , Ácido Desoxicólico/metabolismo , Humanos , Modelos Lineares , Micelas , Reprodutibilidade dos Testes
10.
Pharmazie ; 74(1): 34-38, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30782248

RESUMO

Decontamination of patients' clinical devices in intensive care units is generally performed with an antifungal suspension. Nystatin is a widely-used high spectrum antifungal due to its low systemic absorption. However, nystatin has high hydrophobicity which hinders the contact with the internal lumen of the devices. In this work, hydrophilic micellar systems of nystatin were developed with sodium deoxycholate on silicone endotracheal tubes. The physical characteristics of the micellar system at different nystatin:deoxycholate ratios were studied using scanning electron microscopy, X-ray powder diffraction and differential scanning calorimetry. The electron microscopy results reveal that the deoxycholate micellar system altered the surface morphology, and the size of the aggregates was observed to be smaller. The hydrophilic structures of deoxycholate produce systems with a high surface area containing nystatin molecules on their interior. The X-ray and differential scanning calorimetry assays revealed a typical change in the crystallinity of micellar systems when the deoxycholate proportion increases. The endothermic peak of nystatin was not observed in the micellar systems as a consequence of the reduced crystallinity. Nystatin was homogenously dispersed in the surfactant matrix. Micellar systems with 1:0.8 nystatin:deoxycholate ratio (MS-N:DC [1:0.8]) showed increased antifungal activity compared to nystatin raw material. Micellar systems also achieved an over 40% inhibition of Candida albicans biofilm formation. The results obtained in this study conclude that the higher hydrophilic characteristic of the surfactant deoxycholate enhances nystatin penetration into the surface of the endotracheal tubes.


Assuntos
Antifúngicos/administração & dosagem , Candida albicans/efeitos dos fármacos , Ácido Desoxicólico/química , Nistatina/administração & dosagem , Antifúngicos/química , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Varredura Diferencial de Calorimetria , Cristalização , Interações Hidrofóbicas e Hidrofílicas , Intubação Intratraqueal/instrumentação , Micelas , Microscopia Eletrônica de Varredura , Nistatina/química , Nistatina/farmacologia , Silicones/química , Tensoativos/química , Difração de Raios X
11.
Food Environ Virol ; 11(1): 40-51, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30680674

RESUMO

The presence of pathogenic viruses in drinking water is a major public health concern. Although viability RT-qPCR methods were developed to quantify infectious viruses, they may not always reflect viral infectivity, therefore leading to false-positive results. In this study, sodium deoxycholate (SD) pre-treatment was used to improve the efficiency of viability RT-qPCR methods with respect to exclusive quantification of infectious viruses. The ability of SD pre-treatment to enhance the penetration of three viability markers, namely, ethidium monoazide (EMA, 100 µM), propidium monoazide (PMA, 100 µM), and cis-dichlorodiammineplatinum (CDDP, 1000 µM), into heat-treated (90 °C for 1 min) Aichi virus at various concentrations (0.01-0.5%) was evaluated. The optimal SD concentration was found to be 0.1% for all markers. EMA/PMA/CDDP-RT-qPCR with 0.1% SD pre-treatment was significantly more effective than without SD pre-treatment in determining AiV inactivation after heat (50, 60, 70, 80, or 90 °C for 1 min) or chlorine treatment (1 mgCl2/L for 1, 2, 5, or 10 min). Among the viability RT-qPCR methods tested, CDDP-RT-qPCR with SD pre-treatment (SD-CDDP-RT-qPCR) was the most effective in reflecting viral infectivity. Performance testing of SD-CDDP-RT-qPCR in concentrated drinking water samples did not reveal any significant effects of SD-CDDP treatment. Thus, SD-CDDP-RT-qPCR could be a useful tool for monitoring infectious virus presence in drinking water.


Assuntos
Ácido Desoxicólico/química , Água Potável/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Virologia/métodos , Vírus , Vírus/isolamento & purificação , Vírus/patogenicidade
12.
J Biotechnol ; 292: 39-49, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30690095

RESUMO

Metal-driven papain-surfactant nanocomposite (PA@MSNC), a novel soft nanobiocatalyst, was successfully prepared via one-pot self-assembly technique in aqueous solution for the biosynthesis of N-(benzyloxycarbonyl)-L-alanyl-L-glutamine (Z-Ala-Gln) dipeptide in deep eutectic solvents (DESs). The metal-driven self-assembly process generated PA@MSNC as nanospheres of ˜130 nm in diameter, with high protein loading and relative enzyme activity of 420 mg/g and 80% (4270 U/g protein), respectively. PA@MSNC showed high apparent substrate affinity and catalytic efficiency. The stability of PA@MSNC at high temperature and extreme pH was significantly higher than that of free PA. Catalysis efficiency for the biosynthesis of Z-Ala-Gln by PA@MSNC in choline chloride: glycerol reaction medium was 1.69-fold higher than that of free PA, achieving a high product yield of 75.7% within 4 h. PA@MSNC also showed better techno-economic performance. We propose that enzyme-surfactant nanocomposite via metal-driven dynamically reversible coordination interactions contribute simultaneously promotes catalytic flexibility and configurational stability. The generated PA@MSNC has potential practical implications for green synthesis of dipeptide in DESs.


Assuntos
Ácido Desoxicólico/química , Dipeptídeos/química , Manganês/química , Nanocompostos/química , Papaína/química , Tensoativos/química , Biocatálise , Colina/química , Glicerol/química , Concentração de Íons de Hidrogênio , Solventes/química , Temperatura Ambiente
13.
Food Microbiol ; 79: 41-47, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30621874

RESUMO

Quantitative Polymerase Chain Reaction (qPCR) is a molecular method commonly used to detect and quantify bacterial DNA on food but is limited by its inability to distinguish between live and dead cell DNA. To overcome this obstacle, propidium monoazide (PMA) alone or with deoxycholate (DC) was used to prevent dead cell detection in qPCR. qPCR methods were used to detect strains of Escherichia coli O157, which can cause infection in humans with an infectious dose of less than 10 cells. A 5 strain E. coli O157:H7 cocktail was inoculated onto beef steaks and treated with interventions used in meat facilities (lactic acid (5%), peroxyacetic acid (200 ppm) or hot water (80 °C for 10 s)). Treatment of PMA or PMA + DC was applied to samples followed by DNA extraction and quantification in qPCR. RNA was also quantified in addition to conventional plating. For lactic acid intervention, qPCR DNA quantification of E. coli O157:H7 yielded 6.59 ±â€¯0.21 and 6.30 ±â€¯0.11 log gene copy #/cm2 for control and lactic acid samples, respectively and after treatment with PMA or PMA + DC this was further reduced to 6.31 ± 0.21 and 5.58 ± 0.38, respectively. This trend was also observed for peroxyacetic acid and hot water interventions. In comparison, RNA quantification yielded 7.65 ± 0.13 and 7.02 ± 0.38 log reverse transcript/cm2 for rRNA control and lactic acid samples, respectively, and for plating (LB), 7.51 ±â€¯0.06 and 6.86 ±â€¯0.32 log CFU/cm2, respectively. Our research determined that treatment of PMA + DC in conjunction with qPCR prevented dead cell DNA detection. However, it also killed cells injured from intervention that may have otherwise recovered. RNA quantification was more laborious and results had higher variability. Overall, quantification with conventional plating proved to be the most robust and reliable method for live EHEC detection on beef.


Assuntos
Escherichia coli O157/isolamento & purificação , Microbiologia de Alimentos/métodos , Viabilidade Microbiana , Reação em Cadeia da Polimerase/normas , Carne Vermelha/microbiologia , Animais , Azidas/química , Azidas/farmacologia , Bovinos , Contagem de Colônia Microbiana/normas , DNA Bacteriano/química , DNA Bacteriano/genética , Ácido Desoxicólico/química , Ácido Desoxicólico/farmacologia , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/genética , Manipulação de Alimentos , Temperatura Alta , Ácido Láctico/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Ácido Peracético/farmacocinética , Propídio/análogos & derivados , Propídio/química , Propídio/farmacologia , RNA Bacteriano/genética
14.
Int J Biol Macromol ; 126: 662-672, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599159

RESUMO

A gastric cancer angiogenesis marker peptide, GX1, is promising to be a desirable ligand for anti-angiogenesis targeted drug of gastric cancer treatment. In this study, GX1 was utilized to fabricate a multifunctional vascular targeting docetaxel (DCT)-loaded nanoparticle with N-deoxycholic acid glycol chitosan (DGC) as the carrier and GX1-PEG-deoxycholic acid (GPD) conjugate as the targeting ligand. The mean size of obtained GX1-DGC-DCT was 150.9 nm with a narrow size distribution and their shape was spherical with smooth surface texture. The in vitro drug release test revealed a sustained release manner and an acid pH could accelerate the release compared with the neutral pH. Furthermore, GX1-DGC-DCT showed stronger cytotoxicity against co-cultured gastric cancer cells and human umbilical vein endothelial cells (co-HUVEC) than DCT within 100 µM. In addition, GX1 efficiently enhanced the cellular uptake of nanoparticles in co-HUVEC cells as confirmed by confocal fluorescence scanning microscopy. Moreover, in vivo delivery of GX1-DGC-DCT was demonstrated to inhibit tumor growth in SGC791 tumor-bearing mice with tumor inhibition rate (TIR) of 67.05% and no weight loss of mice was observed. The anti-tumor effects were further confirmed by H&E and TUNEL analysis. Therefore, this new drug delivery system represents a potential strategy for gastric cancer therapy.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Docetaxel/uso terapêutico , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Neoplasias Gástricas/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Quitosana/síntese química , Quitosana/química , Ácido Desoxicólico/síntese química , Ácido Desoxicólico/química , Docetaxel/farmacologia , Liberação Controlada de Fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Espectroscopia de Infravermelho com Transformada de Fourier , Neoplasias Gástricas/patologia , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Gut Microbes ; 10(4): 481-503, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30589376

RESUMO

The human gut hosts trillions of microorganisms that exert a profound influence on human biology. Gut bacteria communicate with their host by secreting small molecules that can signal to distant organs in the body. Bile acids are one class of these signaling molecules, synthesized by the host and chemically transformed by the gut microbiota. Among bile acid metabolizers, bile acid 7-dehydroxylating bacteria are commensals of particular importance as they carry out the 7-dehydroxylation of liver-derived primary bile acids to 7-dehydroxylated bile acids. The latter represents a major fraction of the secondary bile acid pool. The microbiology of this group of gut microorganisms is understudied and warrants more attention. Here, we detail the bile acid transformations carried out by the 7-dehydroxylating bacterium Clostridium scindens in vitro and in vivo. In vitro, C. scindens exhibits not only 7α-dehydroxylating capabilities but also, the ability to oxidize other hydroxyl groups and reduce ketone groups in primary and secondary bile acids. This study revealed 12-oxolithocholic acid as a major transient product in the 7α-dehydroxylation of cholic acid. Furthermore, the in vivo study included complementing a gnotobiotic mouse line (devoid of the ability to 7-dehydroxylate bile acids) with C. scindens and investigating its colonization dynamics and bile acid transformations. Using NanoSIMS (Nanoscale Secondary Ion Mass Spectrometry), we demonstrate that the large intestine constitutes a niche for C. scindens, where it efficiently 7-dehydroxylates cholic acid to deoxycholic acid. Overall, this work reveals a novel transient species during 7-dehydroxylation as well as provides direct evidence for the colonization and growth of 7-dehydroxylating bacteria in the large intestine.


Assuntos
Ácidos e Sais Biliares/metabolismo , Clostridium/metabolismo , Trato Gastrointestinal/microbiologia , Animais , Ácidos e Sais Biliares/química , Biotransformação , Clostridium/crescimento & desenvolvimento , Ácido Desoxicólico/química , Ácido Desoxicólico/metabolismo , Trato Gastrointestinal/química , Vida Livre de Germes , Humanos , Ácido Litocólico/química , Ácido Litocólico/metabolismo , Masculino , Camundongos , Estrutura Molecular
16.
Int J Biol Macromol ; 126: 254-261, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30584933

RESUMO

The aim of this work was to examine the formation and properties of a novel polyelectrolyte complex of drug carrier system for the delivery of doxorubicin (DOX), which consists of hyaluronic acid (HA) coated hydrophobically modified chitosan (CS). Various batches of polyelectrolyte complexes with the molar ratio of deoxycholic acid (DCA) and chitosan (CS) of 0.1, 0.2, 0.3 were prepared, and were termed as CS-DCA10, CS-DCA20, and CS-DCA30 respectively. The samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), nuclear magnetic resonance hydrogen spectrum (1H NMR) and dynamic light scattering (DLS). Particle sizes of synthesized polyelectrolyte complex nanoparticles (PCNs) were found to be in the range of 280-310 nm, larger than those of uncoated nanoparticles (~150 nm). The PCNs have large zeta potentials (about 26 mV) which make them stable and no sizes' change was determined. DOX could be easily incorporated into the PCNs with encapsulation efficiency (56%) and kept a sustained release manner without burst effect when exposed to PBS (pH 7.4) at 37 °C. Overall, these findings confirmed the potential of these PCNs for drug carrier and prolonged and sustained delivery in the bloodstream.


Assuntos
Quitosana/química , Doxorrubicina/administração & dosagem , Ácido Hialurônico/química , Interações Hidrofóbicas e Hidrofílicas , Polieletrólitos/química , Animais , Morte Celular/efeitos dos fármacos , Quitosana/síntese química , Ácido Desoxicólico/síntese química , Ácido Desoxicólico/química , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Feminino , Células HeLa , Humanos , Ácido Hialurônico/síntese química , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Nanopartículas/ultraestrutura , Nefelometria e Turbidimetria , Especificidade de Órgãos , Tamanho da Partícula , Polieletrólitos/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier
17.
J Enzyme Inhib Med Chem ; 33(1): 1453-1459, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30221552

RESUMO

Bile acids have been shown to inhibit human (h) carbonic anhydrases (CA, EC 4.2.1.1) along the gastrointestinal tract, including hCA II. The elucidation of the hormonal inhibition mechanism of the bile acid cholate to hCA II was provided in 2014 by X-ray crystallography. Herein, we extend the inhibition study to a wealth of steroids against four relevant hCA isoforms. Steroids displaying pendants and functional groups of the carboxylate, phenolic or sulfonate types appended at the tetracyclic ring were shown to inhibit the cytosolic CA II and the tumor-associated, transmembrane CA IX in a medium micromolar range (38.9-89.9 µM). Docking studies displayed the different chemotypes CA inhibition mechanisms. Molecular dynamics (MD) gave insights on the stability over time of hyocholic acid binding to CA II.


Assuntos
Anidrases Carbônicas/metabolismo , Esteroides/farmacologia , Sítios de Ligação , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/metabolismo , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/classificação , Simulação por Computador , Ácido Desoxicólico/química , Ácido Desoxicólico/metabolismo , Estabilidade de Medicamentos , Ativação Enzimática/fisiologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Isoformas de Proteínas/química , Esteroides/química
18.
Carbohydr Polym ; 198: 537-545, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30093032

RESUMO

Ginsenoside compound K (CK) has been shown to exhibit anticancer properties. In this study, chitosan nanoparticles loaded with ginsenoside compound K (CK-NPs) were prepared as a delivery system using a self-assembly technique with amphipathic deoxycholic acid-O carboxymethyl chitosan as the carrier, which improved the water solubility of CK. By evaluating drug loading, entrapment efficiency, and in vitro release behavior, the feasibility of CK-NPs as a drug carrier nanoparticle for the treatment of human hepatic carcinoma cells (HepG2) was investigated. Result revealed that CK and CK-NPs showed a dose-dependent inhibitory effect on HepG2 cells with IC50 values of 23.33 and 16.58 µg/mL, respectively. Furthermore, fluorescence imaging demonstrated that CK-NPs promoted cellular uptake in vitro. Therefore, all results indicated that CK-NPs might be a novel drug delivery system to improve the solubility and enhance the cytotoxic and apoptotic potentials of CK for effective liver cancer chemotherapy.


Assuntos
Antineoplásicos/administração & dosagem , Quitosana/análogos & derivados , Ácido Desoxicólico/administração & dosagem , Portadores de Fármacos/administração & dosagem , Ginsenosídeos/administração & dosagem , Nanopartículas/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Quitosana/administração & dosagem , Quitosana/química , Ácido Desoxicólico/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Ginsenosídeos/química , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas/química
19.
J Colloid Interface Sci ; 531: 253-260, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30036849

RESUMO

It was the aim of this study to prepare trypsin decorated mucus permeating self-emulsifying drug delivery systems (SEDDS). Lipophilicity of enzyme was increased by hydrophobic ion pairing (HIP) with the anionic surfactants sodium dodecyl sulfate (SDS), sodium taurocholate (ST) and sodium deoxycholate (SDO) to facilitate its incorporation in SEDDS. Blank SEDDS and trypsin decorated SEDDS were characterized regarding droplet size, polydispersity index (PI), zeta potential and proteolytic activity using Nα-benzoyl-l-arginine ethyl ester (BAEE) assay. Log DSEDDS/release medium of each complex was determined to assess its affinity towards SEDDS oily droplet upon emulsification. Ability of trypsin decorated SEDDS to enhance mucus permeation was studied on mucus gel from porcine small intestine for the period of 4 h at 37 °C. Degree of enzyme precipitation via HIP was 94.5%, 85.7% and 48.2% for SDS, ST and SDO complex, respectively. SEDDS composed of 50% (w/w) cremophor EL, 20% (w/w) captex 300, and 30% (w/w) propylene glycol with a complex payload of 1% (w/w) exhibited a droplet size in the range of 29.92 ±â€¯0.09 nm to 39.15 ±â€¯0.37 nm, a polydispersity index of 0.116-0.265 and zeta potential in the range of -2.36 mv to -4.25 mv. The enzymatic activity of trypsin complexed with SDO, SDS and ST in SEDDS was 51.9%, 44.8%, and 40.7% respectively, of the corresponding activity of free trypsin. Log D values of trypsin, SDS, ST and SDO complex were -2.73, 1.97, 1.89 and 1.68, respectively, suggesting higher lipophilicity of trypsin complexes as compare to free trypsin and ability to reside on SEDDS droplets. Enzyme decorated SEDDS improved mucus permeation 1.6- to 2.6-fold in comparison to blank SEDDS. Results demonstrated that decorating SEDDS with trypsin can be a promising technique to improve their mucus permeating properties.


Assuntos
Portadores de Fármacos/farmacocinética , Emulsificantes/farmacocinética , Intestino Delgado/metabolismo , Muco/metabolismo , Tripsina/farmacocinética , Animais , Ácido Desoxicólico/química , Ácido Desoxicólico/metabolismo , Ácido Desoxicólico/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Sistemas de Liberação de Medicamentos , Emulsificantes/química , Emulsificantes/metabolismo , Emulsões/química , Emulsões/metabolismo , Emulsões/farmacocinética , Permeabilidade , Proteólise , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/metabolismo , Dodecilsulfato de Sódio/farmacocinética , Suínos , Ácido Taurocólico/química , Ácido Taurocólico/metabolismo , Ácido Taurocólico/farmacocinética , Tripsina/química , Tripsina/metabolismo
20.
Soft Matter ; 14(34): 6983-6993, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-29972201

RESUMO

In recent years, it is heartening to witness that carbon quantum dots (CQDs), a rising star in the family of carbon nanomaterials, have displayed tremendous applications in bioimaging, biosensing, drug delivery, optoelectronics, photovoltaics and photocatalysis. However, the investigations toward self-assembly of CQDs are still in their infancy. The participation of CQDs can bring additional functions to supramolecular self-assemblies, with photoluminescent property as the most exciting aspect. Here, we introduce CQDs into two types of classic colloidal systems containing low molecular weight surfactant and gelator to construct fluorescent vesicles and chiral hydrogels. The CQD-based vesicles were constructed through electrostatic interaction between the positively charged CQDs with peripherally substituted imidazolium cations and a negatively-charged biosurfactant, i.e., sodium deoxycholate (NaDC). The chiral hydrogels were prepared by increasing the concentration of NaDC and addition of a tripeptide (glutathione, GSH). It was found that both the hydrogels and corresponding xerogels are highly photoluminescent. A solid sensing system was prepared by coating a uniform layer of the hydrogel onto the silica gel plates by doctor blade technique followed by air-drying, which was then utilized to semiquantitatively detect Cu2+ in aqueous solutions.


Assuntos
Carbono/química , Ácido Desoxicólico/química , Corantes Fluorescentes/química , Glutationa/química , Hidrogéis/química , Pontos Quânticos/química , Cobre/análise , Estereoisomerismo , Água/química
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