New In Vitro Coculture Model for Evaluating Intestinal Absorption of Different Lipid Nanocapsules

Standard models used for evaluating the absorption of nanoparticles like Caco-2 ignore the presence of vascular endothelium, which is a part of the intestinal multi-layered barrier structure. Therefore, a coculture between the Caco-2 epithelium and HMEC-1 (Human Microvascular Endothelial Cell type 1) on a Transwell® insert has been developed. The model has been validated for (a) membrane morphology by transmission electron microscope (TEM); (b) ZO-1 and β-catenin expression by immunoassay; (c) membrane integrity by trans-epithelial electrical resistance (TEER) measurement; and (d) apparent permeability of drugs from different biopharmaceutical classification system (BCS) classes. Lipid nanocapsules (LNCs) were formulated with different sizes (55 and 85 nm) and surface modifications (DSPE-mPEG (2000) and stearylamine). Nanocapsule integrity and particle concentration were monitored using the Förster resonance energy transfer (FRET) technique. The result showed that surface modification by DSPE-mPEG (2000) increased the absorption of 55-nm LNCs in the coculture model but not in the Caco-2. Summarily, the coculture model was validated as a tool for evaluating the intestinal absorption of drugs and nanoparticles. The new coculture model has a different LNCs absorption mechanism suggesting the importance of intestinal endothelium and reveals that the surface modification of LNCs can modify the in vitro oral absorption.

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In vitro and in situ study on characterizationand mechanismofthe intestinal absorptionof 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v3 ◽

2020 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

Concentration Time ◽

In Situ Experiments ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods: This study used Caco-2 cell monolayer model and single-passintestinal perfusion modelto explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed. Results: TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro and in situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2. Conclusions: It wasconcluded that the gastrointestinalabsorption mechanisms ofTSG involved processes passive transport and the participation ofefflux transporters.

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Metabolic Acidosis Induced by Plasmodium Falciparum Intraerythrocytic Stages Alters Blood—Brain Barrier Integrity

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2010.121 ◽

2010 ◽

Vol 31 (2) ◽

pp. 514-526 ◽

Cited By ~ 29

Author(s):

Sergine Zougbédé ◽

Florence Miller ◽

Philippe Ravassard ◽

Angelita Rebollo ◽

Liliane Cicéron ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Metabolic Acidosis ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Microvascular Endothelial Cell ◽

Blood Brain ◽

Coculture Model ◽

Antiparasitic Drugs ◽

Permeability Increase

The pathogenesis of cerebral malaria (CM) remains largely unknown. There is growing evidence that combination of both parasite and host factors could be involved in blood–brain barrier (BBB) breakdown. However, lack of adequate in vitro model of human BBB so far hampered molecular studies. In this article, we propose the use of hCMEC/D3 cells, a well-established human cerebral microvascular endothelial cell (EC) line, to study BBB breakdown induced by Plasmodium falciparum-parasitized red blood cells and environmental conditions. We show that coculture of parasitized erythrocytes with hCMEC/D3 cells induces cell adhesion and paracellular permeability increase, which correlates with disorganization of zonula occludens protein 1 expression pattern. Permeability increase and modification of tight junction proteins distribution are cytoadhesion independent. Finally, we show that permeability of hCMEC/D3 cell monolayers is mediated through parasite induced metabolic acidosis, which in turns correlates with apoptosis of parasitized erythrocytes. This new coculture model represents a very useful tool, which will improve the knowledge of BBB breakdown and the development of adjuvant therapies, together with antiparasitic drugs.

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Orally Active Antiviral Tripeptide Glycyl-Prolyl-Glycinamide Is Activated by CD26 (Dipeptidyl Peptidase IV) before Transport across the Intestinal Epithelium

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.3.1087-1092.2005 ◽

2005 ◽

Vol 49 (3) ◽

pp. 1087-1092 ◽

Cited By ~ 6

Author(s):

Ina Hubatsch ◽

Lucia Lazorova ◽

Anders Vahlne ◽

Per Artursson

Keyword(s):

Intestinal Epithelium ◽

Dipeptidyl Peptidase ◽

Oral Route ◽

Dipeptidyl Peptidase Iv ◽

Drug Candidate ◽

Absorption Mechanism ◽

Apparent Permeability ◽

Cell Monolayers ◽

Orally Active

ABSTRACT The tripeptide amide glycyl-prolyl-glycinamide (GPG-amide) is a new antiretroviral drug candidate, but its absorption mechanism is unknown. In this investigation, the transport and metabolism of GPG-amide were studied in a model of the human intestinal epithelium, Caco-2 cell monolayers. The results show that when the tripeptide amide came into contact with the apical enterocyte membrane, it was degraded by CD26 (dipeptidyl peptidase IV) to glycylproline and the antiretrovirally active metabolite glycinamide. Glycinamide retained antiretroviral activity in vitro after transport through the Caco-2 cell monolayers. The transport of glycinamide across Caco-2 cell monolayers occurred via passive diffusion with an apparent permeability coefficient of about 2 × 10−6 cm s−1, which suggests that it is absorbed by the oral route in sufficient amounts to be considered for oral administration. In conclusion, the tripeptide GPG-amide acts as a prodrug that is activated by CD26 to release the orally active antiretroviral compound glycinamide.

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In vivo and in vitro study on characterization and mechanism of the intestinal absorption of 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v1 ◽

2019 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

In Vitro Study ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

Concentration Time ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibits a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound has poor bioavailability and the underlying absorption mechanisms has not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods: This study used the Caco-2 cell monolayer model and the single-passintestinal perfusion modelto explore the intestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.In addition, the susceptibility of TSG absorption process to treatment with three inhibitors, such as P-gp inhibitors verapamil hydrochloride and quinidine, and the MRP2 inhibitor probenecid were also assessed. Results: TSG is poorly absorbed in the intestines and the absorption of TSG in the stomach is much higher than that in the intestine. Both in vivo and in vitro experiments showed that the absorption of TSG was saturated with increasing concentration. and it was better absorbed in a weakly acidic environment with a pH of 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG is not only the substrate of the P-gp and MRP2, but also affects the expression of P-gp and MRP2. Conclusions: It can be concluded that the intestinal absorption mechanismsofTSG involve processes passive transport and the participation of efflux transporters.

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Vitamin A1 intestinal absorption in vivo: influence of luminal factors on transport.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1977.232.5.e471 ◽

1977 ◽

Vol 232 (5) ◽

pp. E471 ◽

Cited By ~ 1

Author(s):

D Hollander ◽

K S Muralidhara

Keyword(s):

Intestinal Absorption ◽

Absorption Rate ◽

Sodium Taurocholate ◽

Water Layer ◽

Metabolic Inhibitors ◽

Absorption Mechanism ◽

Lymphatic Circulation ◽

Passive Absorption

Intestinal absorption of [3H]retinol was studied in the unanesthetized rat. Luminal perfusate was recirculated through isolated intestinal segments with intact vascular and lymphatic circulation. Apparent saturation kinetics were found in physiological concentrations of retinol, whereas a linear relationship between the concentration and absorption rate was found at pharmacological concentrations of retinol in the perfusate. In physiological concentrations, retinol uptake in vitro by everted gut sacs was unaffected by anoxia or metabolic inhibitors and uncouplers. In vivo retinol absorption rate was decreased when sodium taurocholate concentration was raised above 5 mM, or when 2.5 mM linoleic or linolenic acids were added to the perfusate. Absorption increased markedly as the thickness of the unstirred water layer was diminished. Variations in perfusate pH from 4.5 to 8.6 did not change the retinol absorption rate. In vivo absorption of retinol in physiological concentrations is mediated by a saturable, carrier-mediated passive absorption mechanism modified by the presence of fatty acids of varying chain length.

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In vitro and in situ study on characterizationand mechanismofthe intestinal absorptionof 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v2 ◽

2019 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

In Situ Study ◽

Concentration Time ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods:This study used Caco-2 cell monolayer model and single-passintestinal perfusion modelto explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed. Results: TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro andin situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2. Conclusions: It wasconcluded that the gastrointestinalabsorption mechanisms ofTSG involved processes passive transport and the participation ofefflux transporters.

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Absorption of Ester Prodrugs in Caco-2 and Rat Intestine Models

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.7.2604-2609.2004 ◽

2004 ◽

Vol 48 (7) ◽

pp. 2604-2609 ◽

Cited By ~ 22

Author(s):

Xin He ◽

Mitsuru Sugawara ◽

Yoh Takekuma ◽

Katsumi Miyazaki

Keyword(s):

Oral Absorption ◽

Physiological State ◽

Intracellular Accumulation ◽

Rat Intestine ◽

Absorption Mechanism ◽

Intracellular Degradation ◽

Apical Side ◽

Basolateral Side ◽

Ester Prodrugs

ABSTRACT The aim of this study was to elucidate the absorption mechanism in Caco-2 and rat intestine models in order to improve the accuracy of prediction of oral absorption of ester prodrugs. Pivampicillin and cefcapene pivoxil hydrochloride (CFPN-PI), ester-type oral antibiotics, were chosen as model ester prodrugs. The level of esterase activity in Caco-2 cells was lower than that measured in the rat jejunum when p-nitrophenyl acetate was used as a substrate. Almost complete ester hydrolysis occurred before the ester prodrugs reached the basolateral side of the monolayer, and the disappearance of prodrugs was thought to be due to metabolism or transport after addition to the apical side of the monolayer. When pivampicillin and CFPN-PI were used, the amounts of ampicillin and cefcapene (CFPN) produced by hydrolysis of prodrugs were increased because intracellular degradation of prodrugs resulted in intracellular accumulation. On the other hand, when ampicillin or CFPN was used, only a small amount of the drug reached the basolateral side of the monolayers and no intracellular accumulation was observed. The permeability of CFPN-PI, the solubility of which is dependent on the acidity of gastric juice, across a Caco-2 monolayer or rat intestine, was also investigated by using an in vitro system that mimics the physiological state of the human gastrointestinal tract. The oral absorption of CFPN-PI in humans is predicted to be good either in the Caco-2 model or in the rat intestine model. It is concluded that our system may be a valuable tool for evaluation of oral absorption of ester prodrugs metabolized during permeation through the intestinal epithelium. Broader evaluation of such a system is warranted.

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