Topical protection of human esophageal mucosal integrity

2015 ◽  
Vol 308 (12) ◽  
pp. G975-G980 ◽  
Author(s):  
P. Woodland ◽  
F. Batista-Lima ◽  
C. Lee ◽  
S. L. Preston ◽  
P. Dettmar ◽  
...  

Patients with nonerosive reflux disease exhibit impaired esophageal mucosal integrity, which may underlie enhanced reflux perception. In vitro topical application of an alginate solution can protect mucosal biopsies against acid-induced changes in transepithelial electrical resistance (TER). We aimed to confirm this finding in a second model using 3D cell cultures and to assess prolonged protection in a biopsy model. We assessed the protective effect of a topically applied alginate solution 1 h after application. 3D cell cultures were grown by using an air-liquid interface and were studied in Ussing chambers. The apical surface was “protected” with 200 μl of either alginate or viscous control or was unprotected. The tissue was exposed to pH 3 + bile acid solution for 30 min and TER change was calculated. Distal esophageal mucosal biopsies were taken from 12 patients and studied in Ussing chambers. The biopsies were coated with either alginate or viscous control solution. The biopsies were then bathed in pH 7.4 solution for 1 h. The luminal chamber solution was replaced with pH 2 solution for 30 min. Percentage changes in TER were recorded. In five biopsies fluorescein-labeled alginate solution was used to allow immunohistological localization of the alginate after 1 h. In the cell culture model, alginate solution protected tissue against acid-induced change in TER. In biopsies, 60 min after protection with alginate solution, the acidic exposure caused a −8.3 ± 2.2% change in TER compared with −25.1 ± 4.5% change after protection with the viscous control ( P < 0.05). Labeled alginate could be seen coating the luminal surface in all cases. In vitro, alginate solutions can adhere to the esophageal mucosa for up to 1 h and exert a topical protectant effect. Durable topical protectants can be further explored as first-line/add-on therapies for gastroesophageal reflux disease.

2020 ◽  
Vol 25 (3) ◽  
pp. 234-246
Author(s):  
Charles McRae White ◽  
Mark A. Haidekker ◽  
William S. Kisaalita

New insights into the biomechanical properties of cells are revealing the importance of these properties and how they relate to underlying molecular, architectural, and behavioral changes associated with cell state and disease processes. However, the current understanding of how these in vitro biomechanical properties are associated with in vivo processes has been developed based on the traditional monolayer (two-dimensional [2D]) cell culture, which traditionally has not translated well to the three-dimensional (3D) cell culture and in vivo function. Many gold standard methods and tools used to observe the biomechanical properties of 2D cell cultures cannot be used with 3D cell cultures. Fluorescent molecules can respond to external factors almost instantaneously and require relatively low-cost instrumentation. In this review, we provide the background on fluorescent molecular rotors, which are attractive tools due to the relationship of their emission quantum yield with environmental microviscosity. We make the case for their use in both 2D and 3D cell cultures and speculate on their fundamental and practical applications in cell biology.


2016 ◽  
Vol 69 ◽  
pp. S146-S147
Author(s):  
S. Pignatta ◽  
C. Arienti ◽  
M. Zanoni ◽  
A. Zamagni ◽  
S. Collina ◽  
...  

Author(s):  
Robert H. Utama ◽  
Lakmali Atapattu ◽  
Aidan P. O’Mahony ◽  
Christopher M. Fife ◽  
Jongho Baek ◽  
...  

Abstract3D in vitro cancer models are important therapeutic and biological discovery tools, yet formation of multicellular spheroids in a throughput and highly controlled manner to achieve robust and statistically relevant data, remains challenging. Here, we developed an enabling technology consisting of a bespoke drop-on-demand 3D bioprinter capable of high-throughput printing of 96-well plates of spheroids. 3D-multicellular spheroids are embedded inside a tissue-like matrix with precise control over size and cell number. Application of 3D bioprinting for high-throughput drug screening was demonstrated with doxorubicin. Measurements showed that IC50 values were sensitive to spheroid size, embedding and how spheroids conform to the embedding, revealing parameters shaping biological responses in these models. Our study demonstrates the potential of 3D bioprinting as a robust high-throughput platform to screen biological and therapeutic parameters.Significance StatementIn vitro 3D cell cultures serve as more realistic models, compared to 2D cell culture, for understanding diverse biology and for drug discovery. Preparing 3D cell cultures with defined parameters is challenging, with significant failure rates when embedding 3D multicellular spheroids into extracellular mimics. Here, we report a new 3D bioprinter we developed in conjunction with bioinks to allow 3D-multicellular spheroids to be produced in a high-throughput manner. High-throughput production of embedded multicellular spheroids allowed entire drug-dose responses to be performed in 96-well plate format with statistically relevant numbers of data points. We have deconvoluted important parameters in drug responses including the impact of spheroid size and embedding in an extracellular matrix mimic on IC50 values.


1984 ◽  
Vol 247 (6) ◽  
pp. G695-G702 ◽  
Author(s):  
P. L. Smith ◽  
R. D. McCabe

Stripped rabbit colonic mucosa was studied in vitro in Ussing chambers to determine 1) effects of the divalent cation ionophore A23187 on K and Cl fluxes and electrical properties; 2) effects of the prostaglandin (PG) synthesis inhibitor indomethacin on A23187-, PGE1-, and arachidonic acid-induced changes in electrical parameters and K and Cl fluxes; and 3) changes in PGE2 release in response to A23187, arachidonic acid, indomethacin, or indomethacin and either A23187 or arachidonic acid. Results from these studies demonstrate that A23187, PGE1, and arachidonate increase net K and Cl secretion. Results with indomethacin reveal that this agent abolishes the increase in Cl secretion stimulated by A23187 or arachidonate but not by PGE1. Indomethacin also abolished net K secretion stimulated by arachidonate but not by A23187 or PGE1. These results together with the finding that A23187 like arachidonate increases PGE2 release in the absence but not the presence of indomethacin suggest that A23187-stimulated Cl secretion occurs by a PG-dependent mechanism, while A23187-induced K secretion occurs by an alternate Ca-dependent mechanism.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 756 ◽  
Author(s):  
Qiuhong Chen ◽  
Xiaohong Tian ◽  
Jun Fan ◽  
Hao Tong ◽  
Qiang Ao ◽  
...  

Crosslinking is an effective way to improve the physiochemical and biochemical properties of hydrogels. In this study, we describe an interpenetrating polymer network (IPN) of alginate/gelatin hydrogels (i.e., A-G-IPN) in which cells can be encapsulated for in vitro three-dimensional (3D) cultures and organ bioprinting. A double crosslinking model, i.e., using Ca2+ to crosslink alginate molecules and transglutaminase (TG) to crosslink gelatin molecules, is exploited to improve the physiochemical, such as water holding capacity, hardness and structural integrity, and biochemical properties, such as cytocompatibility, of the alginate/gelatin hydrogels. For the sake of convenience, the individual ionic (i.e., only treatment with Ca2+) or enzymatic (i.e., only treatment with TG) crosslinked alginate/gelatin hydrogels are referred as alginate-semi-IPN (i.e., A-semi-IPN) or gelatin-semi-IPN (i.e., G-semi-IPN), respectively. Tunable physiochemical and biochemical properties of the hydrogels have been obtained by changing the crosslinking sequences and polymer concentrations. Cytocompatibilities of the obtained hydrogels are evaluated through in vitro 3D cell cultures and bioprinting. The double crosslinked A-G-IPN hydrogel is a promising candidate for a wide range of biomedical applications, including bioartificial organ manufacturing, high-throughput drug screening, and pathological mechanism analyses.


1995 ◽  
Vol 269 (2) ◽  
pp. G210-G218
Author(s):  
R. N. Fedorak ◽  
N. Cui ◽  
D. R. Friend ◽  
K. L. Madsen ◽  
L. R. Empey

A recently synthesized novel colon-specific dexamethasone prodrug, dexamethasone-beta-D-glucuronide, delivers efficacious amounts of dexamethasone to the colon with limited adrenal suppressive effects. During experimentally induced colitis in rats, the dexamethasone prodrug is significantly more potent than free dexamethasone in improving colonic fluid and electrolyte absorptive injury. The present studies examined whether the improvement in colonic absorption seen with the prodrug occurred as a consequence of alterations in sodium and chloride epithelial transport. The efficacy of the dexamethasone prodrug and free dexamethasone were tested in an acetic acid-induced rat model of colitis. Healing of the induced colitis was assessed by measuring net colonic fluid absorption and surface area ulceration. Transmural unidirectional fluxes of 22Na and 36Cl across sheets of colonic mucosa were measured in Ussing chambers. Treatment of colitis with the prodrug delivered a sixfold higher concentration of dexamethasone to the colon than did treatment with the free drug. The prodrug accelerated healing of colitis by returning in vivo colonic fluid absorption to normal and virtually eliminated colonic macroscopic ulceration, whereas the free drug did not. In vitro transmural fluxes demonstrated that, in addition to repair of mucosal integrity, the prodrug enhanced electroneutral sodium chloride absorption over and above that seen in control animals or after treatment with the free drug. Both the prodrug and the free drug limited theophylline-mediated net chloride and sodium secretion, an effect that would be consistent with the antidiarrheal effect induced by these drugs in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)


2014 ◽  
Vol 229 ◽  
pp. S145 ◽  
Author(s):  
Terry Riss ◽  
Michael Valley ◽  
Kevin Kupcho ◽  
Chad Zimprich ◽  
Donna Leippe ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document