Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Oct 27, 2018; 10(10): 719-730
Published online Oct 27, 2018. doi: 10.4254/wjh.v10.i10.719
Experimental bio-artificial liver: Importance of the architectural design on ammonia detoxification performance
María Dolores Pizarro, María Eugenia Mamprin, Lucas Damián Daurelio, Joaquín Valentín Rodriguez, María Gabriela Mediavilla
María Dolores Pizarro, María Eugenia Mamprin, Lucas Damián Daurelio, Joaquín Valentín Rodriguez, María Gabriela Mediavilla, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rosario S2002 LRK, Argentina
María Dolores Pizarro, Lucas Damián Daurelio, Laboratorio de Investigaciones en Fisiología y Biología Molecular Vegetal (LIFiBVe), Facultad de Ciencias Agrarias, Universidad Nacional del Litoral, Esperanza 3080, Argentina
María Eugenia Mamprin, Farmacología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario S2002 LRK, Argentina
Joaquín Valentín Rodriguez, Centro Binacional de Criobiología Clínica y Aplicada (CAIC), Universidad Nacional de Rosario, Rosario S2011 BXN, Argentina
María Gabriela Mediavilla, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Consejo Nacional de Investigaciones Científicas y Tecnológicas, y Universidad Nacional de Rosario, Rosario S2002 LRK, Argentina
Author contributions: Pizarro MD performed the majority of experiments, analyzed data, and wrote the manuscript; Mamprin ME and Mediavilla MG designed the research, contributed new reagents, analyzed data, and wrote the manuscript; Daurelio LD designed and supervised the statistical analysis; Rodriguez JV developed the cylindrical bioreactor and metabolite mass balance equations, performed a critical revision, and contributed to the research and the redaction of this article; all the authors were involved in reviewing the literature for latest contributions in the field, writing, and editing the manuscript; Mamprin ME and Mediavilla MG have equally contributed to this work.
Supported by Universidad Nacional de Rosario (UNR), BIO 272, Resol. C.S., No. 677/2013; Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT), PICT-03-14492, BID 1728 OC/AR (Argentina); and a grant from Regione Autonoma Friuli-Venezia Giulia, Italy.
Institutional review board statement: The study was reviewed and approved by the National University of Rosario Institutional Review Board (Resol. C.S. No. 677/2013).
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Faculty of Biochemical and Pharmaceutical Sciences-UNR (Resol. No. 139/2011).
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
Open-Access: This article is an open-access article, which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: María Gabriela Mediavilla, PhD, Associate Researcher, Doctor, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Consejo Nacional de Investigaciones Científicas y Tecnológicas, y Universidad Nacional de Rosario, Suipacha 531, Rosario S2002 LRK, Argentina. mediavilla@ibr-conicet.gov.ar
Telephone: +54-341-4350661 Fax: +54-341-4390465
Received: May 22, 2018
Peer-review started: May 23, 2018
First decision: June 14, 2018
Revised: July 12, 2018
Accepted: August 6, 2018
Article in press: August 7, 2018
Published online: October 27, 2018
Abstract
AIM

To determine the influence of the construction design over the biological component’s performance in an experimental bio-artificial liver (BAL) device.

METHODS

Two BAL models for liver microorgans (LMOs) were constructed. First, we constructed a cylindrical BAL and tested it without the biological component to establish its correct functioning. Samples of blood and biological compartment (BC) fluid were taken after 0, 60, and 120 min of perfusion. Osmolality, hematocrit, ammonia and glucose concentrations, lactate dehydrogenase (LDH) release (as a LMO viability parameter), and oxygen consumption and ammonia metabolizing capacity (as LMO functionality parameters) were determined. CPSI and OTC gene expression and function were measured. The second BAL, a “flat bottom” model, was constructed using a 25 cm2 culture flask while maintaining all other components between the models. The BC of both BALs had the same capacity (approximately 50 cm3) and both were manipulated with the same perfusion system. The performances of the two BALs were compared to show the influence of architecture.

RESULTS

The cylindrical BAL showed a good exchange of fluids and metabolites between blood and the BC, reflected by the matching of osmolalities, and glucose and ammonia concentration ratios after 120 min of perfusion. No hemoconcentration was detected, the hematocrit levels remained stable during the whole study, and the minimal percentage of hemolysis (0.65% ± 0.10%) observed was due to the action of the peristaltic pump. When LMOs were used as biological component of this BAL they showed similar values to the ones obtained in a Normothermic Reoxygenation System (NRS) for almost all the parameters assayed. After 120 min, the results obtained were: LDH release (%): 14.7 ± 3.1 in the BAL and 15.5 ± 3.2 in the NRS (n = 6); oxygen consumption (μmol/min·g wet tissue): 1.16 ± 0.21 in the BAL and 0.84 ± 0.15 in the NRS (n = 6); relative expression of Cps1 and Otc: 0.63 ± 0.12 and 0.67 ± 0.20, respectively, in the BAL, and 0.86 ± 0.10 and 0.82 ± 0.07, respectively, in the NRS (n = 3); enzymatic activity of CPSI and OTC (U/g wet tissue): 3.03 ± 0.86 and 222.0 ± 23.5, respectively, in the BAL, and 3.12 ± 0.73 and 228.8 ± 32.8, respectively, in the NRS (n = 3). In spite of these similarities, LMOs as a biological component of the cylindrical BAL were not able to detoxify ammonia at a significant level (not detected vs 35.1% ± 7.0% of the initial 1 mM NH4+ dose in NRS, n = 6). Therefore, we built a second BAL with an entirely different design that offers a flat base BC. When LMOs were placed in this “flat bottom” device they were able to detoxify 49.3% ± 8.8% of the initial ammonia overload after 120 min of perfusion (n = 6), with a detoxification capacity of 13.2 ± 2.2 μmol/g wet tissue.

CONCLUSION

In this work, we demonstrate the importance of adapting the BAL architecture to the biological component characteristics to obtain an adequate BAL performance.

Keywords: Bio-artificial liver, Ammonia detoxification, Device design, Ornithine Transcarbamylase, Rat liver microorgans, Carbamyl Phosphate Synthetase I

Core tip: This work describes the adaptation of a simplified bio-artificial liver (BAL) prototype to make it suitable to house rat liver microorgans (LMOs) as a biological component, and the evaluation of the performance in this new model. We demonstrate that the modification in the design of the artificial parts employed allows a good performance of LMOs, thus showing the importance of architecture and model configuration on the design of these devices. Besides its application as BAL, this mini bioreactor could serve as a suitable laboratory tool to evaluate the behavior and functionality of LMOs subjected to different incubation conditions due to its simple design and the utilization of standard materials.