POSTERS
Poster Session – Thursday, April 15
01a. LIVER TRANSPLANTATION/ SURGERY: a. EXPERIMENTAL
129 HEPATOCYTE CELL LINE FUNCTION IN A BIOSYNTHETIC HYDROGEL SCAFFOLD FOR LIVER TISSUE ENGINEERING T. Saadi1 , A. Arish2 , J. Carmel1 , Z. Bramnik2 , O. Nayshool3 , I. Mironi-Harpaz4 , D. Seliktar4 , Y. Baruch1,3 . 1 Liver Unit, 2 Department of Surgery B, Rambam – Health Care Campus, 3 Bruce Rappaport Faculty of Medicine, 4 Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel E-mail:
[email protected] Introduction and Aims: We employ a hydrogel scaffold to improve the overall hepatocyte engraftment after transplantation, and to improve efficacy. The scaffold is comprised of a fibrinogen backbone cross-linked with polyethylene glycol diacrylate (PEGDA) side chains that form a hydrogel when mixed with cells and photo-polymerized. This biocompatible and biodegradable hydrogel provides a mechanical support as well as immunological protection, while maintaining cell function for the critical period early after cell transplantation. To assess and optimize the short-term (3 day) viability and function of a hepatocyte cell line after cell encapsulation within the hydrogel construct. Methods: Cell viability (Huh7) was estimated by propidium iodide (PI) labeling and fluorescein diacetate (FDA) staining. Viability was quantified using an MTT assay. Albumin and the urea production (in the medium) was used to assess hepatocyte function. Results were compared with normal cell cultures without a scaffold. Results: The number of polymer encapsulated cells without additional PEG-DA as measured by the MTT assay increased by three-fold within three days, (P < 0.05). The cell number increased by two-fold when adding 2% additional PEG-DA. The viability of the encapsulated cells with 0% PEG-DA as measured by PI/FDA staining was comparable to cell cultures without the polymer (95%±1.1% after 3 days) but lower when adding 2% additional PEGDA (85%±1% after 3 days). Albumin concentration was higher at day 3 in encapsulated cells: 12.8 mg/l (P < 0.05) with 0% PEG-DA, and 15.4 mg/l (P < 0.05) with 2% PEG-DA, compared to 9.5 mg/l in cell cultures without the polymer. The urea concentration also increased to 3.0 mg/dl and 2.7 mg/dl, with and without additional 2% PEGDA, respectively (P < 0.05), compared to 3.3 mg/dl in cell cultures without the polymer. The cell/polymer constructs were injected to rat liver, spleen and subcutis; the constructs were stable for 3 days post transplantation, allowing for new vessels to develop. Conclusions: The in-vitro Huh7 viability and function after polymerization in PEGylated protein hydrogel constructs was comparable to cells without the polymer. This is an important step for the development of injectable tissue engineered liver analogs for transplantation.
130 THE ROLE OF TRANSFORMING GROWTH FACTOR B-1 POLYMORPHISM IN THE FIBROSIS PROGRESSION AFTER LIVER TRANSPLANTATION FOR HCV-INDUCED LIVER DISEASE D. Eurich, M. Schmeding, M. Bahra, S. Boas-Knoop, J. Lock, J. Golembus, R. Neuhaus, P. Neuhaus, U.P. Neumann. Department of General-, Visceral-, Transplantationsurgery, Charite Campus Virchow, Berlin, Germany E-mail:
[email protected] Background: Up to 30% of liver transplants will develop cirrhosis again within 5 years after transplantation (OLT) due to recurrent hepatitis-C. Aim of our study was to analyze graft fibrosis progression based on protocol liver biopsies and to evaluate the role of genetic variants of TGF-b1. Methods: 201 patients who underwent liver transplantation for HCV-induced liver disease were genotyped for TGF-b1 codon 10 (C → T) and 25 (G → C) by polymerase chain reaction on genomic DNA from leucocytes using sequence-specific primers. Histological evaluation of 622 protocol liver biopsies identified 85 patients with fibrosis progression and 116 with a stable disease. Prevalence of TGF-b1-alleles that had been reported to be associated with high secretor phenotypes was determined also according to stages of significant and advanced fibrosis. Results: No difference was observed between the group with fibrosis progression and stable disease regarding recipient’s age, incidence of hepatocellular carcinoma before transplantation and allelic frequencies, genotype / haplotype distribution of TGF-b1-codon-10-polymorphism. However a significant statistical difference of codon 25 (Arg → Pro) distribution was observed between the patients who reached stage 3 and 4 fibrosis within first 5 years after OLT compared to stage 1 and 2 (p = 0.007). Positive association to fibrosis progression was found for older donor age (p = 0.015), male recipient gender (p = 0.030) and viral genotype 1b (p = 0.014). Conclusions: In our trial with the largest sample size of patients with HCV re-infection and well defined fibrosis behavior to date, proline coding C-allele at codon-25, female gender and younger donor age might play a protective role in the development of graft fibrosis. 131 HEPATIC STELLATE CELL ACTIVATION: AN IMPORTANT CONTRIBUTOR TO PERSISTENT HEPATIC RESISTANCE IN SMALL-FOR-SIZE LIVERS AFTER EXTENDED PARTIAL HEPATECTOMY IN THE RAT Y.-D. Fan1 , E. Vanheule2 , D. Meester1 , J. Van Huysse3 , K. Olievier2 , M. Praet3 , I. Colle2 , B. de Hemptinne1 . 1 Department of Hepatobiliary and General Surgery, 2 Department of Hepatology & Gastroenterology, 3 Department of Pathology, Ghent University Hospital, Ghent, Belgium E-mail:
[email protected] Background and Aims: Excessive haemodynamic changes contribute to early hepatic dysfunction in small for size liver (SFS) after either major liver resection or small graft transplantation. Besides other factors, hepatic stellate cell (HSC) activation may play a role in the increase of hepatic resistance. In this study, HSC activation was analysed in relation to hepatic haemodynamics,
Journal of Hepatology 2010 vol. 52 | S59–S182 © 2010 All rights reserved.