Skorup, Ivo (2023). Oral lipid-based treatments for chronic liver disease: from formulation characterization to in vitro assays mimicking pathological conditions. (Thesis). Universität Bern, Bern
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Abstract
A range of different chronic liver diseases such as liver steatosis, non-alcoholic fatty liver disease (NAFLD), fibrosis, and cirrhosis designate the gradual deterioration of liver function. All these conditions arise from sustained liver injury and the subsequent wound-healing response, which can lead to the irreversible alteration of liver structure and function. Liver fibrosis is characterised by the accumulation of extracellular matrix (ECM) arising from the myofibroblastic transdifferentiation of hepatic stellate cells (HSCs) occurring as the natural response to liver damage. To date, no pharmacological treatments have been approved explicitly for liver fibrosis. We recently reported a beneficial effect of polyenylphosphatidylcholines (PPCs)-rich formulations in reverting fibrogenic features of HSCs. However, unsaturated phospholipids’ properties constantly challenge to the development of tablets as the preferred patient-centric dosage form. Profiting from the advantageous physical properties of the PPCs-rich Soluthin® S 80 M, we developed a tablet formulation incorporating 70% w/w of this bioactive lipid. Tablets were extensively characterised through physico-chemical and pharmacopoeial tests and passed the major compendial requirements. To mimic physiological absorption after oral intake, phospholipids extracted from tablets were reconstituted as protein-free chylomicron (PFC)-like emulsions and tested on the fibrogenic human HSC line LX-2 and primary cirrhotic rat hepatic stellate cells (PRHSC). Lipids extracted from tablets and reconstituted in buffer or as PFC-like emulsions exerted the same antifibrotic effect on both activated LX-2 and PRHSCs as observed with plain S 80 M liposomes, showing that the manufacturing process did not interfere with PPCs’ bioactivity. The second part of this work is about the authentic replication of chronic liver disease in an in vitro system which usually represents a significant challenge. A finely tuned interplay between hepatocytes and HSCs modulates pathology progression or regression. The establishment of a new setup based on the transfer of secretome from a human hepatocarcinoma Huh-7 cell line to an immortalised human HSCs LX-2 cells has been explored to obtain a simplified yet representative in vitro model of NAFLD. Steatosis was induced by incubating Huh-7 cells with oleic and palmitic acid, eventually successively treated with PPC-based formulations, with or without experimental drugs elafibranor and obeticholic acid, and the resulting CCM was collected and transferred to LX-2 cells. To investigate the bidirectional cross-talk between hepatocytes HSC, also activated LX-2, either naïve or treated with control conditions or with our proposed bioactive PPC-based treatment, were incubated with Huh-7-derived CCM. The study demonstrated the potential therapeutic effects of positive controls and PPC-based formulations in reverting LX-2 cells to a quiescent-like state when treated with CCM from steatotic Huh-7. This suggests antifibrotic activity and sustains a quiescent, lipid droplet-rich LX-2 cells. An additional model used CCM from steatotic Huh-7 treated with PPC-based formulation including investigational drugs, showing that CCM prevented LX-2 cells from progressing to a perpetuated state but did not revert activated ones while fibrotic markers remained constant. An inverted model attempted to reverse hepatocyte steatosis using CCM from quiescent-like LX-2 without success, suggesting the need for further research.
| Item Type: | Thesis |
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| Dissertation Type: | Cumulative |
| Date of Defense: | 30 August 2023 |
| Subjects: | 500 Science > 570 Life sciences; biology 600 Technology > 610 Medicine & health |
| Institute / Center: | 08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) |
| Depositing User: | Sarah Stalder |
| Date Deposited: | 20 Oct 2025 14:32 |
| Last Modified: | 20 Oct 2025 22:25 |
| URI: | https://boristheses.unibe.ch/id/eprint/6802 |
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