Primary rat hepatocytes are a widely used experimental model to estimate drug metabolism and toxicity. In currently used two-dimensional (2D) cell culture systems, typical problems like morphological changes and the loss of liver cell-specific functions occur. We hypothesize that the use of polymer scaffolds could overcome these problems and support the establishment of three-dimensional (3D) culture systems in pharmaceutical research. Isolated primary rat hepatocytes were cultured on collagen-coated nanofibrous scaffolds for 7 days. Cell loading efficiency was quantified via DNA content measurement. Cell viability and presence of liver-cell-specific functions (albumin secretion, glycogen storage capacity) were evaluated. The activity of liver-specific factors was analyzed by immunofluorescent staining. RNA was isolated to establish quantitative real-time PCR. Our results indicate that primary rat hepatocytes cultured on nanofibrous scaffolds revealed high viability and well-preserved glycogen storage. Albumin secretion was existent during the entire culture period. Hepatocytes remain HNF-4 positive, indicating highly preserved cell differentiation. Aggregated hepatocytes re-established positive signaling for Connexin 32, a marker for differentiated hepatocyte interaction. ZO-1-positive hepatocytes were detected indicating formation of tight junctions. Expression of cytochrome isoenzymes was inducible. Altogether the data suggest that nanofibrous scaffolds provide a good in vitro microenvironment for neo tissue regeneration of primary rat hepatocytes.
Background Laparoscopic pancreatoduodenectomy is a highly challenging procedure. The aim of this study was to analyse post-operative morbidity and mortality as well as long term overall survival in patients undergoing hybrid LPD, as compared to open pancreaticoduodenecomy (OPD) in a single surgeon series. Methods Patients undergoing pancreatoduodenectomy (PD) in the period from 2000 to 2015 were identified from a prospectively maintained database. All LPD procedures were performed by one specialised pancreatic surgeon (TK). Patients were matched 1 : 1 for age, sex, BMI, ASA, histological diagnosis, pancreatic texture and portal venous resection (PVR). All LPD procedures were performed as hybrid LPD – combining laparoscopic resection and open reconstruction via mini laparotomy. Results A total of 549 patients were identified, including 489 patients in the OPD group and 60 patients in the LPD group. 60 patients were identified who underwent LPD between 2010 and 2015 versus 60 OPD patients operated in the same period. Median overall operation time was shorter in the LPD group than with OPD patients (LPD 352 vs. OPD 397 min; p = 0.002). Overall transfusion units were lower in the LPD group (LPD range 0 – 4 vs. OPD range 0 – 11; p = 0.032). Intensive care unit stay (LPD 1 vs. OPD 6 d; p = 0.008) and overall hospital stay (OHS: LPD 14 vs. OPD 18 d; p = 0.012) were shorter in the LPD groups than in the OPD group. As regards postoperative complications, LPD was associated with reduced rates of clinically relevant grade B/C postoperative pancreatic fistula (LPD 15 vs. OPD 36%; p = 0.036) and grade B/C delayed gastric emptying (LPD 8 vs. OPD 20%; p = 0.049). A total of 56 patients were diagnosed with malignant disease. The number of harvested lymph nodes and R0-resection rates were equal for LPD and OPD patients. LPD patients showed a trend to improved median overall survival (LPD mean 56 months vs. OPD mean 48 months; p = 0.056). Conclusion Hybrid LPD is a safe procedure associated with a reduction in clinically relevant postoperative complications and allows faster recovery. Long term oncological outcome of hybrid LPD for malignant disease is equal to that with the standard open approach.
Human hepatocyte transplantation has not been routinely established as an alternative to liver transplantation in liver disease due to low cell engraftment rates. Preimplantation in vitro engineering of liver tissue using primary human hepatocytes on three-dimensional scaffolds could be an alternative model. Alginate bioscaffolds were seeded with 1×10(6) hepatocytes freshly isolated from the livers of three children suffering from different metabolic disorders. During a culture period of 14 days only a marginal loss of hepatocytes was observed via measurement of DNA content per scaffold. Formation of hepatocyte spheroids was detected from day 3 onward using transmission light microscopy. Biochemical assays for albumin, α1-antitrypsin, and urea revealed excellent metabolic function with its maximum at day 7. Low lactate dehydrogenase enzyme release demonstrated minor cellular membrane damage. Hematoxylin and eosin and periodic acid Schiff staining displayed high cell viability and well-preserved glycogen storage until day 7. Immunofluorescent staining of hepatocyte nuclear factor 4, zonula occludens protein 1, and cytokeratin 18 revealed highly differentiated hepatocytes in spheroids with a tissue-like structure on scaffolds. Fluorescent labeling of cytochrome P450 and bile canaliculi demonstrated detoxification ability as well as a well-shaped bile canaliculi network. Almost constant expression levels in most target genes were detected by quantitative real-time polymerase chain reaction. The results of TUNEL reaction implicated a safe scaffold-dissolving procedure. Our results indicate that alginate scaffolds provide a favorable microenvironment for liver neo-tissue recreation and regeneration. Further, we demonstrate that livers from children with inherited metabolic disorders could serve as an alternative cell source for in vitro experiments.
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