ECRT Kickbox – Junior Scientist Grant

Karl Hillebrandt receives one of the 2017 Einstein Center for Regenerative Therapies (ECRT) Kickbox – Junior Scientist Grant. The project is entitled "Fighting liver cirrhosis? Establishment and analysis of decellularized human cirrhotic liver slices as a 3-dimensional model to study cell matrix interactions".

Liver cirrhosis is one of the main indications for liver transplantation. Due to the organ shortage, this therapy option is limited to the minority of patients suffering from cirrhosis. Therefore, there is a need of alternative treatment options.The aim of our project is to establish a decellularization protocol for human cirrhotic livers slices, which preserves the natural extracellular matrix (ECM) of cirrhotic livers. These decellularized liver slices will serve as a 3 dimensional model to study cell matrix interactions. If we are able to establish a protocol which will preserve the ECM, we will conduct in vitro recellularization experiments to study how the cirrhotic ECM will change the genotype and phenotype of different cell types. With this knowledge we aim to modify specific cell types in vivo or vitro for example prior to cell transplantation. Our ambition is to steer the cell matrix interaction via these modified cells after their transplantation and thereby halt or even reverse the progress of liver cirrhosis. This approach may offer an alternative treatment option in the future.
Team : Karl Hillebrandt, Oliver Klein, Ben Strücker, Igor Sauer


BIH Paper of the Month...

Benjamin Strücker, Hendrik Napierala and the rest of the team were awarded with the BIH Paper of the Month for their publication on a new method for developing a transplantable endocrine Neo-Pancreas.
The BIH Paper of the Month is awarded by the BIH Board of Directors to honor a special publication achievement from the joint research space of Charité and MDC. The Paper of the Month is sponsored by the Stiftung Charité as part of its Johanna Quandt Private Excellence Initiative.

H. Napierala, K.-H. Hillebrandt, N. Haep, P. Tang, M. Tintemann, J. Gassner, M. Noesser, H. Everwien, N. Seiffert, M. Kluge, E. Teegen, D. Polenz, S. Lippert, D. Geisel, A. Reutzel Selke, N. Raschzok, A. Andreou, J. Pratschke, I. M. Sauer & B. Struecker. Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans. Scientific Reports 7. Article number: 41777 (2017) doi:10.1038/srep41777

You may download the publication here.

Engineering an endocrine Neo-Pancreas

scientific reports
Scientific Reports accepted our latest paper on „Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans“. Authors are H. Napierala, K. Hillebrandt, N. Haep, P. Tang, M. Tintemann, J. Gassner, M. Noesser, H. Everwien, N. Seiffert, M. Kluge, E. Teegen, D. Polenz, S. Lippert, D. Geisel, A. Reutzel-Selke, N. Raschzok, A. Andreou, J. Pratschke, I.M. Sauer, and B. Struecker.

Decellularization of pancreata and repopulation of these non-immunogenic matrices with islets and endothelial cells could provide transplantable, endocrine Neo- Pancreata. In this study, rat pancreata were perfusion decellularized and repopulated with intact islets, comparing three perfusion routes (Artery, Portal Vein, Pancreatic Duct). Decellularization effectively removed all cellular components but conserved the pancreas specific extracellular matrix. Digital subtraction angiography of the matrices showed a conserved integrity of the decellularized vascular system but a contrast emersion into the parenchyma via the decellularized pancreatic duct. Islets infused via the pancreatic duct leaked from the ductular system into the peri-ductular decellularized space despite their magnitude. TUNEL staining and Glucose stimulated insulin secretion revealed that islets were viable and functional after the process.
We present the first available protocol for perfusion decellularization of rat pancreata via three different perfusion routes. Furthermore, we provide first proof-of-concept for the repopulation of the decellularized rat pancreata with functional islets of Langerhans. The presented technique can serve as a bioengineering platform to generate implantable and functional endocrine Neo-Pancreata.

Recellularization of rat livers: morphology and function

The Journal of Tissue Engineering and Regenerative Medicine accepted our paper Evolution of graft morphology and function after recellularization of decellularized rat liversfor publication.

Decellularization of livers is a well-established procedure. Data on different reseeding techniques or the functional evolution and re-organization processes of repopulated grafts remains limited.
We established a proprietary, customized bioreactor to repopulate decellularized rat livers (n=21) with primary rat hepatocytes (150 x 106 cells) via the hepatic artery and to subsequently evaluate graft morphology and function during seven days of ex vivo perfusion. Grafts were analyzed at 1h, 6h, 12h, 24h, 3d, 5d and 7d after recellularization (all n=3) by immunohistologic evaluation, hepatocyte-related enzyme (AST, ALT, LDH) and albumin measurement in the perfusate.
To the best of our knowledge, this is the first available protocol for repopulation of rat livers via the hepatic artery. Within the first 24 hours after repopulation, the hepatocytes seemed to migrate out of the vascular network and form clusters in the parenchymal space around the vessels. Graft function increased for the first 24 hours after repopulation with a significantly higher function compared to standard 2D culture after 24 hours. Thereafter, graft function constantly decreased with significantly lower values after six and seven days of perfusion, although histologically viable hepatocytes were found even after this period. Our data suggests that due to a constant loss of function, repopulated grafts should potentially be implanted as soon as cell engraftment and graft re-organization are completed.

Authors are Antje Butter, Khalid Aliyev, Karl-Herbert Hillebrandt, Nathanael Raschzok, Martin Kluge, Nicolai Seiffert, Peter Tang, Hendrik Napierala, Muhammad Imtiaz Ashraf, Anja Reutzel-Selke, Andreas Andreou, Johann Pratschke, Igor Maximilian Sauer, and Benjamin Struecker.


Although we do hate Facebook, feel kind of robbed and dislike the music –
We have to admit: 7,201,027 clicks (as of January 25th, 2016) are impressive…

Feature in Berliner Zeitung on Tissue Engineering

Recellularized liver created in our lab featured in Berliner Zeitung.

ESOT | YPT – Interview with Karl Hillebrandt

Being the winner of the Rising Stars Video Session organised by the YPT Committee at the ESOT2015 Brussels Congress Karl Hillebrandt gave an interview for the ESOT | YPT webpage.
His abstract "Optimized decellularization of rat livers byarterial and portal venous perfusion underoscillating pressure conditions" and the accompanying video were the most voted at the Rising Stars Session, where the audience voted live for the best video abstract. You can read Karl's abstract in the special ESOT2015 issue of Transplant International.

Implantation of a Neo Bile Duct in domestic pigs

European Surgical Research accepted our latest paper entitled "Implantation of a tissue engineered Neo Bile Duct in domestic pigs" for publication. Authors are B. Struecker, K. Hillebrandt, N. Raschzok, K. Jöhrens, A. Butter, P. Tang, A. Andreou, H. Napierala, D. Polenz, A. Reutzel-Selke, T. Denecke, J. Pratschke, and I.M Sauer.

Extrahepatic bile duct injuries remain severe complications during cholecystectomy and often require reconstruction by bilioenteric anastomosis (i.e. hepatico-jejunostomy), which comes along with further long-term complications (e.g. recurring ascending cholangitis, secondary biliary cirrhosis). Furthermore, in case of inherent extrahepatic biliary atresia or during liver transplant artificial or engineered bile ducts could enable novel surgical strategies without the need for hepatico-jejunostomy. We present data on the implantation of in vitro generated Neo Bile Ducts in five domestic pigs. Neo Bile Ducts were engineered through decellularization of allogeneic blood vessels and recellularization with autologous cholangiocytes.On postoperative days 0, 1, 7 and 14 blood samples were taken and analyzed (AST, ALT, Bilirubin, Alkaline Phosphatase, Creatinine and Leukocytes). An magnetic resonance cholangiography was performed on postoperative day 14 with one pig. 14 days after implantation pigs were sacrificed and bile ducts were explanted. All pigs survived the complete study period without severe complications. None of the pigs showed signs of biliary leakage or peritonitis. Neo Bile Ducts were infiltrated by neutrophils and neo-angiogenesis was observed around and into the implanted tissue. Whether the presented technique enables the long-term replacement of native bile ducts has to be further evaluated.

Publication in Jove

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„Procedure for Decellularization of Rat Livers in an Oscillating-pressure Perfusion Device“ is available in J Vis Exp. 2015 Aug 10;(102). doi: 10.3791/53029 – accessible via the JOVE servers. Authors are K. Hillebrandt, D. Polenz, A. Butter, P. Tang, A. Reutzel-Selke, A. Andreou, H. Napierala, N. Raschzok, J. Pratschke, I.M. Sauer, and B. Struecker . The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.

Karl Hillebrandt – YPT Rising Star


Karl Hillebrandt won this year's YPT Rising Stars Video Session Award. He presented the studies on „Optimized decellularization of rat livers by arterial and portal venous perfusion under oscillating pressure conditions“ during the 17th congress of the European Society for Organ Transplantation (ESOT) 2015 in Brüssel. Young Professionals in Transplantation (YPT) is a forum for junior professionals throughout Europe working in the field of transplantation.

microRNAs in liver tissue engineering

Our paper "microRNAs in liver tissue engineering - New promises for failing organs" was accepted for publication in Advanced Drug Delivery Reviews (IF: 15.038). Authors are Nathanael Raschzok, Hannes Sallmon, Johann Pratschke and Igor M. Sauer.

miRNA-based technologies provide attractive tools for several liver tissue engineering approaches. Herein, we review the current state of miRNA applications in liver tissue engineering. Several miRNAs have been implicated in hepatic disease and proper hepatocyte function. However, the clinical translation of these findings into tissue engineering has just begun. miRNAs have been successfully used to induce proliferation of mature hepatocytes and improve the differentiation of hepatic precursor cells. Nonetheless, miRNA-based approaches beyond cell generation have not yet entered preclinical or clinical investigations. Moreover, miRNA-based concepts for the biliary tree have yet to be developed. Further research on miRNA based modifications, however, holds the promise of enabling significant improvements to liver tissue engineering approaches due to their ability to regulate and fine-tune all biological processes relevant to hepatic tissue engineering, such as proliferation, differentiation, growth, and cell function.

Cover – march issue of Tissue Engineering

One of the figures of our paper „Porcine liver decellularization under oscillating pressure conditions – A technical refinement to improve the homogeneity of the decellularization process“ made it to the cover of the march issue of Tissue Engineering, Part C : Methods.

Congratulations to Dietrich Polenz, who made the corrosion cast of a decellularized pig liver matrix: red, hepatic artery; blue, portal vein; yellow, bile duct and gallbladder.

Decellularization of pancreata – EPITA Award

Ben Strücker presented our latest results on DECELLULARIZATION OF WHOLE RAT PANCREATA – EVALUATION OF THREE DIFFERENT PERFUSION ROUTES at the 5th EPITA Winter Symposium in Innsbruck from the 25th to the 27th of January 2015. He received the AIDPIT&EPITA Award for the best oral presentation.

Ben Strücker presented three effective protocols for rat pancreas perfusion decellularization, evaluating different perfusion routes. In contrast to liver decellularization the perfusion route seems to have no major impact on decellularization results. The dPECMs could serve for cellular repopulation with islets from a different (xenogene) origin to generate functional, transplantable endocrine pancreata in vitro.

Presentations at DTG 2014

Nathanael Raschzok presented his poster „Protein biomarkers for diagnosis and prediction of acute cellular rejection after liver transplantation“, Benjamin Strücker his work entitled „Oszillierende Druckschwankung verbessern signifikant die Ratten- und Schweineleber Dezellularisierung“ and Rosa Schmuck her posters „Risk of postoperative infections after LTX rises with MELD score“ and „Protein biomarkers in bile as a diagnostic tool after liver transplantation“.

Ben Strücker: Charité Clinical Scientist

Dr. med Benjamin Strücker successfully applied for the Charité Clinical Scientist 2015 program.

His project is entitled „Humanized Porcine Liver““. Clinical mentor is Prof. Dr. Johann Pratschke, scientific mentors is Priv.-Doz. Dr. med Igor M. Sauer.

The program is supported by Stiftung Charité which was endowed by the entrepreneur Johanna Quandt in order to promote biomedical "knowledge entrepreneurs" that is, change makers in biomedicine at the Charité. The goal of this program is to develop new career paths in clinical specialist medical training. The focus of the training program "Clinical Scientist" is translational research ("bench-to-bedside") which will be realized by a reduction in clinical routine and an improved curriculum with defined goals.

Decellularization of porcine livers

Ben Strücker’s paper entitled „Porcine liver decellularization under oscillating pressure conditions – A technical refinement to improve the homogeneity of the decellularization process“ has been accepted for publication in Tissue Engineering, Part C: Methods.
Co-authors are K. Hillebrandt, R. Voitl, A. Butter, R.B. Schmuck, A. Reutzel-Selke, D. Geisel, K. Joehrens, P.A. Pickerodt, N. Raschzok, G. Puhl, P. Neuhaus, J. Pratschke, and I.M. Sauer.

Decellularization and recellularization of parenchymal organs may facilitate the generation of autologous functional liver organoids by repopulation of decellularized porcine liver matrices with induced liver cells. We present an accelerated (7 h overall perfusion time) and effective protocol for human scale liver decellularization by pressure-controlled perfusion with 1% Triton X-100 and 1% SDS via the hepatic artery (120 mmHg) and portal vein (60 mmHg). In addition, we analyzed the effect of oscillating pressure conditions on pig liver decellularization (n=12). The proprietary perfusion device used to generate these pressure conditions mimics intra-abdominal conditions during respiration to optimize microperfusion within livers and thus optimize the homogeneity of the decellularization process. The efficiency of perfusion decellularization was analyzed by macroscopic observation, histological staining (H&E, Sirius red, Alcian blue), immunohistochemical staining (collagen IV, laminin, fibronectin) and biochemical assessment (DNA, collagen, glycosaminoglycans) of decellularized liver matrices. The integrity of the extracellular matrix post-decellularization was visualized by corrosion casting and three-dimensional CT scanning. We found that livers perfused under oscillating pressure conditions (P+) showed a more homogenous course of decellularization and contained less DNA compared to livers perfused without oscillating pressure conditions (P-). Microscopically, livers from the (P-) group showed remnant cell clusters, while no cells were found in livers from the (P+) group. The grade of disruption of the ECM was higher in livers from the (P-) group, although the perfusion rates and pressure did not significantly differ. Immunohistochemical staining revealed that important matrix components were still present after decellularization. Corrosion casting showed an intact vascular (portal vein and hepatic artery) and biliary framework. In summary, the presented protocol for pig liver decellularization is quick (7 h) and effective. The application of oscillating pressure conditions improves the homogeneity of perfusion and thus the outcome of the decellularization process.

Kristina Kähm – Bachelor of Science

Kristina Kähm successfully completed her bachelor thesis entitled “Analyse von Glykosaminoglykanen und Fibronektinen in der extrazellulären Matrix zum Nachweis der erfolgten Dezellularisierung von Rattenleber-Explantaten“ and is now a Bachelor of science.
Her project was supervised in cooperation with Prof. Dr. Marcus Frohme, Division Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences in Wildau, Germany.

Congratulations !

WTC 2014 in San Francisco


Ben Strücker presented the latest results on „Perfusion Decellularization of Pig and Rat Livers Applying Undulating Surrounding Pressure Conditions“. Co-authors were A. Butter, K. Hillebrandt, R. Voitl, D. Polenz, A. Reutzel-Selke, K. Joehrens, D. Geisel, N. Raschzok, P. Neuhaus, J. Pratschke and I.M. Sauer.

Nathanael Raschzok presentation was entitled: „Perioperative Serum Levels of CXCL9 and CD44 Predict the Risk of Acute Cellular Rejection in Liver Graft Recipients“. Co-authors were N. Raschzok, A. Reutzel-Selke, R. Schmuck, M. Morgul, M. Bartels, G. Puhl, D. Seehofer, M. Bahra, A. Pascher, P. Neuhaus, J. Pratschke and I.M. Sauer.

Decellularization and oscillating pressure conditions

The Journal of Tissue Engineering and Regenerative Medicine accepted our latest paper on „Improved rat liver decellularization by arterial perfusion under oscillating pressure conditions“ for publication. Authors are B. Struecker, A. Butter, K. Hillebrandt, D. Polenz , A. Reutzel-Selke, P. Tang, S. Lippert, A. Leder, S. Rohn, D. Geisel, T. Denecke, K. Aliyev, K. Jöhrens, N. Raschzok, P. Neuhaus, J. Pratschke and I.M. Sauer.

One approach of regenerative medicine to generate functional hepatic tissue in vitro is de- and recellularization and several protocols for the decellularization of different species have been published. To the best of our knowledge this is the first report on rat liver decellularization by perfusion via the hepatic artery under oscillating pressure conditions, intending to optimize microperfusion and minimize damage to the ECM. Four decellularization protocols were compared: perfusion via the portal vein (PV) or the hepatic artery (HA), with (+P) or without (-P) oscillating pressure conditions. All rat livers (n=24) were perfused with 1% Triton X-100 and 1% SDS, each for 90 minutes with a perfusion rate of 5ml/min. Perfusion decellularization was observed macroscopically and the decellularized liver matrices (DLMs) were analyzed by histology and biochemical analyses (e.g., levels of DNA, glycosaminoglycans (GAG), and hepatocyte growth factor (HGF). Livers decellularized via the hepatic artery and under oscillating pressure showed a more homogenous decellularization and less remaining DNA, compared to livers of the other experimental groups. The novel decellularization method described is effective, quick (3 hours) and gentle to the ECM and thus represents an improvement of existing methodology. 

Nature Reviews Gastroenterology and Hepatology

Nature Reviews Gastroenterology and Hepatology invited us to provide a review on liver support strategies.

The treatment of end-stage liver disease and acute liver failure remains a clinically relevant issue. Although orthotopic liver transplantation is a well-established procedure, whole-organ transplantation is invasive and increasingly limited by the unavailability of suitable donor organs. Artificial and bioartificial liver support systems have been developed to provide an alternative to whole organ transplantation, but despite three decades of scientific efforts, the results are still not convincing with respect to clinical outcome. In this Review, conceptual limitations of clinically available liver support therapy systems are discussed. Furthermore, alternative concepts, such as hepatocyte transplantation, and cutting-edge developments in the field of liver support strategies, including the repopulation of decellularized organs and the biofabrication of entirely new organs by printing techniques or induced organogenesis are analysed with respect to clinical relevance. Whereas hepatocyte transplantation shows promising clinical results, at least for the temporary treatment of inborn metabolic diseases, so far data regarding implantation of engineered hepatic tissue have only emerged from preclinical experiments. However, the evolving techniques presented here raise hope for bioengineered liver support therapies in the future.

Update: The review „Liver support strategies: cutting-edge technologies“ (authors: Benjamin Struecker, Nathanael Raschzok & Igor M. Sauer) is now available here.

ESAO 2013 in Glasgow

The XXXX ESAO Congress took place in Glasgow, September 11th - 14th, 2013. This year we had three oral presentations focussing on our latest results in decellularization and recellularization of the liver. Ben Strücker presented our latest results on „Improved rat liver decellularization by arterial perfusion under oscillating surrounding pressure“. Antje Butter and Karl Hillebrandt gave two oral presentations during the yESAO Rapid Fire Session on „Proprietary rat liver decellularization device utilizing oscillating surrounding pressure to improve micro perfusion within the organ“ and Pig liver decellularisation through portal vein and hepatic artery perfusion under oscillating surrounding pressure“.
Furthermore, Karl Hillebrandt received the „2. Prize for the best Poster“!