Einstein Visiting Fellow Prof. Stefan G. Tullius
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Prof. Dr. Stefan G. Tullius, Harvard Medical School, became Einstein BIH Visiting Fellow at the Charité, Department of Surgery. 

Vascular Composite Tissue Allotransplantation (VCA) has developed from a pioneering endevour to a clinical reality during the last 15 years. More than 150 extremity, face, knee, and most recently uterus and penis transplants have been performed during the last 15 years. VCA activities have been seen around the globe. Although feasibility of the procedure has been shown, it is still emerging and far from being a standard clinical procedure. 

The Charité has been an international leader in transplantation research for decades. However, neither VCA basic clinical research programs are currently offered in Berlin or Germany in a meaningful way.The involvement of Prof. Tullius as an Einstein BIH Visiting Fellow is expected to synergize and accelerate efforts igniting both a clinical research transplant program and a basic research group of excellence. The overall objective of our integrated basic and clinical research working group Vascular Composite Tissue Transplantation has three main goals:

To establish a basic Research group of Excellence: VCAs offer unique opportunities to study novel aspects of antigenicity, immune modulation and neo-vascularization. One important aspect that distinguishes VCA from solid organ transplants is their blood supply through a vascularized arterial in- and venous outflow in addition to sprouting new vessels at the large interface of VCA with recipient tissue.

To establish a clinical bio-repository as a pre-requisite for a clinical research VCA program.

To implement a clinical VCA research program (hand, abdominal wall, uterus) as a multi- disciplinary and translational effort.

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Engineering an endocrine Neo-Pancreas
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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.
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Recellularization of rat livers: morphology and function
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The Journal of Tissue Engineering and Regenerative Medicine accepted our paper „Evolution of graft morphology and function after recellularization of decellularized rat livers“ for 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.
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Vascular anatomy of the juvenile Göttingen minipig
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Lab Animal accepted our „Computed tomography-based survey of the vascular anatomy of the juvenile Göttingen minipig“ for publication.

Over the past 50 years, image-guided procedures have been established for a wide range of applications. The development and clinical translation of new treatment regimens necessitate the availability of suitable animal models. The juvenile Göttingen minipig presents a favourable profile as a model for human infants. However, no information can be found regarding the vascular system of juvenile minipigs in the literature. Such information is imperative for planning the accessibility of target structures by catheterization.

We present here a complete mapping of the arterial system of the juvenile minipig based on contrast-enhanced computed tomography. Four female animals weighing 6.13 ± 0.72 kg were used for the analyses. Imaging was performed under anaesthesia, and the measurement of the vascular structures was performed independently by four investigators. Our dataset forms a basis for future interventional studies in juvenile minipigs, and enables planning and refinement of future experiments according to the 3R (replacement, reduction and refinement) principles of animal research.

Authors are J. Siefert, K.H. Hillebrandt, M. Kluge, D. Geisel, P. Podrabsky, T. Denecke, M. Nösser, J. Gassner, A. Reutzel-Selke, B. Strücker, M.H. Morgul, S. Guel-Klein, J.K. Unger, A. Reske, J. Pratschke, I.M. Sauer, and N. Raschzok.
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Monitoring of hepatocyte transplantation by MRI
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A new book on Hepatocyte Transplantation Methods and Protocols, part of the series: Methods in Molecular Biology, Vol. 1506 P. Stock, B. Christ (Eds.), Springer, will be available end of November, 2016. We contributed a chapter on Preclinical swine models for monitoring of hepatocyte transplantation by MRI (authors: Nathanael Raschzok, Ulf Teichgräber, Johann Pratschke, and Igor M. Sauer) and are proud to provide the cover image.

This volume features up-to-date protocols for the isolation, preservation, and validation of various cell sources comprising large and small animal models, examining the impact of cell transplantation on acute and chronic liver diseases. Hepatocyte Transplantation: Methods and Protocols guides readers through laboratory protocols for the generation of humanized livers for the assessment of biological actions in vivo and techniques to monitor cell engraftment after cell transplantation in vivo are described and procedures for computational analyses of hepatocyte transplantation.

Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Comprehensive and practical, Hepatocyte Transplantation: Methods and Protocols is an essential resource for researchers and clinicians to assess the biological as well as the therapeutic potential of hepatocyte transplantation.
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HCC: miRNA profiles of the tumor-surrounding tissue
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The presence of hepatocellular carcinoma (HCC) is a significant complication of cirrhosis because it changes the prognosis and the treatment of the patients. By now, contrast-enhanced CT and MR scans are the most reliable tools for the diagnosis of HCC; however, in some cases, a biopsy of the tumor is necessary for the final diagnosis. The aim of the study was to develop a diagnostic tool using the microRNA (miRNA) profiles of the tissue surrounding the HCC tumor combined with clinical parameters in statistical models. At a transplantation setting, 32 patients with HCC and cirrhosis (B) were compared to 22 patients suffering from cirrhosis only (A). The diagnosis and exclusion of HCC was confirmed following the histopathological examination of the explanted liver.

The HCC patients were significantly older than the patients with cirrhosis only (B: 60.6 and A: 49.9, p<0.001) and showed higher levels of ALT (A: 0.76μkat/l, B: 1.02μkat/, p=0.006) and AFP (A: 5.8ng/ml, B: 70.3ng/ml, p<0.001), whereas the bilirubin levels were higher in the cirrhosis only group (p=0.002). Using age (cut-off 50.23years) and AFP (cut-off 4.2ng/ml) thresholds, the levels of expression of miR-1285-3p and miR-943 differentiated between the patients with HCC and cirrhosis from those with cirrhosis only with an accuracy of 96.3%. This is the first report about the use of stepwise penalized logistic regression and decision tree analyses of miRNA expressions in the tumor-surrounding tissue combined with clinical parameters for the diagnosis of HCC.

Authors are Mehmet Haluk Morgul, Sergej Klunk, Zografia Anastasiadou, Ulrich Gauger, Corinna Dietel, Anja Reutzel-Selke, Philipp Felgendref, Hans-Michael Hau, Hans-Michael Tautenhahn, Rosa Bianca Schmuck, Nathanael Raschzok, Igor Maximillian Sauer, and Michael Bartels. Exp Mol Pathol. 2016 Aug 20;101(2):165-171. doi: 10.1016/j.yexmp.2016.07.014. [Epub ahead of print]
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Bile: miRNA Pattern post OLT
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BIOMARKERS accepted our latest paper on "Bile: miRNA Pattern and Protein Based Biomarkers May Predict Acute Cellular Rejection after Liver Transplantation" for publication. Authors are Rosa Bianca Schmuck, Anja Reutzel-Selke, Nathanael Raschzok, Mehmet Haluk Morgul, Benjamin Struecker, Steffen Lippert, Cynthia de Carvalho Fischer, Moritz Schmelzle, Sabine Boas-Knoop, Marcus Bahra, Andreas Pascher, Johann Pratschke, and Igor M. Sauer.

Bile rather than blood depicts the local inflammation in the liver and may improve prediction and diagnosis of acute cellular rejection (ACR) after liver transplantation (OLT). Secretome and miRNAs were analyzed during the first two weeks and on clinical suspicion of ACR in the bile of 45 OLT recipients. Levels of CD44, CXCL9, miR-122, miR-133a, miR-148a and miR-194 were significantly higher in bile of patients who developed ACR within the first 6 months after OLT and during ACR. Analysis of secretome and miRNA in bile could further our understanding of the local inflammatory process during rejection.
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Hepatocyte isolation after laparoscopic liver resection
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Tissue Engineering, Part C: Methods accepted our paper entitled "Hepatocyte isolation after laparoscopic liver resection" for publication. Authors are Horner R*, Kluge M*, Gassner J, Nösser M, Major RD, Reutzel-Selke A, Leder AK, Struecker B, Morgul MH, Pratschke J, Sauer IM, Raschzok N (*contributed equally).

Liver tissue obtained from partial hepatectomy is a common source for isolation of primary human hepatocytes. Until now, liver resections were most commonly performed by conventional open surgery. Although the laparoscopic approach is currently emerging in liver surgery, data on the outcome of hepatocyte isolation from laparoscopically resected liver tissue is not available. A total of 22 hepatocyte isolations were performed using the two-step collagenase perfusion technique from October 2015 until March 2016. Liver tissue was obtained from n=15 open liver resections (OLR) and n=7 laparoscopic liver resections (LLR). Isolation parameters (cell yield, viability, percoll survival) were assessed and hepatocyte function (plating efficiency, urea, albumin, and aspartate aminotransferase) was measured over a culture period of 6 days (OLR: n=13; LLR: n=3). Total cell yield (OLR: 36.81 ± 6.77 x106 cells/g vs. LLR 16.84 ± 10.66 x106 cells/g, p=0.0318) as well as viable yield (OLR 31.70 ± 6.05 x106 cells/g vs. LLL 14.70 ± 9.89 x106 cells/g, p=0.0260) were significantly higher in the OLR group. Subgroup analysis revealed that the worse outcome of isolation of laparoscopically resected liver tissue was associated with right-lateral laparoscopic liver resections, while hepatocyte isolation from left-lateral laparoscopic liver resections was as effective as from open surgery. Hepatocyte function did not differ between hepatocytes from openly resected versus left-lateral laparoscopically resected liver tissue. We here present the first data on hepatocyte isolation from laparoscopic liver surgery. While the overall outcome is worse compared to open surgery, our data suggest that liver tissue from laparoscopic resection of the left lobe is an excellent source for primary human hepatocytes.
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SPARK Berlin supports Fikatas Knot
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The Berlin Institute of Health (BIH) and Stiftung Charité teamed up with Stanford University School of Medicine to initiate SPARK Berlin.

We are very pleased to announce that Dr. Panagiotis Fikatas' project “Device for ready-prepared surgical knots” was selected for both, funding and mentorship. 

SPARK was created to overcome the hurdles associated with translating academic discoveries into therapeutics and diagnostics that address unmet medical needs.  The SPARK mission is to help academics overcome the obstacles involved in moving their early discoveries from bench to bedside, to educate faculty, postdoctoral fellows and graduate students on the translational research process and path to clinical application, so that development of promising discoveries becomes second nature to our institution, and to develop more cost-effective and innovative approaches to drug development .

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