Dr. med. Antje Butter
Stacks Image 24355
Today, Antje Butter successfully defended her doctoral thesis magna cum laude!
Congratulations!

Antje was involved in basic research with respect to liver decellularization and recellularization. A proprietary, customized bioreactor was established to repopulate decellularized rat livers with primary rat hepatocytes via the hepatic artery and to subsequently evaluate graft morphology and function during 7 days of ex vivo perfusion. More information via this link.
Read More
Percoll purification after isolation of Primary Human Hepatocytes
Stacks Image 24360
The manuscript "Isolation of Primary Human Hepatocytes: Is Percoll Purification Really Necessary?" was accepted for publication in Scientific Reports.
Authors are Rosa Horner, Jospeh G.M.V. Gassner, Martin Kluge M, Peter Tang, Steffen Lippert, Karl H. Hillebrandt, Simon Moosburner, Anja Reutzel-Selke, Johann Pratschke, Igor M. Sauer and Nathanael Raschzok.

Research and therapeutic applications create a high demand for primary human hepatocytes. The limiting factor for their utilization is the availability of metabolically active hepatocytes in large quantities. Centrifugation through Percoll, which is commonly performed during hepatocyte isolation, has so far not been systematically evaluated in the scientific literature. 27 hepatocyte isolations were performed using a two-step perfusion technique on tissue obtained from partial liver resections. Cells were seeded with or without having undergone the centrifugation step through 25% Percoll. Cell yield, function, purity, viability and rate of bacterial contamination were assessed over a period of 6 days. Viable yield without Percoll purification was 42.4 x 106 (SEM ± 4.6 x 106) cells/g tissue. An average of 59% of cells were recovered after Percoll treatment. There were neither significant differences in the functional performance of cells, nor regarding presence of non-parenchymal liver cells. In five cases with initial viability of <80%, viability was significantly increased by Percoll purification (71.6 to 87.7%, p=0.03). Considering our data and the massive cell loss due to Percoll purification, we suggest that this step can be omitted if the initial viability is high, whereas low viabilities can be improved by Percoll centrifugation.
Read More
Critical Care for Potential Liver Transplant Candidates
Stacks Image 24371
The book Critical Care for Potential Liver Transplant Candidates
(D. Bezinover and F. Saner [Eds.]) focuses on patients with end-stage-liver disease (ESLD) who could possibly qualify for liver transplant. This patient cohort raises many problems: who should be treated and also, when is it too late for transplant? The authors are all dedicated experts in the field of ESLD/liver transplantation, but from different disciplines with different views of the problem.
In the past 15 years many things have changed in the treatment for these patients: cardiac assessment, treatment of porto-pulmonary hypertension, hemodynamics, coagulation assessment and management, diagnosis of kidney failure, and the timing of dialysis. These issues are comprehensively discussed in this book, in order to provide physicians starting in the field of transplantation an overview of different areas of concern.
This book is aimed at specialists and trainees in critical care, hepatology, anesthesia, surgery, and nephrology.

N. Raschzok, K.H. Hillebrandt and I.M. Sauer contributed with the chapter "Liver Assist Systems for Bridging to Transplantation: Devices and Concepts".

More information via this link.
Read More
Matters of Activity. Image Space Material
Stacks Image 24381
Prof. I.M. Sauer and Prof. J. Pratschke became principal investigators in the new Cluster of Exzellence Matters of Activity. Image Space Material. This Cluster will explore materials’ own inner activity, which can be discovered as a new source of innovative strategies and mechanisms for rethinking the relationship between the analog and the digital and for designing more sustainable and energy-efficient technologies.
The project’s central vision is to develop images, spaces, and materials as active structures of a new physical and symbolic reality, in which nature and culture intertwine in a novel way. In this context, interdisciplinary research and development of sustainable processes and structures is a key priority in all areas of visual-material character, such as wearables, materials technology, medical technology, logistics, architecture, and robotics. More than 40 disciplines are systematically investigating design strategies for materials and structures that adapt to specific requirements and the environment. The cluster relies on a new role for design within the context of growing diversity and the continuous improvement of materials and forms of visualization in all disciplines.
Read More
Composite tissue allotransplantation: opportunities and challenges
Stacks Image 24386
"Composite tissue allotransplantation: opportunities and challenges" is available in Cellular & Molecular Immunology (Cell Mol Immunol. 2019 Mar 6. doi: 10.1038/s41423-019-0215-3. [Epub ahead of print]). Authors are J. Iske, Y. Nian, R. Maenosono, M. Maurer, I.M. Sauer & S.G. Tullius.

Vascularized composite allotransplants (VCAs) have unique properties because of diverse tissue components transplanted en mass as a single unit. In addition to surgery, this type of transplant also faces enormous immunological challenges that demand a detailed analysis of all aspects of alloimmune responses, organ preservation, and injury, as well as the immunogenicity of various tissues within the VCA grafts to further improve graft and patient outcomes. Moreover, the side effects of long-term immunosuppression for VCA patients need to be carefully balanced with the potential benefit of a non-life-saving procedure. In this review article, we provide a comprehensive update on limb and face transplantation, with a specific emphasis on the alloimmune responses to VCA, established and novel immunosuppressive treatments, and patient outcomes.
Read More
Human stem cells promote liver regeneration after partial hepatectomy
Stacks Image 24391
"Human Stem Cells Promote Liver Regeneration After Partial Hepatectomy in BALB/C Nude Mice" will be published in J Surg Res. 2019 (Mar 4;239:191-200. doi: 10.1016/j.jss.2019.02.010. [Epub ahead of print]).
Authors are S. Wabitsch, Ch. Benzing, F. Krenzien, K. Splith, P.K. Haber, A. Arnold, M. Nösser, C. Kamalia, F. Hermann, Ch. Günther, D. Hirsch, I.M. Sauer, J. Pratschke, and M. Schmelzle.

Mesenchymal stem cells (MSCs) have been suggested to augment liver regeneration after surgically and pharmacologically induced liver failure. To further investigate this we processed human bone marrow-derived MSC according to good manufacturing practice (GMP) and tested those cells for their modulatory capacities of metabolic alterations and liver regeneration after partial hepatectomy in BALB/c nude mice.

Human bone marrow-derived MSC attenuate metabolic alterations and improve liver regeneration after partial hepatectomy in BALB/c nude mice. Obtained results using GMP-processed human MSC suggest functional links between fat accumulation and hepatocyte proliferation, without any evidence for cellular homing. This study using GMP-proceeded MSC has important regulatory implications for an urgently needed translation into a clinical trial.
Read More
Diffusion-weighted magnetic resonance imaging using a preclinical 1 T PET/MRI
Stacks Image 24403
"Diffusion-weighted magnetic resonance imaging using a preclinical 1 T PET/MRI in healthy and tumor-bearing rats" was published in EJNMMI Res. 2019 Feb 22;9(1):21. doi: 10.1186/s13550-019-0489-6.
Authors are J. Albrecht, D. Polenz, A.A. Kühl, J.M.M. Rogasch, A. Leder, I.M. Sauer, M. Babos, G. Mócsai, N. Beindorff, I.G. Steffen, W. Brenner, and E.J. Koziolek.

Hybrid positron emission tomography and magnetic resonance imaging (PET/MRI) scanners are increasingly used for both clinical and preclinical imaging. Especially functional MRI sequences such as diffusion-weighted imaging (DWI) are of great interest as they provide information on a molecular level, thus, can be used as surrogate biomarkers. Due to technical restrictions, MR sequences need to be adapted for each system to perform reliable imaging. There is, to our knowledge, no suitable DWI protocol for 1 Tesla PET/MRI scanners.
We established a respiratory-gated DWI protocol for a preclinical 1 T PET/MRI scanner allowing to monitor growth-related changes in ADC values of orthotopic HCC liver tumors. By monitoring the changes in tumor ADCs over time, different cellular stages were described. However, each study needs to adapt the protocol further according to their question to generate best possible results.
Read More
Charité Digital Clinician Scientist Pilot Program (D-CSP)
The Deutsche Forschungsgemeinschaft (DFG) will fund the Charité Digital Clinician Scientist Pilot Program (D-CSP). The ideas is to improve and safeguard the current BIH Charité Clinician Scientist Program by building an additional structure for a novel “digital science” driven career track to prepare academic clinicians for the challenges of the emerging technological transformation of medicine.
Stacks Image 24414
Designated Spokesperson is Prof. Dr. Duska Dragun. Co-applicants are the NeuroCure Cluster of Excellence, Department of Experimental Neurology, Department of Pediatric Oncology and Hematology, Department of Radiology and Pediatric Radiology, Department of Surgery, Berlin Institute for Medical Systems Biology (BIMSB), Institute of Medical Biometrics and Clinical Epidemiology, Department of Neurology and Experimental Neurology, and the Department of Anesthesiology and Intensive Care Medicine.

With the changing dynamics in biomedical research having fully entered into the digital era, it is becoming increasingly clear after seven years of experience that we need more dedicated efforts to create opportunities by establishing stronger interfaces with physics, mathematics, systems biology, and computational sciences for future generations of Clinician Scientists. The newly proposed research and educational structure for integrating these new areas of expertise into the established CSP should act as a “central processing unit” to facilitate biomedical knowledge derived from a variety of clinical disciplines supported by leading technology experts to address the specific challenges of data-driven medicine in the future.

  • Precision medicine in cancer and beyond,
  • Systems biology,
  • Big data science and decision support systems,
  • Quantitative imaging,
  • Computational neuroscience and brain simulation, and
  • Augmented, mixed and virtual reality in surgery
are exemplary research topics highlight how applicants will interact with Digital Clinician Scientists to develop their skills in giving prognoses, optimizing delivery of care, and personalizing patient management and therapeutic choices.
Read More
DFG Research Grant
Stacks Image 24421
Priv.-Doz. Dr. Nathanael Raschzok receives a research grant from the Deutsche Forschungsgemeinschaft (DFG) for his project "Defatting of steatotic liver grafts by normothermic ex vivo machine perfusion with DNP" in collaboration with Prof. Dr. med. Andreas Birkenfeld, Universitätsklinikum Carl Gustav Carus, Dresden.

Transplantation of steatotic marginal liver grafts is associated with a certain risk of graft dysfunction, primary non-function, and biliary complications, which results in a worse outcome compared to transplantation of unimpaired livers.
We hypothesize, that normothermic machine perfusion combined with adequate pharmacological intervention can prevent the deleterious effect of ischemia-reperfusion injury on macrovesicular grafts by a) minimizing the negative effect of cold storage, and by b) actively decreasing the intracellular fat content of the graft.
Mild mitochondrial uncoupling by DNP decreases the intrahepatic fat content of steatotic liver grafts during normothermic ex vivo machine perfusion. Efficient defatting can be safely achieved ex vivo with DNP concentrations that would be toxic in vivo. Systemic side effects of DNP are prevented by exclusive hepatic exposure through machine perfusion, and by washing DNP out of the liver graft at the end of the perfusion period. The synergetic effects of normothermic perfusion and defatting with DNP will prevent ischemia-reperfusion injury and make severely steatotic liver grafts acceptable for transplantation.
Read More
SFB 1365 Renoprotection
Stacks Image 24434
The Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) is establishing ten new Collaborative Research Centres (CRCs, Sonderforschungsbereich, SFB) to further support top-level research in Germany.
Chronic kidney diseases and acute kidney damage are widespread and reduce the life expectancy of those affected. The CRC “Renoprotection” therefore aims to decode specific signalling pathways for kidney damage and develop new approaches to treatment in the long term (Charité Berlin – FU Berlin and HU Berlin, Spokesperson: Prof. Dr. Pontus Börje Persson).
With the project "Renoprotective role of Lipocalin-2 in allograft rejection following kidney transplantation" Priv.-Doz. Dr. Felix Aigner and Dr. Muhammad Imtiaz Ashraf, PhD will be part of this SFB/CRC!

To provide allograft renoprotection, novel strategies are needed, including (i) prevention of renal allograft IRI and (ii) targeted immunosuppression and thus; reduction and avoidance of steroid and CNI usage in the long-run. Using a mouse model of kidney transplantation, we recently demonstrated a renoprotective role of exogenously administered recombinant Lcn2:Siderophore:Fe complex (rLcn2). The rLcn2 mediated mechanism of allograft renoprotection is still unknown; however, the mechanistic insight is essential for comprehensive translation of the rLcn2 therapy into clinical practice. In the funded project, we aim at (i) understanding the route and mechanisms of immunoregulation and/or cytoprotection, mediated by exogenously administered rLcn2 during the allograft damage; and (ii) characterizing the source and nature of endogenous Lcn2 i.e. whether it is complexed with mammalian iron binding catechols and may contribute to allograft survival in the long-run. Our ultimate goal is to pave the way for transplant renoprotection via recombinant Lcn2.

More information…
Read More
Comparison of AR HMDs in Visceral Surgery
Stacks Image 24443
"Real World Usability Analysis of two Augmented Reality Headsets in Visceral Surgery" was accepted for publication in Artificial Organs. Authors are S. Moosburner, C. Remde, P. Tang, M. Queisner, N. Haep, J. Pratschke, and I.M. Sauer.

Recent developments in the field of augmented reality (AR) have enabled new use cases in surgery. Initial set-up of an appropriate infrastructure for maintaining an AR surgical workflow requires investment in appropriate hardware. We compared the usability of the Microsoft HoloLens and Meta 2 head mounted displays (HMDs). Fifteen medicine students tested each device and were questioned with a variant of the System Usability Scale (SUS). Two surgeons independently tested the devices in an intraoperative setting.
In our adapted SUS, ergonomics, ease of use and visual clarity of the display did not differ significantly between HMD groups. The field of view (FOV) was smaller in the Microsoft HoloLens than the Meta 2 and significantly more study subjects (80% vs. 13.3%; p < 0.001) felt limited through the FOV. Intraoperatively, decreased mobility due to the necessity of an AC adapter and additional computing device for the Meta 2 proved to be limiting. Object stability was rated superior in the Microsoft HoloLens than the Meta 2 by our surgeons and lead to increased use.
We examined the Meta 2 and the Microsoft HoloLens and found key advantages in the Microsoft HoloLens which provided palpable benefits in a surgical setting.
Read More
Mathilde Feist and Paul Ritschl: Clinician Scientists
Stacks Image 24463
Dr. Mathilde Feist and Dr. Paul Ritschl successfully applied for the BIH Charité Clinician Scientist Program. Mathilde Feist will work on "Cytokine-armed oncolytic vaccinia virus for pancreatic cancer therapy". Mentors are Prof. Bahra, Prof. Sauer and Prof. Beling.
Paul Ritschl focusses on "The Impact of Donor Derived Microparticles Following Solid Organ Transplantation". Mentors are Priv.-Doz. Dr. Schmelzle and Priv.-Doz Dr. Öllinger.
Read More
Nanomolar sensing of NAD
Stacks Image 24478
"The nanomolar sensing of nicotinamide adenine dinucleotide in human plasma using a cycling assay in albumin modified simulated body fluids." was published in Nature Scientific Reports.
Authors are P. Brunnbauer, A. Leder, C. Kamali, K. Kamali, E. Keshi, K. Splith, S. Wabitsch, P. Haber, G. Atanasov, L. Feldbrügge, I.M. Sauer, J. Pratschke, M. Schmelzle, and F. Krenzien.

Nicotinamide adenine dinucleotide (NAD), a prominent member of the pyridine nucleotide family, plays a pivotal role in cell-oxidation protection, DNA repair, cell signalling and central metabolic pathways, such as beta oxidation, glycolysis and the citric acid cycle. In particular, extracellular NAD+ has recently been demonstrated to moderate pathogenesis of multiple systemic diseases as well as aging. Herein we present an assaying method, that serves to quantify extracellular NAD+ in human heparinised plasma and exhibits a sensitivity ranging from the low micromolar into the low nanomolar domain. The assay achieves the quantification of extracellular NAD+ by means of a two-step enzymatic cycling reaction, based on alcohol dehydrogenase. An albumin modified revised simulated body fluid was employed as standard matrix in order to optimise enzymatic activity and enhance the linear behaviour and sensitivity of the method. In addition, we evaluated assay linearity, reproducibility and confirmed long-term storage stability of extracellular NAD+ in frozen human heparinised plasma. In summary, our findings pose a novel standardised method suitable for high throughput screenings of extracellular NAD+ levels in human heparinised plasma, paving the way for new clinical discovery studies.
Read More
Normothermic ex vivo machine perfusion
Stacks Image 24485
"Improvement of normothermic ex vivo machine perfusion of rat liver grafts by dialysis and Kupffer Cell inhibition with glycine" was accepted for publication in Liver Transplantation.
Authors are J. Gassner, M. Nösser, S. Moosburner, R. Horner, P. Tang, L. Wegener, D. Wyrwal, F. Claussen, R. Arsenic, J. Pratschke, I.M. Sauer, and N. Raschzok.

Normothermic ex vivo liver machine perfusion might be a superior preservation strategy for liver grafts from extended criteria donors. However, standardized small animal models are not available for basic research on machine perfusion of liver grafts. A laboratory-scaled perfusion system was developed consisting of a custom-made perfusion chamber, a pressure-controlled roller pump, and an oxygenator. Male Wistar rat livers were perfused via the portal vein for 6 hours using oxygenated culture medium supplemented with rat erythrocytes. A separate circuit was connected via a dialysis membrane to the main circuit for plasma volume expansion. Glycine was added to the flush solution, the perfusate, and the perfusion circuit. Portal pressure and transaminase release were stable over the perfusion period. Dialysis significantly decreased the potassium concentration of the perfusate and led to significantly higher bile and total urea production. Hematoxylin and eosin staining and immunostaining for ssDNA and activated caspase 3 showed less sinusoidal dilatation and tissue damage in livers treated with dialysis and glycine. While Kupffer cells were preserved, tumor necrosis factor α mRNA levels were significantly decreased by both treatments. For proof of concept, the optimized perfusion protocol was tested with DCD grafts, resulting in significantly lower transaminase release into the perfusate and preserved liver architecture compared to baseline perfusion.
Our laboratory-scale normothermic portovenous ex vivo liver perfusion system enables rat liver preservation for 6 hours. Both dialysis and glycine treatment were shown to be synergistic for preservation of the integrity of normal and DCD liver grafts.
Read More
Tumor-stromal cross-talk in PDAC
Stacks Image 24500
Hepatobiliary Pancreat Dis Int accepted the manuscript "Tumor-stromal cross-talk modulating the therapeutic response in pancreatic cancer" for publication. Authors are C.C.M. Neumann, E. von Hörschelmann, A. Reutzel-Selke, E. Seidel, I.M. Sauer, J. Pratschke, M. Bahra, and R.B.Schmuck.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant solid tumor with a dismal prognosis. The stroma component makes up to 90% of the tumor mass and is thought to be one of the main reasons for the tumor's high chemoresistance. Cancer associated fibroblasts (CAFs) have previously been identified to be the key stromal players. This is the first time we provide detailed in vitro experiments investigating tumor-stromal interactions when exposed to three well-known chemotherapeutic agents.
Monocultures, indirect and direct co-cultures of two PDAC cell lines (AsPC and Panc-1) and six primary patients derived CAFs were treated with gemcitabine, nab-paclitaxel and the γ-secretase-inhibitor (GSI) DAPT. The cell viability of each component was measured with XTT. Finally, IL-6 concentrations of the supernatants were analyzed.
On the contrary to PDAC cell lines, CAF monocultures hardly responded to any treatment which suggested that stroma (CAFs) itself is more resistant to standard chemo-treatments than the epithelial cancer cells. Moreover, only a weak chemotherapeutic response was observed in direct co-cultures of cancer cells with CAFs. A change in the morphology of direct co-cultures was accompanied with the chemoresistance. CAFs were observed to build cage-like structures around agglomerates of tumor cells. High levels of IL-6 were also associated with a reduced response to therapy. Indirect co-cultures make the tumor-stromal interaction more complex.
Read More
Prof. Marcus Bahra Charité W2 professor
Stacks Image 24507
Prof. Dr. Marcus Bahra was appointed as a W2 professor for Pancreato-Biliary Surgery at the Charité – Universitätsmedizin Berlin. Working with other specialists, his team provides treatment for patients with malignancies and diseases in the pancreas and bile duct and conducts research in this field.
Since 2014 he held an extraordinary professorship for Surgery at the Charité.
Read More
<<  Page 6 / 12  >>
© 2025 Prof. Dr. Igor M. Sauer | Charité - Universitätsmedizin Berlin | Disclaimer

This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purpose illustrated in the Disclaimer. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies.