June 2023


Hortman Stem Cell Laboratory



On the occasion of the official opening of the Marga and Walter Boll Laboratory, we had the honour to welcome the director of the Hortman Stem Cell Laboratories (Dubai), Dr Fatma Alhashimi, as our guest. Hortman Laboratories operates the first GMP laboratory for stem cells in the United Arab Emirates. We are looking forward to the cooperation.


June 2023


Official opening Marga-and-Walter-Boll-Laboratory for Cardiac Tissue Engineering.


We invite interested scientists to the opening of the Marga-and-Walter-Boll-Laboratory for Cardiac Tissue Engineering on Thursday, June-22nd 2023 starting at 11:00 a.m.

On the 22nd of June 2023 we will present current projects and hear exciting talks from invited experts. The event will take place in the large lecture hall of the physiology department of the medical faculty of the University of Cologne.

If you want to join, please drop a message via the contact button to arrange everything according to the number of guests!

11:00        Priv.-Doz. Dr. Kurt Pfannkuche (Cologne): "Research at the Laboratory for Cardiac Tissue Engineering"
11:40        Dr. Sarkawt Hamad (Cologne): "Human Cardiac Organoids for Cell Replacement Therapy"

12:00        Lunch break with snacks and drinks

13:00        Prof. Dr. Konrad Brockmeier (Cologne) "Challenges in congenital heart disease: Where to go from here?"
13:30        Prof. Dr. Bastiaan Boukens (Maastricht): "Arrhythmias in structural heart  disease: The anti-arrhythmic potential of the autonomic nervous system."

14:00        Coffee break

14:15        Prof. Dr. Horst Fischer (RWTH Aachen): "The Potential of Acoustics for 3D Tissue Engineering"
14:45        Dr. Nadine Notrodt (Fraunhofer Institute for Lasertechnology, Aachen): "Laser induced forward transfer for cell printing"

15:00        Katharina Schwab (Department Chemistry, Cologne): "Production of highly open macroporous cryogel beads with tunable pore size using microfluidics for cell culture"
15:15        Philipp Jahn (Cologne):        "Cardiac microtissues: Generation of 3D tissue by microfluics"
15:30        Lisa Münchhalfen (Cologne): "Organ complementation in the heart? Development of an intraembryonic organ complementation assay"



December 2022


ZukunftBIO.NRW: Project PERIDIAN receives funding recommendation


Northrhine Westphalia has announced the positively evaluated projects in frame of the call "Zukunftsmedizin".

We are happy to find our project on the list of successful applications. 

Together with our partners innoVitro GmbH and Fraunhofer Institute for Laser technology we look forward to an exciting project.


Follow the link to find the list of all projects: 

Projekte - ZukunftBio.NRW

Juni 2022


High-efficient serum-free differentiation of endothelial cells from human iPS cells


Stem Cell Res Ther. 2022 Jun 11;13(1):251


Sarkawt Hamad, Daniel Derichsweiler, John Antonydas Gaspar, Konrad Brockmeier, Jürgen Hescheler, Agapios Sachinidis, Kurt Paul Pfannkuche


Introduction: Endothelial cells (ECs) form the inner lining of all blood vessels of the body play important roles in vascular tone regulation, hormone secretion, anticoagulation, regulation of blood cell adhesion and immune cell extravasation. Limitless ECs sources are required to further in vitro investigations of ECs' physiology and pathophysiology as well as for tissue engineering approaches. Ideally, the differentiation protocol avoids animal-derived components such as fetal serum and yields ECs at efficiencies that make further sorting obsolete for most applications.

Method: Human induced pluripotent stem cells (hiPSCs) are cultured under serum-free conditions and induced into mesodermal progenitor cells via stimulation of Wnt signaling for 24 h. Mesodermal progenitor cells are further differentiated into ECs by utilizing a combination of human vascular endothelial growth factor A165 (VEGF), basic fibroblast growth factor (bFGF), 8-Bromoadenosine 3',5'-cyclic monophosphate sodium salt monohydrate (8Bro) and melatonin (Mel) for 48 h.

Result: This combination generates hiPSC derived ECs (hiPSC-ECs) at a fraction of 90.9 ± 1.5% and is easily transferable from the two-dimensional (2D) monolayer into three-dimensional (3D) scalable bioreactor suspension cultures. hiPSC-ECs are positive for CD31, VE-Cadherin, von Willebrand factor and CD34. Furthermore, the majority of hiPSC-ECs express the vascular endothelial marker CD184 (CXCR4).

Conclusion: The differentiation method presented here generates hiPSC-ECs in only 6 days, without addition of animal sera and at high efficiency, hence providing a scalable source of hiPSC-ECs.


To read the full text follow this LINK 

Juni 2022


Generation of cardiac microtissues by microfluidic cell encapsulation


Watch the video to see how it works: click

Mai 2022


Generation of cardiac microtissues: Novel technology released


Engineering of cardiac microtissues by microfluidic cell encapsulation in thermoshrinking non-crosslinked PNIPAAm gels


Accepted manuscript, BIOFABRICATION



Philipp Jahn, Rebecca Katharina Karger, Shahab Soso Khalaf, Sarkawt Hamad, Gabriel Peinkofer, Raja Ghazanfar Ali Sahito, Stephanie Pieroth, Frank Nitsche, Junqi Lu, Daniel Derichsweiler, Konrad Brockmeier, Jürgen Hescheler, Annette Schmidt, Kurt Paul Pfannkuche



Multicellular agglomerates in form of irregularly shaped or spherical clusters can recapitulate cell-cell interactions and are referred to as microtissues. Microtissues gain increasing attention in several fields including cardiovascular research. Cardiac microtissues are evolving as excellent model systems for drug testing in vitro (organ-on-a-chip), are used as tissue bricks in 3D printing processes and pave the way for improved cell replacement therapies in vivo. Microtissues are formed for example in hanging drop culture or specialized microwell plates; truly scalable methods are not yet available. In this study, a novel method of encapsulation of cells in Poly-N-isopropylacrylamid (PNIPAAm) spheres is introduced. Murine induced pluripotent stem cell-derived cardiomyocytes (CMs) and bone marrow-derived mesenchymal stem cells (MSCs) were encapsulated in PNIPAAm by raising the temperature of droplets formed in a microfluidics setup above the lower critical solute temperature (LCST) of 32°C. PNIPAAM precipitates to a water-insoluble physically linked gel above the LCST and shrinks by the expulsion of water, thereby trapping the cells in a collapsing polymer network and increasing the cell density by one order of magnitude. Within 24 hours, stable cardiac microtissues were first formed and later released from their polymer shell by washout of PNIPAAm at temperatures below the LCST. Rhythmically contracting microtissues showed homogenous cell distribution, age-dependent sarcomere organizations and action potential generation. The novel approach is applicable for microtissue formation from various cell types and can be implemented into scalable workflows.



Download accepted Manuscript (external link)

März 2022


See our colleagues working at the Marga-and-Walter-Boll Laboratory


Video contains product advertising/ Video enthält Werbung

Video production: Rebecca K. Karger & Sarkawt Hamad

(Thanks to Yrii Semchyshyn, Coma Media for providing free music) 

February 2022


Sarkawt is making progress in the field of human multicellular cardiac organoids. Watch the video and notice how long the cardiomyocytes contract before they relax. Pretty similar to human heart beats.