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.