title: Human endothelial colony-forming cells expanded with an improved protocol are a useful endothelial cell source for scaffold-based tissue engineering.
abstract: One of the major challenges in tissue engineering is to supply larger three-dimensional (3D) bioengineered tissue transplants with sufficient amounts of nutrients and oxygen and to allow metabolite removal. Consequently, artificial vascularization strategies of such transplants are desired. One strategy focuses on endothelial cells capable of initiating new vessel formation, which are settled on scaffolds commonly used in tissue engineering. A bottleneck in this strategy is to obtain sufficient amounts of endothelial cells, as they can be harvested only in small quantities directly from human tissues. Thus, protocols are required to expand appropriate cells in sufficient amounts without interfering with their capability to settle on scaffold materials and to initiate vessel formation. Here, we analysed whether umbilical cord blood (CB)-derived endothelial colony-forming cells (ECFCs) fulfil these requirements. In a first set of experiments, we showed that marginally expanded ECFCs settle and survive on different scaffold biomaterials. Next, we improved ECFC culture conditions and developed a protocol for ECFC expansion compatible with 'Good Manufacturing Practice' (GMP) standards. We replaced animal sera with human platelet lysates and used a novel type of tissue-culture ware. ECFCs cultured under the new conditions revealed significantly lower apoptosis and increased proliferation rates. Simultaneously, their viability was increased. Since extensively expanded ECFCs could still settle on scaffold biomaterials and were able to form tubular structures in Matrigel assays, we conclude that these ex vivo-expanded ECFCs are a novel, very potent cell source for scaffold-based tissue engineering.
authors: Interdisciplinary Centre for Clinical Research Aachen (IZKF Aachen), RWTH Aachen, Germany.
authors: Bernd
authors: B
authors: Denecke
authors: Institute for Transfusion Medicine, University Hospital Essen, Germany.
authors: Liska D
authors: LD
authors: Horsch
authors: Institute for Transfusion Medicine, University Hospital Essen, Germany.
authors: Stefan
authors: S
authors: Radtke
authors: Institute for Transplantation Diagnostics and Cellular Therapeutics, University Hospital Düsseldorf, Germany.
authors: Johannes C
authors: JC
authors: Fischer
authors: Institute for Transfusion Medicine, University Hospital Essen, Germany.
authors: Peter A
authors: PA
authors: Horn
authors: Institute for Transfusion Medicine, University Hospital Essen, Germany.
authors: Bernd
authors: B
authors: Giebel
mesh_terms: D017209:Apoptosis; D001672:Biocompatible Materials / Q000737:chemistry; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism; D001807:Blood Vessel Prosthesis; D002470:Cell Survival; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D006801:Humans; D018919:Neovascularization, Physiologic; D010100:Oxygen / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013234:Stem Cells / Q000166:cytology; D046509:Tissue Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014841:von Willebrand Factor / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D014841:von Willebrand Factor; D010100:Oxygen
keywords: FBS replacement; biomaterials; endothelial colony-forming cells (ECFCs); endothelial progenitor cells (EPCs); human platelet lysate; scaffolds; tissue engineering