title: Effects of Quantum Dot Labeling on Endothelial Progenitor Cell Function and Viability.
abstract: Endothelial progenitor cells (EPC) play an important role in repairing damaged endothelium. An effective imaging method for in vivo tracking of EPCs is essential for understanding EPC-based cell therapy. Fluorescent quantum dots (QDs) have attractive optical characteristics such as extreme brightness and photostability. QDs are currently being investigated as probes for stem cell labeling; however, there is concern about whether QDs can be used safely. We investigated whether quantum dot (QD) labeling would influence EPC viability and function. Rat bone marrow-derived EPCs were cultured and characterized. The cells were labeled with near-infrared-emitting, carboxyl-coated QDs (8 nM) for 24 h. QD labeling efficiency was higher than 97%. Using WST-1 assay, we showed that the viability of the QD-labeled EPCs was not different from that of the control EPCs. Moreover, QD labeling did not influence the ability of EPCs to form capillary tubes on Matrigel and to migrate. The percentage of QD-positive cells decreased with time, probably due to the rapid division of EPCs. These data suggest that the carboxyl-coated QD705 can be useful for labeling EPCs without interrupting their viability and functions.
authors.affiliation: Department of Molecular and Clinical Medicine/Clinical Physiology, The Sahlgrenska Academy and University Hospital, University of Gothenburg, Gothenburg, Sweden; †Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Matyas
authors.initials: M
authors.lastname: Molnar
authors.affiliation: Department of Molecular and Clinical Medicine/Clinical Physiology, The Sahlgrenska Academy and University Hospital, University of Gothenburg , Gothenburg , Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Friberg
authors.affiliation: † Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology , Stockholm , Sweden.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fu
authors.affiliation: ‡ Department of Rheumatology and Inflammation Research, The Sahlgrenska Academy and University Hospital, University of Gothenburg , Gothenburg , Sweden.
authors.forename: Mikeal
authors.initials: M
authors.lastname: Brisslert
authors.affiliation: § Department of Pharmacology and Toxicology, Queen's University , Kingston, Ontario , Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Adams
authors.affiliation: Department of Molecular and Clinical Medicine/Clinical Physiology, The Sahlgrenska Academy and University Hospital, University of Gothenburg, Gothenburg, Sweden; †Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
keywords: Capillary tube formation; Cell labeling; Endothelial progenitor cells; Migration; Quantum dots