Jessica Thomas1, Desiree Jones2, Leni Moldovan3, Mirela Anghelina2, Keith J Gooch1, Nicanor I Moldovan4. 1. Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA. 2. Department of Internal Medicine, The Ohio State University, Columbus, OH, USA. 3. Department of Surgery, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA. 4. Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Walther Hall, R3 Research Building, Room C644, 980 W Walnut St., Indianapolis, IN, 46202, USA. nimoldov@iupui.edu.
Abstract
OBJECTIVES: Attachment of magnetic particles to cells is needed for a variety of applications but is not always possible or efficient. Simpler and more convenient methods are thus desirable. In this study, we tested the hypothesis that endothelial cells (EC) can be loaded with micron-size magnetic beads by the phagocytosis-like mechanism 'angiophagy'. To this end, human umbilical vein EC (HUVEC) were incubated with magnetic beads conjugated or not (control) with an anti-VEGF receptor 2 antibody, either in suspension, or in culture followed by re-suspension using trypsinization. RESULTS: In all conditions tested, HUVEC incubation with beads induced their uptake by angiophagy, which was confirmed by (i) increased cell granularity assessed by flow cytometry, and (ii) the presence of an F-actin rich layer around many of the intracellular beads, visualized by confocal microscopy. For confluent cultures, the average number of beads per cell was 4.4 and 4.2, with and without the presence of the anti-VEGFR2 antibody, respectively. However, while the actively dividing cells took up 2.9 unconjugated beads on average, this number increased to 5.2 if binding was mediated by the antibody. Magnetic pulldown increased the cell density of beads-loaded cells in porous electrospun poly-capro-lactone scaffolds by a factor of 4.5 after 5 min, as compared to gravitational settling (p < 0.0001). CONCLUSION: We demonstrated that EC can be readily loaded by angiophagy with micron-sized beads while attached in monolayer culture, then dispersed in single-cell suspensions for pulldown in porous scaffolds and for other applications.
OBJECTIVES: Attachment of magnetic particles to cells is needed for a variety of applications but is not always possible or efficient. Simpler and more convenient methods are thus desirable. In this study, we tested the hypothesis that endothelial cells (EC) can be loaded with micron-size magnetic beads by the phagocytosis-like mechanism 'angiophagy'. To this end, human umbilical vein EC (HUVEC) were incubated with magnetic beads conjugated or not (control) with an anti-VEGF receptor 2 antibody, either in suspension, or in culture followed by re-suspension using trypsinization. RESULTS: In all conditions tested, HUVEC incubation with beads induced their uptake by angiophagy, which was confirmed by (i) increased cell granularity assessed by flow cytometry, and (ii) the presence of an F-actin rich layer around many of the intracellular beads, visualized by confocal microscopy. For confluent cultures, the average number of beads per cell was 4.4 and 4.2, with and without the presence of the anti-VEGFR2 antibody, respectively. However, while the actively dividing cells took up 2.9 unconjugated beads on average, this number increased to 5.2 if binding was mediated by the antibody. Magnetic pulldown increased the cell density of beads-loaded cells in porous electrospun poly-capro-lactone scaffolds by a factor of 4.5 after 5 min, as compared to gravitational settling (p < 0.0001). CONCLUSION: We demonstrated that EC can be readily loaded by angiophagy with micron-sized beads while attached in monolayer culture, then dispersed in single-cell suspensions for pulldown in porous scaffolds and for other applications.
Entities:
Keywords:
Angiophagy; Electrospun scaffold; Endothelial cells; Magnetic microbeads; Phagocytosis; Poly-capro-lactone
Authors: Sorin V Pislaru; Adriana Harbuzariu; Rajiv Gulati; Tyra Witt; Nicole P Sandhu; Robert D Simari; Gurpreet S Sandhu Journal: J Am Coll Cardiol Date: 2006-10-17 Impact factor: 24.094
Authors: Bryan R Smith; Johannes Heverhagen; Michael Knopp; Petra Schmalbrock; John Shapiro; Masashi Shiomi; Nicanor I Moldovan; Mauro Ferrari; Stephen C Lee Journal: Biomed Microdevices Date: 2007-10 Impact factor: 2.838