부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.tiv.2008.03.014 Byline: D. Bazou (a), W.T. Coakley (a), A.J. Hayes (a), S.K. Jackson (b) Keywords: Alginate; Ultrasound trap; F-actin; 2-/3-D cell aggregate; Viability; Proliferation Abstract: We report proof of principle here of a gel encapsulation technique that departs from the minimum surface area to volume restriction of spherical microcapsules and allows gelation of preformed high-density ([greater than or equal to]2x10.sup.4 cells/aggregate) 3-D HepG2 cell aggregates. The process involves forming a discoid 3-D cell aggregate in an ultrasound standing wave trap (USWT), which is subsequently recovered and encapsulated in alginate/CaCl.sub.2 hydrogel. The size of the ultrasound-formed aggregates was dependent upon the initial cell concentration, and was in the range of 0.4-2.6 mm in diameter (for cell concentrations ranging between 10.sup.4 and 5x10.sup.6/ml). At low cell concentrations (a[c]1/25x10.sup.5/ml), aggregates were 2-D, while at concentrations of [greater than or equal to]10.sup.6/ml, 3-D aggregates were generated. Cells in non- and encapsulated 3-D HepG2 aggregates remained 70-80% viable over 10 days in culture. The proliferative activity of the aggregates resulted in the doubling of the aggregate cell number and a subsequent increase in the aggregate thickness, while albumin secretion levels in encapsulated aggregates was 4.5 times higher compared to non-encapsulated, control aggregates. The results reported here suggest that the ultrasound trap can provide an alternative, novel approach of hydrogel cell encapsulation and thus rapidly (within 5min) produce in vitro models for hepatocyte functional studies (for example, toxicity studies particularly if primary hepatocytes are used) in a tissue-mimetic manner. Author Affiliation: (a) Cardiff School of Biosciences, Cardiff University, Museum Place, Cardiff CF10 3TL, Wales, UK (b) Centre for Research in Biomedicine, Faculty of Applied Sciences, University of the West of England, Bristol BS16 1QY, UK Article History: Received 23 November 2007; Accepted 29 March 2008