title: Effect of mouse VEGF164 on the viability of hydroxyethyl methacrylate-methyl methacrylate-microencapsulated cells in vivo: bioluminescence imaging.
abstract: Bioluminescent imaging was used to track the viability of luciferase transfected L929 cells in poly(hydroxyethyl methacrylate-co-methyl methacrylate) (HEMA-MMA) microcapsules. Bioluminescence, as determined by Xenogen imaging after addition of luciferin to microcapsules in vitro, increased with time, consistent with an increase in cell number. Capsules were suspended in Matrigel and injected subcutaneously. The bioluminesence in vivo increased over the first 3 weeks and then decreased, both with and without the delivery of mVEGF(164) (1.2 ng/24 h/200 microcapsules in vitro); VEGF delivery was from microencapsulated doubly transfected cells (both luciferase and mVEGF(164)). VEGF delivery was sufficient to generate a greater number of vascular structures, but this did not result in the expected increase in microencapsulated cell viability. Interestingly, the number of vessels at day 28 was less than at day 21, consistent with what would be an expected reduction in VEGF secretion when cell viability is lost. The results presented here do not support the hypothesis that transfection of microencapsulated cells with VEGF is sufficient to correct the oxygen transport limitation, at least with this type of tissue engineering construct. On the other hand, bioluminescent imaging proved to be a useful method of monitoring microencapsulated cell viability over many weeks in vivo.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering and Department of Chemical Engineering and Applied Chemistry, University of Toronto, 164 College St., Room 407, Toronto, Canada M5S 3G9.
authors.forename: Dangxiao
authors.initials: D
authors.lastname: Cheng
authors.forename: Chuen
authors.initials: C
authors.lastname: Lo
authors.forename: Michael V
authors.initials: MV
authors.lastname: Sefton
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D017077:Culture Media, Conditioned / Q000737:chemistry; D004339:Drug Compounding; D006801:Humans; D020007:Implants, Experimental; D049409:Luciferases, Firefly / Q000235:genetics / Q000378:metabolism; D049408:Luminescent Agents / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008768:Methylmethacrylates / Q000737:chemistry*; D051379:Mice; D008809:Mice, Inbred C3H; D018919:Neovascularization, Physiologic / Q000187:drug effects; D023822:Tissue Engineering / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D017077:Culture Media, Conditioned; D049408:Luminescent Agents; D008689:Methacrylates; D008768:Methylmethacrylates; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; C005044:hydroxyethyl methacrylate; D049409:Luciferases, Firefly