Factors influencing quantification of in vivo bioluminescence imaging: application to assessment of pancreatic islet transplants.
The aim of this study is to determine and characterize factors influencing in vivo bioluminescence imaging (BLI) and apply them to the specific application of imaging transplanted pancreatic islets. Noninvasive quantitative assessment of transplanted pancreatic islets poses a formidable challenge. Murine pancreatic islets expressing firefly luciferase were transplanted under the renal capsule or into the portal vein of nonobese diabetic-severe combined immunodeficiency mice and the bioluminescence was quantified with a cooled charge coupled device camera and digital photon image analysis. The important, but often neglected, effects of wound healing, mouse positioning, and transplantation site on bioluminescence measurements were investigated by imaging a constant emission, isotropic light-emitting bead (lambda = 600) implanted at the renal or hepatic site. The renal beads emitted nearly four times more light than hepatic beads with a smaller spot size, indicating that light absorption and scatter are greatly influenced by the transplant site and must be accounted for in BLI measurements. Detected luminescence decreased with increasing angle between the mouse surface normal and optical axis. By defining imaging parameters such as postsurgical effects, animal positioning, and light attenuation as a function of transplant site, this study develops BLI as a useful imaging modality for quantitative assessment of islets post-transplantation.
Virostko
John
J
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA.
Chen
Zhongyi
Z
Fowler
Michael
M
Poffenberger
Greg
G
Powers
Alvin C
AC
Jansen
E Duco
ED
D000818:Animals; D017930:Genes, Reporter; D016381:Islets of Langerhans Transplantation / Q000502:physiology; D049409:Luciferases, Firefly / Q000235:genetics; D008163:Luminescent Measurements / Q000379:methods* / Q000706:statistics & numerical data; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009010:Monte Carlo Method; D011994:Recombinant Proteins / Q000235:genetics; D014161:Transduction, Genetic
D011994:Recombinant Proteins; D049409:Luciferases, Firefly