Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization.

TitleSide-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization.
Publication TypeJournal Article
Year of Publication2015
AuthorsLeelawattanachai J, Kwon K-W, Michael P, Ting R, Kim J-Y, Jin MM
JournalPLoS One
Volume10
Issue4
Paginatione0124440
Date Published2015
ISSN1932-6203
KeywordsAnimals, Diagnostic Imaging, Endocytosis, HEK293 Cells, HeLa Cells, Humans, Immunoglobulin G, Intercellular Adhesion Molecule-1, Mice, SCID, Models, Biological, Molecular Weight, Neoplasms, Protein Binding, Proteins, Tissue Distribution, Whole Body Imaging, Xenograft Model Antitumor Assays
Abstract

The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab), serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization.

DOI10.1371/journal.pone.0124440
Alternate JournalPLoS One
PubMed ID25901755
PubMed Central IDPMC4406587
Grant ListR01 CA178007 / CA / NCI NIH HHS / United States
R01CA178007 / CA / NCI NIH HHS / United States
Related Institute: 
Molecular Imaging Innovations Institute (MI3)

Weill Cornell Medicine
Department of Radiology
525 East 68th Street New York, NY 10065