Hepatocyte labeling with ⁹⁹mTc-GSA: a potential non-invasive technique for tracking cell transplantation

Int J Artif Organs. 2012 Jun;35(6):450-7. doi: 10.5301/ijao.5000096.


Background: Hepatocyte transplantation is a promising alternative to orthotopic liver transplantation, however, the fate of transplanted hepatocytes is not well defined. ⁹⁹mTc-galactosyl-serum albumin (⁹⁹mTc-GSA) is a clinical scintigraphic agent which is specifically taken up by the hepatocyte asialoglycoprotein receptor (ASGPR).

Aims: To investigate labeling of fresh and cryopreserved human hepatocytes and fresh rat hepatocytes in vitro using ⁹⁹mTc-GSA.

Methods: Human and rat hepatocytes were isolated from liver tissue by collagenase perfusion. The ASGPR were characterized using immunohistochemistry and RT-PCR. Hepatocytes were incubated with ⁹⁹mTc-GSA in suspension at 4°C and 37°C. Cell viability and function was determined using cell mitochondrial dehydrogenase (MTS) and sulphorhodamine B (SRB) assays.

Results: Fresh and cryopreserved human hepatocytes expressed the ASGPR. Incubation of hepatocytes in suspension with ⁹⁹mTc-GSA reduced the viability of hepatocytes, but this was similar to unlabeled control cells. Greater loss of viability was seen on incubation at 37°C compared to 4°C, but there was a significantly greater uptake of ⁹⁹mTc-GSA at the physiological temperature (6.6 ± SE 0.6-fold increase, p<0.05) consistent with ASGPR-mediated endocytosis. MTS and SRB assays were not significantly affected by labeling with ⁹⁹mTc-GSA in all three cell types. A mean of 18.5% of the radioactivity was released over 120 min when ⁹⁹mTc-GSA -labeled hepatocytes were shaken in vitro at 37°C.

Conclusions: Human and rat hepatocytes can be labeled with ⁹⁹mTc-GSA, which may have potential application for in vivo imaging after hepatocyte transplantation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asialoglycoprotein Receptor / genetics
  • Asialoglycoprotein Receptor / metabolism
  • Biological Transport
  • Cell Survival
  • Cell Tracking / methods*
  • Cells, Cultured
  • Cryopreservation
  • Hepatocytes / diagnostic imaging*
  • Hepatocytes / metabolism
  • Hepatocytes / transplantation*
  • Humans
  • Immunohistochemistry
  • Male
  • Radionuclide Imaging
  • Radiopharmaceuticals* / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • Technetium Tc 99m Aggregated Albumin* / metabolism
  • Technetium Tc 99m Pentetate* / metabolism
  • Temperature
  • Time Factors


  • Asialoglycoprotein Receptor
  • Radiopharmaceuticals
  • Technetium Tc 99m Aggregated Albumin
  • technetium Tc 99m DTPA-galactosyl-human serum albumin
  • Technetium Tc 99m Pentetate