Abstract
1883
Objectives Galactosylated or lactosylated human serum albumins labeled with 99mTc have been used for functional liver imaging agents which bind to asialoglycoprotein receptor of hepatocyte. We tried to develop a 68Ga-labeled lactosylated human serum albumin (LSA) for PET.
Methods Human serum albumin (68 mg) was reacted with α-lactose (100 mg) and sodium cyanoborohydride (100 mg) in 0.2 M potassium phosphate buffer (pH 8.0) at 37°C for 8 days. After purification by a PD10 column, LSA was mixed with 58 eq p-SCN-Bn-NOTA in sodium phosphate buffer (pH 7.5) at 37°C for 2 hr. Resulting conjugate was purified by a PD10 column again. Conjugation numbers of lactose and NOTA were determined by MALDI-TOF. NOTA-LSA was labeled with 68Ga under controlled pH with sodium phosphate buffer. Labeling efficiency was check by ITLC. Biodisrtibition in ICR mice was investigated after tail vein injection of 68Ga-LSA. Micro PET images were obtained after injecting 3.7 MBq per mouse through the tail vein.
Results Conjugation numbers of lactose and NOTA were 27 and 5, respectively. Labeling efficiency and stability of 68Ga-LSA were greater than 99% after 10 min incubation. 68Ga-LSA showed a high liver uptake at 10 min and persisted to 1 hr in biodistribution study. Micro-PET image also showed high persistent liver uptake without any spleen uptake.
Conclusions We developed 68Ga-LSA which is a novel PET agent for asialoglycoprotein receptors of the liver. This compound was characterized by easy labeling procedure, high labeling efficiency, high stability, and high liver uptake.
- © 2009 by Society of Nuclear Medicine