1Nuclear Medicine Division, Indian Institute of Chemical Biology, University of Calcutta
2Infectious Disease and Immunology Div, Indian Institute of Chemical Biology, University of Calcutta
3Dept. of Molecular Biology and Biophysics, University of Calcutta
The objective of this study was to develop a simple, efficient and practical method to label l posome with 99m Tc-Cysteine and Cystine derivatives for Nuclear Brain Imaging
Liposome was formulated with lipid components, egg phosphatidyl choline (PC) and cholesterol (Chol) (molar ratio 2:1 and 7:2) by standard procedure and incubated with 99mTc and Cystine/Cysteine derivatives in presence of SnCl2/Ascorbic acid. Liposome size was measured using electron microscope. All the liposomes chracterized by TLC and HPLC. Biodistribution studies were performed in Sprague Dawley rats with 99mTc Cystine and Cysteine derivative entrapped in liposomes. Images under gamma camera were taken in case of normal and Ischemic rat brain (common carotid artery occlusion) with liposomal formulations and compared with the images obtained by 99mTc ECD.
The entrapment efficiency of 99mTc Cysteine and Cystine derivatives in liposome (70 – 80%) depends upon the size (0.01–0.5 micrometer) and nature of liposomes (small unilamellar). The biodistribution study in normal rats showed significant uptake in brain at two minutes and then gradual decrease at 5, 15 and 30 minutes. The uptake has also been tested in ischemic rat brain under gamma camera.
Entrapment of Cysteine and Cystine derivatives in liposomes with 99mTc is studied. The labelled liposomes were found stable and could be potentially used for nuclear brain imaging.
Liposomes, Biodistribution, Ischemia, Imaging
