Use of liposomes as carriers for radiation synovectomy.
Using [99mTc]pertechnetate as an aqueous space marker, the permeability of liposomes composed of seven different mixtures of distearoylphosphatidylcholine (DSPC) and sphingomyelin (SM) was determined. Liposomes containing 20-33% SM were the least permeable in the presence of rheumatoid synovial fluid. Following injection of 99mTc-containing liposomes into the knee joints of rabbits, retention of 99mTc in the knee was more than 200 times greater than following injection of nonencapsulated [99mTc]pertechnetate. The knee clearance biologic half time of 99mTc with DSPC/SM (4:1) liposomes was 64 h. Most of the activity that had leaked from the knee was not found in extra-articular tissues, suggesting rapid excretion. When DSPC/SM (4:1) liposomes were labeled with 111In(oxine), a knee clearance biologic half time of greater than 1200 h was observed.
Zalutsky
M R
MR
Department of Radiology (Nuclear Medicine), Harvard Medical School, Boston, MA 02115.
Noska
M A
MA
Gallagher
P W
PW
Shortkroff
S
S
Sledge
C B
CB
D000818:Animals; D007205:Indium Radioisotopes; D008081:Liposomes / Q000008:administration & dosage*; D009942:Organometallic Compounds / Q000627:therapeutic use; D015125:Oxyquinoline / Q000031:analogs & derivatives / Q000627:therapeutic use; D010539:Permeability; D010713:Phosphatidylcholines; D011817:Rabbits; D013670:Sodium Pertechnetate Tc 99m / Q000493:pharmacokinetics / Q000627:therapeutic use*; D013109:Sphingomyelins; D013583:Synovial Membrane / Q000528:radiation effects*; D014018:Tissue Distribution
D007205:Indium Radioisotopes; D008081:Liposomes; D009942:Organometallic Compounds; D010713:Phosphatidylcholines; D013109:Sphingomyelins; C032950:indium oxine; D015125:Oxyquinoline; D013670:Sodium Pertechnetate Tc 99m; C010942:1,2-distearoyllecithin