ESR as a valuable tool for the investigation of the dynamics of EPC and EPC/cholesterol liposomes containing a carboranyl-nucleoside intended for BNCT.
Electron Spin Resonance (ESR) spectroscopy of long-chain nitroxides (5-, 7-, and 16-doxyl stearic acid) has been used to evaluate the perturbations induced by beta-5-o-carboranyl-2'-deoxyuridine (CDU) on the structure and dynamics of egg phosphatidylcholine (EPC) and EPC/cholesterol liposomes. Loaded liposomes are intended for the use in Boron Neutron Capture Therapy (BNCT). From a detailed analysis of the motional and order parameters determining the ESR line shape as a function of temperature and of CDU content in liposomes, an increased order and a hindered motion of the phospholipid membranes resulted in the presence of increasing CDU concentration. This occurred particularly at the liposome surface level. Both higher ordering and increased rigidity of the membrane lipids were the result of the constraints exerted by the embedded carboranyl-nucleoside.
Rossi
Simona
S
Dipartimento di Chimica, Università di Firenze, Sesto Fiorentino, Italy. rossi@csgi.unifi.it
Schinazi
Raymond F
RF
Martini
Giacomo
G
D001896:Boron Compounds / Q000494:pharmacology; D016754:Boron Neutron Capture Therapy; D002244:Carbon / Q000737:chemistry; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism; D003857:Deoxyuridine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008956:Models, Chemical; D010713:Phosphatidylcholines / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014466:Ultraviolet Rays
D001896:Boron Compounds; D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines; C087057:5-carboranyl-2'-deoxyuridine; D002244:Carbon; D002784:Cholesterol; D003857:Deoxyuridine