TY - JOUR
T1 - γ-irradiation damage to liposomes differing in composition and their protection by nitroxides
AU - Samuni, Ayelet M.
AU - Barenholz, Yechezkel
AU - Crommelin, Daan J.A.
AU - Zuidam, Nicolaas J.
PY - 1997
Y1 - 1997
N2 - The present study aims to determine the effect of bilayer composition on oxidative damage and the protection against it in lipid multicomponent membranes. Irradiation damage in 200-nm liposomes and the protection provided by the nitroxide radicals, 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) were assessed by monitoring several chemical and physical parameters. Liposomes were prepared in four different lipid compositions (mole ratios), DPPC:DPPG 10:1; DPPC:DPPG:cholesterol 10:1:4; EPC:EPG 10:1; and EPC:EPG:cholesterol 10:1:4, and γ-irradiated with a dose of 32 kGy. Lipid degradation was determined by HPLC and GC analyses, whereas size and differential scanning calorimetry measurements were used to monitor physical changes in the liposomal dispersions. The results indicate that: (1) addition of 5 mM Tempo or Tempol, or freezing of the sample inhibited radiation-induced lipid degradation; (2) Tempo and Tempol caused neither physical nor chemical changes in the liposomal dispersions; and (3) both nitroxides prevented or reduced some of the radiation-induced changes in thermotropic characteristics of the liposomes, preventing a shift in the temperature of the maximum of the main phase transition (T(m)).
AB - The present study aims to determine the effect of bilayer composition on oxidative damage and the protection against it in lipid multicomponent membranes. Irradiation damage in 200-nm liposomes and the protection provided by the nitroxide radicals, 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) were assessed by monitoring several chemical and physical parameters. Liposomes were prepared in four different lipid compositions (mole ratios), DPPC:DPPG 10:1; DPPC:DPPG:cholesterol 10:1:4; EPC:EPG 10:1; and EPC:EPG:cholesterol 10:1:4, and γ-irradiated with a dose of 32 kGy. Lipid degradation was determined by HPLC and GC analyses, whereas size and differential scanning calorimetry measurements were used to monitor physical changes in the liposomal dispersions. The results indicate that: (1) addition of 5 mM Tempo or Tempol, or freezing of the sample inhibited radiation-induced lipid degradation; (2) Tempo and Tempol caused neither physical nor chemical changes in the liposomal dispersions; and (3) both nitroxides prevented or reduced some of the radiation-induced changes in thermotropic characteristics of the liposomes, preventing a shift in the temperature of the maximum of the main phase transition (T(m)).
KW - Free radicals
KW - Liposomes
KW - Tempo
KW - Tempol
UR - http://www.scopus.com/inward/record.url?scp=0030826523&partnerID=8YFLogxK
U2 - 10.1016/S0891-5849(97)00123-8
DO - 10.1016/S0891-5849(97)00123-8
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C2 - 9358239
AN - SCOPUS:0030826523
SN - 0891-5849
VL - 23
SP - 972
EP - 979
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 7
ER -