A method for the synthesis of gadolinium oxide magnetoliposomes, i.e., nanosized gadolinium oxide magnetic particles coated by a phospholipid membrane, is presented. Magnetoliposomes were prepared by reacting lauric acid coated gadolinium oxide nanoparticles with dimyristoylphosphatidylcholine liposomes prepared using a direct injection method. The gadolinium oxide magnetoliposomes were characterized using transmission electron microscopy imaging, x-ray diffraction, and fluorescence. The magnetic properties of the magnetoliposomes were investigated with a superconducting quantum interference device magnetometer and nuclear magnetic resonance (NMR) spectrometry. Our results indicate that the magnetoliposomes contain approximately spherical nanoparticles averaging 20 nm in diameter. The occurrence of a phospholipid bilayer surrounding the magnetic particles is confirmed both by transmission electron micrographs of samples negatively stained with uranyl acetate and by digital fluorescence imaging microscopy measurements of magnetoliposomes labeled with fluorescein. The particles are paramagnetic at room temperature. NMR measurements show that the ratio between the relaxivities of the particles depends largely on their preparation.

1.
M. F.
Doener
and
R. L.
White
,
MRS Bull.
21
,
28
(
1996
).
2.
A. R.
Schweneder
,
Chimica
46
,
69
(
1992
).
3.
K. J. Klabude et al., Nanophase Materials: Synthesis-Properties-Applications, NATO ASI Series E Vol. 260, edited by G. C. Hadjipanayis and R. W. Siegel (Kluwer, Dordrecht, 1994), pp. 1–19, and references therein.
4.
V.
Pillai
,
P.
Kumar
,
M. J.
Hou
,
P.
Ayyub
, and
D. O.
Shah
,
Adv. Colloid Interface Sci.
55
,
241
(
1995
).
5.
N. S.
Kommareddi
,
M.
Tata
,
V. T.
John
,
G. L.
McPherson
,
M. F.
Herman
,
Y. S.
Lee
,
C. J.
O’Connor
,
J. A.
Akkara
, and
D. L.
Kaplan
,
Chem. Mater.
8
,
801
(
1996
).
6.
C. T. Seip, E. E. Carpenter, C. J. O’Connor, V. T. John, and S. Li, IEEE Trans. Magn. (accepted).
7.
N.
Fauconnier
,
J. N.
Pons
,
J.
Roger
, and
A.
Bee
,
J. Colloid Interface Sci.
194
,
423
(
1997
).
8.
K.
Adzamli
,
R. B.
Dorshow
,
M. R.
Hynes
,
D. L.
Nosco
, and
M. D.
Adams
,
Acta Radiol. Suppl.
412
,
73
(
1997
).
9.
M.
de Cuyper
and
M.
Joniau
,
Eur. Biophys. J.
15
,
311
(
1988
).
10.
M.
de Cuyper
and
M.
Joniau
,
Langmuir
7
,
647
(
1991
).
11.
P. F.
Daly
,
J. B.
Zimmerman
,
J. A.
Cannilo
, and
G. L.
Wolf
,
Am. J. Phys. Imaging
5
,
119
(
1990
).
12.
K. R.
Burnett
,
G. L.
Wolf
,
H. R.
Shumacher
, and
E. J.
Goldstein
,
Magn. Reson. Imaging
3
,
65
(
1985
).
13.
L.
Babes
,
B.
Denizot
,
G.
Tanguy
,
J. J.
Le Jeune
, and
P.
Jallet
,
J. Colloid Interface Sci.
212
,
474
(
1999
).
This content is only available via PDF.
You do not currently have access to this content.