A new method for the synthesis of magnetoliposomes, i.e., nanosized magnetic particles coated by a phospholipid membrane, is presented. Magnetoliposomes are prepared by directly using the phospholipid vesicles as nanoreactors for the precipitation of the magnetic particles. The magnetoliposomes have been characterized using transmission electron microscopy imaging and x-ray powder diffraction. The magnetic properties of the magnetoliposomes have been investigated with a superconducting quantum interference device magnetometer. Our results indicate that the magnetoliposomes contain approximately spherical maghemite nanoparticles averaging 25 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 temperature dependence of the zero field cooled and field cooled susceptibilities of the magnetoliposomes is consistent with their expected superparamagnetic nature.

1.
Science and Technology of Nanostructured Magnetic Materials, NATO ASI Series B: Physics Vol. 259, edited by G. C. Hadjipanays and G. Prinz (1991).
2.
A. R.
Schweneder
,
Chimia
46
,
69
(
1992
).
3.
D. L.
Leslie-Pelecky
and
R. D.
Rieke
,
Chem. Mater.
8
,
1770
(
1996
).
4.
K. J. Klabude et al., in NATO ASI Series E, Vol. 260, edited by G. C. Hadjipanayis and R. W. Siegel (Kluwer, Dordrecht, 1994), pp. 1–19, and references therein.
5.
I. I.
Yaacob
,
A. C.
Nunes
, and
A.
Bose
,
J. Colloid Interface Sci.
171
,
73
(
1995
).
6.
C.
Petit
,
P.
Lixon
, and
M. P.
Pileni
,
J. Phys. Chem.
94
,
1528
(
1990
).
7.
V.
Pillai
,
P.
Kumar
,
M. J.
Hou
,
P.
Ayyub
, and
D. O.
Shah
,
Adv. Colloid Interface Sci.
55
,
241
(
1995
).
8.
N. S.
Kommareddi
et al.,
Chem. Mater.
8
,
801
(
1996
).
9.
N.
Fauconnier
,
J. N.
Pons
,
J.
Roger
, and
A.
Bee
,
J. Colloid Interface Sci.
194
,
423
(
1997
).
10.
K.
Adzamli
,
R. B.
Dorshow
,
M. R.
Hynes
,
D. L.
Nosco
, and
M. D.
Adams
,
Acta Radiol., Suppl.
412
,
73
(
1997
).
11.
R. R. C. New, Liposomes—A Practical Approach (Oxford University Press, Oxford, United Kingdom, 1989), pp. 33–104.
12.
M.
Babincova
and
P.
Babinec
,
Cell. Mol. Biol. Lett.
2
,
3
(
1997
).
13.
M.
De Cuyper
and
M.
Joniau
,
Eur. Biophys. J.
15
,
311
(
1988
).
14.
M.
De Cuyper
and
M.
Joniau
,
Langmuir
7
,
647
(
1991
).
15.
A. D. Gee, in Cell Separation Methods and Applications, edited by D. Recktenwald and A. Radbrush (Marcel Dekker, Inc., New York, 1997), p. 175.
16.
S. E.
Wright
and
H.
Leaf
,
J. Lipid Res.
2
,
257
(
1992
).
17.
A. H. Morrish, The Physical Principles of Magnetism (Wiley, New York, 1965).
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