Drug – bio-affecting and body treating compositions – Topical body preparation containing solid synthetic organic...
Reexamination Certificate
1999-06-29
2002-10-15
Jones, Dameron L. (Department: 1616)
Drug, bio-affecting and body treating compositions
Topical body preparation containing solid synthetic organic...
C424S078040, C424S489000, C424S009300, C424S009360
Reexamination Certificate
active
06464968
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to methods for making magnetic fluid compositions useful for treating disorders. More specifically, the invention relates to methods for synthesizing copolymers useful as magnetic dispersion stabilizers.
BACKGROUND OF THE INVENTION
The mammalian eye comprises two chambers. The anterior chamber is bounded by the cornea and lens, and contains the aqueous humor. The volume behind the lens contains the vitreous humor, with the retina attached to the back wall of the eye. The retinal layer is not firmly attached to the eye, and can become detached, resulting in eventual death of the retina and loss of vision. The retina may detach along an edge, e.g. as the result of trauma, or as the result of a tear allowing fluid to leak underneath the retina and separate the retina from the underlying choroid. Retinal detachment can be treated by means of a scleral buckle, a silicone band that encircles the eye and compresses the wall of the eye inward against the retina. Alternatively, the vitreous humor may be replaced in whole or in part with a tamponade, a heavy liquid or gas intended to flatten the retina against the choroid.
Currently used internal tamponades (SF
6
, C
3
F
8
, silicone oil) float up, leaving the inferior retina unprotected, or sink down (fluorosilicone), leaving the superior retina unprotected. Current tamponades also fill the vitreous cavity, decreasing vision, and contact anterior chamber structures, causing cataract and glaucoma.
Stable magnetic fluids are currently known. However, the fluids are typically dispersed in organic media and contain particles that are small in size. Thus, the organic media renders them unsuitable for biomedical applications and the small particle size causes their response to low external magnetic fields to be relatively low. Larger particles tend to aggregate and subsequently precipitate using currently available stabilizers.
SUMMARY OF THE INVENTION
A new method for making compositions useful for treating retinal detachment is provided.
Another object of the invention is to provide a stable magnetic silicone fluid.
Another object of the invention is to provide methods for synthesizing copolymers suitable for use in the method of the invention.
Another object of the invention is to provide specific examples of magnetic fluid preparation.
Still another object of the invention is to provide stable, biocompatible magnetic fluids in polydimethylsiloxane fluid for use in ophthalmology.
Still another object of the invention is to provide block copolymer stabilizers that efficiently stabilize particles as large as about 17-20 nm in diameter.
Yet another object of the invention is to provide stable particles having a relatively high magnetic response to low externally applied fields.
REFERENCES:
patent: 6135118 (2000-10-01), Dailey
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Li, C., et al., “Polydimethylsilexane-b-Poly (3-cyanopropyl) methylsilexane-b-Polydimethylsiloxane Triblock Suspension Stabilizers.” Polymer preprints, Division of Polymer Chemistry, American Chemical Society, vol. 37, No. 2, pp. 660-661 (Aug, 1996).
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Papirer, Eugene, et al., “The preparation of a ferrofluid by decomposition of dicobalt octacarbonyl—I. Experimental paramenters.” Journal of Colloid and Interface science, No. 94(1), pp. 207-219 (1983).
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Dailey James P.
Phillips Janice Paige
Riffle Judy S.
Jones Dameron L.
Virginia Tech Intellectual Properties Inc.
Whitham Curtis & Christofferson, P.C.
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