Encapsulating particles with coatings that conform to size and shape of the particles
First Claim
1. A method for encapsulating particles, the method comprising:
- providing a container having two liquids therein, said liquids having different densities and being substantially immiscible relative to each other and being situated in said container such that an interface exists between the liquids, the liquid of lesser density comprising an upper liquid and the liquid of greater density comprising a lower liquid, the lower liquid comprising a coating liquid and having said particles to be coated entrained therein, the upper liquid having a greater viscosity than the lower liquid;
inserting a tube having an orifice into the container such that said orifice is positioned in the upper liquid above said interface, said tube being operably connected to a pump for withdrawing liquid from the container;
activating said pump and establishing a pumping rate sufficient to form a spout extending between said interface and said orifice of said tube, said spout substantially comprising said lower liquid being withdrawn from said container, said spout having a maximum diameter base portion at said interface and decreasing in diameter as the spout approaches said tube, said base portion diameter being greater than the diameters of the particles to be coated, said pumping rate being sufficient to draw said particles from said lower liquid and through the spout;
coating a particle by drawing the particle upwardly through said spout from said base portion wherein the particle is engulfed by a coating of said spout liquid, to an upper spout portion, said upper spout portion having a diameter less than the diameter of the particle, thereby causing a break in said spout and freeing said coated particle for flow through said tube;
re-establishing said spout by continuing said pumping at said sufficient pumping rate, and coating additional particles by drawing each particle to be coated upwardly through said spout from said base portion to an upper portion of said re-established spout having a diameter less than the diameter of the particle being coated, thereby causing a break in said spout and freeing said coated particle;
repeating said coating process until all of said particles to be coated have been drawn upwardly through said spout and coated with said spout liquid; and
collecting said coated particles.
1 Assignment
0 Petitions
Accused Products
Abstract
Particles such as islet cells are encapsulated by a method that forms a coating of uniform thickness that conforms to the size and shape of the particles. Two substantially immiscible liquids of different densities are provided in a container as upper and lower liquids such that an interface exists between the liquids. The upper liquid is less dense and has a greater viscosity than the lower liquid which is a coating liquid containing particles to be encapsulated. A tube is positioned in the upper liquid such that an orifice of the tube is above the interface. A pump connected to the tube sucks liquid through the tube at a rate sufficient to form a spout containing substantially the lower liquid extending between the interface and the tube orifice. The spout has maximum diameter at the interface and decreases in diameter as the spout approaches the tube orifice. Particles in the lower liquid are drawn up through the spout as liquid is withdrawn, and coated particles are released from the spout at a point where the diameter of the spout is less than the diameter of the particles, and the coated particles flow through the tube. The coating liquid may be a pre-polymer that can be polymerized and crosslinked after coating. The coated particles have therapeutic applications such as administering coated islet cells to treat diabetes.
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Citations
20 Claims
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1. A method for encapsulating particles, the method comprising:
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providing a container having two liquids therein, said liquids having different densities and being substantially immiscible relative to each other and being situated in said container such that an interface exists between the liquids, the liquid of lesser density comprising an upper liquid and the liquid of greater density comprising a lower liquid, the lower liquid comprising a coating liquid and having said particles to be coated entrained therein, the upper liquid having a greater viscosity than the lower liquid;
inserting a tube having an orifice into the container such that said orifice is positioned in the upper liquid above said interface, said tube being operably connected to a pump for withdrawing liquid from the container;
activating said pump and establishing a pumping rate sufficient to form a spout extending between said interface and said orifice of said tube, said spout substantially comprising said lower liquid being withdrawn from said container, said spout having a maximum diameter base portion at said interface and decreasing in diameter as the spout approaches said tube, said base portion diameter being greater than the diameters of the particles to be coated, said pumping rate being sufficient to draw said particles from said lower liquid and through the spout;
coating a particle by drawing the particle upwardly through said spout from said base portion wherein the particle is engulfed by a coating of said spout liquid, to an upper spout portion, said upper spout portion having a diameter less than the diameter of the particle, thereby causing a break in said spout and freeing said coated particle for flow through said tube;
re-establishing said spout by continuing said pumping at said sufficient pumping rate, and coating additional particles by drawing each particle to be coated upwardly through said spout from said base portion to an upper portion of said re-established spout having a diameter less than the diameter of the particle being coated, thereby causing a break in said spout and freeing said coated particle;
repeating said coating process until all of said particles to be coated have been drawn upwardly through said spout and coated with said spout liquid; and
collecting said coated particles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification