Three-dimensional printed structural siloxanes having controlled drug release

Patent metadata

Field	Value
Publication number	US-2020315975-A1
Application number	US-201916374629-A
Country	US
Kind code	A1
Filing date	Apr 3, 2019
Priority date	Apr 3, 2019
Publication date	Oct 8, 2020
Grant date	—

Abstract

According to one embodiment, a core-shell microsphere includes a polyorganosiloxane shell, and a core inside the shell, the core having a carrier and at least one component, where the at least one component is configured to be released post processing. In addition, an average diameter of the polyorganosiloxane shell is in a range of greater than about 1 micron to less than about 100 microns.

First claim

What is claimed is:

1 . A core-shell microsphere, comprising:
a polyorganosiloxane shell; and a core inside the shell, the core having a carrier and at least one component, wherein the at least one component is configured to be released post processing, wherein an average diameter of the polyorganosiloxane shell is in a range of greater than about 1 micron to less than about 100 microns.

2 . A core-shell microsphere as recited in claim 1 , wherein the average diameter of the polyorganosiloxane shell is in a range of greater than about 10 microns to less than about 30 microns.

3 . A core-shell microsphere as recited in claim 1 , wherein the polyorganosiloxane shell comprises polydimethylsiloxane diphenylsiloxane and a reinforcing filler.

4 . A core-shell microsphere as recited in claim 3 , wherein the reinforcing filler is selected from the group consisting of: trimethylsiloxysilicate graft polydimethylsiloxane and fumed silica.

5 . A core-shell microsphere as recited in claim 3 , wherein the at least one component comprises at least one material selected from the group consisting of:
a compound for pharmaceutical application, a monomer, an oligomer, a polymer, a catalyst, and a combination thereof.

6 . A core-shell microsphere as recited in claim 3 , wherein the carrier includes an oil, wherein the oil is at least partially immiscible with a siloxane resin.

7 . A method of forming a plurality of core-shell micro spheres as recited in claim 3 , the method comprising:
forming a homogenous first mixture comprising a cosolvent and a siloxane resin,
wherein the cosolvent comprises an oil and tetrahydrofuran,
wherein the siloxane resin comprises a siloxane prepolymer and a reinforcing filler;
emulsifying a second homogenous mixture with the first homogenous mixture,
wherein the second homogenous mixture is comprised of water and at least one selected from the group consisting of: thickener, a hydrophilic surfactant, and a combination thereof,
wherein the emulsifying forms a reinforced siloxane shell encapsulating the oil, wherein the reinforced siloxane shell comprises a reinforced siloxane resin; and
causing cross-linking of the reinforced siloxane resin within each reinforced siloxane shell to form core-shell microspheres,
wherein the core-shell microspheres are elastomeric.

8 . A core-shell microsphere as recited in claim 1 , wherein the carrier includes a liquid having a boiling point in a range of about 50° C. to about 200° C.

9 . A core-shell microsphere as recited in claim 8 , wherein the core-shell microsphere is a porogen.

10 . A core-shell microsphere as recited in claim 8 , wherein the core-shell microsphere has at least one core.

11 . A core-shell microsphere as recited in claim 8 , wherein the core-shell microsphere has greater than one core inside the shell.

12 . A core-shell microsphere as recited in claim 8 , wherein the liquid includes perfluorocarbon.

13 . A method of forming a plurality of core-shell microspheres as recited in claim 12 , the method comprising:
emulsifying the perfluorocarbon and a siloxane resin comprising a fluorinated surfactant for forming a first emulsion having a siloxane phase encapsulating the perfluorocarbon; emulsifying the first emulsion in an aqueous solution comprising at least one hydrophilic surfactant; and causing cross-linking within each siloxane phase to form a siloxane shell thereby forming unique core-shell microspheres, wherein the core-shell microspheres are elastomeric.

14 . A method as recited in claim 13 , wherein the siloxane resin includes a siloxane having a viscosity less than 2000 centiStokes.

15 . A method as recited in claim 14 , wherein the siloxane resin includes polydimethylsiloxane diphenylsiloxane (PDMS-DPS).

16 . A silicone-based ink for additive manufacturing, the ink comprising:
a vinyl-terminated diphenyl siloxane macromer; a treated silica hydrophobic reinforcing filler; a rheology modifying additive; and a plurality of core-shell microspheres.

17 . An ink as recited in claim 16 , wherein an average diameter of core-shell microspheres is in a range of greater than about 1 micron to less than about 100 microns.

18 . An ink as recited in claim 16 , wherein an average diameter of core-shell microspheres is in a range of greater than about 10 micron to less than about 30 microns.

19 . An ink as recited in claim 16 , wherein the core-shell microspheres comprise a polyorganosiloxane shell and a core inside the shell, the core having a carrier and at least one component, wherein the at least one component is configured to be released post processing.

20 . An ink as recited in claim 19 , wherein the polyorganosiloxane shell comprises polydimethylsiloxane diphenylsiloxane and a reinforcing filler.

21 . An ink as recited in claim 20 , wherein the reinforcing filler is trimethylsiloxysilicate graft polydimethylsiloxane.

22 . An ink as recited in claim 19 , wherein the at least one component comprises at least one material selected from the group consisting of: a compound for pharmaceutical application, a monomer, an oligomer, a polymer, a catalyst, and a combination thereof.

23 . An ink as recited in claim 19 , wherein the core-shell microspheres comprise a first core-shell microsphere and a second core-shell microsphere, wherein the at least one component of the first core-shell microsphere is different from the at least one component of the second core-shell microsphere.

24 . An ink as recited in claim 23 , wherein the at least one component of the first core-shell microsphere is configured to be released from the first core-shell microsphere at a first time, wherein the at least one component of the second core-shell microsphere is configured to be released from the second core-shell microsphere at a second time, wherein the first time is different from the second time.

25 . An ink as recited in claim 16 , wherein the ink is stable without crystallinity at temperatures down to −150° C.

26 . A product of additive manufacturing with a silicone-based ink having core-shell microspheres,
wherein the product has a plurality of continuous filaments, the product comprising: a vinyl-terminated siloxane macromer, a hydrophobic reinforcing filler, a rheology modifying additive, and a plurality of core-shell microspheres.

27 . A product as recited in claim 26 , wherein the product is a silicone-based three-dimensional structure,
wherein an average diameter of the filaments of the three-dimensional structure is greater than about 100 microns, wherein a ratio of an average diameter of core-shell microspheres to the average diameter of the filaments is in a range of greater than 1:100 to less than 3:4.

28 . A product as recited in claim 26 , wherein an average diameter of core-shell microspheres is in a range of greater than about 10 micron to less than about 30 microns.

29 . A product as recited in claim 26 , wherein the core-shell microspheres comprise a polyorganosiloxane shell and a core inside the shell, the core having a carrier and at least one component, wherein the at least one component is configured to be released post processing.

30 . A product as recited in claim 29 , wherein the at least one component comprises at least one material selected from the group consistin

Assignees

• L Livermore Nat Security Llc

Inventors

• Loeb Colin
• Duoss Eric B
• Lenhardt Jeremy
• Nguyen Du
• Wilson Thomas S

Classifications

• B33Y70/10

  Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials · CPC title

• B33Y80/00 Primary

  Products made by additive manufacturing · CPC title

• C09D11/03

  characterised by features other than the chemical nature of the binder · CPC title

• C09D11/102

  containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds · CPC title

• A61K9/5031 Primary

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide) · CPC title