Methods for photopatterning hydrogels
In one aspect, the invention provides methods for forming a photopatterned hydrogel. In some embodiments, the methods comprise the step of exposing a solution comprising a monomer, a crosslinking agent, and a photoinitiator to a pattern of light comprising a first and a second light intensity for a period of time and under suitable conditions for the first light intensity to induce essentially complete conversion of polymerizable groups on the monomer and the crosslinking agent to form a patterned hydrogel, and for the second light intensity to induce partial conversion of the polymerizable groups on the monomer and the crosslinking agent to form partially polymerized polymers that remain soluble. In some embodiments, the first light intensity is lower than the second light intensity. In another aspect, the invention provides methods for forming porous, photopatterned hydrogels.
1. A method for forming a photopatterned hydrogel, comprising the step of:
exposing a solution comprising a monomer, a crosslinking agent, and a photoinitiator to a pattern of light comprising a first and a second light intensity for a period of time and under suitable conditions for the first light intensity to induce essentially complete conversion of polymerizable groups on the monomer and the crosslinking agent to form a patterned hydrogel, and for the second light intensity to induce partial conversion of the polymerizable groups on the monomer and the crosslinking agent to form partially polymerized polymers that remain soluble.
2. The method of claim 1 , wherein the first light intensity is lower than the second light intensity.
3. The method of claim 1 , wherein the monomer is selected from the group consisting of a methacrylates derivative, an acrylate derivative, ethylene, a diene, a styrene, a halogenated olefin, a vinyl ester, an acrylonitrile, an acrylamide, an n-vinyl pyrrolidone, and a mixture thereof.
4. The method of claim 3 , wherein the methacrylate derivative is selected from the group consisting of 2-hydroxyethyl methacrylate, methyl methacrylate, methacrylic acid, n-butyl methacrylate, glycidyl methacrylate, n-propyl methacrylate, poly(ethylene glycol)monomethacrylate, and a mixture thereof.
5. The method of claim 3 , wherein the acrylate derivative is selected from the group consisting of 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, acrylic acid, n-butyl acrylate, glycidyl acrylate, n-propyl acrylate, poly(ethylene glycol)monoacrylate, and a mixture thereof.
6. The method of claim 1 , wherein the crosslinking agent is selected from the group consisting of tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, dipropylene glycol dimethacrylate, dipropylene glycol diacrylate, poly(ethylene glycol)dimethacrylate, poly(ethylene glycol)diacrylate, bisacrylamide, and a mixture thereof.
7. The method of claim 1 , wherein the photoinitiator is selected from the group consisting of 2,2-dimethoxy acetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propoanone, 2-hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone, and a mixture thereof.
8. The method of claim 1 , wherein the photopatterned hydrogel is degradable.
9. The method of claim 8 , wherein the crosslinking agent is hydrolytically degradable.
10. The method of claim 9 , wherein the hydrolytically degradable crosslinking agent is selected from the group consisting of poly(ε-caprolactone)-b-tetraethylene glycol-b-poly(ε-caprolactone) dimethacrylate, poly(ε-caprolactone)-b-poly(ethylene glycol)-b-poly(ε-caprolactone)dimethacrylate, poly(lactic acid)-b-tetraethylene glycol-b-poly(lactic acid) dimethacrylate, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) dimethacrylate, poly(glycolic acid)-b-tetraethylene glycol-b-poly(glycolic acid)dimethacrylate, poly(glycolic acid)-b-poly(ethylene glycol)-b-poly(glycolic acid)dimethacrylate, poly(ε-caprolactone)-b-tetraethylene glycol-b-poly(ε-caprolactone)diacrylate, poly(ε-caprolactone)-b-poly(ethylene glycol)-b-poly(ε-caprolactone)diacrylate, poly(lactic acid)-b-tetraethylene glycol-b-poly(lactic acid)diacrylate, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid)diacrylate, poly(glycolic acid)-b-tetraethylene glycol-b-poly(glycolic acid)diacrylate, poly(glycolic acid)-b-poly(ethylene glycol)-b-poly(glycolic acid)diacrylate, and a mixture thereof.
11. The method of claim 1 , wherein the photopatterned hydrogel has a thickness greater than about 25 micrometers.
12. The method of claim 1 , wherein the photopatterned hydrogel has a thickness between about 50 micrometers and about 1200 micrometers.
13. A method for forming a photopatterned hydrogel, comprising the step of:
exposing a solution comprising a monomer, a cross-linking agent, and a photoinitiator to a pattern of light comprising a first and a second light intensity for a period of time under suitable conditions to form a photopatterned hydrogel defined by regions of the solution exposed to the first light intensity, wherein the first light intensity is lower than the second light intensity.
14. A method for forming a porous, photopatterned hydrogel, comprising the steps of:
(a) exposing a plurality of porogens in a solution comprising a monomer, a crosslinking agent, and a photoinitiator to a pattern of light comprising a first and a second light intensity for a period of time under suitable conditions for the first light intensity to induce essentially complete conversion of polymerizable groups on the monomer and the crosslinking agent to form a patterned hydrogel, and for the second light intensity to induce partial conversion of polymerizable groups on the monomer and the crosslinking agent to form polymers that remain soluble; and
(b) removing the plurality of porogens to form a porous, photopatterned hydrogel.
15. The method of claim 14 , wherein the first light intensity is lower than the second light intensity.
16. The method of claim 14 , wherein the monomer is selected from the group consisting of a methacrylates derivative, an acrylate derivative, ethylene, a diene, a styrene, a halogenated olefin, a vinyl ester, an acrylonitrile, an acrylamide, an n-vinyl pyrrolidone, and a mixture thereof.
17. The method of claim 14 , wherein the crosslinking agent is selected from the group consisting of tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, dipropylene glycol dimethacrylate, dipropylene glycol diacrylate, poly(ethylene glycol)dimethacrylate, poly(ethylene glycol)diacrylate, bisacrylamide, and a mixture thereof.
18. The method of claim 14 , wherein the photoinitiator is selected from the group consisting of 2,2-dimethoxy acetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propoanone, 2-hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone, and a mixture thereof.
19. The method of claim 14 , wherein the porous, photopatterned hydrogel is degradable.
20. The method of claim 19 , wherein the crosslinking agent is hydrolytically degradable.
21. The method of claim 20 , wherein the hydrolytically degradable crosslinking agent is selected from the group consisting of poly(ε-caprolactone)-b-tetraethylene glycol-b-poly(ε-caprolactone)dimethacrylate, poly(ε-caprolactone)-b-poly(ethylene glycol)-b-poly(ε-caprolactone)dimethacrylate, poly(lactic acid)-b-tetraethylene glycol-b-poly(lactic acid)dimethacrylate, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid)dimethacrylate, poly(glycolic acid)-b-tetraethylene glycol-b-poly(glycolic acid)dimethacrylate, poly(glycolic acid)-b-poly(ethylene glycol)-b-poly(glycolic acid)dimethacrylate, poly(ε-caprolactone)-b-tetraethylene glycol-b-poly(ε-caprolactone)diacrylate, poly(ε-caprolactone)-b-poly(ethylene glycol)-b-poly(ε-caprolactone)diacrylate, poly(lactic acid)-b-tetraethylene glycol-b-poly(lactic acid)diacrylate, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) diacrylate, poly(glycolic acid)-b-tetraethylene glycol-b-poly(glycolic acid)diacrylate, poly(glycolic acid)-b-poly(ethylene glycol)-b-poly(glycolic acid)diacrylate, and a mixture thereof.
22. The method of claim 14 , wherein the porous, photopatterned hydrogel has a thickness between about 50 micrometers and about 1200 micrometers.
23. A method for forming a porous, photopatterned hydrogel, comprising the steps of:
(a) exposing a plurality of porogens in a solution comprising a monomer, a crosslinking agent, and a photoinitiator to a pattern of light comprising a first and a second light intensity for a period of time under suitable conditions to form a photopatterned hydrogel defined by regions of the solution exposed to the first light intensity, wherein the first light intensity is lower than the second light intensity; and
(b) removing the plurality of porogens to form a porous, photopatterned hydrogel.