Phase transitioning hydrogels
View Patent ↗A method of forming and the resulting hydrogel composition comprising poly(vinyl alcohol) at a final concentration of about 20% (w/w) to about 65% (w/w) and polyethylene glycol at a final concentration of about 2% (w/w) to about 20% (w/w), wherein the hydrogel composition has a total polymer content, above about 30% (w/w), higher than the total polymer content of a precursor polymer solution formulated prior to the formulation of the hydrogel composition. The hydrogel composition may further comprise poly(vinyl pyrrolidone) at a final concentration of about 0.10% (w/w) to about 0.75% (w/w).
1. A hydrogel composition comprising polyvinyl alcohol having a molecular weight of about 145,000 Da mixed together with water and polyethylene glycol, and separated into a solid phase and a liquid supernatant phase, wherein the solid phase comprises a total polymer content of about 70% to about 80% by weight of the solid phase and water in an amount of about 20% to about 30% by weight of the solid phase, wherein the liquid supernatant phase comprises a total polymer content of about 33% to about 42% by weight of the liquid supernatant phase and water in an amount of about 58% to about 67% by weight of the liquid supernatant phase, and wherein the total polymer content in the solid phase comprises about 20% to about 65% by weight of polyvinyl alcohol and about 2% to about 20% by weight of polyethylene glycol, wherein the hydrogel composition has a compressive chord modulus of about 450 kPa to about 5,000 kPa.
2. The hydrogel composition of claim 1 , wherein the composition further comprises polyvinyl pyrrolidone mixed together with the polyvinyl alcohol, water, and polyethylene glycol, and wherein the total polymer content in the solid phase comprises about 0.10% to about 0.75% by weight of polyvinyl pyrrolidone.
3. The hydrogel composition of claim 1 , wherein the hydrogel composition has an osmotic pressure of at least 0.1 MPa.
4. The hydrogel composition of claim 1 , wherein the hydrogel composition has a compressive chord modulus of about 450 kPa to about 2,500 kPa.
5. The hydrogel composition of claim 1 , wherein the hydrogel composition has a viscosity at 45° C. of about 0.02 kP to about 2.0 kP.
6. The hydrogel composition of claim 1 , wherein the hydrogel composition has a viscosity at 37° C. of at least 0.475 kP.
7. The hydrogel composition of claim 1 , wherein the composition further comprises a radiopaque component mixed together with the poly(vinyl alcohol), water, and polyethylene glycol.
8. The hydrogel composition of claim 7 , wherein the radiopaque component is barium sulfate.
9. A hydrogel composition comprising polyvinyl alcohol having a molecular weight of about 145,000 Da mixed together with water and polyethylene glycol, the hydrogel composition formulated by first preparing and heating an aqueous solution of polyvinyl alcohol, then adding the polyethylene glycol to form a precursor polymer solution, cooling the precursor polymer solution, and allowing a phase separation to occur, thereby producing the hydrogel composition comprising a solid phase and a liquid supernatant phase, wherein the solid phase comprises a total polymer content of about 70% to about 80% by weight of the solid phase and water in an amount of about 20% to about 30% by weight of the solid phase, wherein the liquid supernatant phase comprises a total polymer content of about 33% to about 42% by weight of the liquid supernatant phase and water in an amount of about 58% to about 67% by weight of the liquid supernatant phase, and wherein the total polymer content in the solid phase comprises about 20% to about 65% by weight of polyvinyl alcohol and about 2% to about 20% by weight of polyethylene glycol, and optionally removing the liquid supernatant phase, wherein the hydrogel composition has a compressive chord modulus of about 450 kPa to about 5,000 kPa.
10. The hydrogel composition of claim 9 , wherein the composition further includes polyvinyl pyrrolidone, and the polyvinyl pyrrolidone is mixed together with the aqueous solution of polyvinyl alcohol prior to heating the aqueous solution.
11. The hydrogel composition of claim 10 , wherein the total polymer content in the solid phase comprises about 0.10% to about 0.75% by weight of polyvinyl pyrrolidone.
12. The hydrogel composition of claim 9 , wherein the precursor polymer solution comprises a ratio of polyvinyl alcohol to polyethylene glycol of about 1:10 to about 20:1.
13. The hydrogel composition of claim 10 , wherein the precursor polymer solution comprises a ratio of polyvinyl alcohol to polyethylene glycol of about 1:10 to about 20:1.
14. The hydrogel composition of claim 9 , wherein the total polymer content in the solid phase comprises about 29% to about 35% by weight of polyvinyl alcohol.
15. The hydrogel composition of claim 9 , wherein the total polymer content in the solid phase comprises about 6% to about 8% by weight of polyethylene glycol.
16. The hydrogel composition of claim 9 , wherein the hydrogel composition has an osmotic pressure of at least 0.1 MPa.
17. The hydrogel composition of claim 9 , wherein the hydrogel composition has a compressive chord modulus of about 450 kPa to about 2,500 kPa.
18. The hydrogel composition of claim 9 , wherein the hydrogel composition has a viscosity at 45° C. of about 0.02 kP to about 2.0 kP.
19. The hydrogel composition of claim 9 , wherein the hydrogel composition has a viscosity at 37° C. of at least 0.475 kP.
20. The hydrogel composition of claim 9 , wherein the composition further includes barium sulfate mixed with the hydrogel composition.
21. The hydrogel composition of claim 1 , wherein the hydrogel is a biocompatible hydrogel for intervertebral disc replacement.
22. The hydrogel composition of claim 1 , wherein the polyethylene glycol has a molecular weight of about 10,000 Da.
23. The hydrogel composition of claim 9 , wherein the polyethylene glycol has a molecular weight of about 10,000 Da.