Three-dimensional polymer networks and their use
The disclosure provides three-dimensional cross-linked polymer networks transport channels, arrays comprising the networks, processes for making the networks, and uses of the networks and arrays.
1. A process for making a three-dimensional hydrogel network having one or more transport channels, comprising:
(a) exposing an aqueous salt-polymer solution to salt crystal forming conditions, the aqueous-polymer salt solution comprising:
(i) at least two types of monovalent metal ions having a total concentration of at least 500 mM, and
(ii) water-soluble polymer chains each comprising at least one cross-linker group,
thereby forming a mixture containing one or more salt crystals;
(b) exposing the mixture containing one or more salt crystals to cross-linking conditions, thereby forming a hydrogel containing one or more salt crystals; and
(c) contacting the hydrogel containing one or more salt crystals with a solvent in which the one or more salt crystals are soluble, thereby dissolving the salt crystals;
thereby forming the three-dimensional hydrogel network having one or more transport channels.
2. The process of claim 1 , wherein the aqueous salt-polymer solution is positioned on the surface of a substrate when exposed to the salt crystal forming conditions.
3. The process of claim 1 , wherein the aqueous salt-polymer solution comprises at least two types of monovalent metal ions having a total concentration of 500 mM to 1000 mM.
4. The process of claim 3 , wherein the aqueous salt-polymer solution comprises sodium ions at a concentration of 200 mM or greater and potassium ions at a concentration of 150 mM or greater.
5. The process of claim 4 , wherein:
(a) the concentration of sodium ions ranges from 300 mM to 400 mM; and
(b) the concentration of potassium ions ranges from 200 mM to 350 mM.
6. The process of claim 1 , which further comprises, prior to step (a), forming the aqueous salt-polymer solution by combining an aqueous salt solution comprising monovalent metal cations and one or more polymer solutions comprising the water-soluble polymer chains.
7. The process of claim 6 , wherein the aqueous salt solution has a pH ranging from 6 to 9.
8. The process of claim 6 , wherein the aqueous salt solution is produced by a process comprising dissolving disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate in water.
9. The process of claim 1 , wherein the water-soluble polymer chains comprise methacrylate groups and at least two cross-linker groups per molecule.
10. The process of claim 9 , wherein the cross-linker groups are benzophenone moieties.
11. The process of claim 9 , wherein the water-soluble polymer chains are polymerized from dimethylacrylamide (DMAA), methacryloyloxybenzophenone (MABP), and sodium 4-vinylbenzenesulfonate (SSNa).
12. The process of claim 1 , wherein the aqueous salt-polymer solution of step (a) further comprises probe molecules.
13. The process of claim 12 , wherein the probe molecules are nucleic acid molecules.
14. The process of claim 13 , wherein the aqueous salt-polymer solution is positioned on the surface of a substrate when exposed to the salt crystal forming conditions.
15. The process of claim 13 , wherein the aqueous salt-polymer solution comprises at least two types of monovalent metal ions having a total concentration of 500 mM to 1000 mM.
16. The process of claim 15 , wherein the aqueous salt-polymer solution comprises sodium ions at a concentration of 200 mM or greater and potassium ions at a concentration of 150 mM or greater.
17. The process of claim 16 , wherein:
(a) the concentration of sodium ions ranges from 300 mM to 400 mM; and
(b) the concentration of potassium ions ranges from 200 mM to 350 mM.
18. The process of claim 13 , which further comprises, prior to step (a), forming the aqueous salt-polymer solution by combining an aqueous salt solution comprising monovalent metal cations and one or more polymer solutions comprising the water-soluble polymer chains, and the probe molecules.
19. The process of claim 18 , wherein the aqueous salt solution is produced by a process comprising dissolving disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate in water.
20. The process of claim 13 , wherein the water-soluble polymer chains comprise methacrylate groups and at least two cross-linker groups per molecule.
21. The process of claim 20 , wherein the cross-linker groups are benzophenone moieties.
22. The process of claim 20 , wherein the water-soluble polymer chains are polymerized from dimethylacrylamide (DMAA), methacryloyloxybenzophenone (MABP), and sodium 4-vinylbenzenesulfonate (SSNa).
23. A process for making an array, comprising generating a plurality of three-dimensional hydrogel networks by the process of claim 1 at discrete spots on the surface of the same substrate and cross-linking the networks to the substrate during step (b).