Hydrogels and methods for their production

• US 7,297,726 B2
• Filed: 06/30/2004
• Issued: 11/20/2007
• Est. Priority Date: 04/10/2000
• Status: Expired due to Term

• Current Assignee: Amo Groningen B.V (Johnson & Johnson)
• Original Assignee: Amo Groningen B.V (Johnson & Johnson)
• Inventors: Pennings, Albert Johan, Spaans, Coenraad Jan, deGroot, Jacqueline Hermina
• Primary Examiner(s): Wu; David W.
• Assistant Examiner(s): SASTRI, SATYA B
• Application Number:
  US10/881,543
• Publication Number:
  US 20050008705A1
• Time in Patent Office: 1,238 Days
• Field of Search: 523/113, 523/106
• US Class Current: 523/113
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: C08F 261/00 Macromolecular compounds obtained by polymerising monomers on to polymers of oxygen-containing monomers as defined in group C08F16/00
• CPC Class Codes: C08F 261/04 on to polymers of vinyl alcohol
• CPC Class Codes: C08F 283/00 Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
• CPC Class Codes: C08F 283/006 on to polymers provided for in C08G18/00 C08F283/004 takes precedence
• CPC Class Codes: C08L 29/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 29/06 Copolymers of allyl alcohol

Abstract

The present invention relates to new hydrogels with improved mechanical properties and methods of their preparation. The hydrogels are formed from hydrophilic polymers having function hydroxyl groups and have low elasticity modulus typically less than about 10 kPa, a tensile strength above 1 Mpa, an elongation above 50% which makes suitable as medical implants, in particular intraocular lenses. The hydrogels are prepared by a crosslinking method with a comparatively low concentration of hydrophilic polymer of a sufficiently high molecular weight dissolved in a good solvent.

Claims

1. A method of preparing a hydrogel having a low elasticity modulus from a hydrophilic polymer, comprising the steps of:

(a) selecting a hydrophilic polymer of sufficiently high molecular weight, wherein the hydrophilic polymer has a hydroxyl group-carrying carbon-carbon backbone;

(b) dissolving said polymer in a solvent to a concentration not exceeding about 5% (wt);

(c) adding a crosslinking agent;

(d) mixing and reacting the polymer with the crosslinking agent; and

(e) evaporating said solvent; and

(f) optionally adding water.

2. A method according to claim 1 further comprising degassing the solution of polymer in solvent.

3. A method according to claim 1 further comprising the step of chemically modifying the polymer so as to reduce its hydrophilicity.

4. A method according to claim 1, wherein the hydrophilic polymer is at least one polymer selected from the group consisting of polyvinyl alcohol having the formula —

(CH₂—

CHOH)_n—

;

copolymer of ethylene and vinyl alcohol having the formula —

(CH₂—

CH₂)_n(CH₂—

CHOH)_m—

;

poly(1-hydroxy-1,3-propanediyl) having the formula —

(CH₂—

CH₂—

CHOH)_n—

; and

polyallyl alcohol having the formula —

(CH₂—

CH(CH₂OH))_n—

.

5. A method according to claim 1 further comprising modifying the hydrophilic polymer by reacting it with a mono-isocyanate.

6. A method according to claim 5 comprising modifying less than 15% of the hydroxyl groups.

7. A method according to claim 1 comprising performing the crosslinking at constant volume.

9. A method according to claim 5, comprising modifying less than 10% of the hydroxyl groups.

8. A method of preparing a hydrogel having a low elasticity modulus from a hydrophilic polymer, comprising the steps of:

(a) selecting hydrophilic polymer of sufficiently high molecular weight, wherein the hydrophilic polymer has a hydroxyl group-carrying carbon-carbon backbone;

(b) dissolving said polymer in a solvent to a concentration not exceeding about 5% (wt);

(c) adding a crosslinking agent;

(d) mixing and reacting the polymer with the crosslinking agent; and

(e) evaporating said solvent; and

(f) optionally adding water,

resulting in the formation of a hydrogel having an elasticity modulus less than about 10 kPa.

10. A method according to claim 8, resulting in the formation of a hydrogel having an elasticity modulus less than about 5 kPa.

11. A method of preparing a hydrogel having a low elasticity modulus from a hydrophilic polymer, comprising the steps of:

(a) selecting a hydrophilic polymer of sufficiently high molecular weight;

(b) dissolving said polymer in a solvent to a concentration not exceeding about 5% (wt);

(c) adding a diisocyanate crosslinking agent;

(d) mixing and reacting the polymer with the crosslinking agent; and

(e) evaporating said solvent; and

(f) optionally adding water.

12. A method of preparing a hydrogel having a low elasticity modulus from a hydrophilic (poly(1-hydroxy-1,3-propanediyl)) polymer, comprising the steps of:

(a) selecting a hydrophilic (poly(1-hydroxy-1,3-propanediyl)) polymer of sufficiently high molecular weight;

(b) dissolving said polymer in a solvent to a concentration not exceeding about 5% (wt);

(c) adding a crosslinking agent;

(d) mixing and reacting the polymer with the crosslinking agent; and

(e) evaporating said solvent; and

(f) optionally adding water.

13. A method according to claim 12 wherein the crosslinking agent is a diisocyanate.