Patent ID: 7666339

Claim:
A method for augmentation or replacement of biological tissue, comprising injecting a hydrogel string to augment or replace the tissue, wherein the hydrogel string is formed and delivered using a device that has a gelation chamber in which a prepolymer is crosslinked to form a folly crosslinked hydrogel and from which the fully crosslinked formed hydrogel is extruded as a hydrogel string; wherein the prepolymer comprises two solutions, where one solution includes one component of a redox couple and the other solution includes the other component of the redox couple, and where at least one of the solutions includes macromers having a PVA backbone and at least two pendant chains bearing crosslinkable groups; and wherein the device is a coaxial microcatheter having an inner catheter slidable within an outer catheter, wherein the inner catheter does not extend all the way to the distal end of the outer catheter so that a gelation chamber is formed at the distal end of the outer catheter, wherein the hydrogel string is extruded from the catheter as prepolymer is moved into the gelation chamber, and wherein the distal tip of the outer catheter is substantially the same diameter as the gelation chamber.