Leland Stanford Junior University

The United States Government As Represented by the Department of Veterans Affairs

Laura Hartmann

Curtis W Frank

David Myung

Lampros Kourtis

Stuart Barry Goodman

Dennis R Carter

Jennifer R Cochran

Christopher N Ta

Stayce E Beck

Jean Noolandi

An arthroplasty device is provided having an interpenetrating polymer network (IPN) hydrogel that is strain-hardened by swelling and adapted to be held in place in a joint by conforming to a bone geometry. The strain-hardened IPN hydrogel is based on two different networks: (1) a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups, and (2) a non-silicone network of ionizable monomers. The second network was polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. Within the IPN, the degree of chemical cross-linking in the second network is less than in the first network. An aqueous salt solution (neutral pH) is used to ionize and swell the second network. The swelling of the second network is constrained by the first network resulting in an increase in effective physical cross-links within the IPN.

Hydrogel arthroplasty device

A strain-hardened interpenetrating polymer network (IPN) hydrogel is provided. The interpenetrating polymer network hydrogel is based on two different networks. The first network is a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups. The second network is a non-silicone network of ionizable monomers. The second network has been polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. An aqueous salt solution having a neutral pH is used to ionize and swell the second network in the interpenetrating polymer network. The swelling of the second network is constrained by the first network, and this constraining effect results in an increase in effective physical cross-links within the interpenetrating polymer network, and, in turn, an increase its elastic modulus. The strain-hardened interpenetrating polymer network hydrogel is attractive and useful for medical, industrial, and personal hygiene purposes.

Interpenetrating polymer network hydrogel

Surface modification methods for an interpenetrating polymer network (IPN) hydrogel to provide a basis for cell or tissue attachment are provided. The method involves the activation of functional groups on the surface of the IPN hydrogel. The activated functional groups are then reacted with amine-containing molecules or hydroxyl-containing molecules. The methods (i) can be performed in an aqueous environment and do not require the use of any organic solvent, (ii) do not require UV treatment, thereby avoiding denaturation of the IPN hydrogel or proteins, and/or (iii) can be performed as a one pot reaction.

Surface modification of interpenetrating polymer networks

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Berlin, Germany

Laura Hartmann