Hydrogel balloon prosthesis for nucleus pulposus
First Claim
1. A prosthesis for replacing or supplementing a nucleus pulposus of an intervertebral disk, comprising a pre-formed expandable balloon having flexible walls defining an inner cavity, the flexible walls having a thickness from about 0.02 mm to about 1.00 mm and a filling tube passing through the flexible walls and in communication with the inner cavity so that the prosthesis is fillable, said pre-formed balloon being adapted to be inserted into the intervertebral disk through a cannula, wherein said flexible walls are made from a material comprising a cryogel formed from subjecting an aqueous solution comprising poly (vinyl alcohol) to repeated freeze-thaw cycles, said expandable pre-formed balloon being filled through the filling tube with a biocompatible material selected from the group consisting of a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel in an expanded configuration, and the prosthesis having a tensile modulus of about 0.02 MPa to about 0.8 MPa at 30% strain.
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0 Petitions
Accused Products
Abstract
A prosthesis for replacing or supplementing a nucleus pulposus of an intervertebral disk is an expandable container having flexible walls, the container being adapted to be inserted into a central cavity of an intervertebral disk through a narrow cannula, and the flexible walls are made from a biocompatible hydrogel. A preferred hydrogel is a cryogel formed from an aqueous solution of poly(vinyl alcohol) and poly(vinyl pyrrolidone). The prosthesis may be prepared by dip-coating a mandrel with an aqueous solution of a hydrogel-forming polymer or mixture of such polymers, gelling the coated solution by chilling, and subjecting the gelled coating to a series of repeated freeze-thaw treatments. In use, the prosthesis is inserted into a central cavity of an intervertebral disk and filled with biocompatible material, e.g., a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel, particularly a thermogelling hydrogel.
40 Citations
18 Claims
- 1. A prosthesis for replacing or supplementing a nucleus pulposus of an intervertebral disk, comprising a pre-formed expandable balloon having flexible walls defining an inner cavity, the flexible walls having a thickness from about 0.02 mm to about 1.00 mm and a filling tube passing through the flexible walls and in communication with the inner cavity so that the prosthesis is fillable, said pre-formed balloon being adapted to be inserted into the intervertebral disk through a cannula, wherein said flexible walls are made from a material comprising a cryogel formed from subjecting an aqueous solution comprising poly (vinyl alcohol) to repeated freeze-thaw cycles, said expandable pre-formed balloon being filled through the filling tube with a biocompatible material selected from the group consisting of a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel in an expanded configuration, and the prosthesis having a tensile modulus of about 0.02 MPa to about 0.8 MPa at 30% strain.
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10. A method of replacing or supplementing a nucleus pulposus of an intervertebral disk, comprising the steps of:
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(i) providing a pre-formed flexible-walled balloon having an inner cavity, flexible walls defining the inner cavity, the flexbile walls having a thickness from about 0.02 mm to about 1.00 mm and a filling tube passing through the flexible walls and in communication with the inner cavity so that the prosthesis is fillable, the flexible walls made from a cryogel formed from subjecting an aqueous solution comprising poly (vinyl alcohol) to repeated freeze-thaw cycles, (ii) inserting the pre-formed flexible-walled balloon into the intervertebral disk by a minimally invasive surgical procedure in a collapsed configuration, and (iii) introducing into said inner cavity through said filling tube of said pre-formed flexible-walled balloon a biocompatible material selected from the group consisting of a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel for expanding said pre-formed balloon into an expanded configuration to replace or supplement the nucleus pulposus, the filled balloon in the expanded configuration having a tensile modulus of about 0.02 MPa to about 0.8 MPa at 30% strain. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification