Molds used to produce pva hydrogel implants and related implants

Abstract

Methods of fabricating elastomeric implants employ a mold with PVA crystals and irrigant added to the mold independent of each other. Related molds are also described.

1 . A medical device fabrication mold, comprising:
 a mold having a three-dimensional mold cavity with a target shape, the mold cavity having an upstanding sidewall and a releasably attachable floor and ceiling;   at least one mesh layer disposed in the mold cavity; and   a quantity of polyvinyl alcohol (PVA) material and irrigation fluid disposed in the mold cavity over the at least one mesh layer to form a hydrogel body, such that, during exposure to heat, the PVA permeates the at least one mesh layer to integrally attach the mesh layer to the hydrogel implant body to define a molded medical device.   
     
     
         2 . A mold according to  claim 1 , wherein the at least one mesh layer comprises three mesh liner layers in the mold cavity, one configured to at least partially cover the floor, one configured to at least partially cover the upstanding sidewall, and one configured to at least partially reside under the ceiling over the quantity of polyvinyl alcohol material and irrigation fluid in the mold cavity. 
     
     
         3 . A mold according to  claim 1 , wherein the mold cavity three-dimensional shape substantially corresponds to a shape of a natural spinal disc, and wherein the mold is configured to produce an implantable TDR spinal disc prosthesis. 
     
     
         4 . A mold according to  claim 1 , wherein the releasably attachable ceiling comprises a reservoir and vent path, the vent path in fluid communication with the mold cavity, and the mold further comprises a releasable vent plug sealably attached to the vent path. 
     
     
         5 . A mold according to  claim 1 , wherein the mold is configured to produce a soft tissue implant. 
     
     
         6 . A mold according to  claim 1 , wherein the mold is configured to produce one of the following medical devices: a vascular graft, a heart valve, esophageal tissue, skin, corneal tissue, cartilage, meniscus, tendon and cartilage replacement. 
     
     
         7 . A mold according to  claim 1 , wherein the mold is configured to define a tissue expander. 
     
     
         8 . A mold according to  claim 1 , wherein the mold is configured to define an implantable drug delivery device. 
     
     
         9 . A medical implant mold comprising:
 a mold body having a three dimensional shape and a mold cavity;   a releaseable lid attached to the mold body, the lid comprising a liquid reservoir;   a vent path extending through the lid in fluid communication with the mold cavity and the liquid reservoir; and   a releasably attachable vent plug sealably attached to the vent path.   
     
     
         10 . An implant according to  claim 9 , further comprising a plurality of elongate mold attachment members with heads, the elongate members extending through the lid to releasably sealably attach the lid to the mold body; and
 a plurality of springs, one residing between a respective elongate member head and lid to thereby allow for variation in volume in the cavity during thermal processing while keeping the mold body and lid attached.   
     
     
         11 . A medical implant mold according to  claim 9 , further comprising PVA material held in the sealed mold. 
     
     
         12 . A medical implant mold according to  claim 11 , wherein the mold defines a total disc replacement implant. 
     
     
         13 . A medical implant mold according to  claim 11 , further comprising at least one of calcium sulfate, mesh material and reinforcing material disposed in the mold. 
     
     
         14 . A medical implant mold according to  claim 12 , further comprising at least one radiopaque marker disposed in the sealed mold. 
     
     
         15 . A medical implant mold according to  claim 11 , wherein the mold is configured to produce a soft tissue implant. 
     
     
         16 . A medical implant mold according to  claim 11 , wherein the mold is configured to produce one of the following medical devices: a vascular graft, a heart valve, esophageal tissue, skin, corneal tissue, cartilage, meniscus, tendon and cartilage replacement. 
     
     
         17 . A medical implant mold according to  claim 11 , wherein the mold is configured to define a tissue expander. 
     
     
         18 . A medical implant mold according to  claim 11 , wherein the mold is configured to define an implantable drug delivery device. 
     
     
         19 . A medical implant formed by the following method:
 introducing a quantity of PVA material into a mold cavity of a mold;   inserting a quantity of saline into the mold cavity independently of the introduction of the PVA material;   placing a lid on the mold to close the mold cavity with the PVA material and saline;   heating the mold for a desired time and temperature so that the PVA material and saline reach a desired temperature and form a molded body;   cooling the mold with the molded body after the heating step; and   forming a medical PVA hydrogel implant.   
     
     
         20 . A medical implant according to  claim 19 , wherein the implant consists essentially of molded polyvinylalcohol (PVA) cryogel with an integral external covering fused to the implant by the PVA. 
     
     
         21 . A molded PVA medical implant formed by the following method:
 placing a lid on a mold to substantially close a mold cavity;   introducing a quantity of PVA material into the mold cavity before or after the placing step; then   inserting a quantity of liquid through a vent path extending through the mold lid after the lid is placed on the mold whereby the liquid enters the mold and contacts the PVA material; then   sealing the vent path; then   heating the mold for a desired time and temperature so that the PVA and liquid reach a desired temperature and form a molded body;   cooling the mold with the molded body after the heating step; and   forming a medical PVA hydrogel implant,   wherein the introducing and inserting steps are carried out so that the PVA and liquid are introduced to the mold independently of each other and are subsequently mixed in the sealed mold during the heating step to carry out the forming step to form the molded PVA hydrogel implant.