Lubricious, biocompatible hydrophilic thermoset coating using interpenetrating hydrogel networks

Abstract

A medical electrical lead includes an insulative lead body extending from a distal region to a proximal region and a conductor disposed within the insulative lead body and extending from the proximal region to the distal region. An electrode is disposed on the insulative lead body and is in electrical contact with the conductor. The medical electrical lead also includes a cross-linked hydrophilic polymer coating disposed over at least a portion of the electrode. The cross-linked hydrophilic polymer coating includes a fibrous matrix comprising a plurality of discrete fibers and pores formed between at least a portion of the fibers and a hydrophilic polyethylene glycol-containing hydrogel network disposed within the pores of the fibrous matrix.

We claim: 
     
         1 . A medical electrical lead comprising:
 an insulative lead body extending from a distal region to a proximal region;   a conductor disposed within the insulative lead body and extending from the proximal region to the distal region;   an electrode disposed on the insulative lead body and in electrical contact with the conductor; and   a cross-linked hydrophilic polymer coating disposed over at least a portion of the electrode, the cross-linked hydrophilic polymer coating comprising:
 a fibrous matrix comprising a plurality of discrete fibers and pores formed between at least a portion of the fibers; and 
 a hydrophilic polyethylene glycol-containing hydrogel network disposed within the pores of the fibrous matrix. 
   
     
     
         2 . The medical electrical lead of  claim 1 , wherein the fibers of the fibrous matrix comprise a fluoropolymer. 
     
     
         3 . The medical electrical lead of  claim 2 , wherein the fibers of the fibrous matrix comprise a poly(vinylidene fluoride-co-hexafluoropropene) (PVDF HFP) polymer. 
     
     
         4 . The medical electrical lead of  claim 1 , wherein the fibers of the fibrous matrix comprise a poly(styrene-isobutylene-styrene) (SIBS) tri-block polymer. 
     
     
         5 . The medical electrical lead of  claim 1 , wherein the fibers of the fibrous matrix comprise one of a polyurethane, polycarbonate, polyether, polyester and a polyisobutylene (PIB) polymer. 
     
     
         6 . The medical electrical lead of  claim 1 , wherein the fibrous matrix is a nonwoven fibrous matrix. 
     
     
         7 . The medical electrical lead of  claim 1 , wherein the fibrous matrix is an electrospun fibrous matrix. 
     
     
         8 . The medical electrical lead of  claim 1 , wherein the hydrophilic polyethylene glycol-containing hydrogel comprises a polyethylene glycol (PEG) having a number molecular weight (M N ) range of about 400 g/mol to about 5,000 g/mol. 
     
     
         9 . The medical electrical lead of  claim 1 , wherein the hydrophilic polyethylene glycol-containing hydrogel comprises a polyethylene glycol (PEG) having a number molecular weight (M N ) range of about 5,000 g/mol to about 30,000 g/mol. 
     
     
         10 . The medical electrical lead of  claim 1 , wherein the hydrophilic polyethylene glycol-containing hydrogel network is disposed within at least a portion of the pores of the fibrous matrix, the pores forming a network that extends from a first surface of the fibrous matrix to a second surface of the fibrous matrix which is opposite the first surface. 
     
     
         11 . A medical electrical lead comprising:
 an insulative lead body extending from a distal region to a proximal region;   a conductor disposed within the insulative lead body and extending from the proximal region to the distal region;   an electrode disposed on the insulative lead body and in electrical contact with the conductor; and   a cross-linked hydrophilic polymer coating disposed over at least a portion of the lead body, the cross-linked hydrophilic polymer coating comprising:
 a fibrous matrix comprising a plurality of discrete fibers and pores formed between at least a portion of the fibers; and 
 a hydrophilic polyethylene glycol-containing hydrogel network disposed within the pores of the fibrous matrix. 
   
     
     
         12 . A method of forming a cross-linked hydrophilic coating on an implantable medical electrical lead having an insulative lead body and an electrode disposed on the insulative lead body, the method comprising:
 disposing within at least a portion of pores of a nonwoven fibrous matrix a hydrogel comprising at least one polyethylene glycol containing polymer, such that the hydrogel continuously extends from a first surface to an opposite second surface of the nonwoven fibrous matrix; and   curing the hydrogel to the nonwoven fibrous matrix to form the cross-linked hydrophilic coating.   
     
     
         13 . The method of  claim 12 , wherein the hydrogel is cured using one of a thermoinitiator and a photoinitiator curing initiator. 
     
     
         14 . The method of  claim 13 , wherein the hydrogel is cured using benzoyl peroxide. 
     
     
         15 . The method of  claim 12 , further comprising forming the nonwoven fibrous matrix by using one of an electrospinning process and a melt blowing process. 
     
     
         16 . The method of  claim 12 , further comprising plasma treating the nonwoven fibrous matrix prior to applying the hydrogel to the nonwoven fibrous matrix. 
     
     
         17 . The method of  claim 12 , further comprising disposing the hydrogel within at least a portion of the pores by one of dip coating, roll coating, spray coating, drop coating, and flow coating. 
     
     
         18 . The method of  claim 12 , further comprising disposing the cross-linked hydrophilic coating onto the electrode. 
     
     
         19 . The method of  claim 18 , further comprising disposing the cross-linked hydrophilic coating onto the electrode before the electrode is assembled onto the implantable medical electrical lead. 
     
     
         20 . The method of  claim 12 , further disposing within at least a portion of pores of a nonwoven fibrous matrix the hydrogel such that the hydrogel covers at least a portion of the surfaces of fibers of the nonwoven fibrous matrix.