Filamentary means for introducing agents into tissue of a living host

Abstract

The present invention provides a filamentary structure for the introduction of agents into a living host, comprising a filament comprising a solid core and a porous sheath which coats at least a portion of the solid core. When the filamentary structure is to be permanently implanted into a living host, both the solid core and the porous sheath are bioabsorbable. When the filamentary structure is to be temporarily implanted into the skin of a living host to deliver agents, such as cells, therein, the porous sheath is preferably bioabsorbable but the core need only be biocompatable, not bioabsorabable. The devices and methods of the present invention enable one to regenerate hair follicles, to introduce genetically altered cells or encapsulated cells to a living host transdermally, to regenerate bones, and to deliver drugs transdermally.

1 - 34 . (canceled)  
     
     
         35 . A method of facilitating the growth of new bone comprising the steps of: 
 a) providing an implantable device comprising a plurality of filaments, wherein each filament comprises a solid core and a porous sheath of a bioabsorbable material which coats at least a portion of the core;    b) seeding the implantable device osteogenic substance; and    c) implanting the device in a site where bone regeneration is desired.    
     
     
         36 . (canceled)  
     
     
         37 . The method of  claim 35 , wherein the core is removed from the implantable device before the device is implanted.  
     
     
         38 . The method of  claim 35  wherein the plurality of filaments forms a three-dimensional porous matrix.  
     
     
         39 . The method of  claim 35 , wherein the bioabsorbable sheath polymer is selected from the group consisting of poly(lactic acid), poly(glycolic acid), poly(trimethylene carbonate), poly(amino acid)s, tyrosine-derived poly(carbonate)s, poly(carbonate)s, poly(caprolactone), poly(para-dioxanone), poly(ester)s, poly(ester-amide)s, poly(anhydride)s, poly(ortho ester)s, proteins, carbohydrates, poly(ethylene glycol)s, poly(propylene glycol)s, poly(acrylate ester)s, poly(methacrylate ester)s, poly(vinyl alcohol), and copolymers, blends and mixtures of said polymers.  
     
     
         40 . The method of  claim 39 , wherein the bioabsorbable sheath polymer is poly(lactic acid).  
     
     
         41 . The method of  claim 35 , wherein the core comprises a ceramic.  
     
     
         42 . The method of  claim 35 , wherein the core comprises a glass.  
     
     
         43 . The method of  claim 35 , wherein the core comprises a metal.  
     
     
         44 . The method of  claim 35 , wherein the osteogenic substance comprises a cell selected from the group consisting of an osteoblast and a chondrocyte.  
     
     
         45 . The method of  claim 35 , wherein the implantable device is sculpted prior to implanting the device.  
     
     
         46 . The method of  claim 35 , wherein the site is an intervertebral space in the spine where fusion is desired.  
     
     
         47 . The method of  claim 35 , wherein the site is a bone defect or gap.  
     
     
         48 . The method of  claim 35 , wherein the implantable device is stored in a frozen state prior to implanting the device.  
     
     
         49 . An implantable device comprising a plurality of filaments and an osteogenic substance, wherein each filament comprises a solid core and a porous sheath of a bioabsorbable material which coats at least a portion of the core.  
     
     
         50 . The device of  claim 49 , wherein the plurality of filaments forms a three-dimensional porous matrix.  
     
     
         51 . The device of  claim 49 , wherein the bioabsorbable sheath polymer is selected from the group consisting of poly(lactic acid), poly(glycolic acid), poly(trimethylene carbonate), poly(amino acid)s, tyrosine-derived poly(carbonate)s, poly(carbonate)s, poly(caprolactone), poly(para-dioxanone), poly(ester)s, poly(ester-amide)s, poly(anhydride)s, poly(ortho ester)s, proteins, carbohydrates, poly(ethylene glycol)s, poly(propylene glycol)s, poly(acrylate ester)s, poly(methacrylate ester)s, poly(vinyl alcohol), and copolymers, blends and mixtures of said polymers.  
     
     
         52 . The device of  claim 51 , wherein the bioabsorbable sheath polymer is poly(lactic acid).  
     
     
         53 . The device of  claim 49 , wherein the core comprises a ceramic.  
     
     
         54 . The device of  claim 49 , wherein the core comprises a glass.  
     
     
         55 . The device of  claim 49 , wherein the core comprises a metal.  
     
     
         56 . The device of  claim 49 , wherein the osteogenic substance comprises a cell selected from the group consisting of an osteoblast and a chondrocyte.