Synthetic fibers for medical use and method of making the same

Abstract

A synthetic fiber is formed with a plurality of longitudinally-extending cavities ( 16, 54 and 64 ) which hold a medicament that is intended to be absorbed into tissue brought into contact with the fiber. The fiber can be formed by dissolving a soluble polymer component 14 of an extruded plural-component fiber 10, leaving cavities 16 that extend inward from the outer surface of the fiber in the locations of the dissolved polymer. After the fiber has been exposed to a solvent, the cavities left by the dissolved component are filled with a medicament 18. Specifically, the cavities are filled with a medicament that is mixed with a viscous carrier which solidifies within the cavities. The fibers can be used to make sutures, textile prostheses for insertion into the body, and epidermal pads and bandages. Fibers having internal cavities 64, i.e., cavities not extending to the external surface of the fiber, can be formed by extruding a single-component fiber 60 from a spinneret orifice 72 having a number of T-shaped slots extending from a central hub. A medicament is introduced into the internal cavities by soaking the fiber in a liquid containing the medicament. The internal-cavity fiber is therefore formed of polymer having some capability for liquid transport, e.g., nylon.

What is claimed is:  
     
         1 . A synthetic fiber for use in medical applications in which the fiber interacts with living tissue, comprising: 
 a polymer extending in a longitudinal direction and forming a basic structure of the fiber, said polymer having a plurality of longitudinally-extending cavities formed therein; and    a medicament disposed in the plurality of longitudinally-extending cavities.    
     
     
         2 . The synthetic fiber according to  claim 1 , wherein the fiber has a substantially circular transverse cross-sectional shape.  
     
     
         3 . The synthetic fiber according to  claim 1 , wherein said longitudinally-extending cavities are external cavities that extend inward into said polymer from an outer surface of said polymer.  
     
     
         4 . The synthetic fiber according to  claim 3 , wherein said longitudinally-extending cavities have a substantially circular transverse cross-sectional shape.  
     
     
         5 . The synthetic fiber according to  claim 3 , wherein said longitudinally-extending cavities have a transverse cross-sectional shape that is elongated in a radial direction.  
     
     
         6 . The synthetic fiber according to  claim 1 , wherein said longitudinally-extending cavities are internal cavities formed within said polymer, which do not extend to an outer surface of said polymer.  
     
     
         7 . The synthetic fiber according to  claim 6 , wherein said longitudinally-extending cavities have a substantially arcuate shape.  
     
     
         8 . The synthetic fiber according to  claim 7 , wherein said longitudinally-extending cavities are arranged in a ring within said polymer.  
     
     
         9 . The synthetic fiber according to  claim 1 , wherein said medicament is mixed with a viscous carrier forming a medicament/carrier mixture that substantially fills and solidifies within said longitudinally-extending cavities.  
     
     
         10 . The synthetic fiber according to  claim 1 , wherein said polymer comprises at least one of: an organic high polymer such as nylon, polyethylene terepthalate, and polypropylene; an absorbable polymer such as polymerized vinyl alcohol; and a co-polymer.  
     
     
         11 . A product comprising the synthetic fiber according to  claim 1 , selected from the group consisting of: sutures, textile prostheses, medicated epidermal pads, and bandages.  
     
     
         12 . A method of fabricating a synthetic fiber for medical use, comprising the steps of: 
 extruding a plural-component fiber from an orifice of a spinneret;    dissolving a soluble component of the plural-component fiber in a solvent, thereby forming longitudinally-extending cavities in a remaining polymer component of the fiber; and    securing a medicament in the longitudinally-extending cavities formed in the remaining polymer component of the fiber.    
     
     
         13 . The method according to  claim 12 , wherein: 
 said extruding step includes extruding the plural-component fiber as an island-in-the-sea bicomponent fiber, wherein the soluble component forms longitudinally-extending islands in a sea component that becomes the remaining polymer component;    said dissolving step includes dissolving the soluble component forming the islands, leaving the longitudinally-extending cavities in the location of the islands; and    said securing step includes filling the longitudinally-extending cavities with a mixture of the medicament and a viscous carrier, which mixture solidifies within the longitudinally-extending cavities.    
     
     
         14 . The method according to  claim 13 , wherein said extruding step includes extruding the bicomponent fiber with islands that form a portion of an outer surface of the bicomponent fiber, such that said dissolving step forms the longitudinally-extending cavities as external cavities that extend inward into said remaining polymer component from an outer surface of said remaining polymer component.  
     
     
         15 . The method according to  claim 14 , wherein said dissolving step produces longitudinally-extending cavities having a substantially circular transverse cross-sectional shape.  
     
     
         16 . The method according to  claim 14 , wherein said dissolving step produces longitudinally-extending cavities that have a transverse cross-sectional shape that is elongated in a radial direction.  
     
     
         17 . The method according to  claim 12 , wherein said extruding step includes extruding the fiber with a substantially circular transverse cross-sectional shape.  
     
     
         18 . The method according to  claim 12 , wherein said extruding step includes extruding a plural-component fiber comprising at least one of: an organic high polymer such as nylon, polyethylene terepthalate, and polypropylene; an absorbable polymer such as polymerized vinyl alcohol; and a co-polymer.  
     
     
         19 . A method of fabricating a synthetic fiber for medical use, comprising the steps of: 
 extruding a single-component fiber from an orifice of a spinneret, such that a plurality of longitudinally-extending cavities are formed in the single-component fiber; and    introducing a medicament into the longitudinally-extending cavities formed in the single-component fiber.    
     
     
         20 . The method according to  claim 19 , wherein said extruding step includes extruding the single-component fiber from an orifice having T-shaped slots extending radially from a central hole.  
     
     
         21 . The method according to  claim 19 , wherein the longitudinally-extending cavities are formed beneath an outer surface of the single-component fiber, such that the longitudinally-extending cavities are internal cavities.  
     
     
         22 . The method according to  claim 21 , wherein said introducing step includes soaking the single-component fiber in a solution containing the medicament.  
     
     
         23 . The method according to  claim 19 , wherein the longitudinally-extending cavities are formed as external cavities that extend inward into the single-component fiber from an outer surface of the single-component fiber.  
     
     
         24 . The method according to  claim 19 , wherein said extruding step includes extruding the single-component fiber with a substantially circular transverse cross-sectional shape.  
     
     
         25 . The method according to  claim 19 , wherein said extruding step includes extruding the single-component fiber which comprises at least one of: an organic high polymer such as nylon, polyethylene terepthalate, and polypropylene; an absorbable polymer such as polymerized vinyl alcohol; and a co-polymer.  
     
     
         26 . A method of fabricating a plural-component synthetic fiber for medical use, comprising the steps of: 
 mixing a medicament with a polymer to form a first fiber component;    feeding the first fiber component and a second fiber component to a spinneret in an island-in-the-sea arrangement; and    extruding an island-in-the-sea plural-component fiber from an orifice of a the spinneret, wherein longitudinally extending islands of the plural-component fiber are formed of the first fiber component and lie along an exterior surface of the plural-component fiber.