Strong, flexible, and thrombus-free woven nanotextile based vascular grafts, and method of production thereof

Abstract

The present invention relates to woven tubular nanotextiles, fabrication thereof using a weaving apparatus, and use thereof in vascular graft applications. The woven nanotextile conduit is 0.1 to 50 mm in diameter and includes a multitude of hierarchically arranged nanofibers. They are made from low strength bundled nanoyarns containing thousands of nanofibers with improved mechanical strength. The weaving apparatus interweaves the warp and weft yarns in longitudinal and transverse directions, resulting in a flexible and strong woven product. The physical and biological properties of the woven nanotextile were significantly enhanced when compared to non-woven nanofibrous form and conventional medical textiles. The nanotextile displayed superhydrophilic behavior in an otherwise hydrophobic material and when implanted as a vascular graft was robust, suturable, kink-proof and non-thrombogenic, with complete endothelialization of the graft luminal area.

What is claimed is: 
     
         1 . A vascular graft, comprising: a tubular woven nanotextile conduit in the diameter range of 0.1 to 50 mm comprising a plurality of warp yarns interwoven with a weft yarn, wherein each of the plurality of the warp yarns comprises a first set of polymeric yarn fibers with a diameter in the range of 1 to 1000 μm, wherein the weft yarn comprises a second set of polymeric yarn fibers with a diameter in the range of 1 to 5000 μm. 
     
     
         2 . The graft of  claim 1 , wherein the first and second set of polymeric yarn fibers comprises a polymer selected from the group of polyesters, polyether, polyanhydrides, polycarbonates, polyphosphazenes, poly(amino acids), polypeptides, glycosaminoglycan, polysaccharides, polydioxanone (PDO), poly(lactide-coglycolide) (PLGA), polyglycolic acid (PGA), polylactic acid (PLA), and polycaprolactone (PCL). 
     
     
         3 . The graft of  claim 1 , wherein the first and second set of polymeric yarn fibers further comprises biomolecules selected from the group of collagen, elastin, gelatin, fibrin, fibronectin, chitin, chitosan and laminin. 
     
     
         4 . The graft of  claim 1 , wherein individual fiber diameter of the yarn fibers is in the range of 10 to 5000 nm. 
     
     
         5 . The graft of  claim 1 , wherein the packing density of the conduit is in the range of 50 to 1000 interweaves per cm 2 . 
     
     
         6 . The graft of  claim 1 , wherein sidewall thickness of the graft is in the range of 100 to 750 μm. 
     
     
         7 . The graft of  claim 1 , wherein the first set and second set of polymeric yarn fibers are bundled polymeric yarn fibers. 
     
     
         8 . The graft of  claim 1 , wherein each yarn of the first set and second set of polymeric yarn fibers are electrospun polymeric yarn fibers. 
     
     
         9 . A method of preparing a tubular woven nanotextile conduit using an apparatus, comprising:
 providing a weaving apparatus for making woven nanotextile conduit, comprising:
 a drum assembly mounted on a supporting platform, the drum assembly comprising: 
 a first set of shuttling rods attached equidistant along the circumference of first disc; 
 a second set of shutting rods attached equidistant along the circumference of a second disc, wherein the first set and second set of shuttling rods are aligned to form a closed drum assembly; 
 a stationary carrier comprising a bobbin loaded with nano- or micro-fiber based polymeric weft yarn; 
 a plurality of movable carriers loaded in each of the first set of shuttling rods, wherein each of the movable carriers comprise bobbins loaded with nano- or micro-fiber based polymeric warp yarns, wherein the movable carriers are configured to shuttle between the first set of rods and the second set of rods on alignment thereby interlocking the nano- or micro-fiber based warp and weft yarn; and 
 a weaving rod of predetermined diameter mounted on the first disc, wherein the rod is configured to secure the warp yarns and the base weft yarns from the carriers at predetermined tension; and 
 the supporting platform comprising: a geared motor system configured for synchronous rotation of the first and second discs after shuttling of each movable carrier, 
   
       loading the plurality of movable carriers comprising bobbins loaded with nano or micro-fiber based warp yarn and the stationary carrier comprising the bobbin loaded with base weft yarn; 
       securing the warp yarns and weft yarn to the weaving rod at predetermined tension to form a starting point of the woven conduit; 
       aligning the first set of shuttling rods with the second set of shuttling rods; 
       shuttling one or more warp carriers across aligned shuttling rods to interlock with the base weft yarn; 
       rotating the first and second discs synchronously; and 
       repeating the shuttling and rotating steps to form a woven conduit.
 loading the plurality of movable carriers comprising bobbins loaded with nano or micro-fiber based warp yarn and the stationary carrier comprising bobbin loaded with base weft yarn; 
 securing the warp yarns and weft yarn to the weaving rod at predetermined tension to form a starting point of the woven conduit; 
 aligning the first set of shuttling rods with the second set of shuttling rods; 
 shuttling one or more warp carriers across aligned shuttling rods to interlock with the base weft yarn; 
 rotating the first and second discs synchronously; and 
 repeating the shuttling and rotating steps to form a woven conduit. 
 
     
     
         10 . The method of  claim 9 , wherein the curvature of the conduit is adjusted by changing the radius of curvature of the weaving rod. 
     
     
         11 . The method of  claim 9 , wherein the packing density of the conduit is controlled by varying the number of carriers or by changing the diameter of warp/weft yarns used in the weaving process. 
     
     
         12 . The method of  claim 9 , further comprising drawing the woven conduit continuously through an orifice in the apparatus.