Method of Manufacturing Fibrous Hemostatic Bandages

Abstract

A method of manufacturing a sturdy and pliable fibrous hemostatic dressing by making fibers that maximally expose surface area per unit weight of active ingredients as a means for aiding in the clot forming process and as a means of minimizing waste of active ingredients. The method uses a rotating object to spin off a liquid biocompatible fiber precursor, which is added at its center. Fibers formed then deposit on a collector located at a distance from the rotating object creating a fiber layer on the collector. An electrical potential difference is maintained between the rotating disk and the collector. Then, a liquid procoagulation species is introduced at the center of the rotating disk such that it spins off the rotating disk and coats the fibers.

1 . A method of making a hemostatic dressing using a rotating object comprising,
 (a) introducing a liquid biocompatible fiber precursor containing one or more active biological or abiological procoagulation species at the center of the rotating object such that the liquid can spin off the rotating object and form a first set of fibers;   (b) depositing fibers from the first set of fibers onto a collector positioned at a distance from the rotating object such that a layer of fibers is created and wherein an electrical potential difference is maintained between the rotating object and the collector;   (c) introducing a liquid biocompatible fiber precursor containing one or more active biological or abiological procoagulation species different from those in step (a) at the center of the rotating object such that the liquid can spin off the rotating object and form a second set of fibers; and,   (d) depositing fibers from the second set of fibers onto the collector.   
   
   
       2 . The method of  claim 1  wherein the step of depositing fibers from the second set of fibers onto the collector is performed such that the fibers from the second set of fibers are deposited over the fibers from the first set of fibers on the collector. 
   
   
       3 . The method of  claim 1  wherein the step of depositing fibers from the second set of fibers onto the collector is performed such that these fibers are deposited onto the collector at a location different from the fibers from first set of fibers and further comprising the step of combining the fibers from the first set of fibers on the collector with the fibers from the second set of fibers on the collector. 
   
   
       4 . The method of  claim 1  further comprising the step of drying the fibers from the first set of fibers deposited on the collector before depositing fibers from the second set of fibers. 
   
   
       5 . A method of making a hemostatic dressing using a rotating object comprising,
 (a) introducing a liquid biocompatible fiber precursor at the center of the rotating object such that the liquid can spin off the rotating object and form fibers;   (b) depositing fibers so formed onto a collector positioned at a distance from the rotating object such that such that a layer of fibers is created and wherein an electrical potential difference is maintained between the rotating object and the collector; and,   (c) coating the fibers with one or more procoagulation species.   
   
   
       6 . The method of  claim 5  wherein the step of coating the fibers with one or more procoagulation species is performed by a method selected from a group consisting of,
 (a) introducing said one or more procoagulation species at the center of the rotating object such that said liquid can spin off the rotating object and coat the fibers;   (b) spraying the fibers using dry or wet electrospraying;   (c) soaking the fibers in a solution containing the said one or more procoagulation species causing wet impregnation of the fibers; and,   (d) introducing said one or more procoagulation species at the center of the rotating object while said rotating object is subjected to high frequency vibration.   
   
   
       7 . The method of  claim 5  wherein the liquid biocompatible fiber precursor is selected from a group consisting of polylactic acid, polylactic glycolic acid, chitosan, chitin, polycaprolactone, poly ethylene oxide, poly ethylene glycol, modified and unmodified polysaccharides, modified and unmodified synthetic polyaminoacids, proteins, poly beta-hydroxybutyric acid, poly beta-hydroxyvaleric acid, polydioxanone, polyphosphazene, poly ethylene terephthalate, poly tartronic acid, poly malic acid, random and block copolymers resulting from the polymers in the group and therapeutic agents that do not adversely affect the hemostatic function of the dressing and mixtures thereof. 
   
   
       8 . The method of  claim 5  wherein the liquid biocompatible fiber precursor contains one or more active biological or abiological procoagulation species. 
   
   
       9 . The method of  claim 5  wherein the liquid biocompatible fiber precursor contains fibrinogen and further comprising the steps of,
 (a) introducing, after coating the fibers with one or more procoagulation species, a liquid biocompatible fiber precursor that does not contain fibrinogen at the center of the rotating object such that the liquid biocompatible fiber precursor can spin off the rotating object and form a second set of fibers;   (b) depositing fibers from the second set of fibers onto the collector; and,   (c) introducing a thrombin solution at the center of the rotating object such that said solution can spin off the rotating object and coat the fibers from second set of fibers on the collector.   
   
   
       10 . The method of  claim 5  wherein the rotating object is selected from a group consisting of a disk, a disk having an upward curve, a disk having a downward curve, and a plurality of disks spaced along a rotational axis of the rotating object. 
   
   
       11 . The method of  claim 5  further comprising the step of drying the fibers deposited on the collector. 
   
   
       12 . The method of  claim 5  further comprising the step of drying the fibers coated with said one or more liquid procoagulation species. 
   
   
       13 . The method of  claim 5  wherein the collector is made of wire mesh. 
   
   
       14 . The method of  claim 5  wherein the collector is in continuous motion. 
   
   
       15 . The method of  claim 5  wherein the liquid procoagulation species is a solution of one or more biological and abiological materials selected from a group consisting of fibrinogen, thrombin, prothrombin, prethrombin, von Willebrand factor, factor XIII, factor XIIIa, fibronectin, fibrin, aprotinin, antiplasmin, alpha-2 macro-globulin, plasminogen, alpha-1-antitrypsin, and plasmin activator inhibitors, calcium salts, propyl gallate and other gallic acid derivatives, epsilon aminocaproic acid, tranexamic acid, p-aminomethyl benzoic acid, and derivatives thereof. 
   
   
       16 . A method of making a hemostatic dressing using a rotating object comprising,
 (a) introducing a liquid biocompatible fiber precursor that has ferrofluidic properties at the center of the rotating object such that the liquid can spin off the rotating object and form fibers;   (b) depositing fibers so formed onto a collector positioned at a distance from the rotating object such that such that a layer of fibers is created and wherein a magnetic field is maintained between the rotating object and the collector; and,   (c) coating the fibers with one or more procoagulation species.