Resorbable hollow devices for implantation and delivery of therapeutic agents

Abstract

A method of manufacturing a resorbable balloon designed to contain bone cement for vertebroplasty or kyphoplasty applications is described. The resorbable balloon can be inserted into a vertebral body following vertebral cavitation and filled with bone cement. The balloon remains in place in the vertebral body and resorbs over time. Methods and apparatus are also described for delivering therapeutic agents using collapsible, resorbable balloons. The balloons may be nested and filled with various therapeutic agents that are released over time at rates dependent upon structures and degradation rates of the balloons. Furthermore, the function of the hollow devices can encompass both encapsulation and therapeutic substance delivery roles simultaneously.

1 . A method of forming a resorbable balloon, comprising: 
 heating a region of a tube and pulling tubing along an axis of the tube, thereby thinning a wall of the tube at the heated region;    forcing a gas or liquid through a lumen of the tube while heating the region of the tube, thereby causing a portion of the tubing to expand and form a balloon; and    sealing an end of the tube in proximity to the balloon.    
     
     
         2 . The method as set forth in  claim 1 , wherein the heating is preceded by: 
 extruding resorbable tubing; and    cutting tubing to desired lengths, thereby forming the plurality of tubes.    
     
     
         3 . The method as set forth in  claim 1 , wherein one end of the tube is sealed before forcing a gas or liquid through the lumen of the tube.  
     
     
         4 . The method as set forth in  claim 3 , wherein the sealing of an end of the tube comprises gluing a resorbable plug into the lumen.  
     
     
         5 . The method as set forth in  claim 3 , wherein the sealing of an end of the tube comprises at least one of thermally welding or heat sealing the tube.  
     
     
         6 . The method as set forth in  claim 1 , wherein the sealing is followed by removing excess tubing beyond the sealed point.  
     
     
         7 . The method as set forth in  claim 1 , wherein the liquid or gas is heated air.  
     
     
         8 . A resorbable balloon formed by the method of  claim 1  that is made of a resorbable polymer, including one or more of poly-L-lactide, poly-DL-lactide, polyglycolide, polycaprolactone, polytrimethylene carbonate, polydioxanone, polydioxane, and copolymers or mulit-polymers of the above listed polymers.  
     
     
         9 . A method of performing bone restoration, comprising: 
 providing a cavity within the bone;    inserting a deflated resorbable balloon into the cavity; and    filling the resorbable balloon with bone cement, thereby causing the resorbable balloon to expand and fill the cavity.    
     
     
         10 . The method as set forth in  claim 9 , wherein the providing of a cavity comprises evacuating a volume of bone.  
     
     
         11 . The method as set forth in  claim 10 , wherein increasing the size of the cavity comprises inserting a deflated non-resorbable balloon into the cavity and filling the balloon with a liquid or gas to expand the balloon and increase the size of the bone cavity (e.g. kyphoplasty™).  
     
     
         12 . A method of providing therapy, comprising: 
 providing a first collapsible resorbable hollow device;    identifying a cavity in an anatomical location; and    inserting the first collapsible resorbable hollow device into the cavity.    
     
     
         13 . The method as set forth in  claim 12 , wherein the inserting is followed by injecting at least one therapeutic agent into the first collapsible resorbable hollow device.  
     
     
         14 . The method as set forth in  claim 13 , wherein: 
 the identifying of a cavity in an anatomical location comprises forming a cavity in a desired anatomical location; and    the inserting is preceded by deflating the hollow device; and    
     
     
         15 . The method as set forth in  claim 14 , wherein the inserting is performed laparoscopically.  
     
     
         16 . The method as set forth in  claim 14 , further comprising: 
 providing a second collapsible resorbable hollow device;    inserting the second collapsible resorbable hollow device into the first collapsible resorbable hollow device; and    injecting at least one therapeutic agent into the second collapsible resorbable hollow device.    
     
     
         17 . The method as set forth in  claim 16 , further comprising: 
 providing one or more collapsible resorbable hollow devices;    nesting the collapsible resorbable hollow devices; and    injecting at least one therapeutic agent into each of the collapsible resorbable hollow devices.    
     
     
         18 . The method as set forth in  claim 17 , wherein the injecting of at least one therapeutic agent comprises injecting one or more of a natural organic substance, a synthetic organic substance, an inorganic material, and combinations thereof.  
     
     
         19 . The method as set forth in  claim 18 , wherein the injecting of a natural organic substance comprises injecting one or more of a living biological agent, proteins, a natural polymer, and combinations thereof.  
     
     
         20 . The method as set forth in  claim 18 , wherein the injecting of a natural polymer comprises injecting one or more of a collagen, gelatin, fibrin, hyaluronic acid, polysaccharides, elastin, cellulose, polynucleotides, and combinations thereof.  
     
     
         21 . The method as set forth in  claim 18 , wherein the injecting of a synthetic organic substance comprises injecting one or more of a drug, antibiotic, steroid, glycerol, polymer, and combinations thereof.  
     
     
         22 . The method as set forth in  claim 21 , wherein the injecting of a polymer comprises injecting one or more of polyester, silicone, polyethylene oxide, polypropylene fumarate, pluronics, polyhydroxymethacrylate, polymethylmethacrylate, and combinations thereof.  
     
     
         23 . The method as set forth in  claim 18 , wherein the injecting of an inorganic material comprises injecting one or more of calcium phosphate, allograft bone, ceramics, metals, and combinations thereof.  
     
     
         24 . The method as set forth in  claim 23 , wherein the injecting of calcium phosphate comprises injecting at least one of beta-tricalcium phosphate and hydroxapatite.  
     
     
         25 . The method as set forth in  claim 17 , wherein the providing of one or more collapsible resorbable hollow devices comprises providing a hollow device having perforations, whereby the therapeutic agent is delivered at a predetermined delivery rate.  
     
     
         26 . The method as set forth in  claim 12 , wherein the providing of a first collapsible resorbable hollow device comprises providing a hollow device fabricated with a material containing an additive that accelerates resorption of the first collapsible resorbable hollow device.  
     
     
         27 . The method as set forth in  claim 12 , wherein the providing of a first collapsible resorbable hollow device comprises providing a hollow device fabricated with a material containing an additive that retards resorption of the first collapsible resorbable hollow device.  
     
     
         28 . The method as set forth in  claim 13 , further comprising attaching a conduit to an opening of the first collapsible resorbable hollow device, the conduit acting to facilitate at least one of loading of the first collapsible resorbable hollow device with the at least one therapeutic agent and aiding in positional manipulation of the hollow device.  
     
     
         29 . The method as set forth in  claim 28 , further comprising closing the opening and then removing the conduit.  
     
     
         30 . The method as set forth in  claim 29 , wherein the removing of the conduit forms an opening in the hollow device.  
     
     
         31 . The method as set forth in  claim 13 , wherein a conduit to an opening of the first collapsible resorbable hollow device is formed as a continuous part of the device, the conduit acting to facilitate loading of the first collapsible resorbable hollow device with the at least one therapeutic agent.  
     
     
         32 . The method as set forth in  claim 31 , further comprising: 
 removing the conduit; and    closing the opening.    
     
     
         33 . The method as set forth in  claim 32 , wherein the removing of the conduit forms an opening in the hollow device.  
     
     
         34 . A collapsible, resorbable balloon formed of one or more of aliphatic polyesters, polycarbonates, polyoxaesters, polyorthoesters, polyanhydrides, polyphosphoesters, polyphosphazenes, polypropylene fumarates, polyamino acids, other polyamides, pseudopoly(amino acids), polyamidoesters, polyarylates, polyoxaesters containing amine groups, polyalkylene oxalate, polyhydroxybuyrate, polyhydroxyvalerate, resorbable polyurethanes, resorbable starches, resorbable silk, and combinations (co- or multi-polymers or blend) of any of the above with nonresorbable polymers, and any combination thereof.  
     
     
         35 . The collapsible, resorbable balloon as set forth in  claim 34 , wherein the aliphatic polyesters are selected from a group comprising one or more of polyL-lactide, polyD-lactide, polyglycolide, poly ε-caprolactone, and combinations thereof.  
     
     
         36 . The collapsible, resorbable balloon as set forth in  claim 34 , wherein the polycarbonates are selected from a group comprising polytrimethylene carbonate, tyrosine derived polycarbonates, poly(iminocarbonates), and combinations thereof.  
     
     
         37 . The collapsible, resorbable balloon as set forth in  claim 34 , wherein the polyoxaesters are selected from a group comprising poly(p-dioxanone).