Vascularized tissue graft

Abstract

The present invention relates generally to improved methods for tissue engineering including tissue transplantation, augmentation and regeneration. More particularly, the present invention provides a method for the generation of donor vascularized tissue suitable for use in tissue transplantation, augmentation and/or repair. The present invention further enables the use of a support matrix in the generation of an anatomical construct comprising the donor vascular tissue. The support matrix may be devised such that it has dimensions of a size and shape adapted to simulate those of tissue to be transplanted, augmented and/or repaired. In addition to its use in tissue repair, the methods and support matrix of the present invention may also find application as a means for delivering a desirable gene product to a subject. The method and support matrix of the present invention is conveniently be made available in the form of a kit, for use generally in the field of tissue engineering.

1 . A method for producing a donor vascularized new tissue, suitable for transplantation into a recipient in need of such treatment, comprising the steps of: 
 a) creating a functional circulation on a vascular pedicle in a donor subject;    b) enclosing the vascular pedicle within a fabricated chamber, the chamber having internal dimensions which are of a size and shape adapted to simulate those of a tissue moiety suitable to repair a tissue deficit or to provide tissue augmentation;    c) seeding the chamber with isolated pieces of adipose tissue, thereby to influence the type of the donor vascularized new tissue produced;    d) implanting the chamber containing the vascular pedicle into the donor subject at a site where such an anatomical construct can be created; and    e) leaving the chamber in the implantation site for a period sufficient to allow the growth of the donor vascularized new tissue.    
     
     
         2 . The method according to  claim 1 , comprising the step of: after step (a) surrounding the vascular pedicle with an added extracellular matrix, a mechanical support, or a combination thereof.  
     
     
         3 . The method according to  claim 1 , comprising the step of: after step (b) adding growth factors, drugs, antibodies, inhibitors or other chemicals to the chamber.  
     
     
         4 . The method according to  claim 1 , wherein the vascular pedicle comprises an arterio-venous (AV) loop or shunt.  
     
     
         5 . The method according to  claim 1 , wherein the vascular pedicle comprises a ligated artery and vein.  
     
     
         6 . The method according to  claim 1 , wherein the chamber in step (e) is left in the implantation site for at least 4 weeks.  
     
     
         7 . The method according to  claim 1 , wherein the chamber in step (e) is left in the implantation site for at least 6 weeks.  
     
     
         8 . The method according to  claim 1 , wherein the created vascular pedicle contained within the chamber is connected to an extracorporeal circulation.  
     
     
         9 . The method according to  claim 1 , wherein the donor subject of step (a) is a mammal.  
     
     
         10 . The method according to  claim 9 , wherein the mammal is a human.  
     
     
         11 . The method according to  claim 1 , further comprising an additional step of implanting the vascularized new tissue into an autologous recipient.  
     
     
         12 . The method according to  claim 1 , further comprising an additional step of implanting the vascularized new tissue into a heterologous recipient.  
     
     
         13 . The method according to  claim 2 , wherein the added extracellular matrix is selected from the group consisting of: reconstituted basement membrane preparations, polylactic-polyglycolic acid variants (PLGA), fibrin or plasma glue and native collagen.  
     
     
         14 . The method according to  claim 13 , wherein the added extracellular matrix comprises a PLGA sponge.  
     
     
         15 . The method according to  claim 3 , wherein the additional growth factors, drugs, antibodies, inhibitors or other chemicals added to the chamber are selected from the group consisting of: growth factors, homing factors to attract stem cells from the circulation, exogenous growth factors and promoters of angiogenesis or vasculogenesis.  
     
     
         16 . The method according to  claim 1 , wherein the isolated pieces of adipose tissue of step (c) are autologous to the donor.  
     
     
         17 . The method according to  claim 1 , wherein the isolated pieces of adipose tissue of step (c) are heterologous to the donor.  
     
     
         18 . The method according to  claim 1 , wherein the functional circulation on a vascular pedicle of step (a) comprises an artery and a vein.  
     
     
         19 . The method according to  claim 1 , wherein the functional circulation on a vascular pedicle of step (a) comprises an artery, a venous graft and a vein.  
     
     
         20 . The method according to  claim 1 , wherein the functional circulation on a vascular pedicle of step (a) comprises an artery, a venous graft, an arterial graft and a vein.  
     
     
         21 . The method according to  claim 1 , wherein the functional circulation on a vascular pedicle of step (a) comprises the ligated stumps of an artery and a vein placed side by side.  
     
     
         22 . The method according to  claim 1 , wherein the donor vascularized tissue is vascularized fat.  
     
     
         23 . The method according to  claim 22 , further comprising the step of introducing stem cell homing factors into the chamber.  
     
     
         24 . A vascularized tissue graft produced by the method according to  claim 1 .  
     
     
         25 . A method of delivery of a gene product to a subject, comprising the steps of: 
 a) creating vascularized tissue in a tissue chamber according to the method of  claim 1;     b) removing the chamber with its vascularized tissue from the donor and culturing the chamber in vitro;    c) transforming cells of the tissue in the chamber with a desired gene; and    d) implanting the vascularized and transformed tissue into a patient in need of such treatment, thereby delivering the desired gene product to the patient.    
     
     
         26 . A model system for vascularized tissue, comprising a comprising a tissue chamber comprising an isolated vascular pedicle produced by the method according to  claim 1 , wherein the tissue chamber is operably connected to an extracorporeal circulation apparatus and to a renal dialysis filter.  
     
     
         27 . A construct for producing a donor vascularized tissue suitable for transplantation into a recipient animal, the construct comprising: 
 (a) a fabricated chamber, the chamber having internal dimensions which are of a size and shape adapted to simulate those of a tissue moiety suitable to repair a tissue deficit or to provide tissue augmentation;    (b) a vascular pedicle; and    (c) isolated cells or pieces of the tissue to influence the type of the donor vascularised tissue produced.    
     
     
         28 . The construct according to  claim 27 , wherein the isolated cells or pieces of the tissue comprise adipose tissue.  
     
     
         29 . The construct according to  claim 27 , further comprising an extracellular matrix, a mechanical support, or a combination thereof.  
     
     
         30 . A kit for producing a donor vascularized tissue suitable for transplantation into a recipient animal, the kit comprising: 
 (a) a fabricated chamber, the chamber having internal dimensions which are of a size and shape adapted to simulate those of a tissue moiety suitable to repair a tissue deficit or to provide tissue augmentation; and    (b) instructions for preparing the donor vascularized tissue suitable for transplantation into the recipient animal, using a method according to  claim 1 .    
     
     
         31 . A fabricated chamber for generating an anatomical construct comprising a vascular tissue for transplantation and/or repair, the chamber comprising: 
 (a) an external portion openable to expose an internal portion;    (b) the internal portion adapted to receive a pedicle around which, or part of which, vascular tissue grows wherein the internal portion having a predetermined shape which influences the shape of the vascular tissue which grows around the pedicle.    
     
     
         32 . The method according to  claim 1 , wherein the isolated pieces of adipose tissue of step (c) are autologous to the recipient.  
     
     
         33 . The method according to  claim 1 , wherein the isolated pieces of adipose tissue of step (c) are heterologous to the recipient.  
     
     
         34 . The method according to  claim 1 , wherein the recipient is a mammal.  
     
     
         35 . The method according to  claim 34 , wherein the mammal is a human.  
     
     
         36 . The chamber of  claim 31 , wherein the internal portion is adapted to receive a support material around the pedicle.  
     
     
         37 . A system for forming a cardiac tissue construct, comprising: a chamber; and 
 cardiac myocytes provided within the chamber, wherein the chamber is arranged to at least partially surround an intact blood vessel in vivo to facilitate formation of the three-dimensional cardiac tissue construct within the chamber.    
     
     
         38 . The system according to  claim 37 , wherein the cardiac myocytes are provided within a suspension including a fibrin gel.  
     
     
         39 . The system according to  claim 37 , wherein the chamber includes a tube.  
     
     
         40 . The system according to  claim 37 , wherein the chamber includes an opening therein to aid in placement of the chamber with respect to the blood vessel.  
     
     
         41 . A method of forming a cardiac tissue construct, comprising: providing a chamber; placing cardiac myocytes within the chamber, the chamber arranged to at least partially surround an intact blood vessel in vivo to allow formation of the three-dimensional cardiac tissue construct within the chamber.  
     
     
         42 . The method according to  claim 41 , wherein placing cardiac myocytes includes providing the cardiac myocytes within a suspension including a fibrin gel.  
     
     
         43 . The method according to  claim 41 , further comprising implanting the chamber in a host such that the chamber includes the cardiac myocytes and the blood vessel.  
     
     
         44 . The method according to  claim 43 , wherein the blood vessel includes an artery.  
     
     
         45 . The method according to  claim 43 , wherein implanting the chamber includes separating the chamber along an opening provided therein and placing the blood vessel at least partially inside the chamber.  
     
     
         46 . The method according to  claim 41 , further comprising incubating the chamber and contained cardiac myocytes in vivo for a period of time.  
     
     
         47 . The method according to  claim 46 , further comprising removing the construct from the chamber following incubation.  
     
     
         48 . A cardiac tissue construct, comprising: cardiac myocytes provided within a chamber which is incubated in vivo at least partially surrounding an intact blood vessel in order to form the three-dimensional cardiac tissue construct.  
     
     
         49 . The construct according to  claim 48 , wherein the cardiac myocytes are provided within a suspension including a fibrin gel.  
     
     
         50 . The construct according to  claim 48 , wherein the chamber includes generally cylindrical tubing.  
     
     
         51 . The construct according to  claim 48 , wherein the chamber includes an opening therein to aid in placement of the chamber with respect to the blood vessel.