Decellularized tissue engineered constructs and tissues

Abstract

New methods for producing tissue engineered constructs and engineered native tissues are disclosed. The methods include producing a tissue engineered construct by growing cells in vitro on a substrate and then decellularizing the construct to produce a decellularized construct consisting largely of extracellular matrix components. The construct can be used immediately or stored until needed. The decellularized construct can be used for further tissue engineering, which may include seeding the construct with cells obtained from the intended recipient of the construct. During any of the growth phases required for production of the construct, the developing construct may be subjected to various tissue engineering steps such as application of mechanical stimuli including pulsatile forces. The methods also include producing an engineered native tissue by harvesting tissue from an animal or human, performing one or more tissue engineering steps on the tissue, and subjecting the tissue to decellularization. The decellularized, engineered native tissue may then be subjected to further tissue engineering steps.

1 - 218 . (canceled)  
     
     
         219 . A scaffold comprising: 
 a porous, proteinaceous extracellular matrix having three dimensions, wherein the scaffold is substantially acellular, and wherein the scaffold comprises fragments of a synthetic polymer, wherein the smallest of the three dimensions is greater than 50 microns.    
     
     
         220 . The scaffold of  claim 219  further comprising a first population of cells growing on the scaffold.  
     
     
         221 . The scaffold of  claim 220  wherein the first population of cells is allogeneic to a second population of cells which secreted the porous, proteinaceous extracellular matrix.  
     
     
         222 . The scaffold of  claim 220  wherein the first population of cells is autologous to a second population of cells which secreted the porous, proteinaceous extracellular matrix.  
     
     
         223 . The scaffold of  claim 220  wherein the first population of cells is xenogeneic to the second population of cells which secreted the porous, proteinaceous extracellular matrix.  
     
     
         224 . The scaffold of  claim 219  wherein the synthetic polymer is polyglycolic acid.  
     
     
         225 . The scaffold of  claim 224  wherein the fragments of a synthetic polymer are fragments of a polyglycolic acid mesh.  
     
     
         226 . A method of making a decellularized scaffold comprising: 
 seeding a substrate with first cells which produce an extracellular matrix;    culturing the first cells on the substrate until the cells form a tissue of greater than 50 microns thickness;    removing the first cells to yield a scaffold comprised of extracellular matrix;    wherein the substrate comprises a degradable polymer which substantially degrades during the steps of culturing and/or removing.    
     
     
         227 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are allogeneic to the first cells.  
     
     
         228 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are xenogeneic to the first cells.  
     
     
         229 . The method of  claim 227  further comprising implanting the scaffold in an individual, wherein the second cells are from said individual.  
     
     
         230 . The method of  claim 228  further comprising implanting the scaffold in an individual, wherein the second cells are from said individual.  
     
     
         231 . The method of  claim 227  further comprising implanting the scaffold in an individual, wherein the second cells are allogeneic to said individual.  
     
     
         232 . The method of  claim 228  further comprising implanting the scaffold in an individual, wherein the second cells are allogeneic to said individual.  
     
     
         233 . The method of  claim 226  further comprising the step of implanting the scaffold in an individual.  
     
     
         234 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are endothelial cells.  
     
     
         235 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are smooth muscle cells.  
     
     
         236 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are fibroblast cells.  
     
     
         237 . The method of  claim 226  further comprising the step of seeding the scaffold with second cells which are precursor cells.  
     
     
         238 . The method of  claim 226  wherein the substrate is rotated during the step of seeding.  
     
     
         239 . The method of  claim 226  wherein the step of removing comprises freezing the first cells.  
     
     
         240 . A method of treating a patient to repair damaged or lost tissue, comprising: 
 implanting the scaffold of  claim 219  into the patient, whereby cells of the patient attach and grow on the scaffold.    
     
     
         241 . A method of treating a patient to repair damaged or lost tissue, comprising: 
 implanting the scaffold of  claim 220  into the patient, wherein the first population of cells is allogeneic to the patient, whereby cells of the patient attach and grow on the scaffold.    
     
     
         242 . A method of treating a patient to repair damaged or lost tissue, comprising: 
 implanting the scaffold of  claim 220  into the patient, wherein the first population of cells is autologous to the patient, whereby cells of the patient attach and grow on the scaffold.