Omentum based scaffold and delivery system

Abstract

Compositions of matter comprising decellularized omentum are disclosed. The compositions may be scaffolds, hydrogels or hydrogel precursor compositions. Methods of generating the compositions are disclosed as well as uses thereof.

What is claimed is: 
     
         1 . A composition of matter comprising decellularized omentum which comprises less than 50 ng DNA per mg dry omentum, having a mean fiber diameter of at least 1 μm, wherein the porosity of the composition is at least 50%. 
     
     
         2 . The composition of matter of  claim 1 , wherein said mean fiber diameter is between 1-2 μm. 
     
     
         3 . The composition of matter of  claim 1 , further comprising a biodegradable polymer. 
     
     
         4 . The composition of matter of  claim 3 , wherein said biodegradable polymer is selected from the group consisting of collagen, chitosan, chitin, gelatin, alginate, hyaluronic acid, Fibrin, Albumin, Chondroitin sulfate, Natural poly(amino acids), Elastin, Elastin-like peptides, Poly (α-esters), Polyglycolide, Poly(lactide-co-glycolide), Polycaprolactone, Polylactides, Polydioxanone, Poly(trimethylene carbonate), Polyurethanes, Poly(ester amide), Poly(ortho esters), Polyanhydrides, Poly(anhydride-co-imide), Cross-linked polyanhydrides, Pseudo poly(amino acid), Poly(alkyl cyanoacrylates), Polyphosphazenes, Polyphosphoester, synthetic poly(amino acids). 
     
     
         5 . The composition of matter of  claim 1  being devoid of lipids. 
     
     
         6 . The composition of matter of  claim 1 , comprising less than 20% of the cells as compared to the amount of cells in the omentum prior to decellularization. 
     
     
         7 . A method of decellularizing omentum comprising:
 (a) exposing the omentum to a hypotonic solution;   (b) dehydrating said omentum following step (a);   (c) extracting fat from the dehydrated omentum using polar and non-polar extraction agents following step (b);   (d) rehydrating the dehydrated omentum following step (c); and   (e) extracting cells from said rehydrated omentum following step (d).   
     
     
         8 . The method of  claim 7 , further comprising lyophilizing said omentum following step (e). 
     
     
         9 . The method of  claim 7 , wherein said extracting cells from said rehydrated omentum is effected using a protease. 
     
     
         10 . The method of  claim 9 , wherein said protease comprises trypsin. 
     
     
         11 . The method of  claim 7 , further comprising mechanically rupturing cells of said omentum following step (a) and prior to step (b). 
     
     
         12 . The method of  claim 7 , wherein said non-polar extraction solvent is hexane. 
     
     
         13 . The method of  claim 7 , wherein said polar extraction solvent is acetone or isopropanol. 
     
     
         14 . The method of  claim 7 , wherein said polar extraction solvent is acetone and said non-polar extraction solvent is hexane. 
     
     
         15 . The method of  claim 7 , wherein said dehydrating is effected using a dehydrating agent selected from the group consisting of methanol, ethanol, isopropanol, propanol and combinations thereof. 
     
     
         16 . The method of  claim 9 , wherein said protease is contacted with said dehydrated omentum for at least one hour. 
     
     
         17 . A composition of matter comprising decellularized omentum generated by:
 (a) exposing the omentum to a hypotonic solution;   (b) dehydrating said omentum following step (a);   (c) extracting fat from the dehydrated omentum using polar and non-polar extraction agents following step (b);   (d) rehydrating the dehydrated omentum following step (c); and   (e) extracting cells from said rehydrated omentum following step (d).   
     
     
         18 . A scaffold fabricated from the composition of matter of  claim 1 . 
     
     
         19 . A method of generating a cell-seeded scaffold comprising:
 (a) providing the scaffold of  claim 18 ; and   (b) seeding cells on the scaffold, thereby generating the cell-seeded scaffold.   
     
     
         20 . The method of  claim 18 , wherein said cells comprise cardiac cells. 
     
     
         21 . The method of  claim 20 , wherein said cells further comprise endothelial cells and/or fibroblasts. 
     
     
         22 . The method of  claim 21 , wherein said endothelial cells and said fibroblasts do not originate from cardiac tissue. 
     
     
         23 . The method of  claim 21 , wherein a ratio of said cardiac cells:endothelial cells is greater than 60:40. 
     
     
         24 . A composition of matter comprising a population of cells seeded on the scaffold of  claim 18 . 
     
     
         25 . The composition of matter of  claim 24 , wherein said cells comprise cardiac cells. 
     
     
         26 . The composition of matter of  claim 24 , wherein said cells comprise stem cells. 
     
     
         27 . The composition of matter of  claim 24 , being devoid of feeder cells. 
     
     
         28 . The composition of matter of  claim 24 , wherein said cells further comprise endothelial cells. 
     
     
         29 . The composition of matter of  claim 28 , wherein said endothelial cells do not originate from cardiac tissue. 
     
     
         30 . The composition of matter of  claim 27 , wherein a ratio of said cardiac cells:endothelial cells is greater than 60:40. 
     
     
         31 . An isolated composition of matter comprising vascularized cardiac cells seeded on a decellularized omentum scaffold, said vascularized cardiac cells being able to contract more than 20 times per minute. 
     
     
         32 . The isolated composition of matter of  claim 31 , wherein said vascularized cardiac cells are able to contract more than 40 times per minute. 
     
     
         33 . The isolated composition of matter of  claim 31 , wherein an amplitude of contraction of said vascularized cardiac cells is greater than 5 m. 
     
     
         34 . A hydrogel comprising solubilized decellularized omentum. 
     
     
         35 . The hydrogel of  claim 34 , wherein said decellularized omentum is devoid of lipids. 
     
     
         36 . The hydrogel of  claim 34 , wherein said omentum is human omentum. 
     
     
         37 . The hydrogel of  claim 34 , comprising collagen, laminin, elastin, fibronectin and glycosaminoglycans. 
     
     
         38 . The hydrogel of  claim 34 , wherein said omentum is decellularized by:
 (a) exposing the omentum to a hypotonic solution;   (b) dehydrating said omentum following step (a);   (c) extracting fat from the dehydrated omentum using polar and non-polar extraction agents following step (b);   (d) rehydrating the dehydrated omentum following step (c); and   (e) extracting cells from said rehydrated omentum following step (d).   
     
     
         39 . The hydrogel of  claim 34 , comprising less than 50 ng DNA per dry weight. 
     
     
         40 . The hydrogel of  claim 34 , comprising greater than 1 μg sulfated GAG per dry weight. 
     
     
         41 . A precursor composition comprising solubilized decellularized omentum which is capable of forming a gel on heat activation. 
     
     
         42 . The precursor composition of  claim 41 , further comprising cells. 
     
     
         43 . A method of generating a 3D structure comprising extruding the precursor composition of  claim 41  through an aperture thereby generating the 3D structure. 
     
     
         44 . The precursor composition of  claim 41 , wherein said omentum is decellularized by:
 (a) exposing the omentum to a hypotonic solution;   (b) dehydrating said omentum following step (a);   (c) extracting fat from the dehydrated omentum using polar and non-polar extraction agents following step (b);   (d) rehydrating the dehydrated omentum following step (c); and   (e) extracting cells from said rehydrated omentum following step (d).   
     
     
         45 . A method of treating a cardiac disease or disorder in a subject in need thereof comprising administering to the subject a therapeutically effective amount of a composition of matter of  claim 1 , thereby treating the cardiac disease or disorder. 
     
     
         46 . A method of treating a cardiac disease or disorder in a subject in need thereof comprising administering to the subject a therapeutically effective amount of the hydrogel of  claim 34 , thereby treating the cardiac disease or disorder. 
     
     
         47 . A method of treating a cardiac disease or disorder in a subject in need thereof comprising administering to the subject a therapeutically effective amount of the precursor composition of  claim 41 , thereby treating the cardiac disease or disorder. 
     
     
         48 . The method of  claim 45 , wherein said omentum is autologous to the subject. 
     
     
         49 . The method of  claim 45 , wherein said omentum is non-autologous to the subject. 
     
     
         50 . A method of regenerating tissue in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of the composition of  claim 1 , thereby regenerating the tissue in a subject. 
     
     
         51 . The method of  claim 50 , wherein said omentum is autologous to the subject. 
     
     
         52 . The method of  claim 50 , wherein said omentum is non-autologous to the subject. 
     
     
         53 . A method of generating a precursor composition, which upon temperature activation is capable of forming a hydrogel, the method comprising:
 (a) decellularizing omentum to generate decellurized omentum;   (b) lyophilizing said decellularized omentum to generate lyophilized omentum; and   (c) solubilizing said lyophilized omentum, thereby generating the composition of matter.   
     
     
         54 . The method of  claim 53 , wherein said solubilizing is effected using a protease enzyme. 
     
     
         55 . The method of  claim 54 , wherein said protease comprises pepsin.