Three-dimensional nanostructured hybrid scaffold and manufacture thereof

Abstract

A method of making a three-dimensional biocompatible scaffold capable of supporting cell activities such as growth and differentiation, the method includes providing a supporting grid that forms an open network and provides mechanical support of a second biocompatible material. The second biocompatible material has interconnected cavities that allow nutrients, metabolites and soluble factors to diffuse throughout the scaffold. The scaffold design can be understood as a hierarchically organised structure. At the micron to submicron length scale a top/down manufacturing approach is used to make a structure that will constitute the frame into which a bottom/up processing approach is applied to form an open porous scaffold with specific nano sized features. The advantage of this hierarcially organised design is that benefits can be drawn independently from both the micron and the nano sized structures, promoting specific cell activities and providing sufficient mechanical compliance.

What is claimed is: 
     
         1 . A method of making a three-dimensional biocompatible scaffold capable of supporting cell activities, the method comprising:
 a) providing a supporting grid comprising a first biocompatible material, said grid providing mechanical support of a second biocompatible material, said first biocompatible material comprising one or more polymers, said grid forming an open network,   b) adding a solution comprising a mixture of one or more biocompatible polymers and one or more solvents to a substantial part of the open network,   c) removing said solvents resulting in said second biocompatible material within the open network, said second biocompatible material having interconnected cavities, said interconnected cavities in the second biocompatible material allowing cells to grow functional tissues and allowing the diffusion of nutrients, metabolites and soluble factors throughout the scaffold;   d) seeding the three-dimensional biocompatible scaffold with cells; and   e) coating the cell-seeded scaffold with one or more biocompatible polymers;   wherein said grid protects the three-dimensional biocompatible scaffold against compressive forces during preparation, insertion and use.   
     
     
         2 . The method according to  claim 1 , wherein the one or more biocompatible polymers of step b) are positively charged at physiological pH; and wherein the coating step e) is with one or more biocompatible polymers that are negatively charged at physiological pH. 
     
     
         3 . The method according to  claim 2 , further comprising a step f1) coating the cell-seeded scaffold with one or more biocompatible polymers that are positively charged at physiological pH. 
     
     
         4 . The method according to  claim 1 , wherein the one or more biocompatible polymers of step b) are negatively charged at physiological pH; and wherein the coating step e) is with one or more biocompatible polymers that are positively charged at physiological pH. 
     
     
         5 . The method according to  claim 4 , further comprising a step f2) coating the cell-seeded scaffold with one or more biocompatible polymers that are negatively charged at physiological pH. 
     
     
         6 . The method according to  claim 1 , the method further comprising a step in between steps c) and d), said step being:
 coating the scaffold surface with one or more biocompatible polymers that are negatively charged at physiological pH.   
     
     
         7 . The method according to  claim 1 , the method further comprising a step in between steps c) and d), said step being:
 coating the scaffold surface with one or more biocompatible polymers that are positively charged at physiological pH.   
     
     
         8 . The method according to  claim 1 , wherein the supporting grid is made by solid freeform fabrication. 
     
     
         9 . The method according to  claim 1 , wherein said interconnected cavities are formed by thermal induced phase separation. 
     
     
         10 . The method according to  claim 1 , wherein the scaffold surface is coated with a coating material comprising one or more of a protein, a peptide, a nucleotide and a small interfering RNA. 
     
     
         11 . The method according to  claim 1 , wherein said mixture comprises two or more solvents. 
     
     
         12 . A method of making a three-dimensional biocompatible scaffold capable of supporting cell activities, the method comprising:
 a) providing a supporting grid comprising a first biocompatible material, said grid providing mechanical support of a second biocompatible material, said first biocompatible material comprising one or more polymers, said grid forming an open network,   b) adding a solution comprising a mixture of one or more biocompatible polymers and one or more solvents to a substantial part of the open network,   c) removing said solvents resulting in said second biocompatible material within the open network, said second biocompatible material having interconnected cavities, said interconnected cavities in the second biocompatible material allowing cells to grow functional tissues and allowing the diffusion of nutrients, metabolites and soluble factors throughout the scaffold;   d) coating the scaffold with a first biocompatible polymer coating;   e) seeding the three-dimensional biocompatible scaffold with cells; and   f) coating the cell-seeded scaffold with a second biocompatible polymer coating;   wherein said grid protects the three-dimensional biocompatible scaffold against compressive forces during preparation, insertion and use.   
     
     
         13 . The method according to  claim 12 , wherein the first biocompatible polymer coating is positively charged at physiological pH and wherein the second biocompatible polymer coating is negatively charged at physiological pH. 
     
     
         14 . The method according to  claim 12 , wherein the first biocompatible polymer coating is negatively charged at physiological pH and wherein the second biocompatible polymer coating is positively charged at physiological pH. 
     
     
         15 . The method according to  claim 12 , wherein the supporting grid is made by solid freeform fabrication. 
     
     
         16 . The method according to  claim 12 , wherein said interconnected cavities are formed by thermal induced phase separation. 
     
     
         17 . The method according to  claim 12 , wherein the scaffold surface is coated with a coating material comprising one or more of a protein, a peptide, a nucleotide and a small interfering RNA. 
     
     
         18 . The method according to  claim 12 , wherein said mixture comprises two or more solvents.