Super-sparger microcarrier beads and precision extrusion deposited poly-epsilon-caprolactone structures for biological applications

Abstract

In on aspect, the invention includes a microcarrier bead having a porous three-dimensional core having (a) a polymeric porous three-dimensional body having porosity of about 15 to about 90% such that at least 99% of pores are interconnected and have diameters of at most 200 microns, (b) an outer protective layer and optionally (c) a filler. In another aspect, the invention includes a method of making an artificial scaffold wherein a scaffolding material is extruded into a coolant and thereby creating a porous material having a porosity of between 15-90% such that at least 99% of pores are interconnected and have diameters of at most 200 microns.

1 . A microcarrier bead comprising a porous three-dimensional core having (a) a polymeric porous three-dimensional body having porosity of about 15 to about 90% such that at least 99% of pores are interconnected and have diameters of at most 200 microns, (b) an outer protective layer and optionally (c) a filler material in communication with the polymeric porous three-dimensional core.  
   
   
       2 . (canceled)  
   
   
       3 . The microcarrier bead of  claim 1 , wherein the porous three-dimensional core is made from a scaffold material comprising at least one of a biodegradable polymer, fibrin, collagen, and mixtures thereof.  
   
   
       4 . The microcarrier bead of  claim 3 , wherein the scaffolding material further comprises hydroxyapatite.  
   
   
       5 . The microcarrier bead of  claim 3 , wherein the scaffold material is at least one of poly-caprolactone, polylactic acid, polyglycolic acid, and poly(lactide co-glycolide).  
   
   
       6 . The microcarrier bead of  claim 1 , wherein the filler material is at least one of fibrin, collagen, and dextran.  
   
   
       7 . The microcarrier bead of  claim 1 , wherein the outer protective layer comprises hydrogel.  
   
   
       8 . The microcarrier bead of  claim 3 , wherein the scaffold material comprises a biodegradable polyester and the outer protective layer comprises alginate.  
   
   
       9 . The microcarrier bead of  claim 1 , wherein the porous three-dimensional core is made by depositing poly-caprolactone in a layered pattern such that at least 99% of pores is interconnected and at least 99% of pores lead to the external surface of the microcarrier bead.  
   
   
       10 . The microcarrier bead of  claim 1 , further comprising cells.  
   
   
       11 . A method for making an artificial scaffold having porosity of about 15 to about 90% such that at least 99% of pores are interconnected and have diameters of at most 200 microns, the method comprising: 
 providing a scaffolding material;    providing a coolant having a thermal conductivity of greater than 0.026; and    extruding the scaffolding material into the coolant and thereby making the artificial scaffold having a porous three-dimensional body wherein at least 99% of pores in the porous three-dimensional body are interconnected and lead to an external surface of the porous three-dimensional body and wherein pores have diameters of at most 200 microns.    
   
   
       12 . The method of  claim 11 , wherein extruding the scaffolding material into the coolant is performed in a layered pattern such that each subsequently extruded layer of the scaffolding material is deposited on top of a previously extruded layer of the scaffolding material.  
   
   
       13 . The method of  claim 11 , wherein the scaffolding material comprises at least one of a biodegradable polymer, fibrin, collagen, and mixtures thereof.  
   
   
       14 . The method of  claim 13 , wherein the scaffolding material further comprises hydroxyapatite.  
   
   
       15 . The method of  claim 11 , wherein the coolant is at least one of a liquid, a foam, and a hydrogel.  
   
   
       16 . The method of  claim 11 , wherein at least one of the scaffolding material or the coolant comprises a biomaterial.  
   
   
       17 . The method of  claim 11 , wherein the coolant has a temperature at least 5° C. lower than the scaffolding material.  
   
   
       18 . The method of  claim 11 , further comprising providing a filler to the porous three-dimensional body.  
   
   
       19 . The method of  claim 11 , further comprising providing cells to the porous three-dimensional body.  
   
   
       20 . The method of  claim 18 , further comprising providing cells to the porous three-dimensional body.  
   
   
       21 . The method of  claim 19 , further comprising encapsulating the porous three-dimensional body with an outer protective layer.  
   
   
       22 . The method of  claim 20 , further comprising encapsulating the porous three-dimensional body with an outer protective layer.  
   
   
       23 . An artificial tissue comprising a scaffold having a polymeric porous three-dimensional body having porosity of about 15 to about 90% such that at least 99% of pores are interconnected and have diameters of at most 200 microns and optionally, cells.  
   
   
       24 . In a process for manufacturing an artificial scaffold comprising (a) utilizing a computer aided design program to design the artificial scaffold; (b) converting the computer aided design program designed artificial scaffold into a heterogeneous material and multi-part assembly model which can be used for multi-nozzle printing; and (c) printing the designed artificial scaffold using different nozzles, the improvement comprising extruding a scaffolding material into a coolant having a thermal conductivity greater than 0.026, wherein the coolant has a temperature at least 5° C. lower than the scaffolding material and thereby making the artificial scaffold having porosity of about 15 to about 88% such that at least 99% of pores are interconnected and have diameters of at most 100 microns and optionally an outer protective layer encapsulating the artificial scaffold.  
   
   
       25 . A method of growing cells, the method comprising: 
 providing the microcarrier bead of  claim 1;     providing cells within the microcarrier bead; and    providing a bioreactor having an agitation rate and a sparging rate beyond the shear limit of cells in suspension.