Apparatus for making engineered tissue using self-assembling cell aggregates

Abstract

A composition comprising a plurality of cell aggregates for use in the production of engineered organotypic tissue by organ printing. A method of making a plurality of cell aggregates comprises centrifuging a cell suspension to form a pellet, extruding the pellet through an orifice, and cutting the extruded pellet into pieces. Apparatus for making cell aggregates comprises an extrusion system and a cutting system. In a method of organ printing, a plurality of cell aggregates are embedded in a polymeric or gel matrix and allowed to fuse to form a desired three-dimensional tissue structure. An intermediate product comprises at least one layer of matrix and a plurality of cell aggregates embedded therein in a predetermined pattern. Modeling methods predict the structural evolution of fusing cell aggregates for combinations of cell type, matrix, and embedding patterns to enable selection of organ printing processes parameters for use in producing an engineered tissue having a desired three-dimensional structure.

1 . (canceled) 
     
     
         2 . A bioprinting apparatus comprising:
 a. a cartridge comprising a storage chamber, the storage chamber comprising one or more cell aggregates, the cell aggregates comprising extruded cellular material;   b. a dispensing platform;   c. a deposition apparatus configured to deposit the one or more cell aggregates onto the dispensing platform in a pre-determined position; and   d. a computerized control system in electronic communication with the deposition apparatus configured to store three-dimensional structure information, generate dispensing instructions based on the three-dimensional structure information, and provide the instructions to the deposition apparatus to deposit the one or more cell aggregates in the pre-determined position.   
     
     
         3 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are between 100 and 600 microns in their smallest dimension. 
     
     
         4 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are cylindrical, spherical, or cuboidal. 
     
     
         5 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are substantially uniform in shape and size. 
     
     
         6 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates consist essentially of cells. 
     
     
         7 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are a component of a bio-ink, the bio-ink further comprising one or more extracellular matrix components. 
     
     
         8 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are a component of a bio-ink, the bio-ink further comprising a biodegradable gel. 
     
     
         9 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are homocellular. 
     
     
         10 . The bioprinting apparatus of  claim 2 , wherein the cell aggregates are heterocellular. 
     
     
         11 . The bioprinting apparatus of  claim 2 , comprising a plurality of cartridges. 
     
     
         12 . The bioprinting apparatus of  claim 2 , wherein the dispensing platform is temperature controlled. 
     
     
         13 . The bioprinting apparatus of  claim 2 , wherein the deposited cell aggregates are characterized by a high cellular concentration comparable to native mammalian tissues. 
     
     
         14 . A bioprinting system comprising:
 a. an extrusion and cutting unit comprising:
 i. an extruding apparatus comprising a motor, a piston, and a container comprising an orifice, the motor operable to drive the piston through the container to extrude cellular material through the orifice to shape the cellular material; 
 ii. a cutting apparatus comprising an actuator and a blade, the actuator operable to cause the blade to reciprocate across the orifice to cut the extruded cellular material into uniform cell aggregates as the cellular material is extruded through the orifice; 
 iii. a computerized control system in electronic communication with the extrusion apparatus and the cutting apparatus, the first control system configured to provide instructions to the extrusion apparatus and the cutting apparatus; 
   b. a dispensing unit comprising:
 i. a cartridge comprising a storage chamber, the storage chamber comprising one or more of the cell aggregates; 
 ii. a dispensing platform; 
 iii. a deposition apparatus configured to deposit the one or more cell aggregates onto the dispensing platform in a pre-determined position; 
 iv. a computerized control system in electronic communication with the deposition apparatus configured to store three-dimensional structure information, generate dispensing instructions based on the three-dimensional structure information, and provide the instructions to the deposition apparatus to deposit the one or more cell aggregates in the pre-determined position. 
   
     
     
         15 . The bioprinting system of  claim 14 , wherein the orifice is between 100 to 600 microns. 
     
     
         16 . The bioprinting system of  claim 14 , wherein the computerized control system in electronic communication with the extrusion apparatus and the cutting apparatus and the computerized control system in electronic communication with the deposition apparatus are the same computerized control system. 
     
     
         17 . The bioprinting system of  claim 14 , wherein the computerized control system in electronic communication with the extrusion apparatus and the cutting apparatus and the computerized control system in electronic communication with the deposition apparatus are different computerized control systems. 
     
     
         18 . The bioprinting system of  claim 14 , wherein the extrusion and cutting unit is separate from the dispensing unit. 
     
     
         19 . The bioprinting system of  claim 14 , wherein the extrusion and cutting unit is integrated with the dispensing unit. 
     
     
         20 . The bioprinting system of  claim 14 , further comprising a maturation unit, the maturation unit comprising a bioreactor adapted to receive the deposited cell aggregates.