Self-assembling cell aggregates and methods of making engineered tissue using the same

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 - 66 . (canceled) 
     
     
         67 . A bioprinting system comprising:
 a. an extrusion and cutting unit comprising:
 i. an extrusion 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 apparatus in electronic communication with the extrusion apparatus and the cutting apparatus, the computerized 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 apparatus 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, 
   
       wherein the computerized control apparatus in electronic communication with the extrusion and cutting unit and the computerized control apparatus in electronic communication with the dispensing unit are the same computerized control apparatus. 
     
     
         68 . The bioprinting system of  claim 67 , wherein the orifice is between 100 to 600 microns. 
     
     
         69 . The bioprinting system of  claim 67 , wherein the extrusion and cutting unit is separate from the dispensing unit. 
     
     
         70 . The bioprinting system of  claim 67 , wherein the extrusion and cutting unit is integrated with the dispensing unit.