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 . (canceled) 
     
     
         2 . An automated device for producing a plurality of bio-ink cell aggregates comprising:
 a. a container for containing a cell aggregate, the cell aggregate comprising a plurality of living cells, the container comprising an orifice;   b. a cell aggregate advancement component comprising a motor operable to move a piston through the container to advance the cell aggregate through the orifice; and   c. a cell aggregate cutting component comprising an actuator connected to a cutting blade, the cutting blade operable to cut the cell aggregate into pieces to produce the plurality of bio-ink cell aggregates as the cell aggregate is advanced.   
     
     
         3 . The device of  claim 2 , wherein the piston comprises a wire rod. 
     
     
         4 . The device of  claim 2 , wherein the container comprises a micropipette. 
     
     
         5 . The device of  claim 2 , wherein the orifice has a circular cross section. 
     
     
         6 . The device of  claim 2 , wherein the orifice is between 100 to 600 microns. 
     
     
         7 . The device of  claim 2 , wherein the motor comprises a linear servo motor. 
     
     
         8 . The device of  claim 2 , further comprising a computerized control system in electronic communication with the cell aggregate advancement component, the control system configured to provide instructions to the advancement component. 
     
     
         9 . The device of  claim 8 , wherein the instructions comprise a motion profile. 
     
     
         10 . The device of  claim 8 , wherein the control system provides instructions to the motor to operate at a substantially constant speed. 
     
     
         11 . The device of  claim 8 , wherein the control system provides instructions to the motor to operate at a variable speed to produce a bio-ink cell aggregates with a predetermined size distribution. 
     
     
         12 . The device of  claim 2 , further comprising a computerized control system in electronic communication with the cell aggregate cutting component, the control system configured to provide instructions to the cutting component. 
     
     
         13 . The device of  claim 12 , wherein the instructions comprise a motion profile. 
     
     
         14 . The device of  claim 12 , wherein the control system provides instructions to the actuator to operate at a substantially constant speed. 
     
     
         15 . The device of  claim 12 , wherein the control system provides instructions to the actuator to operate at a variable speed to produce a bio-ink cell aggregates with a predetermined size distribution. 
     
     
         16 . The device of  claim 2 , wherein the cutting blade is a reciprocating blade. 
     
     
         17 . The device of  claim 2 , wherein the cutting blade is a microtome blade. 
     
     
         18 . The device of  claim 2 , wherein the cell aggregate consists essentially of living cells. 
     
     
         19 . The device of  claim 2 , configured to produce bio-ink cell aggregates between 100 and 600 microns in their smallest dimension. 
     
     
         20 . The device of  claim 2 , configured to produce bio-ink cell aggregates substantially uniform in shape and size. 
     
     
         21 . The device of  claim 2 , wherein the bio-ink cell aggregates comprise one or more extracellular matrix components. 
     
     
         22 . The device of  claim 2 , wherein the bio-ink cell aggregates comprising a biodegradable gel. 
     
     
         23 . The device of  claim 2 , wherein the bio-ink cell aggregates are homocellular. 
     
     
         24 . The device of  claim 2 , wherein the bio-ink cell aggregates are heterocellular. 
     
     
         25 . The device of  claim 2 , comprising a plurality of containers and pistons for producing bio-ink cell aggregates in parallel to increase production rate. 
     
     
         26 . The device of  claim 2 , further comprising a temperature control component. 
     
     
         27 . The device of  claim 2 , further comprising a maturation unit, the maturation unit comprising a bioreactor adapted to receive the produced bio-ink cell aggregates. 
     
     
         28 . The device of  claim 2 , wherein the produced bio-ink cell aggregates are characterized by a high cellular concentration comparable to native mammalian tissues.