3D Printing Of Gel Networks

A process according to any one of the preceding claims wherein the gel network comprises at least 50 joined gel objects.

A process according to any one of the preceding claims wherein the region for producing the gel network comprises a liquid medium which is immiscible with the gel objects.

A process according to any one of the preceding claims wherein the region for producing the gel network comprises a liquid medium which is immiscible with a flowable gel precursor material from which the gel objects are formed.

A process according to any one of the preceding claims which further comprises moving a microfluidic channel relative to the region for producing the network in between dispensing gel objects from said microfluidic channel.

A process according to any one of the preceding claims wherein each gel object is dispensed adjacent to at least one other gel object in said region for producing the network.

A process according to any one of the preceding claims which comprises controlling the position at which each gel object is dispensed relative to other gel objects in said region for producing the network.

A process according to any one of the preceding claims which comprises controlling the orientation of each gel object that is dispensed relative to other gel objects in said region for producing the network.

A process according to any one of the preceding claims which comprises controlling the position at which each gel object is dispensed, and controlling the orientation of each gel object that is dispensed, relative to other gel objects in said region for producing the network.

A process according to any one of the preceding claims which comprises controlling the sequence in which different types of gel objects are formed within a microfluidic channel, and thus controlling the relative position of said gel objects within the gel network.

A process according to any one of the preceding claims wherein the gel network has the shape of an organ or tissue within the human or animal body.

A process according to any one of the preceding claims wherein the gel objects are incompletely gelled when they are contacted with one another and the process comprises contacting each gel object with at least one other gel object in said region for producing the network to form a gel bond between each gel object and at least one other gel object at a region of contact between the gel objects.

A process according to any one of the preceding claims wherein joining each gel object to at least one other gel object comprises forming a gel bond between each gel object and at least one other gel object at said region of contact between the gel objects.

A process according to any one of the preceding claims which comprises forming the gel objects in the one or more microfluidic channels from a flowable gel precursor material, which gel precursor material comprises a gel-forming agent and a fluid.

A process according to any one of the preceding claims wherein the one or more microfluidic channels have a diameter of from 10 to 2000 μm.

A process according to any one of the preceding claims wherein:

• forming each gel object in a microfluidic channel comprises forming said gel object and an adjacent plug in the microfluidic channel;
• and
• dispensing a gel object from a microfluidic channel comprises dispensing said gel object and dispensing an adjacent plug from said microfluidic channel.

A process according to any one of the preceding claims wherein the process is controlled by a computer program.

A process according to any one of the preceding claims wherein the gel objects are hydrogel objects.

A process according to any one of the preceding claims which further comprises incubating the network of joined gel objects for an incubation period.

A process according to any one of the preceding claims which further comprises a cross-linking step.

A process according to any one of the preceding claims wherein the process is performed in the absence of surfactants.

A process according to any one of the preceding claims wherein the gel objects are rod-shaped.

A process according to any one of the preceding claims wherein each gel object has a volume of from 1.0×10−7 μl to 10 μl, preferably from 1.0×10−3 μl to 1 μl.

A process according to any one of the preceding claims wherein the gel network has a volume of from 1 mm3 to 500 cm3, preferably from 0.5 cm3 to 200 cm3, more preferably from 5 cm3 to 100 cm3, and more preferably from 10 cm3 to 80 cm3.

A process according to any one of the preceding claims wherein the gel objects comprise gel objects which have regions of differing composition, wherein each gel object which has regions of differing composition comprises:

• a first region and a second region, the first region having a composition which is different from that of the second region.

A process according to any one of the preceding claims wherein forming a plurality of gel objects in one or more microfluidic channels comprises introducing a portion of a second gel precursor material adjacent to a portion of a first gel precursor material within the or each microfluidic channel, wherein the compositions of the first and second gel precursor materials are different.

A process according to any one of the preceding claims wherein the gel objects comprise Janus rods.

A process according to any one of the preceding claims wherein the gel network is as defined in any one of claims 54 to 78.

A network of joined gel objects, which network comprises a plurality of gel objects, wherein each gel object is joined to an adjacent gel object at a region of contact between the gel objects.