Utilizing Low Temperatures to Reduce Deformation in 3D Printed Hydrogel Lattices

Patients who experience end-stage organ failure frequently require life-saving transplants. In order to mitigate the impact of the shortage, researchers have aimed to produce 3D bioprinted multi cellular constructs that can effectively replace damage organs in the human body and improve patient outcomes. Extrusion-based bioprinting is commonly used to create cell-laden lattice structures that have been implanted in animals to enhance the function of diseased organs. Extrusion-based bioprinting provides the printing resolution necessary to produce the morphological and cellular complex tissue lattices including intricate vascular channels necessary to support cell growth and proliferation. However, extrusion-based bioprinting requires the use of hydrogels with rheological properties that are such to produce stiffer tissues in order to maintain the 3D structures printer, and it is not ideal for softer tissues like brain and lung. There is the need to develop methods that enable the bioprinting of softer tissues. Cryogenic-based bioprinting has been used as a method to bioprint soft tissues. We produced a low-temperature 3D bioprinting assembly with a Peltier platform and investigated the effect of low-temperature on bioink deformation upon deposition. A custom build platform installed into a Cellink™ Inkredible Bioprinter stabilized the implanted Peltier device and enhanced heat dissipation for the achievement of lower temperatures. We hypothesized that a reduction in deformation and collapse might increase bioprint shape fidelity and resolution. Upon initial inspection, the proof of concept studies indicated the trend that low-temperature lattices have a smaller area of deformation in comparison to room temperature lattices. Further analyses indicated no statistically significant difference between pore size and compactness of lattices printed at room and low-temperatures. Future studies should continue to analyze printing parameters and conduct identical analyses with layered lattices of significant height in which filament fusion and collapse becomes a larger concern.