Printing biological tissues, a necessary precursor to creating replacement organs, is not easy, but constructing extremely soft and fragile tissues that resemble the brain and lungs is even more difficult. Researchers at Imperial College London and Kings College London are now using extremely cold temperatures in combination with 3D printing to create objects out of a composite hydrogel that are about as stiff as grey matter and lung tissue.
The team used solid CO2 (dry ice) to quickly cool a composite hydrogel ink below its freezing point while in an alcohol bath, allowing the structure to solidify and take on whatever shape the scientists wanted.
The team was then able to seed the artificial tissue, itself coated with collagen, poly-L-lysine, and gelatine, with living skin cells and demonstrated that they were happy to remain in place and continue living within the hydrogel structure.
Much still needs to be done to perfect and further test the technology, but it’s pointing to a future in which replacement tissues, and eventually organs, will be regularly implanted into stricken patients.
Top image: Structure of a single unit; how eight units fit together; two views of a printed and set eight-unit structure.
Study in Scientific Reports: Cryogenic 3D Printing of Super Soft Hydrogels…