Advances in 3D printing have benefited the production of artificial organs, replacement joints and other body parts. Once printed these products must be implanted using invasive surgical procedures that can pose risk of infection and other complications for patients. An ideal solution would be to print tissues directly in the body using a bio-ink engineered specifically for this application by Ohio State University, Pennsylvania State University and California-based Teraski Institute researchers.

The 3D printable gelatin methacryloyl/Laponite/methylcellulose biomaterial is formulated to be crosslinkable using visible light, safe to native tissues and feasible for use at the physiological temperature of 37° C. LaponiteA 3D lattice structure of a tissue implanted directly onto a soft living tissue. Source: Teraski InstituteA 3D lattice structure of a tissue implanted directly onto a soft living tissue. Source: Teraski Institute and methylcellulose function as viscosity modifiers and extend the degradation time of the produced scaffolds. The ink is dispensed from the fine tip of a robotically controlled nozzle surgically inserted into the patient's body through a small incision.

The technology was demonstrated using raw chicken strip and agarose substrates to model human tissue. To hold each strand of the bio-ink in place, the nozzle punctures a small void in the soft internal tissue and deposits an anchoring blob of the ink within that space. As the nozzle is subsequently withdrawn, it places more ink on the outside of that tissue, serving as an additional anchor. The rest of the strand is then drawn over to another anchoring point. Cell viability of 71-77% and consistent mechanical properties over 21 days were observed for the engineered tissue.

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