Direct 3D printing of freeform anisotropic bioactive structure based on shear-oriented ink system

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• 3D Bioprinting

Background:

• Anisotropic tissue structures like muscle, skin, and nerves are vital in organisms.
• Replicating these complex anisotropic structures *in vitro* presents a significant challenge in regenerative medicine.
• Current 3D printing methods struggle with direct fabrication of freeform anisotropic bioactive constructs.

Purpose of the Study:

• To develop a novel 3D printable ink system for fabricating freeform anisotropic tissue structures.
• To demonstrate the bioactivity and cell-guiding capabilities of the printed anisotropic constructs.
• To advance the potential for *in vitro* tissue repair and replacement of native anisotropic tissues.

Main Methods:

• Development of a ternary ink system combining Pluronic F127 (F), gelatin methacryloyl (G), and high-molecular-weight polyethylene glycol (P).
• Utilized shear-induced alignment within the ink during 3D printing.
• Characterization of the printed anisotropic structures' bioactivity and cellular response.

Main Results:

• Successfully 3D printed freeform anisotropic tissue structures directly using the ternary ink system.
• The printed anisotropic structures demonstrated excellent bioactivity.
• Promoted orientational growth of various cell types, indicating biomimetic potential.

Conclusions:

• The developed ternary ink system enables direct 3D printing of freeform anisotropic tissue constructs.
• These constructs possess inherent bioactivity and guide cell orientation.
• This technology offers a promising new avenue for anisotropic tissue regeneration and replacement therapies.