3D Bioprinting of Cellulose with Controlled Porous Structures from NMMO

In the present work, dissolved cellulose has been 3D bioprinted to produce complex structures with ordered interconnected pores. The process consists of the dissolution of dissolving pulps in N-methylmorpholine-N-oxide (NMMO), multilayered dispensing, water removal of NMMO and freeze-drying. 3D bioprinting of cellulose/NMMO solution at 70 ℃ was analogous to that of thermoplastics by the process of melting and solidification to produce cellulose/NMMO objects in the solid form. However, 3D bioprinting of cellulose/NMMO solution at a higher temperature than 70 ℃ produced cellulose/NMMO objects in the gel form. Cellulose was regenerated by water; thereafter, freeze-drying treatment maintained the 3D bioprinted structures without collapsing. The final cellulose products had remarkable Young’s compressive modulus (12.9 MPa) and tensile modulus (160.6 MPa). This work demonstrated the feasibility of cellulose as an alternative in the 3D printing industry to the production of complex structures.