title: A 3D bioprinted complex structure for engineering the muscle-tendon unit.
abstract: Three-dimensional integrated organ printing (IOP) technology seeks to fabricate tissue constructs that can mimic the structural and functional properties of native tissues. This technology is particularly useful for complex tissues such as those in the musculoskeletal system, which possess regional differences in cell types and mechanical properties. Here, we present the use of our IOP system for the processing and deposition of four different components for the fabrication of a single integrated muscle-tendon unit (MTU) construct. Thermoplastic polyurethane (PU) was co-printed with C2C12 cell-laden hydrogel-based bioink for elasticity and muscle development on one side, while poly(ϵ-caprolactone) (PCL) was co-printed with NIH/3T3 cell-laden hydrogel-based bioink for stiffness and tendon development on the other. The final construct was elastic on the PU-C2C12 muscle side (E = 0.39 ± 0.05 MPa), stiff on the PCL-NIH/3T3 tendon side (E = 46.67 ± 2.67 MPa) and intermediate in the interface region (E = 1.03 ± 0.14 MPa). These constructs exhibited >80% cell viability at 1 and 7 d after printing, as well as initial tissue development and differentiation. This study demonstrates the versatility of the IOP system to create integrated tissue constructs with region-specific biological and mechanical characteristics for MTU engineering.
authors.affiliation: Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA. Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Tyler K
authors.initials: TK
authors.lastname: Merceron
authors.forename: Morgan
authors.initials: M
authors.lastname: Burt
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Seol
authors.forename: Hyun-Wook
authors.initials: HW
authors.lastname: Kang
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: James J
authors.initials: JJ
authors.lastname: Yoo
authors.forename: Anthony
authors.initials: A
authors.lastname: Atala
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D062028:Bioprinting / Q000379:methods*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051379:Mice; D066330:Printing, Three-Dimensional; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials