3D printing facilitated scaffold-free tissue unit fabrication.
Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing microdroplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit microdroplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation.
Department of Bioengineering, Clemson University, Clemson, SC, USA. Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA.
Yu
Y
Tan
Dylan J
DJ
Richards
Thomas C
TC
Trusk
Richard P
RP
Visconti
Michael J
MJ
Yost
Mark S
MS
Kindy
Christopher J
CJ
Drake
William Scott
WS
Argraves
Roger R
RR
Markwald
Ying
Y
Mei
D000464:Alginates / Q000737:chemistry; D000465:Algorithms; D062028:Bioprinting / Q000379:methods*; D002460:Cell Line; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D066330:Printing, Three-Dimensional; D018874:Spheroids, Cellular / Q000166:cytology; D023822:Tissue Engineering / Q000379:methods*
D000464:Alginates; D006603:Hexuronic Acids; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid