Abstract
Bioprinting of cellular aggregates, such as tissue spheroids or organoids, in complex three-dimensional (3D) arrangements has been a major obstacle for scaffold-free fabrication of tissues and organs. In this research, we unveiled a new approach to the bioprinting of tissue spheroids in a yield stress granular gel, which exhibited unprecedented capabilities in freeform positioning of spheroids in 3D. Due to its Herschel-Bulkley and self-healing properties as well as its biological inertness, the granular gel supported both the positioning and self-assembly of tissue spheroids. We studied the underlying physical mechanism of the approach to elucidate the interactions between the aspirated spheroids and the gel’s yield-stress during the transfer of spheroids from cell media to the gel. We demonstrate the application of the proposed approach in the realization of various freeform shapes and self-assembly of human mesenchymal stem cell spheroids for the construction of cartilage and bone tissues.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
↵* Ibrahim T. Ozbolat: ito1{at}psu.edu, Engineering Science and Mechanics Department, Biomedical Engineering Department, The Huck Institutes of the Life Sciences, Material Research Institute, Penn State University, W313 Millennium Science Complex, University Park, PA, 16802, USA