Structural Reinforcement of Cell-Laden Hydrogels with Microfabricated Three Dimensional Scaffolds.
Hydrogels commonly used in tissue engineering are mechanically soft, thus often display structural weakness. Herein, we introduce a strategy for enhancing the structural integrity and fracture toughness of cell-laden hydrogels by incorporating a three-dimensional (3D) microfabricated scaffold as a structural element. A digital micromirror device projection printing (DMD-PP) system, a rapid prototyping technology which employs a layer-by-layer stereolithographic approach, was utilized to efficiently fabricate 3D scaffolds made from photocrosslinkable poly(ethylene glycol) diacrylate (PEGDA). The scaffold was incorporated into a photocrosslinkable gelatin hydrogel by placing it in a pre-gel solution, and inducing in situ hydrogel formation. The resulting scaffold-reinforced hydrogels demonstrated significant increase in ultimate stress and provided structural support for weak hydrogels. In addition, the scaffold did not affect the rigidity of hydrogels, as it was not involved in the crosslinking reaction to form the hydrogel. Therefore, the presented approach could avoid inadvertent and undesired changes in the hydrogel rigidity which is a known regulator of cellular activities. Furthermore, the biocompatibility of scaffold-reinforced hydrogels was confirmed by evaluating the viability and proliferation of encapsulated fibroblasts. Overall, the strategy of incorporating 3D scaffolds into hydrogels as structural reinforcements presented in this study will be highly useful for enhancing the mechanical toughness of hydrogels for various tissue engineering applications.
Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA. Tel: +1-617-388-9271; ; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Chaenyung
C
Cha
Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093, USA. Tel: +1-858-822-7856;
Pranav
P
Soman
Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093, USA. Tel: +1-858-822-7856;
Wei
W
Zhu
Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA. Tel: +1-617-388-9271; ; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Mehdi
M
Nikkhah
Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA. Tel: +1-617-388-9271; ; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Gulden
G
Camci-Unal
Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093, USA. Tel: +1-858-822-7856;
Shaochen
S
Chen
Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA. Tel: +1-617-388-9271; ; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA ; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.
Ali
A
Khademhosseini