title: On-demand three-dimensional freeform fabrication of multi-layered hydrogel scaffold with fluidic channels.
abstract: One of the challenges in tissue engineering is to provide adequate supplies of oxygen and nutrients to cells within the engineered tissue construct. Soft-lithographic techniques have allowed the generation of hydrogel scaffolds containing a network of fluidic channels, but at the cost of complicated and often time-consuming manufacturing steps. We report a three-dimensional (3D) direct printing technique to construct hydrogel scaffolds containing fluidic channels. Cells can also be printed on to and embedded in the scaffold with this technique. Collagen hydrogel precursor was printed and subsequently crosslinked via nebulized sodium bicarbonate solution. A heated gelatin solution, which served as a sacrificial element for the fluidic channels, was printed between the collagen layers. The process was repeated layer-by-layer to form a 3D hydrogel block. The printed hydrogel block was heated to 37 degrees C, which allowed the gelatin to be selectively liquefied and drained, generating a hollow channel within the collagen scaffold. The dermal fibroblasts grown in a scaffold containing fluidic channels showed significantly elevated cell viability compared to the ones without any channels. The on-demand capability to print fluidic channel structures and cells in a 3D hydrogel scaffold offers flexibility in generating perfusable 3D artificial tissue composites.
authors: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors: Wonhye
authors: W
authors: Lee
authors: Vivian
authors: V
authors: Lee
authors: Samuel
authors: S
authors: Polio
authors: Phillip
authors: P
authors: Keegan
authors: Jong-Hwan
authors: JH
authors: Lee
authors: Krisztina
authors: K
authors: Fischer
authors: Je-Kyun
authors: JK
authors: Park
authors: Seung-Schik
authors: SS
authors: Yoo
mesh_terms: D003094:Collagen / Q000737:chemistry; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D005780:Gelatin / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D010477:Perfusion / Q000295:instrumentation / Q000379:methods; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D005780:Gelatin; D003094:Collagen