title: Multi-material bio-fabrication of hydrogel cantilevers and actuators with stereolithography.
abstract: Cell-based biohybrid actuators are integrated systems that use biological components including proteins and cells to power material components by converting chemical energy to mechanical energy. The latest progress in cell-based biohybrid actuators has been limited to rigid materials, such as silicon and PDMS, ranging in elastic moduli on the order of mega (10(6)) to giga (10(9)) Pascals. Recent reports in the literature have established a correlation between substrate rigidity and its influence on the contractile behavior of cardiomyocytes (A. J. Engler, C. Carag-Krieger, C. P. Johnson, M. Raab, H. Y. Tang and D. W. Speicher, et al., J. Cell Sci., 2008, 121(Pt 22), 3794-3802, P. Bajaj, X. Tang, T. A. Saif and R. Bashir, J. Biomed. Mater. Res., Part A, 2010, 95(4), 1261-1269). This study explores the fabrication of a more compliant cantilever, similar to that of the native myocardium, with elasticity on the order of kilo (10(3)) Pascals. 3D stereolithographic technology, a layer-by-layer UV polymerizable rapid prototyping system, was used to rapidly fabricate multi-material cantilevers composed of poly(ethylene glycol) diacrylate (PEGDA) and acrylic-PEG-collagen (PC) mixtures. The incorporation of acrylic-PEG-collagen into PEGDA-based materials enhanced cell adhesion, spreading, and organization without altering the ability to vary the elastic modulus through the molecular weight of PEGDA. Cardiomyocytes derived from neonatal rats were seeded on the cantilevers, and the resulting stresses and contractile forces were calculated using finite element simulations validated with classical beam equations. These cantilevers can be used as a mechanical sensor to measure the contractile forces of cardiomyocyte cell sheets, and as an early prototype for the design of optimal cell-based biohybrid actuators.
authors: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors: Vincent
authors: V
authors: Chan
authors: Jae Hyun
authors: JH
authors: Jeong
authors: Piyush
authors: P
authors: Bajaj
authors: Mitchell
authors: M
authors: Collens
authors: Taher
authors: T
authors: Saif
authors: Hyunjoon
authors: H
authors: Kong
authors: Rashid
authors: R
authors: Bashir
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000818:Animals; D001696:Biomechanical Phenomena; D002448:Cell Adhesion; D003094:Collagen / Q000737:chemistry; D003198:Computer Simulation; D055119:Elastic Modulus; D020342:Finite Element Analysis; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D008954:Models, Biological; D008958:Models, Molecular; D008970:Molecular Weight; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000166:cytology / Q000502:physiology*; D036103:Nanotechnology; D011092:Polyethylene Glycols / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
chemical_list: D000179:Acrylates; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D003094:Collagen