title: Design and testing of a cyclic stretch and flexure bioreactor for evaluating engineered heart valve tissues based on poly(glycerol sebacate) scaffolds.
abstract: Cyclic flexure and stretch are essential to the function of semilunar heart valves and have demonstrated utility in mechanically conditioning tissue-engineered heart valves. In this study, a cyclic stretch and flexure bioreactor was designed and tested in the context of the bioresorbable elastomer poly(glycerol sebacate). Solid poly(glycerol sebacate) membranes were subjected to cyclic stretch, and micromolded poly(glycerol sebacate) scaffolds seeded with porcine aortic valvular interstitial cells were subjected to cyclic stretch and flexure. The results demonstrated significant effects of cyclic stretch on poly(glycerol sebacate) mechanical properties, including significant decreases in effective stiffness versus controls. In valvular interstitial cell-seeded scaffolds, cyclic stretch elicited significant increases in DNA and collagen content that paralleled maintenance of effective stiffness. This work provides a basis for investigating the roles of mechanical loading in the formation of tissue-engineered heart valves based on elastomeric scaffolds.
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Nafiseh
authors.initials: N
authors.lastname: Masoumi
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA.
authors.forename: M Christian
authors.initials: MC
authors.lastname: Howell
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Johnson
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Niesslein
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Gene
authors.initials: G
authors.lastname: Gerber
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA engelmayr@humacyte.com.
authors.forename: George C
authors.initials: GC
authors.lastname: Engelmayr
keywords: Artificial tissue; biodegradable materials; biomaterials; biomechanical testing/analysis; biomimetics; cardiovascular prostheses; rapid prototyping; scaffold development; tissue culture techniques