Flexural characterization of cell encapsulated PEGDA hydrogels with applications for tissue engineered heart valves

TitleFlexural characterization of cell encapsulated PEGDA hydrogels with applications for tissue engineered heart valves
Publication TypeJournal Article
Year of Publication2011
AuthorsDurst, CA, Cuchiara, MP, Mansfield, EG, West, JL, Grande-Allen, JK
JournalActa Biomaterialia
Volume7
Issue6
Pagination2467 - 2476
Date Published6/2011
ISSN17427061
KeywordsFlexure and bending mechanics; Heparin; hydrogels; Polyethylene glycol diacrylate; Tissue engineered heart valve
Abstract

The limitations of the current clinical options for valve replacements have inspired the development of enabling technologies to create a tissue engineered heart valve (TEHV). Poly(ethylene glycol) diacrylate (PEGDA) hydrogel scaffolds permit greater biological and biomechanical customization than do non-woven mesh scaffold technologies. However, the material characterization of PEGDA hydrogels has been predominantly limited to compression and tension, as opposed to bending. Since large flexural deformations result in points of maximum stress in native valves as well as TEHVs, it is crucial to evaluate any potential scaffold material in this mode. The effect of formulation parameters on the bending mechanics of cell-seeded PEGDA hydrogels were investigated with a custom designed bending tester. Three molecular weights (3.4, 6, and 8 kDa) and three weight fractions (5%, 10%, and 15%, w/v) were subjected to three-point bending tests and the flexural stiffness was calculated. Manipulating the composition of the hydrogels resulted in flexural stiffnesses comparable with native tissues (15–220 kPa) with varied mesh sizes and swelling ratios. Hydrogels containing encapsulated valve cells, methacrylated heparin (Hep-MA), or both were substantially less stiff than acellular hydrogels. In conclusion, PEGDA hydrogels are an attractive potential scaffold system for TEHVs because they are not only cytocompatible and modifiable but can also withstand bending deformations. These studies are the first to explore the encapsulation of valvular interstitial cells in pure PEGDA hydrogels as well as to investigate the bending properties of PEGDA gels.

DOI10.1016/j.actbio.2011.02.018
Short TitleActa Biomaterialia
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