Accordion-Like Honeycombs for Tissue Engineering of Cardiac Anisotropy

Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-330 Cambridge, Massachusetts 02139, USA.
Nature Materials (Impact Factor: 36.5). 12/2008; 7(12):1003-10. DOI: 10.1038/nmat2316
Source: PubMed


Tissue-engineered grafts may be useful in myocardial repair; however, previous scaffolds have been structurally incompatible with recapitulating cardiac anisotropy. Here, we use microfabrication techniques to create an accordion-like honeycomb microstructure in poly(glycerol sebacate), which yields porous, elastomeric three-dimensional (3D) scaffolds with controllable stiffness and anisotropy. Accordion-like honeycomb scaffolds with cultured neonatal rat heart cells demonstrated utility through: (1) closely matched mechanical properties compared to native adult rat right ventricular myocardium, with stiffnesses controlled by polymer curing time; (2) heart cell contractility inducible by electric field stimulation with directionally dependent electrical excitation thresholds (p<0.05); and (3) greater heart cell alignment (p<0.0001) than isotropic control scaffolds. Prototype bilaminar scaffolds with 3D interconnected pore networks yielded electrically excitable grafts with multi-layered neonatal rat heart cells. Accordion-like honeycombs can thus overcome principal structural-mechanical limitations of previous scaffolds, promoting the formation of grafts with aligned heart cells and mechanical properties more closely resembling native myocardium.

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Available from: Christopher J Bettinger
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    • "The SILICOMB features a zero-ν behaviour by using a geometry inspired to the tessellation of the β-cristobalite lattice [29] [30]. One example of application of ZPR honeycombs with accordion-like honeycomb microstructures is biomedical scaffolds [31], and in the field of morphing aircraft flexible sandwich structures with cellular cores and flexible face sheets have been proposed as a promising solution for morphing skins [23] [32] [33]. ZPR honeycombs have been used in flexible skins undergoing one-dimensional spanwise morphing [22] [23] [32] [33] and have also demonstrated their potential in planar morphing applications [34]. "
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    • "In the analysis of matrix coatings, fibronectin proved to be the most suitable for this experiment in terms of viable cell area and cell density. The measured Young's modulus value of PDMS device ( $ 150 kPa) matches the stiffness values in the previously studied cardiac tissue models, and native rat myocardium has a Young's modulus in the range of 10–150 kPa (Bhana et al., 2010; Engelmayr et al., 2008a; Jawad et al., 2007). This suggests that the fabricated PDMS devices are able to create a mechanical environment similar to that of heart tissue. "
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