Silk fibroin scaffolds with muscle-like elasticity supportin vitrodifferentiation of human skeletal muscle cells

Abstract

Human adult skeletal muscle has a limited ability to regenerate after injury and therapeutic options for volumetric muscle loss are few. Technologies to enhance regeneration of tissues generally rely upon bioscaffolds to mimic aspects of the tissue extracellular matrix (ECM). In the present study, silk fibroins from four Lepidoptera (silkworm) species engineered into three‐dimensional scaffolds were examined for their ability to support the differentiation of primary human skeletal muscle myoblasts. Human skeletal muscle myoblasts (HSMMs) adhered, spread and deposited extensive ECM on all the scaffolds, but immunofluorescence and quantitative polymerase chain reaction analysis of gene expression revealed that myotube formation occurred differently on the various scaffolds. Bombyx mori fibroin scaffolds supported formation of long, well‐aligned myotubes, whereas on Antheraea mylitta fibroin scaffolds the myotubes were thicker and shorter. Myotubes were oriented in two perpendicular layers on Antheraea assamensis scaffolds, and scaffolds of Philosamia/Samia ricini (S. ricini) fibroin poorly supported myotube formation. These differences were not caused by fibroin composition per se, as HSMMs adhered to, proliferated on and formed striated myotubes on all four fibroins presented as two‐dimensional fibroin films. The Young's modulus of A. mylitta and B. mori scaffolds mimicked that of normal skeletal muscle, but A. assamensis and S. ricini scaffolds were more flexible. The present study demonstrates that although myoblasts deposit matrix onto fibroin scaffolds and create a permissive environment for cell proliferation, a scaffold elasticity resembling that of normal muscle is required for optimal myotube length, alignment, and maturation. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. StartCopTextStartCopText© 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

Design of Bio-Conjugated Hydrogels for Regenerative Medicine Applications: From Polymer Scaffold to Biomolecule Choice

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Obstacles and challenges for tissue engineering and regenerative medicine: Australian nuances

“…Silk fibroin protein can be spun to various thicknesses and cells readily attach and grow on this surface and thus it is attractive as a substrate for bioengineering purposes. The composition varies between different types of silk moths and a comparison of 4 sources of silk in tissue culture showed an excellent capacity to support myogenesis . Acellular silk sheets have been used in vivo to repair tympanic membranes perforations in the ear of rodent models: they are biocompatible, with excellent acoustic and mechanical properties, and hold promise for clinical applications.…”

“…The composition varies between different types of silk moths and a comparison of 4 sources of silk in tissue culture showed an excellent capacity to support myogenesis. 44 Acellular silk sheets have been used in vivo to repair tympanic membranes perforations in the ear of rodent models: they are biocompatible, 45 with excellent acoustic and mechanical properties, 46 and hold promise for clinical applications. Other natural materials include alginate (a polysaccharide derived from seaweed) and even apple derived cellulose 3D scaffolds have been used for mammalian cell culture 47 : many creative possibilities can be explored in vitro.…”

Growth factor-free salt-leached silk scaffolds for differentiating endothelial cells

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