Creating Biomimetic Anisotropic Architectures with Co-Aligned Nanofibers and Macrochannels by Manipulating Ice Crystallization

An icy grip on tissue engineering

28 September 2018

Ice crystals could help tissue engineers create templates on which to grow replacement tissues for damaged body parts. 

Cells use many cues, including their physical surroundings, to grow into functioning tissues in the body. In muscle, for example, an extracellular scaffold of aligned collagen nanofibers helps muscle cells line up so they all pull in the same direction. Making artificial tissue scaffolds is challenging, because it is difficult to create networks of aligned nanofibers that also incorporate the pores that cells need to penetrate the scaffold and grow. Now, Deakin University researchers have used ice crystals to emulate these nanoscale pores.

When the team dunked a solution of silk strands into a beaker of liquid nitrogen, the high temperature gradient triggered the rapid formation of fine ice crystals aligned along that gradient. Silk strand nanofibers then grew along the crystals, forming an aligned nanofiber network. When this material was placed in a regular freezer, large ice crystals slowly grew between the nanofibers, creating a network of pores that remained when the scaffold was thawed.

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References

1. ACS Nano 12, 5780–5790 (2018). doi: 10.1021/acsnano.8b01648