Freeze Casting Peptide-Enabled Biomaterials for Tissue Regeneration

While considerable progress has been made over the past years and decades, the challenge persists to synthesize, ideally off-the-shelf materials and scaffolds, with structural, mechanical, and chemical cues akin to the natural tissue or custom- designed for a desired regenerative outcome. Freeze casting permits to manufacture such complex, hybrid materials with excellent control of structural and mechanical properties. As a cold process, freeze casting additionally offers several pathways to introduce what could broadly be called chemical cues such as growth factors, viral vectors and peptides at several processing steps to enhance the functional properties of the final biomaterial. Chemical cues can be introduced already before the freeze casting step through peptide loading and peptide-functionalized components, such as collagen, chitosan, and nanocellulose for soft and hydroxyapatite and tricalcium phosphate for hard tissues, for example. Alternatively, the hierarchical architecture of the freeze-cast scaffolds can be modified with peptides or peptide-enhanced entities once the structure has been ice-templated and lyophilized (freeze-dried). Freeze casting and related manufacturing techniques therefore hold great promise for the manufacture of peptide-enabled biomaterials.