. Author manuscript; available in PMC: 2017 Jan 1.

Published in final edited form as: Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2015 Jun 26;8(1):123–138. doi: 10.1002/wnan.1350

Table 1. Engineered biopolymers and the structures they assemble.

Biopolymer	Response to heating	Nature of assembly	Reversible	Structures formed	Applications	References
Oligonucleotides
DNA	Disassemble	ssDNA to dsDNA	Yes	Origami	Scaffolding, Encapsulation, Bioreactors	^{23-26, 28}

Polysaccharides
Chitosan	Disassemble	Conferred by PNIPAM	Yes	Nanogel	Drug delivery, Food science	^32-35
κ-carrrageenan	Disassemble	Double helix to random coil	Yes	Nanosphere, Nanogel	Drug delivery, Thickening agent	^37-39
Gellan Gum	Disassemble	Double helix to random coil	Yes	Hydrogel	Tissue engineering	^{40, 41}
Xanthan Gum	Disassemble	Ordered helix to disordered coil	Yes	Hydrogel	Drug delivery	^{31, 42, 43}

Polypeptides
Coiled-coil	Disassemble	Alpha helix to random coil	Yes	Nanorope, Origami	Nanoreactor, Drug targeting, Drug delivery	^{49, 52, 77, 78}
Collagen-like	Disassemble	Triple helix to random coil	No	Nanofiber, Nanosheet	Tissue engineering	^54-56
Elastin-like	Assemble	Random coil to β-turn spiral	Yes	Micelle, Vesicle, Nanofiber, Hydrogel	Protein purification, Drug delivery, Intracellular switches	^{1, 58-63, 66, 67, 79}
Silk-like	Assemble	β-sheet	Yes/No^*	Hydrogel, Micelle,	Drug delivery	^{68-71, 80}
Resilin	Disassemble/Assemble	Spherical network to particles	Yes	Spherical nanoparticle	Biosensors, Drug delivery	^{46, 72}

Polypeptides (de novo)
17-H-6	Disassemble/Assemble	Folded α-helix to unfolded β-sheet	Yes/No	Multimer, Nanofiber	Drug delivery	^{73, 74}
YEHK	Disassemble	Antiparallel β-sheet to random coil	Yes	Nanofiber	Nanoelectronics	^{75, 76}

Silk-like polymer reversibility is contingent on ratio of silk to elastin polymer ratio