Ionic strength responsive properties of SELP dynamic hydrogels. LCST was
determined by DSC heat flow vs. temperature curves for 2% SELPs, suggesting (a)
a silk-to-elastin ratio and (b) the position of the
“X” residue governed the chemical response. Keys:
SE8Y (orange curves), S2E8Y (green curves),
S4E8Y hydrogel (grey curves) and
S2E8R (blue curves) in 1M NaCl (solid curves) or
deionized water (dashed curves). Storage modulus of 10% SELP hydrogels was
determined by DMA at 4, 10, 22 and 37°C, suggesting the response to ionic
strength depended on (c) silk-to-elastin ratio and (d) position
“X” residue in elastin block. (e) Optical and
(f) SEM images showing the size and micro-morphology of 2%
S2E8R hydrogel samples in swollen states at 4°C
(<LCST) and in contracted states at 37°C (>LCST) in
deionized water and 1M NaCl.