TY - JOUR
T1 - Ultrasound-Mediated Self-Healing Hydrogels Based on Tunable Metal-Organic Bonding
AU - Huang, Wei Chen
AU - Zhao, Jingsi
AU - Rhee, Kelsey
AU - Bettinger, Christopher J.
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/4/10
Y1 - 2017/4/10
N2 - Stimulus-responsive hydrogels make up an important class of programmable materials for a wide range of biomedical applications. Ultrasound (US) is a stimulus that offers utility because of its ability to permeate tissue and rapidly induce chemical alterations in aqueous media. Here we report on the synthesis and US-mediated disintegration of stimulus-responsive telechelic Dopa-modified polyethylene glycol-based hydrogels. Fe3+-[PEG-Dopa]4 hydrogels are formed through Fe3+-induced cross-linking of four-arm polyethylene glycol-dopamine precursors to produce networks. The relative amounts of H-bonds, coordination bonds, and covalent bonds can be controlled by the [Fe3+]:[Dopa] molar ratio in precursor solutions. Networks formed from precursors with high [Fe3+]:[Dopa] ratios create mechanically robust networks (G′ = 6880 ± 240 Pa) that are largely impervious to US-mediated disintegration at intensities of ≤43 W/cm2. Conversely, lightly cross-linked networks formed through [Fe3+]:[Dopa] molar ratios of <0.73 are susceptible to rapid disintegration upon exposure to US. Pulsatile US exposure allows temporal control over hydrogel disintegration and programmable self-healing. Sustained US energy can also stabilize hydrogels through the formation of additional cross-links via free radical-mediated coupling of pendant catechols. Taken together, the diverse ranges of mechanical behavior, self-healing capability, and differential susceptibility to ultrasonic disintegration suggest that Fe3+-[PEG-Dopa]4 hydrogels yield a class of application-specific stimulus-responsive polymers as smart materials for applications ranging from transient medical implants to matrices for smart drug delivery.
AB - Stimulus-responsive hydrogels make up an important class of programmable materials for a wide range of biomedical applications. Ultrasound (US) is a stimulus that offers utility because of its ability to permeate tissue and rapidly induce chemical alterations in aqueous media. Here we report on the synthesis and US-mediated disintegration of stimulus-responsive telechelic Dopa-modified polyethylene glycol-based hydrogels. Fe3+-[PEG-Dopa]4 hydrogels are formed through Fe3+-induced cross-linking of four-arm polyethylene glycol-dopamine precursors to produce networks. The relative amounts of H-bonds, coordination bonds, and covalent bonds can be controlled by the [Fe3+]:[Dopa] molar ratio in precursor solutions. Networks formed from precursors with high [Fe3+]:[Dopa] ratios create mechanically robust networks (G′ = 6880 ± 240 Pa) that are largely impervious to US-mediated disintegration at intensities of ≤43 W/cm2. Conversely, lightly cross-linked networks formed through [Fe3+]:[Dopa] molar ratios of <0.73 are susceptible to rapid disintegration upon exposure to US. Pulsatile US exposure allows temporal control over hydrogel disintegration and programmable self-healing. Sustained US energy can also stabilize hydrogels through the formation of additional cross-links via free radical-mediated coupling of pendant catechols. Taken together, the diverse ranges of mechanical behavior, self-healing capability, and differential susceptibility to ultrasonic disintegration suggest that Fe3+-[PEG-Dopa]4 hydrogels yield a class of application-specific stimulus-responsive polymers as smart materials for applications ranging from transient medical implants to matrices for smart drug delivery.
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U2 - 10.1021/acs.biomac.6b01841
DO - 10.1021/acs.biomac.6b01841
M3 - Article
C2 - 28245355
AN - SCOPUS:85018522779
SN - 1525-7797
VL - 18
SP - 1162
EP - 1171
JO - Biomacromolecules
JF - Biomacromolecules
IS - 4
ER -