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 - Funding Information:
The authors acknowledge the financial support provided by the following organizations: the National Institutes of Health (R21NS095250), the Defense Advanced Research Projects Agency (D14AP00040), the National Science Foundation (DMR1542196), and the Carnegie Mellon University (CMU) School of Engineering. The authors thank the CMU Thermomechanical Characterization Facility in the Department of Materials Science and Engineering. NMR instrumentation at CMU was partially supported by the National Science Foundation (CHE-0130903 and CHE-1039870). W.-C.H. thanks the Ministry of Science and Technology of Taiwan for providing Postdoctoral Scholarship 104-2917-I-564-005-A1.
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 -