Binary Thiol-Acrylate Photopolymerization for the Design of Degradable Acetal-Functionalized Hydrogels

James R. Brown; Jana Herzberger; Glenn Allen Spiering; Emily Wilts; Robert B. Moore; Timothy E. Long

doi:10.1021/acsapm.2c01978

Binary Thiol-Acrylate Photopolymerization for the Design of Degradable Acetal-Functionalized Hydrogels

James R. Brown, Jana Herzberger, Glenn Allen Spiering, Emily Wilts, Robert B. Moore, Timothy E. Long

Molecular Sciences, School of (SMS)

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

Degradable poly(ethylene glycol) (PEG) hydrogels provide a versatile platform for drug delivery and tissue engineering, and acetal functionalization now enables photo-processible PEG oligomers with selective and facile degradation in acidic environments. Tailored morphologies within acetal-functionalized hydrogels provided fundamental understanding of the multiphase network degradation. End group modification of poly(ethylene glycol) (Mn = 2,000 g/mol) with 2-(vinyloxy)ethyl acrylate yielded polyether precursors with both pH-sensitive acetals and photo-curable acrylate end groups. UV-initiated binary thiol-acrylate crosslinking of the acetal-functionalized PEG diacrylate with varied amounts of a thiol-functionalized three-armed PEG provided pH-degradable networks. Controlled stoichiometric imbalance of thiol and acrylate functionalities ensured predictable plateau storage moduli from 2 × 105 to 8 × 105 Pa. Small-angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA) confirmed that the thiol/acrylate molar ratio provided hydrogels with varying network architectures and crosslink densities. Spectroscopic monitoring of an imbedded mobile dye (Direct Red-81) quantified hydrogel degradation rates. Degradable hydrogels exhibited bulk degradation in acidic solution. Gels with the lowest crosslink density fully degraded in aqueous solutions at pH 3.4 within 60 h, while the highly crosslinked gels fully degraded over 3 weeks. All hydrogels displayed long-term stability in phosphate-buffered saline (pH 7.4) beyond 3 mo, suggesting stable hydrogels for selective degradation and cargo release in low pH environments.

Original language	English (US)
Journal	ACS Applied Polymer Materials
DOIs	https://doi.org/10.1021/acsapm.2c01978
State	Accepted/In press - 2022

Keywords

acetal
binary thiol-acrylate
controlled release
degradable hydrogel
network morphology

ASJC Scopus subject areas

Process Chemistry and Technology
Polymers and Plastics
Organic Chemistry

Access to Document

10.1021/acsapm.2c01978

Cite this

@article{a91c4c7f253249efa2c5a8b2acd5255a,

title = "Binary Thiol-Acrylate Photopolymerization for the Design of Degradable Acetal-Functionalized Hydrogels",

abstract = "Degradable poly(ethylene glycol) (PEG) hydrogels provide a versatile platform for drug delivery and tissue engineering, and acetal functionalization now enables photo-processible PEG oligomers with selective and facile degradation in acidic environments. Tailored morphologies within acetal-functionalized hydrogels provided fundamental understanding of the multiphase network degradation. End group modification of poly(ethylene glycol) (Mn = 2,000 g/mol) with 2-(vinyloxy)ethyl acrylate yielded polyether precursors with both pH-sensitive acetals and photo-curable acrylate end groups. UV-initiated binary thiol-acrylate crosslinking of the acetal-functionalized PEG diacrylate with varied amounts of a thiol-functionalized three-armed PEG provided pH-degradable networks. Controlled stoichiometric imbalance of thiol and acrylate functionalities ensured predictable plateau storage moduli from 2 × 105 to 8 × 105 Pa. Small-angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA) confirmed that the thiol/acrylate molar ratio provided hydrogels with varying network architectures and crosslink densities. Spectroscopic monitoring of an imbedded mobile dye (Direct Red-81) quantified hydrogel degradation rates. Degradable hydrogels exhibited bulk degradation in acidic solution. Gels with the lowest crosslink density fully degraded in aqueous solutions at pH 3.4 within 60 h, while the highly crosslinked gels fully degraded over 3 weeks. All hydrogels displayed long-term stability in phosphate-buffered saline (pH 7.4) beyond 3 mo, suggesting stable hydrogels for selective degradation and cargo release in low pH environments.",

keywords = "acetal, binary thiol-acrylate, controlled release, degradable hydrogel, network morphology",

author = "Brown, {James R.} and Jana Herzberger and Spiering, {Glenn Allen} and Emily Wilts and Moore, {Robert B.} and Long, {Timothy E.}",

note = "Funding Information: The authors would like to thank both Arizona State University and Virginia Tech for their efforts to support collaboration of this work. We would also like to thank the Biodesign Institute for their continuous support of research within our group. We would also like to thank Garvit Nayyar for his contribution to the additive manufacturing presented in this work. This material is based in-part upon work supported by the National Science Foundation under grant no. DMR-1809291. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Publisher Copyright: {\textcopyright} 2022 American Chemical Society.",

year = "2022",

doi = "10.1021/acsapm.2c01978",

language = "English (US)",

journal = "ACS Applied Polymer Materials",

issn = "2637-6105",

publisher = "American Chemical Society",

}

TY - JOUR

T1 - Binary Thiol-Acrylate Photopolymerization for the Design of Degradable Acetal-Functionalized Hydrogels

AU - Brown, James R.

AU - Herzberger, Jana

AU - Spiering, Glenn Allen

AU - Wilts, Emily

AU - Moore, Robert B.

AU - Long, Timothy E.

N1 - Funding Information: The authors would like to thank both Arizona State University and Virginia Tech for their efforts to support collaboration of this work. We would also like to thank the Biodesign Institute for their continuous support of research within our group. We would also like to thank Garvit Nayyar for his contribution to the additive manufacturing presented in this work. This material is based in-part upon work supported by the National Science Foundation under grant no. DMR-1809291. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Publisher Copyright: © 2022 American Chemical Society.

PY - 2022

Y1 - 2022

N2 - Degradable poly(ethylene glycol) (PEG) hydrogels provide a versatile platform for drug delivery and tissue engineering, and acetal functionalization now enables photo-processible PEG oligomers with selective and facile degradation in acidic environments. Tailored morphologies within acetal-functionalized hydrogels provided fundamental understanding of the multiphase network degradation. End group modification of poly(ethylene glycol) (Mn = 2,000 g/mol) with 2-(vinyloxy)ethyl acrylate yielded polyether precursors with both pH-sensitive acetals and photo-curable acrylate end groups. UV-initiated binary thiol-acrylate crosslinking of the acetal-functionalized PEG diacrylate with varied amounts of a thiol-functionalized three-armed PEG provided pH-degradable networks. Controlled stoichiometric imbalance of thiol and acrylate functionalities ensured predictable plateau storage moduli from 2 × 105 to 8 × 105 Pa. Small-angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA) confirmed that the thiol/acrylate molar ratio provided hydrogels with varying network architectures and crosslink densities. Spectroscopic monitoring of an imbedded mobile dye (Direct Red-81) quantified hydrogel degradation rates. Degradable hydrogels exhibited bulk degradation in acidic solution. Gels with the lowest crosslink density fully degraded in aqueous solutions at pH 3.4 within 60 h, while the highly crosslinked gels fully degraded over 3 weeks. All hydrogels displayed long-term stability in phosphate-buffered saline (pH 7.4) beyond 3 mo, suggesting stable hydrogels for selective degradation and cargo release in low pH environments.

AB - Degradable poly(ethylene glycol) (PEG) hydrogels provide a versatile platform for drug delivery and tissue engineering, and acetal functionalization now enables photo-processible PEG oligomers with selective and facile degradation in acidic environments. Tailored morphologies within acetal-functionalized hydrogels provided fundamental understanding of the multiphase network degradation. End group modification of poly(ethylene glycol) (Mn = 2,000 g/mol) with 2-(vinyloxy)ethyl acrylate yielded polyether precursors with both pH-sensitive acetals and photo-curable acrylate end groups. UV-initiated binary thiol-acrylate crosslinking of the acetal-functionalized PEG diacrylate with varied amounts of a thiol-functionalized three-armed PEG provided pH-degradable networks. Controlled stoichiometric imbalance of thiol and acrylate functionalities ensured predictable plateau storage moduli from 2 × 105 to 8 × 105 Pa. Small-angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA) confirmed that the thiol/acrylate molar ratio provided hydrogels with varying network architectures and crosslink densities. Spectroscopic monitoring of an imbedded mobile dye (Direct Red-81) quantified hydrogel degradation rates. Degradable hydrogels exhibited bulk degradation in acidic solution. Gels with the lowest crosslink density fully degraded in aqueous solutions at pH 3.4 within 60 h, while the highly crosslinked gels fully degraded over 3 weeks. All hydrogels displayed long-term stability in phosphate-buffered saline (pH 7.4) beyond 3 mo, suggesting stable hydrogels for selective degradation and cargo release in low pH environments.

KW - acetal

KW - binary thiol-acrylate

KW - controlled release

KW - degradable hydrogel

KW - network morphology

UR - http://www.scopus.com/inward/record.url?scp=85143637565&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85143637565&partnerID=8YFLogxK

U2 - 10.1021/acsapm.2c01978

DO - 10.1021/acsapm.2c01978

M3 - Article

AN - SCOPUS:85143637565

SN - 2637-6105

JO - ACS Applied Polymer Materials

JF - ACS Applied Polymer Materials

ER -

Binary Thiol-Acrylate Photopolymerization for the Design of Degradable Acetal-Functionalized Hydrogels

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this