title: High-water-content and resilient PEG-containing hydrogels with low fibrotic response.
abstract: Hydrogels such as those based on polyethylene glycol (PEG) are broadly used in biomedicine where high water contents, robust mechanical properties such as resilience and favorable interactions with the body are often simultaneously desirable. However, the mechanical properties of conventional hydrogels often degrade rapidly after swelling or with increasing water content, limiting their potential in many applications. Here we describe a new class of PEG-containing hydrogels that remain highly resilient after maximum swelling. We achieved the hydrogels by incorporating reversible "dual" hydrogen bonding into highly coiled, elastic PEG networks. These hydrogels, due to their high water content and high mechanical resilience, can form highly permeable, yet durable and easy-to-handle cell delivery devices without any additional structural support. In addition, optimization of chemical composition resulted in hydrogels with superior bio-inertness, inducing much less fibrosis upon subcutaneous implantation in mice than a polyhydroxyethylmethacrylate (PHEMA) hydrogel control.
  
  
  
  Hydrogels such as polyethylene glycol (PEG)-based ones are broadly used in the biomedical world. Examples include wound dressings, tissue scaffolds, medical implants, biosensors and drug or cell delivery devices. In many of these applications, robust mechanical property, high water content (or facile mass transfer) and favorable interactions with the body are often simultaneously desirable. However, the mechanical property of hydrogels often degrades rapidly after swelling or with increasing water content. Here we report a new class of PEG-based hydrogels that simultaneously possess high water content, high mechanical resilience and low fibrotic response upon subcutaneous implantation in mice. These hydrogels may therefore find broad applications in biomedicine.
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Duo
authors.initials: D
authors.lastname: An
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Yehudah
authors.initials: Y
authors.lastname: Pardo
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Alan
authors.initials: A
authors.lastname: Chiu
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States.
authors.forename: Sean P
authors.initials: SP
authors.lastname: McDonough
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States. Electronic address: mm826@cornell.edu.
authors.forename: Minglin
authors.initials: M
authors.lastname: Ma
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001696:Biomechanical Phenomena; D002460:Cell Line; D005355:Fibrosis / Q000517:prevention & control; D020100:Hydrogels / Q000737:chemistry; D006860:Hydrogen Bonding; D008297:Male; D008422:Materials Testing; D051379:Mice; D008810:Mice, Inbred C57BL; D011092:Polyethylene Glycols / Q000737:chemistry*; D014867:Water / Q000032:analysis
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D014867:Water; D011092:Polyethylene Glycols
keywords: Cell delivery; Fibrotic response; High water content; Hydrogel; Resilient