bm9b01689_si_002.mp4 (7.32 MB)
Dynamic Covalent CC Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation
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posted on 2020-02-25, 15:46 authored by Caicai Jiao, Lilong Gao, Hui Zhang, Bing Yu, Hailin Cong, Youqing ShenHydrogels
have a wide range of applications in the fields of biomedicine,
flexible electronics, and bionics. In this study, injectable and self-healable
hydrogels were first prepared based on a dynamic covalent CC
bond formed via the Knoevenagel condensation reaction between poly(ethylene
glycol) dicyanoacetate and water-soluble poly(vanillin acrylate).
Three kinds of catalysts (phosphate buffer, zeolitic imidazolate framework-8,
and tertiary amine) were used in Knoevenagel condensation for preparing
hydrogels. All hydrogels in this study could be formed in situ, and
their gelation time ranged from seconds to minutes. The properties
and application of hydrogels could be customized according to the
type of catalyst employed. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium
bromide (MTT) results indicated that all the components and hydrogels
exhibited low toxicity, and the hydrogels could be used as 3D cell
culture scaffolds. Because of the dynamic covalent CC bond
formed by Knoevenagel condensation, the resultant hydrogels were found
to be dynamic and showed good self-healing properties. This work presents
a new dynamic covalent chemistry for the preparation of self-healable
materials.