1. Salivary esterases dramatically reduce biostability of dentin collagen treated with galloylated polyphenols
- Author
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Viviane Hass, Yong Li, Saleha Nisar, Zhonghua Peng, and Yong Wang
- Subjects
Molecular Weight ,Mechanics of Materials ,Dentin ,Esterases ,Humans ,Polyphenols ,General Materials Science ,Collagen ,General Dentistry - Abstract
To investigate the effects of salivary esterases on biostability of collagen treated by galloylated polyphenols.Human dentin was microtomed into 6-μm-thick films, which were demineralized and treated for 60 s using solutions containing 0.6% and 2% of one of the crosslinkers: tannic acid (TAC), epigallocatechin gallate (EGCG), epigallocatechin (EGC), and N-[3-dimethylaminopropyl]-N'-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS), and for 1 h using EDC/NHS. Half of the treated and untreated (control) films were subjected to human saliva incubation. Collagen biostability was assessed via exogenous protease biodegradation by weight loss and hydroxyproline release, and endogenous MMPs by in situ zymography. The degradation products of galloylated polyphenols (TAC and EGCG) by saliva were monitored using proton nuclear magnetic resonance (Collagen films treated with TAC and EGCG exhibited significantly improved biostability (p 0.05); however, the enhanced biostability was severely reduced after saliva incubation (p 0.001). For EDC/NHS treated collagen, saliva incubation showed negligible effect on the biostability.The galloyl group plays important role in collagen crosslinking, inducing higher biostability. However, galloylated polyphenols crosslinked on collagen are highly susceptible to metabolism of human saliva by salivary esterase, dramatically compromising the enhanced biostability.
- Published
- 2022