Mechanism and Effects of Polyphenol Derivatives for Modifying Collagen

Abstract

This study is aimed to investigate the relationship of the mechanism and the effect of polyphenol derivatives cross-linking collagen with polyphenol molecular structural complexity and reaction conditions of polyphenols with collagen and to present a reference for cross-linker selection. Three kinds of polyphenols were selected to cross-link collagen under nonoxidized and oxidized conditions in vitro. These polyphenols included tannic acid, which represents the most complex stereo structure and the highest number of phenolic hydroxyl groups; epigallocatechin gallate, which represents a moderately complex structure and contains fewer phenolic hydroxyl groups than tannic acid; and N-2-(3,4dihydroxylphenyl) ethyl acrylamide, which represents only one hydroxyl phenol group. Particle size analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, attenuated total reflection Fourier transform infrared spectroscopy, and cross-linking degree analysis were conducted. Mechanical properties, thermal stability, swelling properties, hydrophilicity, and antienzymolysis properties were also determined. Results showed that all polyphenol derivatives cross-linked collagen mainly by noncovalent bonding under acidic nonoxidized conditions and by covalent bonding under alkaline-oxidized conditions. In general, the modification effect of polyphenol on collagen was related to its molecular complexity and the number of its phenolic hydroxyls. Several phenolic hydroxyls in the polyphenol derivative caused a good modification effect on collagen, especially under acidic nonoxidized conditions. Under alkaline conditions, each polyphenol was oxidized, resulting in improved cross-linking strength by covalent bonding compared to that under acidic nonoxidized condition via noncovalent bonding. The selection of cross-linkers and cross-linking conditions should be based on the purpose of collagen modification consistent with the effect of cross-linking.

Collagen-Based Materials Modified by Phenolic Acids—A Review

“…Tannic acid (TA; Figure 1) is a compound which belongs to the phenolic acid group. It has the most complex stereo structure with the highest number of hydroxylic groups [97]. The cross-linking process accompanying tannic acid addition to collagen does not affect the integrity of the triple helical structure of collagen [98].…”

Effect of Chitosan Deacetylation on Its Affinity to Type III Collagen: A Molecular Dynamics Study

“…Many studies, dealing with pharmaceutical, cosmetic, and tissue engineering applications of collagen Materials 2022, 15, 463 2 of 15 materials modified by various low-and high-molecular components, have appeared recently. For special attention deserve collagen blends containing phenolic compounds [9][10][11][12][13][14][15], polysaccharides, and their analogs, including carboxymethylcellulose, hyaluronic acid (HA), and chitosan [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Probably one of the most important modifications is associated with mechanical properties' improvement.…”

Tannic acid induces dentin biomineralization by crosslinking and surface modification

“… 37 TA crosslinked collagen mainly by noncovalent bonding under nonoxidized conditions. 38 The H bond between amide NH and OH of the TA galloyl group was shown in Fig. 10 .…”