Collagen-collagen interactions mediated by plant-derived proanthocyanidins: A spectroscopic and atomic force microscopy study. (1st September 2016)

• Record Type: Journal Article
• Authors: Vidal, Cristina M.P.; Zhu, Weiying; Manohar, Suresh; Aydin, Berdan; Keiderling, Timothy A.; Messersmith, Phillip B.; Bedran-Russo, Ana K.
• Is Part Of: Acta biomaterialia. Volume 41(2016)
• Page Start: 110
• Page End: 118
• Publication Date: 2016-09-01
• Subjects: Collagen cross-linking -- Dentin -- Proanthocyanidins -- Atomic force microscopy -- ATR-FTIR spectroscopy; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1016/j.actbio.2016.05.026
• Languages: English
• ISSNs: 1742-7061

Abstract

Graphical abstract: Abstract: Collagen cross-linkings are determinant of biological tissue stability and function. Plant-derived proanthocyanidins (PACs) mimic different hierarchical levels of collagen cross-links by non-enzymatic interactions resulting in the enhancement to the biomechanics and biostability of collagen-rich tissues such as dentin. This study investigated the interaction of PACs from Vitis vinifera grape seed extract with type I collagen in solubilized form and in the demineralized dentin matrix (DDM) by fluorescence spectral analysis; collagen-collagen binding forces in presence of cross-linking solutions by atomic force microscopy (AFM); and spectroscopic analysis of the DDM using attenuated total reflectance Fourier transform-infrared spectroscopy (ATR-FTIR). Glutaraldehyde (GA) and carbodiimide hydrochloride (EDC) with known cross-linking mechanisms were selected for comparative analyses. Changes in fluorescence upon interaction of solubilized type I collagen with PACs, EDC and GA reflected pronounced modifications in collagen conformation. PACs also promoted stronger collagen-collagen fibrils interaction than EDC and GA. A new feature was observed using ATR-FTIR spectroscopic analysis in PACs-treated collagen and DDM. The findings suggest covalent interactions between collagen and PACs. The mechanisms of interaction between PACs-collagen hold attractive and promising tissue-tailored biomedical applications and the binding forces that potentially drive such interaction were characterized. Statement of Significance: Connective tissues such as skin, bone and dentin are mainly composed of type I collagen, which is cross-linked to promote tissue stability, strength and function. Novel therapies using substances that mimic cross-links have been proposed to promote repair of collagen-based-tissues. In dentistry, naturally occurring proanthocyanidins (PACs) have the potential to enhance dentin mechanical properties and reduce its enzymatic degradation, but their mechanisms of cross-linking are unclear. The present study investigated the specific interactions between PACs-type I collagen in purified and dentin collagen and compared to the well described cross-linking mechanisms promoted by synthetic chemical substances. Findings reveal that covalent-like bonds are induced by plant PACs in type I collagen as well as in complex dental native tissue, promoting strong collagen-collagen interactions.