Tannic acid-crosslinked chitosan matrices enhance osteogenic differentiation and modulate epigenetic status of cultured cells over glutaraldehyde crosslinking

ABSTRACT

Tannic acid (TA) is a polyphenol with potential to crosslink biomacromolecules. Though, feasibility of TA crosslinking is known, the more toxic glutaraladehyde (GA) continue to be used extensively for developing novel chitosan-based scaffolds, hindering in vivo translation. Thus, a direct comparison between TA- and GA-crosslinked chitosan membranes with respect to physico-chemical, biocomptability and biofunctional properties is required. Role of TA to modulate epigenetic changes in cultured cells is also investigated. TA-crosslinked scaffolds differed from GA in contact angle and swelling by 20–25% while mechanical properties and degradation differed by 50%. Cell viability on TA-crosslinked scaffolds was ~1.4 times higher compared to GA-crosslinked samples, osteocalcin expression was two-fold higher and ROS and cox-2 expression was reduced by ~1.4 times (p < .01). TA crosslinking modulated epigenetic changes in cultured cells by evidencing global DNA hypomethylation. It is concluded that TA can provide a flexible scaffold with ability to modulate epigenetics and osteogeneticity.

KEYWORDS:

• Polysaccharides
• non-covalent crosslinking
• DNA methylation
• osteogenic differentiation
• scaffolds

Acknowledgments

Authors thank TEQIP-II and CRF, IIEST Shibpur for their help in characterization. Authors also thank Ms. Neha Kumari for her help in some experiments.

Conflicts of interest

The authors have no conflicts of interest to declare that are relevant to the content of this article.