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

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.