Investigation on Interaction of Tannic Acid with Type I Collagen and its Effect on Thermal, Enzymatic, and Conformational Stability for Tissue Engineering Applications

Collagen is an essential component of tissues, which is the most abundant component in extracellular matrix and highly conserved across the animal kingdom. It can assemble into fiber and play an essential role in cell adhesion and growth and could be extremely useful in tissue engineering. In this study, the effect of tannic acid (TA) on the thermal, enzymatic and conformational stability of type I collagen has been investigated for the development of collagen-based biomaterials. Interaction of TA with collagen demonstrates the role of hydrogen bonding and hydrophobic interaction in providing the thermal and enzymatic stability. Thermal analysis studies reveal that, hydrothermal stability of collagen increases as well as inhibits the breakdown of collagenase by formation of hydrogen bonds and hydrophobic interactions. TA binds to the collagen with high affinity because the structural flexibility of the collagen compensates for the structural rigidity of the phenolics. Increase in concentration of TA induces significant change in the conformation of triple helix. The free binding energy of TA with collagen-like peptide was determined to be in the range of -9.4 to -11.2 kcal mol(-1), which was calculated by using Autodock Vina software and showed numerous hydrophobic and hydrogen bond interactions. We anticipate that these collagen-based biomaterials hold great potential for biomedical applications. (c) 2013 Wiley Periodicals, Inc. Biopolymers 101: 471-483, 2014.