Sarker & Jani et. al, Journal of Colloid and Interface Science (2023)

DOI

This study investigates the potential of collagen and tannic acid (TA) particles as biomaterials for advanced hybrid biobased systems. Both collagen and TA possess therapeutic functionalities and unique structural properties, with pH responsiveness allowing for non-covalent interactions and tunable macroscopic properties. The experiment focuses on examining the impact of pH on the interactions between collagen and TA particles. TA particles added at physiological pH to collagen at both acidic and neutral pH reveal significant findings through various analytical techniques. Rheology results indicate a noteworthy increase in the elastic modulus with higher collagen concentrations, while TA particles at physiological pH exhibit stronger mechanical reinforcement to collagen at pH 4 due to increased electrostatic interactions and hydrogen bonding. Isothermal titration calorimetry (ITC) results support this observation, showing larger changes in enthalpy when collagen is at acidic pH, suggesting enthalpy-driven collagen-TA interactions. Turbidimetric analysis and quartz crystal microbalance with dissipation monitoring (QCM-D) further contribute to identifying structural differences in collagen-TA complexes formed at both acidic and neutral pH conditions.