Mechanistic insights on stabilization and destabilization effect of ionic liquids on type I collagen fibrils

Tuned assembly of collagen has tremendous applications in the field of biomedical and tissue engineering owing to its targeted biological functionalities. In this study, ionic liquids choline dihydrogen citrate (CDHC) and diethyl methyl ammonium methane sulfonate (AMS) have been used to regulate the self-assembly of collagen at its physiological pH by probing the assembled systems at certain concentration ratios of ionic liquids and the systems were studied using various characterization methods. Due to interaction with collagen, choline dihydrogen citrate causes delay in the collagen fibrillisation process showing no binding interactions with collagen. In contrast, diethyl methyl ammonium methane sulfonate shows crosslinking effect on collagen fibrillisation due to the electrostatic interaction with the tetrahedral hydration shell of collagen moieties. From rheological studies it was observed that the AMS treated collagen fibril at 1:1 % (w/v) has highest linear viscoelastic range, this can bear the stress under high strain compare to native collagen fibril as well as all CDHC composites. For a sustainable biomaterial or bio-scaffold, mechanical property plays pivotal role on it and from our experimental analysis we found certain composites of ionic liquid treated collagen fibrillar assembly which may act as a sustainable biomaterial or bio-scaffold. It was also evolved that, how the structure-function relationship of ionic force modulated fibrillar assembly controlling the mechanical properties of the tuned system. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application.