Role of Preferential Ions of Ammonium Ionic Liquid in Destabilization of Collagen

Abstract

Ions play a key role in the destabilization of collagen. This study explores the effect of diethyl methyl ammonium methane sulfonate (AMS), an ionic liquid (IL), on different hierarchical orderings of collagen, namely, at the molecular and fibrillar levels. The rheological behavior and secondary structural changes reveal changes in the hydrogen-bonding environment of collagen, leading to alterations in the triple helical structure of collagen. An increase in the concentration of AMS resulted in swelling of rat-tail tendon fibers, and also, decreased thermal stability signifies that ions are obliged to destabilize collagen at the fibrillar level. Molecular modeling studies confirm that anions are judiciously held responsible for structural deformities in collagen, whereas cations have a tenuous effect. Thus, the preferential role of ions present in an ammonium IL has been elucidated in this study.

Factors affecting thermal stability of collagen from the aspects of extraction, processing and modification

“…Organic cations in ILs mainly include imidazolium, ammonium, phosphonium, cholinium and pyridinium and anions can be various organic or inorganic ions. ILs of different concentrations and types would show distinct effect on the thermal stability of collagen, as reported by Tarannum and her colleagues [146,147]. Collagen of rat tail tendon (RTT) was treated with diethyl methyl ammonium methane sulfonate (AMS) of different concentrations.…”

“…The Td values of collagen fibers gradually reduced from 63°C (0% AMS) to 55°C (5% AMS) and then obviously decreased to 48°C as AMS was 10%. AMS was shown not to affect the secondary structure of collagen and just to decrease thermal stability at interfibrillary level [146]. RTT collagen solution was added with the other two ILs, namely bis-choline sulphate (BCS) and 1-butyl-3-methyl imidazolium dimethyl phosphate (IDP), of same concentration (10%) respectively to make final collagen concentration of 1.33 μM (pH 4.0) at 4°C.…”

Investigation of the solubility and dispersion degree of calf skin collagen in ionic liquids

“…Also, since complete dissolution of collagen in ILs was not achieved, the insoluble part of collagen had not been thoroughly studied. Furthermore, it should be noted that both the sorts and concentrations of ILs, which are closely related to their polarity, have great influences on the properties of collagen [10,19,[23][24][25][26][27][28]. For example, the differences in composition of imidazolium-based ILs endowed by varying anions with different polarity namely acetate, hydrogen sulfate, dicyanamide, dimethyl phosphate, dihydrogen phosphate and sulfate, had resulted in different destabilizing effects on the triple helical structure of collagen [25]; a notable decreasing trend in denaturation temperature of collagen fibers was discovered with the increase of ILs concentration from 0.1% to 10% (w/v) [10].…”

Marine-Derived Polymers in Ionic Liquids: Architectures Development and Biomedical Applications

“…Moreover, the interaction of the matrices, especially of proteins with ILs, has been assessed with various ILs, being the dominance of anionic interactions considered mostly responsible for governing stabilization [34][35][36][37][38]. Considering collagen, ILs based on imidazolium, phosphonium, and ammonium had destabilizing effects because of the chaotropic of anions resulting in collagen structural degradation rather than the strengthening of interactions, although choline dihydrogen phosphate (Ch)(DHP) stabilized the collagen structure [37,[39][40][41].…”

“…Imidazolium-based ILs have brought about significant changes at the higher structural hierarchical level of collagen, developing a different hierarchical ordering [40]. Phosphonium and ammonium-based ionic liquids have a destabilizing effect on collagen [35,36]. On the other hand, (Ch)(DHP) IL stabilized collagen by exerting an electrostatic force on collagen, and due to its biocompatibility, has potential as biocompatible crosslinkers [90].…”