On the electrical properties of collagen macromolecule solutions: Role of collagen-water interactions

Collagen is the most abundant protein of the extracellular matrix in connective tissue in the mammalians with potential applications in the coverage of cardiovascular prostheses, regenerative medicine, pharmaceutical industry, controlled drug delivery, and proliferation, migration and cellular differentiation. In this research, the electrical properties (conductivity and permittivity) of type I collagen solution with different concentrations were measured in the frequency range 10 kHz-5 MHz and electrical analysis of the measurement results was performed. Analysis shows that special interactions with water molecules have a significant effect on the electrical properties of collagen solutions beyond what is predicted considering the rules of physical composition, such as the Maxwell-Garnet model of mixing rules. Very small variations in the amount of collagen in water, significantly changed solution conductivity and dielectric permittivity. Finally, to simplify the representation of the impedance measurements and to better understanding of the electrical behavior of the solutions, an equivalent electrical circuit model was developed to describe the measured data. The results obtained from the fitted electrical model were in good agreement with the experimental results. (C) 2018 Published by Elsevier B.V.