Modeling the surfactant uptake in cross-linked DNA gels.
The deswelling behavior of cross-linked DNA gels reports on DNA-cosolute interactions and gives a basis for the development of responsive DNA formulations. An investigation of the deswelling kinetics shows that an increase in the surfactant tail length gives a pronouncedly slower deswelling kinetics. In the same conditions, single stranded gels exhibited faster deswelling kinetics when compared with double stranded networks. It was also found that DNA gels display a nonmonotonic volume change with time, deswelling followed by reswelling, when immersed in surfactant solutions. Kinetic modeling of surfactant uptake by the DNA gel was done using a stochastic approach of mass transfer between the bulk solution, the surface, and the inner volume of the gels. Diffusion coefficients and kinetic constants can be derived from the separated model uptake curves for the gel surface and the gel interior volume.