Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as an insulin carrier in silk fibroin hydrogels for transdermal delivery <i>via</i> iontophoresis
Phimchanok Sakunpongpitiporn, Rawita Morarad, Witthawat Naeowong, Sumonman Niamlang, Anuvat Sirivat
Abstract
release and release-permeation experiments, the amounts of insulin release and release-permeation were investigated using a modified Franz diffusion cell, under the effects of SF concentrations, electric fields, and pH values. The amounts of insulin release and release-permeation from the pristine SF hydrogel and the PEDOT:PSS/SF hydrogel followed the power laws with the scaling exponents close to 0.5, indicating the Fickian diffusion or the concentration gradient. Under electric fields, with or without PEDOT:PSS used as the drug carrier, the insulin amount and diffusion coefficient were shown to increase with the increasing electric field due to the electro-repulsive forces between the cathode and insulin molecules and SF chains, electroosmosis, and SF matrix swelling. The SF hydrogel and PEDOT:PSS as the drug carrier are demonstrated herein as new components in the transdermal delivery system for the iontophoretically controlled insulin basal release applicable to diabetes patients.