Electrochemically Controlled Dissolution of Nanocarbon–Cellulose Acetate Phthalate Microneedle Arrays

Transdermal microneedles have captured the attention of researchers in relation to a variety of applications, and silicone-based molds required to produce these systems are now widely available and can be readily manufactured on the lab bench. The production of nanocomposite microneedle arrays through micromolding techniques is described. The formulation of nanoparticulate carbon along with pH sensitive cellulose acetate phthalate as a polymeric binder is shown to produce conductive microneedles whose swelling/dissolution properties can be controlled electrochemically. Through exploiting hydrogen evolution at the microneedle array, changes in local pH can induce swelling within the needle structure and could lay the foundations for a new approach to the smart device controlled delivery of therapeutic agents. The surface modification of the carbon needles with palladium and cysteine is critically assessed from sensing and drug delivery perspectives.