The skin is the most expansive and readily accessible organ of the human body. As a physiological regulator it plays a major role in the general metabolism of water in the body. The moisture level of the outermost layer, the stratum corneum, is crucial in maintaining the integrity of the cutaneous surface. Natural moisturising factors (NMFs) and cutaneous lipids play a critical role in the maintenance of this.
Skin adhesives are partially hydrated gels that have a high affinity for water. When applied to the skin, they absorb interfacial water which promotes their adhesiveness. The ready chain rotation of the hydrogel polymer backbone enables optimisation of hydrophobic interactions with skin. Control of surface chemistry is therefore required to maximise molecular interactions at the adhesive-skin interface. The polymer structure influences the water binding and viscoelastic properties of the gel. Skin adhesive requirements are specific to their application and thus requiring appropriate structural changes to the polymer backbone.
The low enzymatic activity of skin makes it a good candidate for systemic and dermal drug delivery in a timed controlled manner. This has various biomedical benefits over oral or intravenous drug administration. Skin adhesives and polymer systems (such as hydrocolloids) that contain naturally-occuring hydrophilic molecules have many important dermal applications. These include skin adhesives, ostomy devices, drug delivery systems, wound dressings and bioelectrodes for use in electrotherapeutic applications such as iontophoresis. We are interested in designing smart adhesives for these applications.