Fast dissolving nanofibrous matrices prepared by electrospinning of polyaspartamides

Abstract

Owing to their versatile chemistry, polyaspartamides have recently attracted increased interest in various biomedical uses such as drug delivery systems and scaffolding materials. Solubility of these polymers in organic solvents and in water at certain values of pH can be fine-tuned by their chemical composition, which was exploited here to fabricate fast-dissolving electrospun matrices in ethanol with no additives. Various side groups were tested to control the solubility of the polymers as well as the morphology and moisture uptake of the matrices produced. Tertiary amine groups were immobilized to ensure high solubility around neutral pH, while modification with alkyl side groups limited moisture uptake. Finally, 3-(diethylamino)propyl and n-butyl side groups were used in equal amounts. The effect of viscosity, surface tension and specific conductivity of polymer solutions on the fiber morphology was determined in order to optimize the conditions for preparing fibers with a narrow size distribution and large specific surface area. The polymer withstood the electrospinning process without any chemical degradation, as determined by IR, and was thermally stable. Furthermore, the matrices exhibited a glass transition temperature above room temperature. The complete release of vitamin B12 was observed within one minute due to the fast dissolution of the matrices in simulated salivary fluid at pH = 6.8, supporting the potential of the developed materials in oral drug delivery.