Fabrication and bioevaluation of a medicated electrospun mat based on azido-cellulose acetate via click chemistry

Cellulose acetate (CA) electrospun fibers have been used in different medical applications such as drug delivery systems to release various drugs. CA, usually available with a typical degree of substitution (DS) of 2.4-2.5, shows little control over the release rate of the incorporated substances, due to the lack of active functional groups. In this work, click chemistry was used to activate CA and produce crosslinked electrospun mats to provide sustained release for topical administration. CA was activated by introducing azide functional groups on the residual hydroxyl groups of the polymer chains with a DSAzido of 0.24 by a coupling reaction. Azido-CA was then electrospun to produce nanofibers, in which capsaicin and sodium diclofenac, as pain-relieving drugs were encapsulated. Propargylated maltose was synthesized as a crosslinker to the Azido-CA via triazole chemistry. Spectral analysis was used to confirm the chemical structure of the new derivatives and the click-matrices. SEM morphological analysis of the Azido-CA electrospun fibers showed a range of diameters from 140 to 270 nm, with clear, smooth surfaces. Samples of the matrices were assessed for cytotoxicity and showed an acceptable cell viability. In a rat model, sodium diclofenac and capsaicin-loaded electrospun mats of Azido-CA showed superior closure rates over the untreated rats and those treated with a commercial cream. Rats treated with electrospun mat of CA, Azido-CA loaded with drugs showed normal intact histological structure of the epidermis and dermis.