Development of electrospun Ion jelly fibers® for drug delivery

Dissertação para obtenção do Grau de Mestre em Biotecnologia

The aim of this work was the development of a drug delivery system based on Ion Jelly fibers. Ion Jelly (IJ) is a highly versatile polymeric material and is the result from the combination of gelatin and an ionic liquid (IL). For that purpose, different IJs were created using ILs based on choline and active pharmaceutical ingredients. The ILs used were choline acetate ([Ch][Ac]), choline mandelate([Ch][Ma]), choline tiglate ([Ch][Ti]) and choline ibuprofenate([Ch][Ib]). IJ fibers for drug delivery systems were produced through electrospinning, owing to its ability of producing polymeric fibers with reduced diameters and high surface area. The aim of this approach was to overcome the low diffusion rate that the above ILs exhibit due to their high viscosity. The impacts of electrospinning parameters on fiber production were evaluated. We verified that the most important parameter to achieve defect-free and thin IJ fibers was IL concentration. Morphological studies of IJ electrospun fibers were performed through optical microscopy and scanning electron microscopy. It was observed that IJ - [Ch][Ib] yielded slightly thinner fibers when compared with IJ-[Ch][Ti] fibers. The results from antibacterial tests using mandelic acid, [Ch][Ma] and IJ-[Ch][Ma] fibers as antibacterial agents against Escherichia coli K-12 and Bacillus subtilis T-168 prove that[Ch][Ma] encapsulation in IJ electrospun fibers greatly increased the IL properties. In addition,toxicological data suggest that the ILs studied were not toxic with the exception of [Ch][Ib] which shows a similar toxicity to crystalline ibuprofene. In addition, tensile tests suggest that water content has an important impact on both IJ mechanic behavior and elasticity. Additionally, we also evaluated the fabrication of IJ fibers using other polymers beyond gelatin, namely DNA and N,N-Dimethylchitosan. Nevertheless, no fibers were obtained.