THEDES – Therapeutic Deep Eutectic Solvents: New solvents for the functionalization of natural-based polymers

Natural-based biopolymers are now seen as safe and green alternatives for traditional plastics, and find applications in areas ranging from biomedicine to electronics. Their major drawback is still related to their low processability.

In this work, a blend of starch and poly-ε-caprolactone (SPCL 30:70) is used. Previous work has established that the combination of ionic liquids (ILs) and supercritical carbon dioxide (scCO₂) increases the processability of this polymeric blend, enabling the formation of foamed materials.

The strategy in the present work, is to replace the IL with a deep eutectic solvent (DES), thus circumventing the limitations of IL regarding their biocompatibility, greenness and high cost.

It is known that there are a number of deep eutectic solvents that can be constituted by substances that are bioactive or even active pharmaceutical ingredients (APIs). The synthesis of bioactive DES (THEDES) based in ibuprofen (a non-steroidal anti-inflamatory agent) and R-mandelic acid (known for its antibacterial activity) was performed. SPCL matrixes were doped with 10% of THEDES and processed by compression moulding into a homogeneous structure. The processed polymers were then foamed with scCO2 at 200 bar and 40 °C. Mechanical and morphological characterization of the samples were performed to access their applicability. Furthermore, in vitro drug release studies were carried out and the results suggest that the proposed approaches provide interesting cues for the development of new drug delivery systems.