Enzymatic degradation of 3D scaffolds of starch-poly-(ɛ-caprolactone) prepared by supercritical fluid technology

Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ɛ-caprolactone) (SPCL) was processed using supercritical fluid technology, namely, by supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing α-amylase and/or lipase. The effect of the presence of these enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material.