On the development of functionalized polylactic acid porous films

The porous polymer substrates, which hold high porosity, suitable mechanical properties as well as specific functionality, can be employed in various fields for their retention capacity. The extension of their applicability to the biomedical context also requires additional features related to biodegradability and biocompatibility. The aim of the present study was to design and develop porous, biodegradable, biocompatible, highly functionalized, and easy-to handle polymer films. Furthermore, in order to ensure an easy and scalable production method, the non-solvent induced phase separation (NIPS) technique was selected. The polymer matrix, based on polylactic acid (PLA), was supplemented with another biopolymer, polycaprolactone (PCL). In particular, a PCL with star-shaped geometry, controlled molecular mass and maleic end groups (PCL-COOH) was prepared ad hoc in order to obtain a system characterized by a high concentration of acid end groups. Morphological analysis performed using FE-SEM revealed that the preparation technique used, namely NIPS, ensured a uniform distribution of PCL-COOH domains within the polymer matrix. Moreover, the thermal and mechanical properties of the films were investigated by means of differential scanning calorimetry and thermogravimetric analysis, and mechanical tensile tests. Adsorption and time-controlled release tests were carried out using pararosaniline hydrochloride, a positive charged dye, as a model molecule. These experiments demonstrated the possibility of modulating the retention capacity by adjusting the PCL-COOH concentration and the pH of the system. Furthermore, the porous film containing the highest concentration of PCL-COOH was tested for the retention and release of doxorubicin, a commonly used chemotherapeutic agent. The results showed that the developed system exhibited remarkable adsorption capacity and controlled drug release, highlighting its effectiveness as a potential drug delivery system. Finally, the biocompatibility of the films, which proved to be enzymatically degradable, was investigated through cell viability and hemocompatibility tests.