Optimization of HYAFF membranes morphology produced by supercritical phase separation for biomedical applications

In this study, it was evaluated the capability to generate HYAFF membranes by phase inversion assisted by supercritical fluids. HYAFF is a biopolymer, hyaluronic acid ester, much used in the pharmaceutical and biomedical applications. Several techniques have been tested to generate structures (membranes and scaffolds) for biomedical applications; but, all of them present several limitations. For these reasons, supercritical fluids assisted processes have been implemented for biomedical applications. Using SC-CO2 phase inversion process, we obtained HYAFF membranes with different morphological characteristics, depending on the process conditions adopted, such as polymer starting concentrations, pressure (ranging from 90 to 200 bar) and temperature (ranging from 35 to 55°C). The behavior of membranes structure has been studied and has been related to the ternary diagram HYAFF-DMSO-SC-CO2 analyzing the thermodynamic and kinetic aspect of the process.