Generation of Loaded PMMA Scaffolds Using Supercritical CO2 Assisted Phase Separation

Poly (methyl methacrylate) (PMMA) is a polymer largely used in tissue engineering applications. It has a good degree of compatibility with human tissues. A relevant biomedical application of PMMA is represented by the production of scaffolds to be used as controlled release devices for pharmaceutical products. Loaded PMMA scaffolds were prepared using a supercritical fluid-phase separation process, in which CO2 acts as the non-solvent. Supercritical carbon dioxide (SC-CO2) phase separation process has several advantages with respect to traditional scaffold formation processes (foaming, electrospinning, phase separation, etc); for this reason, in this work we tested this method to produce PMMA scaffolds loaded with two different pharmaceutical compounds: Cefuroxime and Diclofenac sodium, respectively, an antibiotic and an anti-inflammatory drug. We prepared PMMA scaffolds using two different procedures: dissolving PMMA and Diclofenac sodium in acetone or suspending Cefuroxime in the organic solution formed by PMMA and acetone. The effect of the drug concentration on scaffold morphology and pore size was analyzed. The obtained scaffolds, produced in correspondence of various drug loadings, were characterized by SEM, to study the morphology and pore size, and by EDX to analyze the drug distribution in the scaffolds. Some drug release rate analyses were also performed, observing very different release behaviors, depending of the solution/suspension process adopted. The results obtained confirmed the feasibility of the loading process and the advantages with respect to traditional methods: efficient encapsulation of the drug and absence of burst effects.