Production of Bioglass® 45S5 – Polycaprolactone composite scaffolds via salt-leaching

Abstract Polycaprolactone (PCL)-Bioglass® 45S5 (45S5) composite scaffolds were produced by means of the salt-leaching technique. Various salts (NaCl, NaHCO 3 , and a mixture of them) were used with the aim of optimising the pores network; moreover several glass weight fractions and glass particle sizes were tested. The so-obtained composite scaffolds were characterized from a microstructural, mechanical and biological point of view; in particular, in view of the biomedical application of the materials, both in vitro and cytotoxicity tests were performed. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity, ideal for bone regeneration and vascularization. The mechanical properties of the PCL matrix were not altered by the introduction of the glass and the scaffolds ensured an easy handling. As regards the bioactivity, the prolonged contact of the 45S5 particles with the water used to remove the salt probably induced a reaction which promoted the development of calcite and altered the glass composition, suppressing the development of hydroxyapatite in vitro; however the response to the cytotoxicity test was promising, confirming the relevance of the PCL-45S5 composite scaffolds and justifying future efforts to improve the production technique, in order to limit the glass alteration.