Preparation and characterization of poly(ε-caprolactone)/ZnO foams for tissue engineering applications

Fabrication of polymer scaffolds via various preparation procedures generally leads to creation of different morphologies, microstructure and properties. In this work, porous nanocomposite scaffolds of poly(epsilon-caprolactone) filled with different quantities of ZnO nanoparticles (0.5-5 wt%) were prepared by thermally induced phase separation (TIPS), using freeze-extraction method for solvent removal. The aim of this research was to investigate the influence of the fabrication procedure and the ZnO loadings on the PCL thermal, morphological and bioactivity properties. The TIPS procedure was confirmed to induce significantly high degree of crystallinity (up to 81%) in all investigated scaffolds, besides the nucleation capacity of the nanofiller. The in vitro bioactivity and biodegradability were tested by immersing produced scaffolds in standard simulated body fluid (SBF) for different periods of time (15 and 30 days). Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction were used to assess the variations in scaffolds after their incubation in SBF. No bioactivity was identified for 15 days of immersion, while the mineralization process was confirmed in all investigated scaffolds for the incubated period of 30 days. Thermogravimetric analysis was used to quantify the mineralization properties, confirming best mineralization properties in scaffolds containing lower contents of ZnO nanofiller (0.5 and 1 wt%).