Polymer (PCL) fibers with Zn-doped mesoporous bioactive glass nanoparticles for tissue regeneration

Composite fibrous membranes based on poly(e-caprolactone) (PCL) and mesoporous bioactive glass nanoparticles (MBGNs) were fabricated by electrospinning. MBGNs and Zn-doped MBGNs prepared by microemulsion sol-gel method were successfully incorporated inside the polymeric fibers of 240 and 385 nm in diameter for undoped and Zn-doped PCL_MBGNs fibers, respectively. Thermal analysis showed that the concentration of MBGNs reached a maximum of around 21 wt% for Zn-doped MBGNs. Both PCL_MBGNs and PCL_MBGNs_Zn composite membrane exhibited bioactivity after immersion in simulated body fluid (SBF). X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) showed the evolution of composite membranes, confirming the formation of hydroxyapatite (HAp). However, the degradation products of membranes did not affect the viability and proliferation of murine stromal cells (ST-2) and thus the new fiber structures represent a suitable environment for cell adhesion. Therefore, the incorporation of mesoporous glass nanoparticles doped with therapeutically active Zn2+ ions inside the PCL fibers offers the possibility to create a multifunctional biomaterial suitable for drug delivery and tissue engineering.