Fabrication and assessment of bifunctional electrospun poly(L-lactic acid) scaffolds with bioglass and zinc oxide nanoparticles for bone tissue engineering

Electrospun scaffolds based on poly(L-lactic acid) (PLLA) with bioglass (n-BG) and zinc oxide (n-ZnO), and mixture of both, were developed to design bifunctional biomaterials with enhanced bioactive and biocidal properties. The presence of n-BG increased the fiber diameter of the pure PLA from 1.5 ± 0.3 μm to 3.0 ± 0.8 μm for 20 wt%. ZnO and the mixed nanoparticles did not significantly affect the morphology. The mechanical properties decreased with the presence of nanoparticles. Scaffolds based on PLA/n-BG promoted hydroxyapatite (HA) formation in simulated body fluid (SBF) that was inhibited with the presence of ZnO. Notably, mixed particles produced bioactivity although at longer times. The incorporation of n-ZnO produced a biocidal capacity against S. aureus in the polymeric scaffold, reaching a viability reduction of 60 % after 6 h of exposure. When both types of nanoparticles were combined, the bacterial viability reduction was 30 %. Pure PLA scaffolds and the composites with n-BG showed good ST-2 bone marrow-derived cell line viability, scaffolds with n-BG (pure or mixture) presented lower viability. Results validated the use of both n-BG and n-ZnO fillers for the development of novel bifunctional PLA-based scaffolds with both bioactive and biocidal properties for bone tissue engineering applications.P.A. Zapata acknowledge the financial support of Direccion de Investigacion Científica y Tecnologica, Universidad de Santiago de Chile (DICYT) project: 052241ZR_DAS. D. Canales thanks the financial support of FONDECYT under postdoctoral project No. 3210810. Finally, D. Canales is immensely grateful to Katharina Schuhladen, Sonja Kuth, Lena Vogt, Irem Unalam, and Florian Ruther, members of Institute of Biomaterials of University of Erlangen-Nuremberg, for their support in the mechanical and biological analysis