Synthesis, characterization, and cell viability of bifunctional medical-grade polyurethane nanofiber: Functionalization by bone inducing and bacteria ablating materials

There is an extensive possibility of improving characteristics of fibers used in hard tissue engineering, being hydrophobic and less osteoconductive, resulting in the dynamic growth of new tissues. The current work focuses on the fabrication of nanofibers incorporated with titanium dioxide (TiO2) ''as osteoconductive'' and silver (Ag) ''as self-healing'' nanoparticles (NPs). The incorporation of AgNO3 by in situ method not only helped to impart the antibacterial activity but also changed the contact angle from 81 +/- 03 degrees in the case of pristine nanofibers to 74 +/- 03 degrees, 61 +/- 03 degrees, 50 +/- 08 degrees, and 39 +/- 1.1 degrees, in the composite scaffolds containing 0.01, 0.03, 0.05, and 0.07 M of Ag salts. The incubation in simulated body fluid at 37 degrees C to induce mineralization on nanofiber scaffolds indicated Ca and P crystals' formation. The antibacterial activity showed significantly more toxicity toward E. coli (8.3 +/- 0.9 mm) than S. aureus (1.2 +/- 0.1 mm). Biocompatibility studies using MTT assay on the pre-osteoblasts showed that both TiO2 and Ag NPs present in the nanofibers are non-toxic to the bone-like cells. However, results show that a higher concentration of Ag NPs (i.e., 0.07 M) is toxic to cells growing. Finally, all the results suggest that the nanofiber scaffolds have considerable scope for future bone tissue engineering materials.

Automated summary

The study focused on fabricating nanofibers incorporated with TiO2 and Ag NPs, showing good antibacterial activity and biocompatibility. The results indicate a promising potential for future bone tissue engineering materials.