Abstract
Introduction: Nanoscale scaffolds play a significant role in bone tissue engineering due to their appropriate biological activity which can be enhanced by the incorporation of nanoparticles such as graphene oxide (GO). This study aimed to develop a growth factor-free scaffold based on polyurethane (PU), cellulose acetate (CA) and GO nanoparticles for bone regeneration using electrospinning technique.
Methods: Here, the scaffolds composed of PU, PU-CA and PU-CA-GO, were fabricated to assess the bone differentiation of human adipose-derived mesenchymal stem cells (MSCs). The scaffolds were characterized and after cell culture, the biological assessments such as Alizarin Red staining (ARS), alkaline phosphatase (ALP) activity and calcium mapping were employed to evaluate the osteogenic differentiation of MSCs.
Results: Scanning electron microscopy (SEM) results demonstrated that GO nanoparticles were successfully dispersed within the PU-CA polymer matrix any agglomerations. The fiber diameters of PU-CA and PU-CA-GO scaffolds were 1500±400 and 1250±320 nm. Plasma-treated PU-CA-based scaffolds exhibited hydrophilic surfaces with water contact angles of 19° and 0° for PU-CA and PU-CA-GO scaffolds after 10s, respectively. Moreover, the incorporation of GO increased the Young’s modulus of the scaffolds from 1290 to 1380 kPa and the strain from 8.54 to 9.37 %. In addition, osteogenic differentiation as assessed by ARS staining, ALP activity and calcium deposition, indicated that PU-CA-GO scaffold provided a suitable matrix for the osteogenic differentiation of MSCs after 21 days. The ARS values for the scaffolds without and with GO nanosheets were 14.41±0.7% and 32.88±1.1%, respectively. Furthermore, the ALP levels for both scaffold types were 8±1 and 17±2.5 IU/mg. Accordingly, calcium deposition was 1.03 W% Ca for the GO-free control group and 1.23 W% Ca for the GO-containing scaffold.
Conclusion: In general, this scaffold could be considered a promising growth factor-free candidate for bone tissue engineering. However, further in vivo evaluations are recommended in future studies.