2LL-6 : Ion releasing nanoparticles to increase the wound healing efficacy of stem cell

Herein, we investigated that Fe ion can be delivered into hMSCs using pH-sensitive gold-iron nanoparticles (AuFe NPs) to enhance angiogenic paracrine factor secretion. Based on the different redox potential of Au and Fe, only Fe ion released from AuFe NPs whereas Au remained intact at low pH condition. The low pH (pH 4.5-5.5) condition of the endosomes made Fe ion release from the AuFe NPs. Treatment with AuFe NPs increased the ROS level in hMSCs through Fe ion release. Intracellular delivery of Fe ion to hMSCs promoted hypoxia-inducible factor-1 alpha expression, which could trigger the secretion of angiogenic growth factors such as, VEGF, FGF2, CXCR4, and CXCL12. Compared to hMSCs without AuFe NPs treatment, hMSCs treated AuFe NPs showed significantly enhanced angiogenic gene expression. Also, hMSCs with AuFe NPs treatment promoted angiogenesis and therapeutic efficacy in mouse wound closing model compared to no treatment or the conventional hMSCs group.