Similarly, tumor spheroids consisting of A431 cells (only EGFR+) grown with MSCs (only PDGFRβ+) up to 13 days (Supplementary Fig. 10B and Fig. 6F) were higher affected by EGFR/PDGFRβ bispecific nanoformulations than those single-targeted, with a reduction of cell viability of approximately 90% for Iren-AuSiO2_CL4_Gint4.T, 40% for Iren-AuSiO2_CL4 and 30% for Iren-AuSiO2_Gint4.T relative to untreated cultures (Fig. 6G). Here, PDGFRB is linked to neoplasm.