Caspase-3,7 is activated by AbCs formed with α-DR5 antibody (A), but not the free antibody, in RCC4 renal cancer cells (B). C-D, controls (α-DR5 AbCs (C), but not Fc AbC D) reduce cell viability 4 days after treatment. E, α-DR5 AbCs reduce viability 6 days after treatment. F-G, o42.1 α-DR5 AbCs enhance PARP cleavage, a marker of apoptotic signaling; G, quantification of F relative to PBS control. H, The F-domain from Angiopoietin-1 was fused to Fc (A1F-Fc) and assembled into octahedral (o42.1) and icosahedral (i52.3) AbCs. I, Representative Western blots show that A1F-Fc AbCs, but not controls, increase pAKT and pERK1/2 signals. J, quantification of I: pAKT quantification is normalized to o42.1 A1F-Fc signaling (no pAKT signal in the PBS control); pERK1/2 is normalized to PBS. K, A1F-Fc AbCs increase vascular stability after 72 hours. Left: quantification of vascular stability compared to PBS. Right: representative images. All error bars represent means ± SEM; means were compared using ANOVA and Dunnett post-hoc tests (Tables S8, S9).