Fig. 2

Optimization and characterization of PIC-conjugated nanoparticles. Azide-functionalized photoimmunoconjugates were conjugated to DBCO-containing nanoparticles via copper-free click chemistry (a) and visualized by cryoEM (b). Scale bar: 500 nm. Volume ratio of PIC:NP was varied and changes in size (c), PIC conjugation efficiency (d), and number of PICs per nanoparticle (e) were characterized. The absorbance spectra are shown for BPD-containing formulations (f) and talazoparib-containing formulations (g) from 300–800 nm in DMSO. Next, comparison of 690 nm absorbance was performed in DMSO versus PBS (h). Photoactivity was evaluated, as described in Materials & Methods, for BPD, PIC, PIC-NP, and PIC-NP-Tal (i). Singlet oxygen was next quantified using SOSG (Invitrogen) (j). Uptake of 1 μM PIC versus 1 μM PIC-NP-Tal in EGFR-negative J774 cells compared to EGFR-positive OVCAR8 cells after 30 min incubation (k). Data is normalized to J774 uptake of PIC. * p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.001; **** p ≤ 0.0001