Figure 1. Synthesis and characterization of SPNs.

a) Scheme of F8BT-F modification via S_NAr reaction with poly(ethylene glycol) derivatives and subsequent nanoparticle formation. b) Hydrodynamic diameter of SPNs in water, PBS (at room temperature), and 10 v/v% FBS (in PBS, at 37 °C) after 24 h of incubation, calculated from FCS autocorrelation analysis. c) Hydrodynamic diameter of SPN–PEG₂₀₀₀ in water and PBS after 24 h of incubation, via DLS analysis (average of n = 3 technical replicates). d) TEM image and the corresponding histogram of SPN–PEG₂₀₀₀ (n = 126 particles counted, mean diameter of 24 ± 8 nm, scale bar = 50 nm). e) Normalized absorption and fluorescence spectra (λ_Ex = 450 nm) of SPN–PEG₂₀₀₀ in water. f) Zeta potential of SPN–PEG₂₀₀₀ in water (average of n = 3 technical replicates). g) FCS analysis of coprecipitated (with DSPE–PEG₂₀₀₀) and graft copolymer SPNs (with Cy5-labeled PEG chains) incubated in FBS. Reported values are the concentration changes in the red channel (Cy5 fluorescence). All FCS data above is N = 1, n ≥ 14 technical replicates. Box plots: 5th and 95th percentile values (top and bottom horizontal lines), the lower quartile (lower boundary of the box), the median (the line inside the box), and the upper quartile (upper boundary of the box).