Figure 3. Stability assessments of different nanoparticle architectures using drug (CG₈₂₀) and particle (PLL₇₀₀) tracking via in vivo imaging. (top of each image panel).

Schematic detailing the fluorescent trackers used for stability assessment of NP architectures. CG₈₂₀ is the cargo encapsulated in the LbL NP architecture with the first polycationic layer of the 3 bilayer structure labeled with Cy5.5. (A) CG₈₂₀ stability panel, surveying drug bioavailability up to 30 minutes post-injection. (i) free CG₈₂₀; (ii) PLGA^50:50_CG; (iii) HA-terminated 6L NP; (iv) Alg-terminated 6L NP; (v) DXS-terminated 6L NP. Representative 48 h study shown in Supplemental Figure 1. IVIS images at CG channel (λ_ex = 745 nm, λ_em = 820nm), surveyed up to 30 min and subsequently opened. Region of interest analysis shows ~70% injected dose associated with the liver (white dashed circle identified with an arrow) after 5 minutes for free CG, ~55% for PLGA^50:50_CG, ~28% for DXS-terminated and ~15% for Alg- and HA_500K-terminated 6L NPs; n = 3. (B) Carrier stability panel, surveying nanoparticle biodistribution up to 30 minutes post-injection. (i) free PLL₇₀₀; (ii) DXS-terminated 6L NP; (iii) HA-terminated 6L NP; (iv) Alg-terminated 6L NP. Nanoparticle tracking facilitated by labeling of first polycationic layer (PLL) in 6L NP architecture with Cy5.5. Representative 48 h study shown in Supplemental Figure 2. IVIS images at PLL₇₀₀ carrier channel (λ_ex = 640 nm, λ_em = 700 nm) were surveyed up to 30 minutes. Region of interest analysis yields ~50% injected dose associated with the liver (white dashed circle identified with an arrow) after 5 minutes for free PLL₇₀₀, as compared to ~25% for DXS-terminated, ~15% for HA500K-terminated, ~12% for Alg-terminated 6L NPs. (PLGA) poly(lactic-co-clycolic acid), (PLL) poly(L-lysine), (DXS) dextran sulfate, (Alg) alginate, (HA) hyaluronic acid, (CG) cardiogreen; n = 3.