Figure 3.

Cumulative effect of repetitive administrations of EVs resulting in buildup of drug nanocarriers. CLN2 mice (2 mo. old) were injected with DIR-labeled EVs through the combination of i.p. (6 × 10¹¹ particles/200 µL) and i.t injections (1.5 × 10¹¹ particles/50 µL) once a week and imaged up to 24 days by IVIS. (A) Representative images show a buildup of DIR signal in the brain and main organs. (B) Quantification of DIR-EVs distribution in the brain at various time points confirmed elevated DIR-EVs signal in the brain. (C) Twenty-four days later, the main organs were imaged by IVIS, and (D) the fluorescence levels of DIR-EVs signals were quantified by Aura software. Data were analyzed using two-way ANOVA analysis. Values are means ± SEM, N = 4. Arrows—days of injections.