In utero
ICV delivery of ADP-LNPs is safe and well tolerated. (A)
Schematic diagram of the experimental protocol used to assess the
safety of in utero ICV injection of ADP-LNPs and standard MC3-LNPs
(Std-LNPs). (B) Intraoperative images showcasing the ICV injection
procedure performed in utero. (a) All fetuses on either side of the
uterine bifurcation (right or left) were noted; (b) a glass pipet
was used to inject the LNPs into the fetal lateral cerebral ventricular
space; and (c) successful injection into the ventricular system was
determined by the spreading of the blue food dye into the ventricular
zone (VZ). (C) Survival outcomes at birth for mouse fetuses subjected
to LNP injections of either ADP-LNPs or Std-LNPs. ADP-LNP-treated
fetuses had a significantly higher survival rate than fetuses treated
with Std-LNPs (****p < 0.0001). (D) Kaplan–Meier
survival curve of fetuses from E15.5 to postnatal day 7, comparing
Std-LNPs and ADP-LNPs. ADP-LNPs demonstrated significantly higher
survival probability (**p = 0.0062). (E,F) Normalized
cytokine concentrations in brain (E) and liver (F) tissues 48 h postinjection
exhibited significant differences between LNP-treated groups and the
PBS control group 48 h postinjection. ADP-LNPs showed significantly
lower cytokine levels compared to Std-LNPs, indicating reduced inflammatory
response. (G) Body and brain weights at 10 weeks postnatal, comparing
ADP-LNP/mRNA-treated mice and controls. No significant differences
were observed, indicating normal postnatal development (data are represented
as mean ± SEM, n = 6 for the ADP-LNP/mRNA group
and n = 4 for the PBS control group).