Nanoparticles as drug delivery agents specific for CNS: in vivo biodistribution

(A) SEM image of peptide-modified NPs (Rh-123-M-NP) (magnification 10,000×). (B) SEM image of unmodified NPs (Rh-123-B-NP) (magnification 8500×).

PCS analysis: histogram of size distribution by intensity of a representative sample of Rh-123-loaded peptide-modified NPs (Rh-123-M-NP), Rh-123–loaded unmodified NPs (Rh-123-B-NP), and loperamide-loaded peptide-modified NPs (Lop-M-NP).

In vitro release of loperamide (◊, gray line) and Rh-123 (▪, broken black line) from peptidide-modified NPs performed in pH 7.4 buffered solution. Each value is the mean of at least three experiments.

(A) Antinociceptive effect exerted by the ICV administration of loperamide (square) in comparison with the effect exerted by loperamide loaded in the peptide-modified NPs (Lop-M-NP) (triangle). (B) Antinociceptive effect exerted by loperamide ICV administration at different dosages. Data are presented as mean of at least three experiments ± SEM (bars) and were analyzed by means of ANOVA followed by Student-Neuman-Keuls tests for multiple comparisons. At each time point every group is significantly (at least P < .05) different from the other groups; some exceptions were recognized, namely: at 1 hour, control group vs 5 μg and 40 μg vs 20 μg; at 1.5 hours 20 μg vs 10 μg and 0 μg vs 5 μg; at 2 hours, control vs 5 μg, control vs 10 μg, 5 μg vs 10 μg, and 20 μg vs 40 μg. MPE, maximum possible effect.

Biodistribution results of Rh-123–loaded peptide-modified NPs (Rh-123-M-NP) (black) in comparison with Rh-123–loaded unmodified NPs (Rh-123-B-NP) (white). Each value is the mean of at least three experiments. *P < .05 (Student's test) Rh-123-M-NP vs Rh-123-B-NP.

Brain amounts of Rh-123–loaded peptide-modified NPs (Rh-123-M-NP). Each value is the mean of at least three experiments. Bars represent SD.