Cellular uptake in (a) bEnd.3, (b) astrocytes and (c) primary neuronal cells treated with Plain-, Tf-, Pen- and PenTf-liposomes for 0.1, 0.25, 1 and 4 h. Data expressed as mean ± SD (n=4). Significantly higher uptake of liposomes in all cells was observed at 4 h (*** p<0.001) compared to 0.1, 0.25, 0.5 and 1 h. Significantly higher uptake of PenTf-liposomes in bEnd.3 cells was observed at 4 h (### p<0.001) compared to uptake of Plain-, Tf- and Pen-liposome at 4 h. Effect of chemical inhibitors on uptake of Plain-, Tf-, Pen- and PenTf-liposomes in (d) bEnd.3, (e) astrocytes and (f) primary neuronal cells at 4 h. Data expressed as mean ± SD (n=4). Statistically significant uptake (p<0.001) compared to sodium azide treatment is represented as ***.