Antennapedia crosses the blood-brain barrier
The Antennapedia peptide, also known as penetratin is a 16-mer peptide (RQIKIWFQNRRMKWKK-amide) derived from the third helix of the Drosophila Antennapedia homodomain (residues 43-58).
Antennapedia is able to translocate through the plasma membrane to the cytosol and nucleus of living cells, both at 37 °C and 4 °C.
Antennapedia has been shown to aid in the cellular uptake of drugs across the blood-brain barrier. In one study it was found that polymer nanoparticles coupled to penetratin exhibited increased cellular uptake in vitro and improved pharmacokinetics in vivo. These penetratin-nanoparticles were found mainly brain tissue and less so in other tissues compared to unmodified nanoparticles. Similarly, addition of penetratin onto a liposomal surface improved liposomal accumulation and delivery of encapsulated doxorubicin to brain tumors (Sharma, Modgil, Zhong, Sun, & Singh, 2014).