Elucidating mechanism cellular uptake
Due to their small size they have the capability to cross the highly electrically resistant blood brain barrier as well as tight junctions .
The common structural feature of these CPPs is the presence of basic or cationic amino acids, in particular lysine and arginine, conferring the translocation properties .
The first discovered CPP was the HIV transactivator of transcription (tat) peptide, which is a non-toxic curtailed version of the naturally existing protein [13,14].
Dowdy suggested in 2001 that they are basically charged , with 48-60 amino acid residues being mainly responsible for the translocation properties of the membrane .
Two promising methods employed to this end include functionalization of m NPs with cell-penetrating peptides to promote efficient translocation of cargo into the cell and the use of external magnetic fields for enhanced delivery.
This study aimed to compare the effect of both penetratin and a static magnetic field with regards to the cellular uptake of 200 nm magnetic NPs and determine the route of uptake by both methods.