ABSTRACT
Since the discovery of pAntp/penetratins by Alain Prochiantz’ group,1 numerous
peptides have been reported to have cell-penetrating properties (CPPs). In Part I of
this book, the reader will find five chapters on different representatives of CPPs.
Penetratins, Tat peptides, MAPs, and transportans are certainly among the most
studied CPPs today, and their inclusion in this book was not a difficult decision.
However, the selection among more recently discovered/designed CPPs was
considerably more difficult due to the enormous number of interesting newcomers.
The choice was made to favor cis-g-amino-L-Pro-derived peptides and the CPP prediction approach. Both approaches are especially innovative in that they enable
the application, besides traditional/coded L-amino acids, of noncoded amino acids in
the efficient CPP sequences. This is likely to be an important step towards the
commercialization of CPPs, as well as towards their applications in drug delivery.
Additionally, the CPP prediction algorithm presented in chapter 5 may enable the
exciting possibility of using prodrug concepts for the targeted delivery of drugs in
future. Certainly, the first steps in this direction are being made, though many
unsolved questions will probably arise along the way. Nonetheless, we believe that it
is a good start in rationalizing the CPP design and for understanding of the CPP
transfer mechanisms.