Webinar November 2023 – PD Dr. Leneweit

On Wednesday, November 22, 2023, an online seminar on "How to avoid the ’PEG dilemma’ in liposomal targeting?" was held at 3.30 p.m. (CET).

The speaker was Priv.-Doz. Dr. habil. Gero Leneweit from the Karlsruhe Institute of Technology and the Carl Gustav Carus-Institute in Germany.

If you are interested in the slides of the presentation, please get in touch with us!


The authorization of many chemotherapeutics in liposomal formulation is a great success for the enduring efforts of drug delivery research. A meta-analysis by Petersen et al. in 2016, however, showed that liposomal anti-cancer therapeutics are capable to improve the tolerability, but do not lead to prolonged overall survival or progression-free survival so far. This raises the questions how better tolerability can be translated into better clinical outcomes in the future for any drug applied by a drug delivery system?

One issue among several might be the surface coating: Coatings are needed to avoid rapid clearance and enable long circulation of the delivery system for passive or active targeting. However, despite many breakthroughs in the development of new classes of drug substances and new delivery systems, no real improvements have been achieved for polyethylene glycol (PEG) coatings so far. This is even more astonishing in the light of various obvious drawbacks: i) the accelerated blood clearance upon repeated injection due to anti-PEG IgM antibody formation, ii) the lack of biodegradability of PEG and iii) its hindrance in cellular uptake and endosomal escape. The latter effect is known as the “PEG dilemma”, indicating the need for a coating which achieves two goals equally: 1) an immuno-compatible coating to avoid rapid clearance from the blood to reach the target tissue. 2) drug release and endosomal escape after cellular uptake to reach the cytosol.

In this webinar, different approaches will be discussed, also in the light of novel drug delivery systems such as lipid nanoparticles (LNPs).

If you are interested in the slides of the presentation, please get in touch with us!