Biophysical Society Thematic Meeting | Ascona, Switzerland

Liposomes, Exosomes, and Virosomes: From Modeling Complex Membrane Processes to Medical Diagnostics and Drug Delivery

Poster Abstracts

61-POS Board 31 Peptide Features Determining Its Translocation and Pore Formation Ivo Kabelka 1 , Daan Frenkel 2 , Robert Vacha 1 . 1 Masaryk University, Brno, Czech Republic, 2 University of Cambridge, Cambridge, United Kingdom. Amphiphilic peptides can interact with phospholipid membrane and severely affect its barrier function by translocation or pore formation. This is particularly important for antimicrobial and cell-penetrating peptides as it can determine their lethalness or ability to act as drug delivery systems against bacteria or pathological cells. However, the necessary peptide properties and conditions for membrane translocation and pore formation are not well understood. Using coarse-grained simulations, we have calculated the free energy of pore formation and translocation of amphiphilic helical peptides under various conditions. We found that the most effective in pore formation are peptides with length similar to membrane thickness. Moreover, the preferred peptide orientation in the pore and during the translocation was found to agree well with the hydrophobic mismatch rationalization. Long peptides were thus observed to orient parallel to membrane plane forming a ‘double-belt’ pore. The obtained understanding of peptide behavior at the membrane may be useful for the rational design of peptides that are more effective and specific against given target cells or bacteria.

64-POS Board 32 Simulation of Nanoparticle-Membrane Interaction Xianren Zhang , Beijing University of Chemical Technology, Beijing, China.

Nanoparticles are widely used in biomedical fields, such as gene and drug delivery, nanoparticle- based sensing and imaging etc. In these applications, the efficient uptake of nanoparticles (NPs) into cells becomes a critical issue, because NPs are required to be capable of transporting through cell membranes. On the other hand, nanoparticles adhering on cells may cause damage to cell membranes and induce adverse biological effects, with the potential to create cytotoxicity. In this regard, understanding of the mechanism of NP uptake is essential to bio-applications of nanoparticles. I will summarize our recent simulation works on the interaction between cell membrane and nanoparticles are addressed. The internalization pathways of nanoparticles, including endocytosis and penetration, depends on the size, shape and rigidness of nanoparticles.

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