Biophysical Society Thematic Meeting | Ascona, Switzerland

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

Poster Abstracts

38-POS Board 19 Targeting Liposomes for Uptake into CEACAM-Expressing Human Cells Using a Bacterial Membrane Protein Jason Kuhn , Alison K. Criss, Asya Smirnov, Linda Columbus. University of Virginia, Charlottesville, VA, USA. The pathogenic bacteria Neisseria gonorrhoeae and N. meningitidis induce their own phagocytosis into human host cells prior to replication. Bacterial cell entry is promoted by the binding of Neisserial outer membrane opacity-associated (Opa) proteins to human carcinoembryonic antigen-like cell adhesion molecule (CEACAM) receptors, a widely- distributed class of cell receptors in the human body. Binding of Opa proteins to either CEACAM1, CEACAM3, CEACAM5, or CEACAM6 generates intracellular signalling events which lead to bacterial internalization by both phagocytes and epithelial cells. We are interested in determining whether Opa proteins reconstituted in liposomes retain the ability to promote entry of liposomes into epithelial cells similar to Neisseria . Because CEACAM receptors targeted by Opa may demonstrate tissue-specific expression or increased expression in various cancers, the ability to target Opa-proteoliposomes to CEACAM + cells could prove valuable in therapeutic delivery. Our results indicate that Opa-proteoliposomes target CEACAM + cells for internalization using an active-uptake mechanism. Additionally, Opa-proteoliposome uptake into CEACAM+ cells correlates with both cell size and CEACAM expression levels. With uptake established, CEACAM selectivity is currently being investigated. 41-POS Board 21 H2 Fueled ATP Synthesis on an Electrode: Mimicking Cellular Respiration Ivan Lopez-Montero 1,2 , Oscar Gutiérrez-Sanz 3 , Paolo Natale 1,2 , Ileana Marquez 3 , Marta C. Marques 4 , Sonia Zacarias 4 , Marcos Pita 3 , Ines A. Pereira 4 , Antonio L. De Lacey 3 , Marisela Velez 3 . 1 Complutense University, Madrid, Spain, 2 Instituto Hospital 12 de Octubre, Madrid, Madrid, Spain, 3 CSIC, Madrid, Madrid, Spain, 4 Universidade Nova de Lisboa, Oeiras, Portugal. ATP, the molecule used by living organisms to supply energy to many different metabolic processes, is synthesized mostly by the ATPase synthase using a proton gradient generated across a lipid membrane. We present evidence that a modified electrode surface integrating a NiFeSe hydrogenase and a F1Fo-ATPase in a lipid membrane can couple the electrochemical oxidation of H2 to the synthesis of ATP. This electrode-assisted conversion of H2 gas into ATP could serve to generate this biochemical fuel locally when required in biomedical devices or enzymatic synthesis of valuable products.

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