The production of drug-loaded EVs and to explore attainable application for in situ drug delivery method. PTPRF Proteins Gene ID Funding: This study is funded by Focused Ultrasound Foundation.OS23.Extracellular Vesicles for new Molecular Insight to Biomolecular Interactions Tamas Beke-Somfaia, Priyanka Singhv, Imola Szigyarto and Zoltan VargacaPI, TAPA-1/CD81 Proteins Recombinant Proteins Budapest, Hungary; bMs, Budapest, Hungary; cResearch Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, HungaryIntroduction: The possible of extracellular vesicles (EVs) to revolutionize the diagnosis and therapy of a variety of ailments has been realized and therefore it is actually an extensively studied path. Having said that, EVs are also in the size range suitable for membrane biophysics, though they preserve the complicated composition of a biological bilayer. Consequently, they are optimal for monitoring the structure, orientation and function of biomolecules related to EVs.Techniques: The investigated red blood cell-derived vesicles (REVs) have been isolated from blood using a normal protocol and purified working with size-exclusion chromatography. REVs were subjected to IR, CD and flow-Linear Dichroism spectroscopy, freeze-fracture Transmission Electron Microscopy as well as Dynamic Light Scattering. Benefits: Here we demonstrate that polarized light spectroscopy tactics can give critical facts on REVs and molecules inserting into their bilayer. Flowlinear dichroism (flow-LD) measurements show that EVs could be oriented by shear force, insight into properties of oriented macromolecules in the vesicles. The Soret-band in the LD spectra demonstrates that hemoglobin molecules are oriented and associated to the lipid bilayer in freshly released REVs . Further on, we chosen 3 unique antimicrobial peptides (AMPs), CM15, melittin and gramicidin and investigated their interactions with REVs employing a diverse set of techniques. The peptide-membrane interactions reveal a number of novel function of AMPs, including their capability to get rid of connected proteins in the surface of REVs (Figure 1).  I. Cs. Szigy t R. De , J. Mih y, S. Rocha, F. Zsila, Z. Varga, T. Beke-Somfai. Flow-alignment of extracellular vesicles: structure and orientation of membrane related biomacromolecules studied with polarized light. ChemBioChem. 2018;19:54551 Summary/Conclusion: In conclusion, EVs give fantastic opportunities to far better fully grasp the function and mechanism of all-natural membrane active biomolecues. Funding: This work was funded by the Momentum programme (LP2016-2), by the National Competitiveness and Excellence System (NVKP_16-1-20160007) and BIONANO_GINOP-2.3.2-15-2016-00017. The J os Bolyai Research Scholarship (Z.V.) is drastically acknowledged.JOURNAL OF EXTRACELLULAR VESICLESSymposium Session 24: Mechanisms of EV Delivery Chairs: Pieter Vader; Hang Hubert Yin Location: Level B1, Hall B 13:004:OS24.State on the art microscopy for live cell study in the extracellular vesicle-mediated drug delivery Ekaterina Lisitsynaa, Kaisa Rautaniemia, Heikki Saarib, Timo Laaksonena, Marjo Yliperttulab and Elina Vuorimaa-Laukkanena Laboratory of Chemistry and Bioengineering, Tampere University of Technologies, Tampere, Finland; bDivision of Pharmaceutical Biosciences and Drug Study System, Faculty of Pharmacy, University of Helsinki, Helsinki, FinlandaSummary/Conclusion: This analysis presents new realtime solutions to investigate EV kinetics with living cells and complements the existing approaches. The findings from the study improve the.