Self-assembled vesicles obtained by electrohydrodynamic technique using different sources of phospholipids

SANCHEZ CERVIÑO, M. CELINA; DI GIANVINCENZO, PAOLO; MOYA, SERGIO; RIVERO, GUADALUPE

Mar del Plata

Congreso; XII Latin-American Congress of Artificial Organs and Biomaterials; 2023

INTEMA - LABOATEM

Introduction and objective: Vesicles are supramolecular structures composed of one or multiple bilayers of amphiphilic molecules that surround an aqueous compartment. Due to the characteristics and versatility of the structures, they can hold both hydrophobic and/or hydrophilic therapeutic agents. However, their production requires many steps, and they are unstable in storage. In this work, vesicles were obtained from a non-traditional method, using solid electrospun membranes as templates that form vesicles by self-assembly when dissolved in water [1]. The objective is to test different compositional parameters, raw materials´ qualities and their storage stability.Methodology:Membranes were electrospun from a 10% m/v dissolution of polyvinylpyrrolidone (PVP-360, Sigma®) and different sources of phospholipids 5%m/v: A) high purity phosphatidylcholine 95,8% (Saporiti®), B) raw soy lecithin (Saporiti®) and C) soybean lecithin (14-29% choline basis, Sigma®) using different solvents: chloroform, ethanol, and a 1:1 mixture of both. The membranes were physicochemical characterized and stored under different conditions (temperature, vacuum) to assess their stability in time. The size and Z potential of the vesicles obtained by dissolving the electrospun membranes were evaluated by Dynamic Light Scattering (DLS). The morphology of those with the best features was evaluated using transmission electron microscopy (TEM).Results and discussion: Ethanol could not completely solubilize the mixture of PVP and C lecithin. Vesicles obtained from fresh membranes and those that were stored for 2 months were compared and measured by DLS, and no significant changes were observed in the hydrodynamic diameter. The membrane electrospun with phosphatidylcholine (A) using a mixed solvent was the one that best preserved its properties, as indicated by both the PDI and the diameter measurements in time. Besides, this type of vesicles showed a single peak and a negative zeta potential around -30mV, indicating higher stability compared to the other templates composed of different phospholipid sources. The TEM inspection of vesicles (A) showed supramolecular structures of an average diameter of 97 nm. Agglomerated clusters and foreign particles were detected in systems B and C. Conclusions: It was possible to obtain vesicles by dissolving electrospun hybrid templates, and these solid membranes can be preserved over time. The use of high-purity phosphatidylcholine resulted in vesicles with the best properties. However, it may also be interesting to explore the application of soybean lecithin for in-situ vesicle formation, especially if there is a need to incorporate specific adjuvants agents for diverse applications. This approach could potentially yield a cost-effective products. The stability of the already formed vesicle solutions will be also assessed over time.References [1] Sánchez-Cerviño, M.C.et al. Polymers 2023, 15, 795