Interaction of model membranes and Zinc Phthalocyanines using the Martini 3 Coarse Grained force field

GOROD NOELIA S.; PEYLOUBET, AGUSTIN; BORIONI, JOSÉ L.; PUIATTI, MARCELO; CINO, E.A.; TIELEMAN, D.P.

Córdoba

Simposio; LI Reunión Anual de la Sociedad Argentina de Biofisica; 2023

Sociedad Argentina de Biofisica

Zinc Phthalocyanines (ZnPc) are important agents in PDT [2]. Their use is favored byproperties such as high singlet oxygen generation rate and excitation at wavelengthsgreater than 630 nm, which allows greater tissue penetration of the radiation thatactivates them. Since these photosensitizers are highly hydrophobic, due in part to theirhigh planarity and lack of polar groups, they aggregate in aqueous solution, the currentformulations developed involve delivery of ZnPc using carriers such as liposomes,polymers, and nanoparticles [2]. Different ZnPcs loaded in liposomes have already beensuccessfully employed in PDT against glioblastoma cells [3]. However, the incorporationmechanism into either cells, or organelles is not known in detail. Moreover, it was reportedthat Tetraamine ZnPc (TaZnPc), a ZnPc derivative, does not accumulate in mitochondriawhile ZnPc does, [3] and the causes for this behavior are not yet explained.A molecular description of these interactions can be achieved by using MolecularDynamics. In order to properly and efficiently model organelles interacting with ZnPc,decreasing the degrees of freedom of the simulation system by employing a CoarseGrained force field allows for greater timescales, system size and complexity of lipidcomposition on the model membrane. The widely used Martini model [4] already hascommon mitochondrial components available for use. Using the latest Martini 3 forcefield,a coarse grained description for ZnPc that correctly interacts with lipid bilayers wasdeveloped. This work is one for the first attempts to parametrize a highly planar and rigidstructure on Martini 3, and will allow for further research not only on modelinginteractions with realistic membranes, but also developing further descriptions of planarconjugated structures.