Interaction of cytotoxic photoproducts of Merocyanine 540 (pMC540) with Bovine Serum Albumin Nanoparticles (BSA NP)

SIRI, M; CALZETTA N.L.; MARANZANA, E.S.B.; ALONSO, S. DEL V.

Santiago del Estero

Congreso; SAB XLIV, XLIV Reunión anual de la Sociedad Argentina de Biofisica; 2015

SAB, Sociedad Argentina de Biofisica

Bovine serum albumin nanoparticles (BSA NP) are prepared via intramolecular crosslinking by gamma irradiation and have been characterized as a candidate for drug delivery system [1].Previous work have demonstrated that light irradiation of MC540, a non-cytotoxic photosensitizer dye, produces a mixture of non-fluorescent photoproducts (pMC540) biologically active which resulted cytotoxic for several human adenocarcinoma cell lines [2]The aim of this work is to study the interactions of BSA NP with the fluorescent probe merocyanine 540 (MC540) in order to test structure/function of BSA NP as a drug delivery system and test encapsulation conditions and release kinetic profile for both, MC540 and pMC540 by fluorescence spectroscopy.Our preliminary results showed that MC540 has more affinity for BSA NP than BSA and this probe preferentially bind at two subdomains IIA and III A corresponding to Sudlow site I and Sudlow site II, which contain hydrophobic cavities with similar polarity environment.The encapsulation efficiency resulted higher for BSA than BSA NP. However both systems have similar release kinetic profiles for MC540.By the other side, merocyanine photoproducts (pMC540) showed to have a ten times higher affinity for BSA NP respect to MC540.Under our test conditions we are able to confirm that pMC540 is able to be encapsulated in our BSA NP nanoparticles.