Optimization of Second Generation Photosensitizers by Vehiculization in Polyacrylamide Nanoparticles.

GUALDESI, MARÍA S.; VARA, JIMENA; ALVAREZ IGARZABAL,CECILIA I.; ORTIZ, CRISTINA S.

Córdoba

Congreso; XIII ELAFOT; 2017

XIII ELAFOT - October 23th- 27th, 2017 ? Villa Carlos Paz, ArgentinaOptimization of Second Generation Photosensitizers by Vehiculization inPolyacrylamide Nanoparticles.María S. Gualdesia, Jimena Varaa, Cecilia I. Alvarez Igarzabalband Cristina S. Ortiza.aDepartamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba; Email:sgualdesi@fcq.unc.edu.arbDepartamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional deCórdoba. IMVIB-CONICET.e-mail (Presenting Author): jvara@fcq.unc.edu.arPolyacrylamide nanoparticles (PAA-NPs) are promising vehicles for the incorporation of drugs inphotodynamic therapy (PDT) and photodynamic inactivation (PDI). The polymeric matrix of PAANPsprotects the active form of the photosensitizer (PS) from possible enzymatic degradations or fromthe biological environment and prevents its aggregation. Thus, new NPs of different PAA, (2-hydroxyethyl methacrylate (HEMA-NPs) and (+) N,N´-Diallyl-L-Tartardianide (DAT-NPs), weresynthesized to incorporated two second generation PS: monobrominated Neutral Red (NRBr) andmonobrominated Azure B (AzBBr), with activity in PDT and PDI [1-2]. In this study, the PAA-NPswere prepared based on the inverse microemulsion polymerization. The obtained HEMA-NPs andDAT-NPs were characterized by size and zeta potential analysis with promising results. In addition,the oxidative activity was evaluated. Photooxidation of 9,10- Anthracenediyl-bis (methylene)dimalonic acid (ABDA) was also used to determine oxygen quantum yield (ΦΔ) by thephotosensitizers. NRBr and AzBBr were used as references (ΦΔ= 1).According to the obtained results, it is possible to affirm that for the NRBr dye, the production ofsinglet oxygen increases considerably when this one is loaded in the nanoparticles, in comparisonwith it is free in water. Thus, for NRBr-HEMA-NPs, the value of ΦΔ was 3.5 times greater than thatobtained for free NRBr. While NRBr-DAT-NPs, the value of ΦΔ tripled to the free PS. These resultsare very promising and would indicate that the PAA-NPs have the capacity to induce the reactiveoxygen species generation of PS and lead to the formation of more singlet oxygen at the site.On the other hand, for the AzBBr, the observed behavior was similar to that for NRBr, the thiazinevehiculized dye, caused greater decomposition of ABDA than the free one. From the above, it can bededuced that the vehiculization of these dyes (NRBr and AzBBr) in the PAA-NPs is able to optimizethe photochemical properties of the PS, which is an important advantage for the probable applicationsof these.AcknowledgmentsThis work was supported by grants from Secretaría de Ciencia y Técnica (SeCyT) 316/2016; ConsejoNacional de Investigaciones Científicas y Técnicas (CONICET) PIP N° 11220150100344CO andFondo para la Investigación Científica y Tecnológica (FonCyT). JV gratefully acknowledges receiptof a fellowship from the CONICET.References list[1] M. N. Montes de Oca, J. Vara, L. Milla, V. Rivarola, C. S. Ortiz, Arch Pharm Chem Life Sci.2013, 346, 255.[2] M. N. Urrutia, F. L. Alovero, C. S. Ortiz, Dyes and Pigments. 2015, 116, 27