Design and development of new nanophotosensitizers with probable phototoxic action.

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

Congreso; Reunión Anual de Sociedades de Biociencia 2019; 2019

Polymeric nanoparticles (NP) have been investigated for their properties that enable them to be widely applied in drug entrapment. The Polyacrylamide (PAA)-NP matrix protects the embedded active form of the photosensitizers (PS) from enzymatic or environmental degradation and permits singlet oxygen and other kinds of reactive oxygen species (ROS) diffusion through the pores. Thus, new NP of different PAA, (N-isopropylacrylamide (NIPA-NP) and N,N-methylene bis acrylamide (BIS-NP), were synthesized to incorporated two second generation PS: monobrominated Neutral Red (NRBr) and monobrominated Azure B (AzBBr). In this study, the PAA-NP were prepared based on the inverse microemulsion polymerization. The obtained NP were characterized by size and zeta potential analysis with promising results. In addition, the oxidative activity was evaluated by photooxidation of 9,10-Anthracenediyl-bis (methylene) dimalonic acid (ABDA). Singlet oxygen quantum yield (ΦΔ) were calculated using the free PS as references (ΦΔ= 1). According to the results obtained it is possible to affirm that for both PS the production of ΦΔ was greater when they were loaded in the NP compared to the free form. The ΦΔ of NRBr loaded in PAA-BIS-NP increased 4.5 times compared to that observed for free NRBr. In addition, when it was loaded in PAA-NIPA-NP its ΦΔ was 6.6 times higher than for free PS.On the other hand, AzBBr presented a behavior similar to that described for NRBr. So, when AzBBr was loaded in PAA-BIS-NP the value of ΦΔ was 1.7 times higher than when it was free. In PAA-NIPA-NP, the found value was 1.9 times higher than for free form. The vehiculization of these dyes in the NP is able to optimize the photochemical properties of the PS, which is an important advantage for their probable applications. The results obtained are very promising and would indicate that the NP have the capacity to induce the ROS generation of PS and lead to the formation of more singlet oxygen at the action site.