Multifunctional magnetic and photoresponsive nanoparticles prepared by polymer self-assembly

G. LAVORATO; DANIEL MÁRTIRE; FONTICELLI, MARIANO; BELÉN RIVAS-AIELLO; CAROLINA VERICAT

Viña del Mar

Encuentro; Encuentro Latinoamericano de Fotoquímica y Fotobiología (ELAFOT); 2019

Cancer is one ofthe main causes of mortality around the world. One of the most sought objectivesin Nanomedicine is to develop new nanomaterials that can improve the efficiencyof cancer treatments while minimizing their undesired side effects. This workaims to demonstrate the synthesis of a multifunctional nanomaterial thatcombines magnetic nanoparticles and a photoresponsive agent in a singletheranostic platform. We synthesized monodispersehydrophobic iron oxide nanoparticles (MNPs) with a diameter of 10.8±1.5 nm bythe method of Sun et al.1. To prepare water-dispersible nanoparticles loaded with aphotoresponsive agent, the MNPs were assembled with the amphiphilic polymer poly(maleicanhydride-alt-1-octadecene) (PMAO) and dispersed in a sodium borate buffer. Thehydrophobic MNPs are encapsulated by the non-polar ends of the polymer, allowingthe incorporation of phenalenone (PN) as a photoactive agent.By takingadvantage of the magnetic properties of the nanoparticles, we employed magneticdecantation as a purification method2 and investigated the spectroscopic properties of the precipitatedand supernatant portions of the colloidal dispersion. Steady-state fluorescencespectroscopy confirmed that the PS is effectively incorporated into theassembly and revealed a photoluminescence band at λ≈500 nm (λexc=360nm), which is red-shifted compared to the spectra obtained for the PS in theabsence of MNPs. Thismultifunctional nanoparticle system is a proof-of-concept demonstration of an integratedmaterial that would allow simultaneous application of magnetic hyperthermia andphotodynamic therapies. Our approach is also a promising way to deliverhydrophobic photosensitizers, as the solubilization and targeting of these moleculesremains one of the biggest problems for the effective of these therapies. Finally,the use of a polymer that is sensitive to changes in temperature or pHconditions could favor the release of the photosensitizer during the combinedtreatment. 1. Sun,S. & Zeng, H. Size-controlled synthesis of magnetite nanoparticles. J.Am. Chem. Soc. 124, 8204?8205 (2002).2. Lassenberger, A. et al. Evaluation of High-YieldPurification Methods on Monodisperse PEG-Grafted Iron Oxide Nanoparticles. Langmuir32, 4259?4269 (2016).