Ruthenium-phthalocyanine complexes conjugated to aminofunctionalized surface of Er3+ and Yb3+ doped yttrium oxide upconverting nanoparticles. Chemical, photochemical and photobiological characterization

Author(s)

Alexia Marques Silva

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC)
• Defense date: 2019-09-12

Examining board members

Roberto Santana da Silva; José Maurício Almeida Caiut; Sidney José Lima Ribeiro

• Advisor: Roberto Santana da Silva

Abstract

Photodynamic therapy (PDT) studies are based on singlet oxygen (1O2) production as reactive species, but the hypoxic characteristic of small size neoplasms are a big barrier for the effectiveness of PDT in clinic tests. A new potentiality is to use complexes that can photochemically release nitric oxide (NO), which owns remarkable characteristics in biological environment and can cause a cytotoxic action through a reaction with superoxide anion (O2-), that can be found in biological medium, forming other radicals. Besides the oxygen reactive species (ORS) production, PDT can also be used to targeted treatment of neoplasms, once the activation of photossensitizers (PS) is through luminous stimulus in a pontual way. Once the depth reached in tissue by the light used in PDT is not large, the coupling of PS to upconverting nanoparticles allows the use of higher penetration radiation, activating the PS in deeper regions, producting singlet oxygen and releasing NO. In this work, the phototossensitizer were the ruthenium phthalocyanines [Ru(PC-R)] (KTC) and [Ru(NO)(PC-R)] (KTC(NO)),where (PC-R) is a carboxylic terminated phthalocyanine. Boht can produce singlet oxygen and the last can also release nitric oxide. The upconverting material was Er3+ and Yb3+ doped yttrium oxide in nanoparticle shape, covered by tetraethyl orthosilicate (TEOS) na functionalized by (3-aminopropyl)triethoxysilane) (APTES) in order to obtain amino terminations over the surface. The complex immobilization in the nanoparticle surface was proposed by adsorption and covalent bond between the carboxylic complex termination and nanoparticle\'s surfacce aminogroup. The structural analysis was made by X-rays difratometry and showed the crystalline phase of material after thermic treatment. The photoluminescence spectroscopy showed the 660nm light emission from nanoparticles after 980 nm irradiation (up conversion phenomenon). Infrared vibrational spectroscopy corroborate TEOS overlay and APTES functionalization. Micrographies obtained from electronic transmission microscopy (ETM) showed independente particles as well as he crystallization, coverage and functionalization steps. Zero charge point confirms the surface modification. Preliminary celular viability assays, followed by optical microscopy demonstrated the low toxicity in healthy cells and a propensy of the system to accumulate around neoplasic cells. (AU)

• FAPESP's process: 17/04099-2 - Evaluation of ruthenium-phtalocyanine complex conjugated with lanthanide dopped silica theranostic effect over neoplastic cells
• Grantee: Alexia Marques Silva
• Support Opportunities: Scholarships in Brazil - Master