Methylene blue-covered superparamagnetic iron oxide nanoparticles combined with red light as a novel platform to fight non-local bacterial infections: A proof of concept study against Escherichia coli

Autor(es)

Toledo, Victor Hladkyi ^[1] ; Yoshimura, Tania Mateus ^[2] ; Pereira, Saulo Toledo ^[2] ; Castro, Carlos Eduardo ^[3] ; Ferreira, Fabio Furlan ^[3] ; Ribeiro, Martha Simoes ^[2] ; Haddad, Paula Silvia ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ Sdo Paulo UNIFESP, Dept Chem, BR-09961400 Diadema, SP - Brazil

^[2] Energy & Nucl Res Inst IPEN, Ctr Laser & Applicat, BR-05508000 Sao Paulo, SP - Brazil

^[3] Fed Univ ABC UFABC, Ctr Nat & Human Sci CCNH, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY; v. 209, AUG 2020.
• Citações Web of Science: 0

Resumo

Currently, antimicrobial photodynamic therapy (APDT) is limited to the local treatment of topical infections, and a platform that can deliver the photosensitizer to internal organs is highly desirable for non-local ones; SPIONs can be promising vehicles for the photosensitizer. This work reports an innovative application of methylene blue (MB)-superparamagnetic iron oxide nanoparticles (SPIONs). We report on the preparation, characterization, and application of MB-SPIONs for antimicrobial photodynamic therapy. When exposed to light, the MB photosensitizer generates reactive oxygen species (ROS), which cause irreversible damage in microbial cells. We prepare SPIONs by the co-precipitation method. We cover the nanoparticles with a double silica layer - tetraethyl orthosilicate and sodium silicate - leading to the hybrid material magnetite-silica-MB. We characterize the as-prepared SPIONs by Fourier transform infrared spectroscopy, powder X-ray diffraction, and magnetic measurements. We confirm the formation of magnetite using powder X-ray diffraction data. We use the Rietveld method to calculate the average crystallite size of magnetite as being 14 nm. Infrared spectra show characteristic bands of iron-oxygen as well as others associated with silicate groups. At room temperature, the nanocomposites present magnetic behavior due to the magnetite core. Besides, magnetite-silica-MB can promote ROS formation. Thus, we evaluate the photodynamic activity of Fe3O4-silica-MB on Escherichia coli. Our results show the bacteria are completely eradicated following photodynamic treatment depending on the MB release time from SPIONs and energy dose. These findings encourage us to explore the use of magnetite-silica-MB to fight internal infections in preclinical assays. (AU)

• Processo FAPESP: 17/15061-6 - Preparação, Caracterização e Ensaios Biológicos de Materiais Nanoestruturados Baseados em Nanopartículas Superparamagnéticas Metálicas e Bimetálicas
• Beneficiário: Paula Silvia Haddad Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular