Diamond Nanoparticles-Porphyrin mTHPP Conjugate as Photosensitizing Platform: Cytotoxicity and Antibacterial Activity
Carolina Ramos Hurtado,
Gabriela Ramos Hurtado,
Gabrielle Lupeti de Cena,
Rafaela Campos Queiroz,
Alexandre Vieira Silva,
Milton Faria Diniz,
Verônica Ribeiro dos Santos,
Vladimir Trava-Airoldi,
Maurício da Silva Baptista,
Ncediwe Tsolekile,
Oluwatobi Samuel Oluwafemi,
Katia Conceição,
Dayane Batista Tada
Affiliations
Carolina Ramos Hurtado
Federal Institute of São Paulo (IFSP), São José dos Campos 12223-201, São Paulo, Brazil
Gabriela Ramos Hurtado
Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos 12247-004, São Paulo, Brazil
Gabrielle Lupeti de Cena
Peptide Biochemistry Laboratory, Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos 12231-280, São Paulo, Brazil
Rafaela Campos Queiroz
Federal Institute of São Paulo (IFSP), São José dos Campos 12223-201, São Paulo, Brazil
Alexandre Vieira Silva
Institute of Medicinal Chemistry, Helmholtz Zentrum München, 30167 Hanover, Germany
Milton Faria Diniz
Fundamental Sciences Division, Technological Institute of Aeronautics (ITA), São José dos Campos 12228-900, São Paulo, Brazil
Verônica Ribeiro dos Santos
Bioceramics Laboratory, Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos 12231-280, São Paulo, Brazil
Vladimir Trava-Airoldi
Sensors and Materials Associated Laboratory, National Institute for Space Research (INPE), São José dos Campos 12227-010, São Paulo, Brazil
Maurício da Silva Baptista
Department of Biochemistry, Institute of Chemistry, University of São Paulo (USP), São Paulo 05508-000, São Paulo, Brazil
Ncediwe Tsolekile
Department of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg 2028, South Africa
Oluwatobi Samuel Oluwafemi
Department of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg 2028, South Africa
Katia Conceição
Peptide Biochemistry Laboratory, Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos 12231-280, São Paulo, Brazil
Dayane Batista Tada
Nanomaterials and Nanotoxicology Laboratory, Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos 12231-280, São Paulo, Brazil
Conjugation of photosensitizers (PS) with nanoparticles has been largely used as a strategy to stabilize PS in the biological medium resulting in photosensitizing nanoparticles of enhanced photoactivity. Herein, (Meso-5, 10, 15, 20-tetrakis (3-hydroxyphenyl) phorphyryn (mTHPP) was conjugated with diamond nanoparticles (ND) by covalent bond. Nanoconjugate ND-mTHPP showed suitable stability in aqueous suspension with 58 nm of hydrodynamic diameter and Zeta potential of −23 mV. The antibacterial activity of ND-mTHPP was evaluated against Escherichia coli for different incubation times (0–24 h). The optimal activity was observed after 2 h of incubation and irradiation (660 nm; 51 J/cm2) performed right after the addition of ND-mTHPP (100 μg/mL) to the bacterial suspension. The inhibitory activity was 56% whereas ampicillin at the same conditions provided only 14% of bacterial growth inhibition. SEM images showed agglomerate of ND-mTHPP adsorbed on the bacterial cell wall, suggesting that the antimicrobial activity of ND-mTHPP was afforded by inducing membrane damage. Cytotoxicity against murine embryonic fibroblast cells (MEF) was also evaluated and ND-mTHPP was shown to be noncytotoxic since viability of cells cultured for 24 h in the presence of the nanoconjugate (100 μg/mL) was 78%. Considering the enhanced antibacterial activity and the absence of cytotoxic effect, it is possible to consider the ND-mTHPP nanoconjugate as promising platform for application in antimicrobial photodynamic therapy (aPDT).
