Diamond Nanoparticles-Porphyrin mTHPP Conjugate as Photosensitizing Platform: Cytotoxicity and Antibacterial Activity

• DOI: 10.3390/nano11061393
• Publication Date: 2021-05-26T02:02:23Z
• Authors: Carolina Ramos Hu...; Gabriela Ramos Hu...; Gabrielle Lupeti ...; Rafaela Campos Qu...; Alexandre Vieira ...; Milton Faria Diniz; Verônica Ribeiro ...; Vladimir Trava-Ai...; Maurício da Silva...; Ncediwe Tsolekile; Oluwatobi Samuel ...; Katia Conceição; Dayane Batista Tada
• Keywords: Bacterial growth; Zeta potential; Conjugate; Viability assay; Methylene blue

Conjugation of photosensitizers (PS) with nanoparticles has been largely used as a strategy to stabilize PS in the biological medium resulting photosensitizing enhanced photoactivity. Herein, (Meso-5, 10, 15, 20-tetrakis (3-hydroxyphenyl) phorphyryn (mTHPP) was conjugated diamond (ND) by covalent bond. Nanoconjugate ND-mTHPP showed suitable stability aqueous suspension 58 nm hydrodynamic diameter and Zeta potential −23 mV. The antibacterial activity evaluated against Escherichia coli for different incubation times (0–24 h). optimal observed after 2 h irradiation (660 nm; 51 J/cm2) performed right addition (100 μg/mL) bacterial suspension. inhibitory 56% whereas ampicillin at same conditions provided only 14% growth inhibition. SEM images agglomerate adsorbed on cell wall, suggesting that antimicrobial afforded inducing membrane damage. Cytotoxicity murine embryonic fibroblast cells (MEF) also shown be noncytotoxic since viability cultured 24 presence nanoconjugate 78%. Considering absence cytotoxic effect, it is possible consider promising platform application photodynamic therapy (aPDT).