Pp IX Silica Nanoparticles Demonstrate Differential Interactions with In Vitro Tumor Cell Lines and In Vivo Mouse Models of Human Cancers

Abstract

Protoporphyrin IX (Pp IX) silica nanoparticles, developed for effective use in photodynamic therapy (PDT), were explored in in vitro and in vivo models with the ambition to improve knowledge on the role of biological factors in the photodamage. Pp IX silica nanoparticles are found efficient at temperature with extreme metabolic downregulation, which suggest a high proportion of passive internalization. For the first time, clearance of silica nanoparticles on tumor cells is established. Cell viability assessment in six tumor cell lines is reported. In all tumor types, Pp IX silica nanoparticles are more efficient than free Pp IX. A strong fluorescence signal of reactive oxygen species generation colocalized with Pp IX silica nanoparticles, correlates with 100% of cell death. In vivo studies performed in HCT 116, A549 and glioblastoma multiforme tumors-bearing mice show tumor uptake of Pp IX silica nanoparticles with better tumor accumulation than the control alone, highlighting a high selectivity for tumor tissues. As observed in in vitro tests, tumor cell type is likely a major determinant but tumor microenvironment could more influence this differential time accumulation dynamic. The present results strongly suggest that Pp IX silica nanoparticles may be involved in new alternative local applications of PDT.

Can nanotechnology potentiate photodynamic therapy?

“…The intracellular accumulation of PPIX SiNPs takes place in the cytoplasm of cells. Higher ROS generation, which leads to cell destruction, was found correlated to the presence of PPIX SiNPs in both HCT 116 and HT-29 colon cancer cells [131] .…”

“…They showed PDT effect performed on HeLa cells, and the cell structures were destroyed by a 532-nm light source at low dose (2 mW/cm 2 , 2 min). Simon et al [131] recently published the synthesis and properties of PPIX in ORMOSIL nanoparticles prepared by Prasad ' s method. There is a strong relationship between the sites of subcellular localization of the PPIX and photodamage to nearby organelles involved in cell death.…”

Nanoparticles for Photodynamic Therapy Applications

“…Simon et al recently published (Simon et al 2010) the synthesis and properties of PpIX, (Fig. 7) ORMOSIL nanoparticles prepared by Prasad's method, and performed in vitro and in vivo studies.…”

Nanoscale Materials for Tackling Brain Cancer: Recent Progress and Outlook

“…At the same time polymer matrices are believed to have a sufficient degree of porosity to allow an entrapped PS to react with molecular oxygen. [ 22 ] The encapsulation of dyes into a polymeric matrix can reduce certain side effects of PDT. Moreover, this approach allows the introduction of additional functional building blocks for site-specifi c delivery, multimodal imaging, and enhanced therapeutic effi cacy.…”