Functionalization of Photosensitized Silica Nanoparticles for Advanced Photodynamic Therapy of Cancer

Abstract

BODIPY dyes have recently attracted attention as potential photosensitizers. In this work, commercial and novel photosensitizers (PSs) based on BODIPY chromophores (haloBODIPYs and orthogonal dimers strategically designed with intense bands in the blue, green or red region of the visible spectra and high singlet oxygen production) were covalently linked to mesoporous silica nanoparticles (MSNs) further functionalized with PEG and folic acid (FA). MSNs approximately 50 nm in size with different functional groups were synthesized to allow multiple alternatives of PS-PEG-FA decoration of their external surface. Different combinations varying the type of PS (commercial Rose Bengal, Thionine and Chlorine e6 or custom-made BODIPY-based), the linkage design, and the length of PEG are detailed. All the nanosystems were physicochemically characterized (morphology, diameter, size distribution and PS loaded amount) and photophysically studied (absorption capacity, fluorescence efficiency, and singlet oxygen production) in suspension. For the most promising PS-PEG-FA silica nanoplatforms, the biocompatibility in dark conditions and the phototoxicity under suitable irradiation wavelengths (blue, green, or red) at regulated light doses (10–15 J/cm2) were compared with PSs free in solution in HeLa cells in vitro.

Photolon Nanoporous Photoactive Material with Antibacterial Activity and Label-Free Noncontact Method for Free Radical Detection

“…The proposed approach, that is based on the packing of the PS monomer, allows it to be retained in the silica matrix which enables more precise control of its concentration. Although, following the path of the antitumor application of PS in combination with mesoporous silica nanoparticle carriers (MSN) [ 25 , 26 ], MSN-PS conjugate against C. albicans was also designed [ 27 ], but such solutions are based on the PS delivery directly to the cells. However, such an approach requires taking into account the different pathways of anionic and cationic photosensitizers into the bacteria [ 28 ].…”

Photosensitizer‐Mesoporous Silica Nanoparticles Combination for Enhanced Photodynamic Therapy†

“…MSN allows multiple combinations to carry the different molecules of interest. For example, some components could be physically embedded in the pores without any covalent union (36), whereas others could be covalently anchored at the external functionalized shell (66,69,(75)(76)(77)(78)(79)(80).…”

“…Particularly, Rose Bengal (RB) (Fig. 1), is extensively used as a singlet oxygen reference (79,(97)(98)(99)(100)(101)(102)(103)(104). According to its absorption range (no absorbance above 600 nm), RB is not considered a suitable PS for PDT.…”

Importance of Rose Bengal Loaded with Nanoparticles for Anti-Cancer Photodynamic Therapy

“…Prieto-Montero et al [64] synthesized biocompatible MSNs (with a size of 50 nm) with RB-PEG-FA covalently decorated onto their outer surface. Several sizes of PEG were tested, and the NPs that showed the highest stability in aqueous medium were the RB-PEG5000-NPs with a hydrodynamic diameter of 99 nm.…”