Audrey Gallud

Biodegradable Ethylene‐Bis(Propyl)Disulfide‐Based Periodic Mesoporous Organosilica Nanorods and Nanospheres for Efficient In‐Vitro Drug Delivery

Periodic mesoporous organosilica nanorods and nanospheres are synthesized from 1,4-bis(triethoxysilyl)ethylene and bis(3-ethoxysilylpropyl)disulfide. The nanosystems present the long-range order of the hexagonal nanostructure. They are degraded in simulated physiological conditions. The loading and release of doxorubicin with these nanosystems are both pH dependent. These nanoparticles are endocytosed by breast cancer cells and are very efficient for doxorubicin delivery in these cells.

Two‐Photon‐Triggered Drug Delivery via Fluorescent Nanovalves

Mesoporous silica nanoparticles (MSN) are functionalized in the walls with an original fluorophore with a high two-photon absorption cross-section. The pores of the MSN filled with anticancer drug are blocked with a pseudo-rotaxane constituted by an azobenzene stalk and a β-cyclodextrin moiety. After incubation of the nanosystem with MCF-7 breast cancer cells, two-photon irradiation at low power is used to image the cells. At high power, cancer cell killing is observed due to the two-photon-triggered opening of the pores through FRET and the release of the anticancer drug from the MSN.

Two‐Photon Excitation of Porphyrin‐Functionalized Porous Silicon Nanoparticles for Photodynamic Therapy

Porous silicon nanoparticles (pSiNPs) act as a sensitizer for the 2-photon excitation of a pendant porphyrin using NIR laser light, for imaging and photodynamic therapy. Mannose-functionalized pSiNPs can be vectorized to MCF-7 human breast cancer cells through a mannose receptor-mediated endocytosis mechanism to provide a 3-fold enhancement of the 2-photon PDT effect.

Two-Photon-Triggered Drug Delivery in Cancer Cells Using Nanoimpellers†

A therapy of cancer cells: Two-photon-triggered camptothecin delivery with nanoimpellers was studied in MCF-7 breast cancer cells. A fluorophore with a high two-photon absorption cross-section was first incorporated in the nanoimpellers. Fluorescence resonance energy transfer (FRET) from the fluorophore to the azobenzene moiety was demonstrated.

Multifunctionalized mesoporous silica nanoparticles for the in vitro treatment of retinoblastoma: Drug delivery, one and two-photon photodynamic therapy

In this work, we focused on mesoporous silica nanoparticles (MSN) for one photon excitated photodynamic therapy (OPE-PDT) combined with drug delivery and carbohydrate targeting applied on retinoblastoma, a rare disease of childhood. We demonstrate that bitherapy (camptothecin delivery and photodynamic therapy) performed with MSN on retinoblastoma cancer cells was efficient in inducing cancer cell death. Alternatively MSN designed for two-photon excited photodynamic therapy (TPE-PDT) were also studied and irradiation at low fluence efficiently killed retinoblastoma cancer cells.

Anionic porphyrin-grafted porous silicon nanoparticles for photodynamic therapy

Non-toxic porous silicon nanoparticles carry porphyrin covalently attached to their surface inside breast cancer cells for a more efficient photodynamic effect.

Enhanced Two‐Photon Fluorescence Imaging and Therapy of Cancer Cells via Gold@Bridged Silsesquioxane Nanoparticles

A two-photon photosensitizer with four triethoxysilyl groups is synthesized through the click reaction. This photosensitizer allows the design of bridged silsesquioxane (BS) nanoparticles through a sol-gel process; moreover, gold core BS shells or BS nanoparticles decorated with gold nanospheres are synthesized. An enhancement of the two-photon properties is noted with gold and the nanoparticles are efficient for two-photon imaging and two-photon photodynamic therapy of cancer cells.

Hybrid mesoporous silica nanoparticles with pH-operated and complementary H-bonding caps as an autonomous drug-delivery system.

Mesoporous silica nanoparticles (MSNPs) are functionalized with molecular-recognition sites by anchoring a triazine or uracil fragment on the surface. After loading these MSNPs with dyes (propidium iodide or rhodamine B) or with a drug (camptothecin, CPT) they are capped by the complementary fragments, uracil and adenine, respectively, linked to the bulky cyclodextrin ring. These MSNPs are pH-sensitive and indeed, the dye release was observed at acidic pH by continuously monitored fluorescence spectroscopy studies. On the other hand, no dye leakage occurred at neutral pH, hence meeting the non-premature requirement to minimize side effects. In vitro studies were performed and confocal microscopy images demonstrate the internalization of the MSNPs and also dye release in the cells. To investigate the drug-delivery performance, the cytotoxicity of CPT-loaded nanoparticles was tested and cell death was observed. A remarkably lower amount of loaded CPT in the MSNPs (more than 40 times less) proved to be as efficient as free CPT. These results not only demonstrate the drug release after pore opening under lysosomal pH, but they also show the potential use of these MSNPs to significantly decrease the amount of the administered drug.

Imidazopyridine-fused [1,3]-diazepinones: synthesis and antiproliferative activity.

A series of 15 pyrido-imidazo-1,3-diazepin-5-ones and pyrido-1,3-diazepine-2,5-diones were synthesized and their anticancer activities were evaluated. Among tested compounds on a cell lines panel, compound 6a presents the best growth inhibition activity on 21 cell lines with a cytotoxic effect on MDA-MB-435 melanoma cells. This compound led to deep cell morphological changes and revealed to be an inhibitor of the Hepatocyte progenitor kinase-like kinase (HGK), which is known to be implicated in the migration, adhesion and invasion of various tumor cells.

Targeting Multiplicity: The Key Factor for Anti-Cancer Nanoparticles

In this mini-review, we focus on different strategies to bring nanotools specifically to cancer cells. We discuss about a better targeting of tumor, combining the characteristics of tumor environment, the increase in nanoparticles life time, the biomarkers overexpressed on cancer cells and different physical methods for non invasive therapies. Here we detail the necessity of a synergy between passive and active targeting for an actual specificity of cancer cells.