CONTEXT

Photodynamic therapy (PDT) is an emerging modality for the treatment of a variety of oncological, cardiovascular, dermatological and ophthalmic diseases. In PDT, irradiated photosentisizers that surround or enter cells transfer their energy to molecular oxygen, thus forming highly reactive singlet oxygen (1O2) and other reactive oxygen species which, in turn, kill the nearby cells. This invention related to nanovectors which jointly ensure cancer cells targeting and two-photon imaging as well as their mono or biphotonic photodynamic therapy (PDT).

TECHNICAL DESCRIPTION

The vectors are silica-based nanoparticles that encapsulate fluorescent photosensitizers. The confinement of a photosensitizer in a solid matrix allow its use in biological environments. The photosensitizers are enable, by mean of biphotonic excitation, a high resolution cancer cells imaging. A singlet oxygen production inside the cells are assured by mono or biphotonic excitation.

BENEFITS

Nanoparticules are biocompatible, biodegradable, and highly specific. With this technology, PDT side effects are reduced thanks to a cell targeting. Moreover, irradiations at near infrared light confer a better tissue penetration leading to improved treatment efficiency. PDT also offers a lot of advantages such as minimally invasive and minimally toxic therapy. Furthermore, PDT is non mutagenic compared to radio or chemotherapy which is an advantage for cancers such as retinoblastoma. Comparing current treatment of cancers, PDT is much cheaper alternative. Moreover, for patient, PDT post-operative recovery is better requiring hours or days rather than weeks.

INDUSTRIAL APPLICATIONS

Treatment of a wide variety of solid cancers, including deep tissue and multisite cancers.
Treatment of a variety of dermatologic conditions, including actinic keratoses, photoaging and other cutaneous concerns.

DEVELOPMENT STAGE

The PDT treatments are under study in vivo with mice bearing xenografted tumors. Preliminary experiments with two-photon PDT on mice with colon cancer showed a reduction of 70% of the tumor mass.

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