CEA-Leti launches study on photodynamic therapy for cancer treatment
14 June 2010
CEA-Leti has launched the TARGET-PDT project designed to
increase the effectiveness of photodynamic therapy (PDT) for treating
cancer by developing a novel nano carrier-based approach.
PDT is a minimally invasive treatment that destroys cancer cells
with a combination of a photoactive drug known as a photosensitizer
and a specific wavelength of light. When the photosensitizers are
activated by the laser light, they produce a form of oxygen that
destroys illuminated cancer cells.
Focusing on using PDT against bone cancer and head-and-neck
squamous cell carcinoma, which is a tumor eg of the oral cavity, the
project will study the delivery and targeting of photosensitizers
encapsulated into lipid nano-particles. For both cancer forms,
current treatment regimes often result in low cure rates and show
serious side effects or a poor functional outcome. The nano-carriers
offer a high payload that will include antibodies targeting specific
PDT has already shown significant potential for improving cancer
treatment because it offers strictly focused application,
biocompatibility with other forms of treatment, the option for
repeated use, excellent cosmetic or functional outcomes and fast
recovery. Indeed, typically there is a modest enhanced accumulation
of the photosensitizer in tumor tissues and an additional
selectivity is mainly provided by the confined illumination of the
But, the use of PDT has been restrained by limited effectiveness
of the photosensitizers on reaching the tumour and the potential
damage to healthy cells near the tumour. Improved targeting of the
photosensitizer and nano-particles is necessary to prevent damage to
the surrounding healthy tissue.
CEA-Leti, which is coordinating this European project, expects
the nano carrier-based approach will significantly improve delivery
and targeting of the photosensitizer, enhancing concentrations at
the tumor site even after systemic application.
The TARGET-PDT project will allow the partners to study all
aspects of PDT treatment: nano-carrier size and payload,
photosensitizers such as chlorines and phthalocyanines, targeting
method and types of laser irradiation.
The experimental approach will be developed into a preclinical
validation to deliver an optimised combination for first clinical “nano-PDT”
at a later stage. By using nanotechnology-based photosensitizer
delivery systems, the project will set the stage for improved
control of the therapy and more comfort for cancer patients.