Molecular nanogels as nanocarriers. Intracellular transport of photosensitizers and nitric oxide probes

Résumé

The preparation of molecular nanogels is reported in this thesis. These new nanoparticles, formed by low molecular weight gelators, represent an exciting alternative to their polymeric counterparts considering their intrinsic characteristics (fully reversible stimuli-regulated assembly, easy biodegradation, excellent biocompatibility and possibility of tailored properties). Novel hydrogel@liposome particles were also obtained by molecular gel formation inside liposomes. This type of nanocarriers merges the benefits of liposomal vehicles with the inherent characteristics of molecular gels. The capability of molecular nanogels to incorporate and release actives and act as intracellular carriers was demonstrated, improving the efficiency of photoactive molecules in their biomedical use. The photosensitizers loaded in the nanogels (Rose Bengal and hypericin) showed enhanced cellular uptake and improved performance in photodynamic therapy for cancer. Besides, the encapsulation in the nanogels of nitric oxide probes lead to an enhanced cellular uptake of DAF-2 and an increased solubility in water of DAQ.