Orthogonal functionalisation of upconverting NaYF4 nanocrystals.
A simple and straightforward method for the orthogonal functionalisation of upconverting NaYF4 nanocrystals (UCNCs)-doped withYb(3+) and Er(3+)-based on N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide (EDC/NHS) selective reactions between two dyes and two different reactive groups present at the periphery of the upconverting nanocrystals is reported. Organic-soluble UCNCs of 10 and 50 nm in size are encapsulated efficiently in a 1:1 mixture of two commercial 3000 Da poly(ethylene glycol) derivatives with two different reactive groups (amino and carboxylic groups). The water-dispersible UCNCs are non-cytotoxic, stable in the physiological environment, and present free ami…
Cancer phototherapy in living cells by multiphoton release of doxorubicin from gold nanospheres
Doxorubicin is a widely used but toxic cancer chemotherapeutic agent. In order to localize its therapeutic action and minimize side effects, it was covalently conjugated to peptide-encapsulated gold nanospheres by click-chemistry and then photo-released in a controlled fashion by a multiphoton process. Selective treatment of a chosen region in a 2D layer of U2Os cancer cells is shown by driving photorelease with 561 nm irradiation at mu W power. These results show promising directions for the development of practical applications based on nanocarriers that can ensure drug delivery with high spatial and temporal control.
Synergistic photo-release of drugs by non-linear excitation
ABSTRACTNanomaterials engineered in novel multi-modular systems in which every component works in a synergistic way with others could potentially lead to a completely new type of tools for nanomedicine. The development of nanostructures able to release drugs directly within the target after a stimulus can drastically improve the therapeutics efficiency by reducing side effects. Gold nanoparticles offer one of the most suitable platforms for the development of modular nano-devices. On the one hand, their surface properties enable effective coating by peptides containing at least one cysteine, thus yielding stable and non-cytotoxic systems. On the other, their intriguing photophysics, charact…