BackgroundPhotodynamic therapy (PDT) combines light, molecular oxygen and a photosensitizer to induce oxidative stress in target cells. Certain hydrophobic photosensitizers, such as aluminium-phthalocyanine chloride (AlPc), have significant potential for antitumor PDT applications. However, hydrophobic molecules often require drug-delivery systems, such as nanostructures, to improve their pharmacokinetic properties and to prevent aggregation, which has a quenching effect on the photoemission properties in aqueous media. As a result, this work aims to develop and test the efficacy of an AlPc in the form of a nanoemulsion to enable its use in anticancer PDT.ResultsThe nanoemulsion was developed using castor oil and Cremophor ELP®, and a monodisperse population of nanodroplets with a hydrodynamic diameter of approximately 25 nm was obtained. While free AlPc failed to show significant activity against human breast adenocarcinoma MCF-7 cells in an in vitro PDT assay, the AlPc in the nanoemulsion showed intense photodynamic activity. Photoactivated AlPc exhibited a 50 % cytotoxicity concentration (CC50) of 6.0 nM when applied to MCF-7 cell monolayers and exerted a powerful cytotoxic effect on MCF-7 cell spheroids.ConclusionThrough the use of spontaneous emulsification, a stable AlPc nanoemulsion was developed that exhibits strong in vitro photodynamic activity on cancer cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-015-0095-3) contains supplementary material, which is available to authorized users.

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We demonstrate air-stable copper-doped nanostructured borophosphate samples, which were prepared by a facile, low cost, and green synthesis method. The thermal annealing, in a reducing hydrogen atmosphere, enables the formation of metallic copper nanostructures, which was confirmed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and optical absorption. The optical spectra show a main intense surface plasmon resonance (SPR) band centered at 579 nm. The shapes of the nanostructures, morphology, and thickness of the copper nanostructures coating are chosen to be suitable for SERS applications. These samples exhibited very high SERS enhancement factors (EF), depending on thermal annealing time, with excellent reproducibility. The estimated EFs have been found in the range between 10 7 and 10 8 .

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