Zinc phthalocyanines attached to gold nanorods for simultaneous hyperthermic and photodynamic therapies against melanoma in vitro

Abstract

Studies indicate that hyperthermic therapy using gold nanorods and photodynamic activity with many photosensitizers can present a synergistic effect, and offer a great therapeutic potential, although more investigation needs to be performed before such approach could be implemented. We proposed to investigate the effect of the attachment of phthalocyanines on the surface of gold nanorods (well-characterized devices for hyperthermia generation) for the elimination of melanoma, one of the most important skin cancers due to its high lethality. Following the synthesis of nanorods through a seed-mediated method, the efficacy of photodynamic therapy (PDT) and hyperthermia was assessed separately. We chose to coat the nanorods with two tetracarboxylated zinc phthalocyanines - with or without methyl-glucamine groups. After the coating process, the phthalocyanines formed ionic complexes with the cetyltrimethylammonium bromide (CTAB) that was previously covering the nanoparticles. The nanorod-phthalocyanines complexes were analyzed by transmission electron microscopy (TEM), and their singlet oxygen and hydroxyl radical generation yields were assessed. Furthermore, they were tested in vitro with melanotic B16F10 and amelanotic B16G4F melanoma cells. The cells with nanoparticles were irradiated with laser (at 635 nm), and the cell viability was assessed. The results indicate that the photodynamic properties of the phthalocyanines tested are enhanced when they are attached on the nanorods surface, and the combination of PDT and hyperthermia was able to eliminate over 90% of melanoma cells. This is a novel study because two tetracarboxylated phthalocyanines were used and because the same wavelength was irradiated to activate both the nanorods and the photosensitizers.

Effects of major parameters of nanoparticles on their physical and chemical properties and recent application of nanodrug delivery system in targeted chemotherapy

“…The synergistic effect of hyperthermia and photodynamic therapy in this novel nanodrug delivery system has the potential to effectively treat tumors. 119 A novel β-cyclodextrin-{poly(lactide)-poly (2- …”

Nanomaterials for Enhanced Photodynamic Therapy

“…Gold nanorods have been developed by different authors in order to carry phthalocyanines via adsorption onto the nanoparticle surface, either chemically with a thiol group or via electrostatic interaction. The formation of a phthalocyanine layer covering the nanoparticle prevents the aggregation of the hydrophobic photosensitizer and enhances the photodynamic activity [2,9].…”

“…Several cases of enhancement of the photosensitizer efficiency by plasmonic nanoparticles (due to a strong energy transfer and the prevention of photobleaching) have been reported in the literature, with various photosensitizers and nanoparticle morphologies and materials [9][10][11][12][13]. One interesting example was demonstrated by [14], because the PDT efficiency of the photosensitizer conjugated with gold Nanomaterials for Enhanced Photodynamic Therapy DOI: http://dx.doi.org/10.5772/intechopen.94255 nanoparticles was comparable to the free photosensitizer, but the hyperthermal effect contributed to a more intense cytotoxicity against the tumor cells.…”

Susceptibility and Resistance Mechanisms During Photodynamic Therapy of Melanoma

“…This was achieved by incorporating the PS into a nanocarrier and by using peptides or antibodies for selective delivery of PSs to tumors. The second generation PSs combined with carrier can circumvent the skin barrier and improve selective delivery to melanoma cells (120,146,149,150,165). The use of nanocarriers can improve the activity of photosensitizing agents through preferential accumulation of the carrier at the tumor site and facilitating slow, controlled release of the PS (166).…”