A multi-photoresponsive supramolecular hydrogel with dual-color fluorescence and dual-modal photodynamic action

We have developed an engineered supramolecular hydrogel, formed in the absence of any toxic solvents or reagents, by the self-assembly of four different components: a poly-β-cyclodextrin polymer, a hydrophobically modified dextran, a commercial zinc phthalocyanine and a tailored nitric oxide photodonor. The formation of this supramolecular assembly is based on a "lock-and-key" mechanism in which the alkyl side chains of the modified dextran form inclusion complexes with the cyclodextrin cavities of the poly-β-cyclodextrin polymer. The multivalent character of the interactions between all the components ensures the stability of the hydrogel and the negligible leaching of the photoactive components from the gel network under physiological conditions, even in the absence of protective coating agents. The combination of steady-state and time-resolved spectroscopic techniques together with photoamperometric measurements shows that the two chromo-fluorogenic components do not interfere with each other while being enclosed in their supramolecular matrix and can thus be operated in parallel under the control of light stimuli. Specifically, excitation with visible light results in the red and green fluorescence emission typical of the two photoactive centers and in their capability to generate singlet oxygen and nitric oxide, two cytotoxic species playing a key role in photodynamic cancer and bacterial therapies.

Fluorescent cyclodextrin carriers for a water soluble ZnII pyrazinoporphyrazine octacation with photosensitizer potential

Novel, negatively charged, fluorescent cyclodextrin oligomers form highly stable complexes with a water soluble, octacationic porphyrazine photosensitizer in dimeric form.

A multi-photoresponsive molecular-hybrid for dual-modal photoinactivation of cancer cells

A bichromophoric molecular conjugate combines red fluorescence with the simultaneous photogeneration of singlet oxygen and nitric oxide, inducing amplified photomortality on melanoma cancer cells.

A hollow porous magnetic nanocarrier for efficient near-infrared light- and pH-controlled drug release

A NIR light and pH dual responsive nanocarrier was fabricated for anti-cancer drug delivery as well as MRI and fluorescence cell imaging.

Applications of nanotechnology for melanoma treatment, diagnosis, and theranostics

Melanoma is the most aggressive type of skin cancer and has very high rates of mortality. An early stage melanoma can be surgically removed, with a survival rate of 99%. However, metastasized melanoma is difficult to cure. The 5-year survival rates for patients with metastasized melanoma are still below 20%. Metastasized melanoma is currently treated by chemotherapy, targeted therapy, immunotherapy and radiotherapy. The outcome of most of the current therapies is far from optimistic. Although melanoma patients with a mutation in the oncogene v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) have an initially higher positive response rate to targeted therapy, the majority develop acquired drug resistance after 6 months of the therapy. To increase treatment efficacy, early diagnosis, more potent pharmacological agents, and more effective delivery systems are urgently needed. Nanotechnology has been extensively studied for melanoma treatment and diagnosis, to decrease drug resistance, increase therapeutic efficacy, and reduce side effects. In this review, we summarize the recent progress on the development of various nanoparticles for melanoma treatment and diagnosis. Several common nanoparticles, including liposome, polymersomes, dendrimers, carbon-based nanoparticles, and human albumin, have been used to deliver chemotherapeutic agents, and small interfering ribonucleic acids (siRNAs) against signaling molecules have also been tested for the treatment of melanoma. Indeed, several nanoparticle-delivered drugs have been approved by the US Food and Drug Administration and are currently in clinical trials. The application of nanoparticles could produce side effects, which will need to be reduced so that nanoparticle-delivered drugs can be safely applied in the clinical setting.