RESUMEN
OBJECTIVE: Nanotechnology-based photodynamic therapy (PDT) is a relatively new anti-tumor strategy. However, its efficacy is limited by the hypoxic state in the tumor microenvironment. In the present study, a poly(lactic-co-glycolic acid) (PLGA) nanoparticle that encapsulated both IR820 and catalase (CAT) was developed to enhance anti-tumor therapy. MATERIALS AND METHODS: HA-PLGA-CAT-IR820 nanoparticles (HCINPs) were fabricated via a double emulsion solvent evaporation method. Dynamic light scattering (DLS), transmission electron microscopy (TEM), laser scanning confocal microscopy, and an ultraviolet spectrophotometer were used to identify and characterize the nanoparticles. The stability of the nanoparticle was investigated by DLS via monitoring the sizes and polydispersity indexes (PDIs) in water, PBS, DMEM, and DMEM+10%FBS. Oxygen generation measurement was carried out via visualizing the oxygen bubbles with ultrasound imaging system and an optical microscope. Inverted fluorescence microscopy and flow cytometry were used to measure the uptake and targeting effect of the fluorescent-labeled nanoparticles. The live-dead method and tumor-bearing mouse models were applied to study the HCINP-induced enhanced PDT effect. RESULTS: The results showed that the HCINPs could selectively target melanoma cells with high expression of CD44, and generated oxygen by catalyzing H2O2, which increased the amount of singlet oxygen, ultimately inhibiting tumor growth significantly. CONCLUSION: The present study presents a novel nanoplatform for melanoma treatment.
Asunto(s)
Receptores de Hialuranos/metabolismo , Melanoma/tratamiento farmacológico , Nanopartículas/química , Oxígeno/metabolismo , Fotoquimioterapia/métodos , Animales , Catalasa/metabolismo , Línea Celular Tumoral , Femenino , Humanos , Receptores de Hialuranos/genética , Peróxido de Hidrógeno/metabolismo , Verde de Indocianina/análogos & derivados , Verde de Indocianina/química , Melanoma/metabolismo , Melanoma/patología , Ratones Endogámicos BALB C , Nanopartículas/administración & dosificación , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Oxígeno Singlete/metabolismo , Microambiente Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A novel coreshell type thermonanoparticle (CSTNP) coloaded with temozolomide (TMZ) and the fluorescein new indocyanine green dye IR820 (termed ITCSTNPs) was designed and combined with a nearinfrared (NIR) laser to realize its photothermal conversion. The ITCSTNPs were prepared using a twostep synthesis method and comprised a thermosensitive shell and a biodegradable core. IR820 and TMZ were entrapped in the shell and the core, respectively. Dynamic light scattering results demonstrated that the average hydrodynamic size of the ITCSTNPs was 196.4±3.1 nm with a ζ potential of 24.9±1.3 mV. The encapsulation efficiencies of TMZ and IR820 were 6.1 and 16.6%, respectively. Temperature increase curves under NIR laser irradiation indicated that the ITCSTNPs exhibited the desired photothermal conversion efï¬ciency. The in vitro drug release curves revealed a suitable release capability of ITCSTNP under physiological conditions, whereas NIR laser irradiation accelerated the drug release. Inverted fluorescence microscopy and flow cytometry results revealed that the uptake of ITCSTNPs by A375 melanoma cells occurred in a concentrationdependent manner. Confocal laser scanning microscopy results indicated that ITCSTNPs entered tumour cells via endocytosis and were located in intercellular lysosomes. In summary, the present study explored the photothermal conversion capability, cellular uptake, and intracellular localization of ITCSTNPs.