A versatile Pt-Ce6 nanoplatform as catalase nanozyme and NIR-II photothermal agent for enhanced PDT/PTT tumor therapy

Abstract

The hypoxic nature of solid tumors has severely negative effects on oxygen-based photodynamic therapy. In this study, we used porous Pt nanoparticles as a catalase (CAT) nanozyme, the second near-infrared (NIR-II) region photothermal transition agents (PTAs), and carriers of photosensitizer chlorin e6 (Ce6) to synthesize a composite nanosystem Pt-Ce6. In this system, Pt-Ce6 can continuously and stably decompose H 2 O 2 into oxygen, thereby alleviating tumor hypoxia and improving the effect of photodynamic therapy (PDT). With 650 nm illumination, the reactive oxygen species (ROS) produced by Ce6 will decrease the mitochondrial membrane potential (MMP, ΔΨ m) to release cytochrome c (Cyt-c) from the mitochondria into the cytoplasm, eventually leading to mitochondrial-mediated cellular apoptosis during the PDT process. In addition, Pt-Ce6 has good photothermal stability and high photothermal conversion efficiency (52.62%) in the NIR-II region. In U14 tumor-bearing mice, Pt-Ce6 completely suppressed tumor growth and recurrence under laser irradiation. Thus the nanocomposite shows excellent PDT/photothermal therapy (PTT) synergistic performance in vitro and in vivo.

A Review on Metal- and Metal Oxide-Based Nanozymes: Properties, Mechanisms, and Applications

“…In this system, Pt-CuS Janus hollow structure was used as sonosensitizers carrier, showing photothermal conversion capacity under laser irradiation, and could decompose endogenous H 2 O 2 expeditiously. The Pt NPs [ 442 ] with CAT-mimicking capacity and Ru–Te hollow nanorods [ 436 ] with OXD, POD-, CAT- and SOD-type activity both acted as carriers and relieved TME hypoxia to enhance cancer PDT/PTT effect. Different from most nanozyme-based synergistic therapy, Yang et al [ 443 ] covered Pt-carbon integrated nanozymes as PSs via one-step reduction.…”

Nucleus-Targeted Photosensitizer Nanoparticles for Photothermal and Photodynamic Therapy of Breast Carcinoma

“…Under irradiation with NIR light, it can produce 1 O 2 to activate a series of immune responses, leading to apoptosis of tumor cells and the destruction of tumor tissue. 38–40 At the same time, ICG can also generate thermal energy to increase the temperature of the nucleus. This effect destroys biologically active molecules (such as protein denaturation, enzyme inactivation) in the cell and induces ROS to cause tumor cell damage, necrosis, or thermal ablation of tumor tissue.…”

Selective inactivation of Gram-positive bacteria in vitro and in vivo through metabolic labelling

“…Recently, photothermal therapy (PTT) has attracted extensive attention for bactericidal applications, on the basis of generating localized hyperthermia to inactivate enzymes or proteins, disrupt membrane permeability, and disorder metabolic signals upon near-infrared (NIR) light irradiation with photothermal agents [14][15][16][17]. PTT holds advantageous characteristics of spatiotemporal control, noninvasiveness, and little possibility to induce drug resistance.…”