On-Demand Triggered Chemodynamic Therapy by NIR-II Light on Oxidation-Prevented Bismuth Nanodots

Abstract

As the least toxic heavy metal, monoelemental bismuth nanomaterials with several superiorities are the ideal theranostic agents. However, bismuth nanoparticles are easily oxidized by oxygen in air or media, limiting their clinical application. In contrast, the oxidization of Bi0 to Bi3+ can activate the chemodynamic therapy (CDT) by transferring endogenous H2O2 into •OH. Herein, a well-designed Bi-DMSNs@PCM nanosystem was prepared via in situ growth of Bi nanodots and a coating of phase-change material (PCM) on the surface of dendritic mesoporous silica nanoparticles (DMSNs). The coated PCM protects the Bi nanodots from oxidation by keeping them in the Bi0 state for more than 15 d. When irradiated using the near infrared-II (NIR-II) laser with a low power density (0.5 W/cm2), the heat generated from the Bi nanodots melts the PCM shell to trigger CDT through a Fenton-like reaction, accompanied by heat-induced photothermal therapy (PTT). Notably, the CDT can also compensate for the reduced PTT effect caused by the oxidation of Bi nanodots, and a satisfactory treatment effect is realized. Additionally, photoacoustic and computed tomography imaging properties were obtained. Our strategy transfers the detrimental self-oxidation of bismuth to a beneficial therapeutic mode, enhancing the potential of Bi for clinical use.

Recent advances in ecofriendly 2D monoelemental bismuthene as an emerging material for energy, catalysis and biomedical applications

“…The heat produced by the Bi nanodots caused the PCM shell to melt, triggering CDT and heat-induced photothermal therapy (PTT). 122 Recently, Xue et al developed an ultrathin bismuthene-based sensing platform (Fig. 13a–c) for the quantitative and specific detection of microRNA (miRNA), capable of discriminating even single-base mismatches with a detection limit of up to 60 pM.…”

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

“…Copper chloride, hydrogen peroxide, and sodium hydroxide have been used in an aqueous reaction system to easily create multifunctional copper peroxide (CuO 2 ) nanodots [100,101]. Tis procedure included polyvinylpyrrolidone (PVP) which not only regulates nanodot particle diameter but also supplies the surface functionalization necessary to ensure the excellent stability of nanodots under a physiological environment [102,103]. Teir particle size of about 5 nm allowed for efective accumulation in tumors [102,103].…”

“…Tis procedure included polyvinylpyrrolidone (PVP) which not only regulates nanodot particle diameter but also supplies the surface functionalization necessary to ensure the excellent stability of nanodots under a physiological environment [102,103]. Teir particle size of about 5 nm allowed for efective accumulation in tumors [102,103]. By reacting with water, the created CuO 2 nanodots sparked a chemical change that produced hydrogen peroxide, and the presence of Cu 2+ as catalysts sparked a Fenton-like process that produced the very reactive hydroxyl radicals with hydrogen peroxide acting as the reactant on its own [104].…”

Multifunctional nanomedicines-enabled chemodynamic-synergized multimodal tumor therapy via Fenton and Fenton-like reactions

“…Nowadays, a variety of nanocatalysts (transition metal nanomaterials, metal-organic nanomaterials, monoatomic nanomaterials, and electron-rich nanomaterials) are synthesized to improve CDT efficiency [30][31][32][33]. Moreover, adding physical energy fields such as light, temperature, ultrasonic field, X-ray, and magnetic field can also promote the speed of the Fenton reaction [34][35][36][37][38][39]. Another option for CDT enhancement is modulating the nutrition or immune system of the tumor to reinforce the overall therapeutic effect [40].…”