In Situ Synthesis of FeOCl in Hollow Dendritic Mesoporous Organosilicon for Ascorbic Acid-Enhanced and MR Imaging-Guided Chemodynamic Therapy in Neutral pH Conditions

Abstract

Chemodynamic therapy (CDT) based on the Fenton reaction is a promising strategy for nonlight cancer treatment. However, the traditional Fenton reaction is only efficient in strongly acidic conditions (pH = 2−4), resulting in the limited curative effect in a weakly acidic tumor microenvironment (TME). Herein, we first developed a simple in situ growth method to confine FeOCl nanosheets into hollow dendritic mesoporous organosilicon (H-DMOS) nanoparticles to obtain FeOCl@H-DMOS nanospheres. Ascorbic acid (AA) was then absorbed on the nanosystem as a H 2 O 2 prodrug and, meanwhile, was used for the regeneration of Fentons reagent for Fe 2+ . Finally, poly(ethylene glycol) (PEG)

Chemodynamic Therapy via Fenton and Fenton‐Like Nanomaterials: Strategies and Recent Advances

“…One method is to enhance the conversion efficiency between Fe 2+ and ferric ions (Fe 3+ ). [ 27–31 ] For example, to deal with the contradiction between acidic environment‐dependent CDT and the neutral pH condition at the tumor surface, [ 32 ] Zhao et al. synthesized a type of chelating complex ferrous‐cysteine–phosphotungstate nanoparticles (FcPWNPs) to improve the CDT efficiency by introducing cysteine and phosphotungstate ( Figure a).…”

Recent Development on Controlled Synthesis of Mn‐Based Nanostructures for Bioimaging and Cancer Therapy

“…[34,46,47] In general, it was the overexpression of superoxide dismutase in the tumor region that converted superoxide negative ions produced by the mitochondria of tumor cells into H 2 O 2 . [48] Since H 2 O 2 was one of the necessary reactants of CDT, the low concentration level in normal tissue cells was inadequate to cause destructive Fenton or Fenton-like reactions, providing CDT with high selectivity. [49] The typical Fenton reaction was derived from iron-based nanomaterials, of which the optimal pH was between 2.0 and 4.0.…”

Iron Oxychloride/Bovine Serum Albumin Nanosheets as Chemodynamic Therapy Agents

“…synthesized FeOCl@H‐DMOS‐AA/PEG for the intracellular production of ROS by catalyzing H 2 O 2 with the help of ascorbic acid. [ 8 ] According to their MTT results, a high concentration of H 2 O 2 (0.6 × 10 −3 m ) could trigger the cytotoxicity of the nanoparticles. In our study, however, by adding 100 × 10 −6 m H 2 O 2 to the culture medium, we observed higher cytotoxicity at an almost equal concentration of the nanoparticle.…”

“…Recently, the nanocomposites of FeOCl have been employed for tumor chemodynamic therapy (CDT). [ 8,9 ] In CDT, the acidity and overproduction of hydrogen peroxide in the tumor microenvironment favors the progression of the Fenton reaction. [ 10,11 ] In the presence of a Fenton or Fenton‐like reagent, hydroxyl radicals generate from the decomposition of hydrogen peroxide, which ultimately induces in situ toxicity to cancer cells.…”

“…[ 23,24 ] A challenge facing an efficient CDT is the inability of some Fenton reagents to induce cell toxicity using the endogenous hydrogen peroxide. For example, in a study by Li et al., a considerable in vitro cytotoxicity of FeOCl‐based nanocomposite was observed only in the presence of high concentration of hydrogen peroxide (0.6 × 10 −3 m ) in the cell culture medium, [ 8 ] which is far from the physiological condition of solid tumors. Therefore, to manipulate the CDT effectiveness, it is important to study the cytotoxic effect of the Fenton reagent under the experimental conditions that mimic the tumor microenvironment.…”