A biocompatible and pH-responsive nanohydrogel based on cellulose nanocrystal for enhanced toxic reactive oxygen species generation

MnO2-Based Nanomotors with Active Fenton-like Mn2+ Delivery for Enhanced Chemodynamic Therapy

“…Unlike oxygen-dependent photodynamic therapy (PDT) and ultrasound-assisted sonodynamic therapy (SDT), CDT can exert a significant anticancer effect under the hypoxic tumor microenvironment without any external facilities. In recent years, Fe 2+ -based CDT therapeutic platforms have been proposed for cancer treatment by utilizing Fe 2+ -triggered Fenton reactions. − However, GSH, as an intracellular antioxidant (2–10 mM), which is thousand times higher than that in the extracellular microenvironment (2–10 μM), , has a strong scavenging effect on the produced ·OH, leading to the limited efficacy of CDT. , Therefore, to reduce the intracellular GSH is an effective strategy for the improvement of CDT efficacy . In addition to Fe 2+ , Mn 2+ has recently been confirmed to have Fenton-like activity in the presence of bicarbonate (HCO 3– ). , Meanwhile, as Mn 2+ sources, MnO 2 NPs are possible to undergo redox reactions with GSH to generate Mn 2+ and glutathione disulfide (GSSG) .…”

Multiple Strikes Achieve Remarkable Tumor-Inhibition Efficiency via Multi-mechanism Combination

“…In order to detect the production of intracellular ROS, the 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) probe was used to evaluate the result. , Several groups were set: control, mFe 3 O 4 , DOX, rapamycin, mFe 3 O 4 –DOX, mFe 3 O 4 –DOX–HA, Rap@mFe 3 O 4 –DOX–HA, and Rap@mFe 3 O 4 –DOX–HA + M. After incubating overnight at 37 °C, 2 mL medium containing drugs (DOX: 5 μg/mL, Rap: 5 μg/mL) in each group were added into six-well plates. Continuously being cultured for 4 h, the medium was discarded and washed with sterilized PBS two to three times.…”

“…9,10 The presence of Fe 2+ greatly accelerates the lipid peroxidation reaction of saturated fatty acids, 11−15 which produces reactive oxygen species (ROS) and then causes cell damage or death. 16,17 In addition, autophagy is a common cell death pathway too. Autophagy cell death is a process that means "self-digestion, end self" when cells are exposed to hunger or external stimuli; 18,19 furthermore, autophagy can degrade heavy chain ferritin 1 (FTH1) and release Fe 2+ , which could promote ferroptosis.…”

“…Based on this, abundant research has been devoted to breast cancer treatment. , Unfortunately, only one of these pathways can be inhibited with a single agent, so the therapeutic effect was poor; − meanwhile, combination therapy offers the potential to simultaneously inhibit multiple targets and pathways to effectively kill cancer cells, ,− which may consequently cause multiple kinds of cell death pathways. Among all kinds of pathways, ferroptosis is a kind of iron-dependent programmed cell death, which is mainly caused by the abnormal increase of iron-dependent lipid oxygen free radicals in cells and imbalance of redox homeostasis. , The presence of Fe 2+ greatly accelerates the lipid peroxidation reaction of saturated fatty acids, − which produces reactive oxygen species (ROS) and then causes cell damage or death. , In addition, autophagy is a common cell death pathway too. Autophagy cell death is a process that means “self-digestion, end self” when cells are exposed to hunger or external stimuli; , furthermore, autophagy can degrade heavy chain ferritin 1 (FTH1) and release Fe 2+ , which could promote ferroptosis. , Due to the promoting effect of autophagy on ferroptosis, studies have shown that autophagy often cooperates with ferroptosis in tumor treatment.…”

Self-Supply Oxygen ROS Reactor via Fenton-like Reaction and Modulating Glutathione for Amplified Cancer Therapy Effect

“…Malignant neoplasms are one of the most dreaded diseases due to their high mortality and difficulty in curing [ 1 ]. The tumor microenvironment (TME), characterized by hypoxia, high expression of glutathione (GSH), weak acidity, and high concentration of H 2 O 2 , is closely related to the immunosuppression, multidrug resistance and aggressive metastasis of cancer cells, and has become a new target for cancer therapy [ 2 , 3 ]. Reactive oxygen species (ROS) are highly oxidizing species such as hydroxyl radicals, singlet oxygen, superoxide radicals, and hydrogen peroxide.…”