Silica-Supported Assemblage of CuII Ions with Carbon Dots for Self-Boosting and Glutathione-Induced ROS Generation

Abstract

The present work introduces coordinative binding of CuII ions with both amino-functionalized silica nanoparticles (SNs) and green-emitting carbon dots (CDs) as the pregrequisite for the CuII-assisted self-assembly of the CDs at the surface of the SNs. The produced composite SNs exhibit stable in time stimuli-responsive green fluorescence derived from the CuII-assisted assemblage of CDs. The fluorescence response of the composite SNs is sensitive to the complex formation with glutathione (GSH), enabling them to detect it with the lower limit of detection of 0.15 μM. The spin-trap-facilitated electron spin resonance technique indicated that the composite SNs are capable of self-boosting generation of ROS due to CuII→CuI reduction by carbon in low oxidation states as a part of the CDs. The intensity of the ESR signals is enhanced under the heating to 38 °C. The intensity is suppressed at the GSH concentration of 0.35 mM but is enhanced at 1.0 mM of glutathione, while it is suppressed once more at the highest intracellular concentration level of GSH (10 mM). These tendencies reveal the concentrations optimal for the scavenger or reductive potential of GSH. Flow cytometry and fluorescence and confocal microscopy methods revealed efficient cell internalization of SNs-NH2-CuII-CDs comparable with that of “free” CDs.

Poly(styrene-co-maleic acid) Micelle of Photosensitizers for Targeted Photodynamic Therapy, Exhibits Prolonged Singlet Oxygen Generating Capacity and Superior Intracellular Uptake

“…To date, tumor targeted PDT has been developed by using various macromolecular formulations of PSs with sizes of several to several hundred nanometers, in which biocompatible polymers, liposomes, and antibodies are utilized to modify PSs [ 15 , 16 , 17 ]. In line with the PDT principle, recently, redox-triggered light-independent therapy, i.e., chemodynamic therapy by using silica nanoparticles of carbon dots and copper, has been developed which exhibits promising potential for cancer theranostics [ 18 , 19 ]. In our laboratory, by using biocompatible polymers of polyethylene glycol (PEG), styrene maleic acid copolymer (SMA), and poly(N-(2-hydroxypropyl) methacrylamide) copolymer (HPMA), we have developed several polymeric micellar PSs including PEG conjugated zinc protoporphyrin (ZnPP) [ 20 , 21 ], SMA micelles of ZnPP and temoporfin [ 7 , 21 , 22 , 23 ], HPMA conjugated ZnPP [ 24 , 25 ], and HPMA conjugated pyropheophorbide-a [ 26 ], all of which showed superior PDT effect and safety profiles benefiting from their tumor-targeting properties.…”

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

“…CDT is a highly selective ROS-mediated cancer therapy developed in recent years [ 15 , 16 , 17 , 18 ]. CDT can convert endogenous H 2 O 2 in TME into • OH and O 2 to alleviate TME hypoxia [ 19 , 20 , 21 ].…”

A triphenylphosphine coordinated Cu(i) Fenton-like agent with ferrocene moieties for enhanced chemodynamic therapy

“…In recent years, chemodynamic therapy (CDT), as an emerging tumor treatment strategy, has attracted extensive attention in cancer treatment because of its tumor specificity, low systemic toxicity and side effects without needing field stimulation in the treatment process. [1][2][3][4] Specifically, CDT uses Fenton or Fenton-like active drugs to catalyze the conversion of overexpressed hydrogen peroxide (H 2 O 2 ) into highly toxic hydroxyl radicals ( • OH) in tumor tissues, thus inducing tumor cell apoptosis and inhibiting tumor growth. [5][6][7][8] Although CDT has many advantages in the field of cancer treatment, the efficiency of Fenton/Fenton-like reactions is still restricted by its metallic nature.…”