Manganese-doped gold nanoclusters with ultrasmall size andmicroenvironment-responsive visualized theranostics of tumor

Abstract

Inorganic nanoprobes with ultrasmall size have the advantage of kidney clearance, which was very meaningful for achieving clinical application. In this paper, Mn 2+ -doped gold nanoclusters (Mn-AuNCs) with ultrasmall size were synthesized, by which magnetic resonance imaging (MRI) and tumor-microenvironmentresponsive chemodynamic therapy (CDT) and photodynamic therapy (PDT) were achieved. The results showed that Mn-AuNCs nanoprobe occupied ultrasmall size of about 2-3 nm, and excellent T1-weighted MRI performance with a high longitudinal relaxivity of 31.71 mM -1 •s -1 . In tumor microenvironment, Mn-AuNCs nanoprobes can catalyze H2O2 to produce •OH, O2 and singlet oxygen, showing CDT and enhanced PDT performances. Under the irradiation of 635 nm laser, the viability of 4T1 cells incubated with Mn-AuNCs was decreased to be 10%, and tumors were disappeared completely, achieving MRI-guided CDT/PDT combination therapy.

Mn-Doped Nano-Hydroxyapatites as Theranostic Agents with Tumor pH-Amplified MRI-Signal Capabilities for Guiding Photothermal Therapy

“… 29 Previous studies have shown that Mn 2+ in doped materials mainly oxidizes to Mn 4+ . 11 , 46 , 47 Therefore, the XPS data of Mn 2p were carefully peak fitted and are presented in the inset of Figure 7 . The results show that Mn 2+ and Mn 4+ exist simultaneously, and the proportions of Mn 2+ and Mn 4+ are 42.77% and 57.23%, respectively.…”

“…The nHAPMn10 sample exhibited the highest magnetization value (0.34 emu/g), and the magnetization level of nHAP increased with increasing Mn doping concentrations, which is consistent with previous reports. 47 , 48 In addition, nHAPMn5 prepared at pH=12 showed relatively weak magnetization compared to that prepared at pH=10; however, the underlying mechanism is still unclear ( Figure S6 ).

Figure 9 Magnetization curves of nHAP and nHAPMn powders measured at room temperature.

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