Abstract
Local photothermal hyperthermia for tumor ablation and specific stimuliresponsive gas therapy feature the merits of remote operation, noninvasive intervention, and in situ tumor-specific activation in cancer-therapeutic biomedicine. Inspired by synergistic/sequential therapeutic modality, herein a novel therapeutic modality is reported based on the construction of two-dimensional (2D) core/shell-structured Nb(2)C-MSNs-SNO composite nanosheets for photonic thermogaseous therapy. A phototriggered thermogas-generating nanoreactor is designed via mesoporous silica layer coating on the surface of Nb(2)C MXene nanosheets, where the mesopores provide the reservoirs for NO donor (S-nitrosothiol (RSNO)), and the core of Nb(2)C produces heat shock upon second near-infrared biowindow (NIR-II) laser irradiation. The Nb(2)C-MSNs-SNO-enabled photonic thermogaseous therapy undergoes a sequential process of phototriggered heat production from the core of Nb(2)C and thermotriggered NO generation, together with photoacoustic-imaging (PAI) guidance and monitoring. The constructed Nb(2)C-MSNs-SNO nanoreactors exhibit high-NIR-induced photothermal effect, intense NIR-controlled NO release, and desirable PAI performance. Based on these unique theranostic properties of Nb(2)C-MSNs-SNO nanocomposites, sequential photonic thermogaseous therapy with limited systematic toxicity on efficiently suppressing tumor growth is achieved by PAI-guided NIR-controlled NO release as well as heat generation. Such a thermogaseous approach representes a stimuli-selective strategy for synergistic/sequential cancer treatment.