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The second near-infrared (NIR-II) window (1000–1350 nm) usually offers further improved light penetration, a higher maximum permissible exposure (MPE), and a lower background signal. Development of NIR-II optical diagnosis and phototherapy technologies is of great significance for precise, efficient tumor therapy. In this work, a new type of Ti-based targeting agent (B-TiO2@SiO2–HA) nanotheranostic system with strong NIR-II absorption was designed and fabricated for the first time. Oxygen vacancies were formed in B-TiO2 and its band gap was narrowed, resulting in nanotheranostic systems with full-spectrum responses to stimulation with light. The experimental results showed that B-TiO2@SiO2–HA not only can enable high NIR-II photothermal conversion and provide excellent reactive oxygen species (ROS) production capacity, but also can enable high-resolution photoacoustic imaging (PAI) under NIR-II laser irradiation. Moreover, HA modification gives the nanotheranostic systems the useful ability to target high-CD44-expression tumor cells and tissues. In vitro and in vivo experiments demonstrated that B-TiO2@SiO2–HA exhibited a targeted photothermal/photodynamic (PTT/PDT) effect that produced tumor-cell ablation and apoptosis under the guidance of real-time NIR-II PA imaging. B-TiO2@SiO2–HA exhibits precise nanotheranostic potential for PAI-guided tumor-targeting phototherapy. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR)-responsive hydrogels have exhibited remarkable advantages in biomedical applications especially for in situ therapeutic delivery, because of their deep-tissue penetration capacity, minimal invasiveness, and high spatiotemporal selectivity. Nevertheless, conventional NIR-responsive nanocomposite hydrogels suffer from the disadvantages of limited photothermal effect and potential leakage of the physically mixed photothermal nanoagents. To overcome these limitations, we herein designed an injectable thermosensitive photothermal-network hydrogel (PNT-gel) through the host-guest self-assembly of a photothermal conjugated polymers and ɑ -cyclodextrin. The conjugated-polymer backbones can directly convert incident light into heat, endowing the PNT-gel with high photothermal conversion efficiency (η = 52.6%) and enhanced photothermal stability. Meanwhile, the mild host-guest assembly enable the shear-thinning injectability, photothermally-driven and reversible gel-sol conversion of the hydrogel. Consequently, the remotely controlled on-demand release of doxorubicin (DOX) was achieved via photothermal-induced gel-sol transition. Because the backbone of the hydrogel absorbs NIR light and mediates the photothermal conversion itself, the PNT-gel demonstrated the advantage of a prolonged retention time and thus permitting repeatable NIR treatment after a one-time intratumoral injection of this hydrogel. Under repeated NIR laser irradiation (0.15 W cm−2), the synergistic photothermal-chemotherapy mediated by the PNT-gel almost completely eradicated 4T1 breast cancer. This work not only presents a multifunctional therapeutic platform integrated with inherent photothermal characteristic and reversible stimuli responsiveness for on-demand delivery and combinatorial photothermal-chemotherapy, but also provides a new strategy for the development of the next-generation of light-modulated intelligent hydrogels. The conventional NIR-responsive nanocomposite hydrogels suffer from the disadvantages of limited photothermal effect and possible leakage of the physically mixed photothermal nano-components. To overcome these limitations, we hereby fabricated a NIR-responsive themosensitive photothermal-network hydrogel through the supramolecular assembly of conjugated polymer. The conjugated polymeric backbones of the hydrogel directly convert NIR light to heat, endowing the hydrogel with good photothermal effect and long-term photothermal stability. Meanwhile, the dynamic crosslinkages via supramolecular assembly enabled the shear-thinning injectability and reversible gel-sol transition of the hydrogel, facilitating the photothermal-induced drug release. Our strategy demonstrated the efficacy of using conjugated polymer as the backbone of hydrogel for the construction of a new injectable NIR-responsive hydrogel system with enhanced photothermal capabilities and improved therapy outcomes. [ABSTRACT FROM AUTHOR]

Effectively eliminating mercury pollution in aqueous solutions remains an onerous task and important environmental challenge for protecting the public health and environment. Herein, we report a facile one-step hydrothermal approach to synthesis widened molybdenum disulfide (W-MoS 2) nanosheets/natural cellulose fiber composite (W-MoS 2 /NCF) for highly efficient elimination of Hg(II) from aquatic systems. Benefiting from the synergistic advantages of the intrinsically sulfur-rich characteristic of W-MoS 2 combined with its enlarged interlayer spacing (0.94 nm) that fully exposes the sulfur atoms as binding sites, as well as the vertical immobilization of W-MoS 2 nanosheets on the cellulose fibers that enables the easy accessibility of all the S binding sites, the maximum adsorption capacity of W-MoS 2 /NCF towards Hg(II) was 1206 mg g−1, implying that almost all the S binding sites were fully utilized for mercury uptake. Moreover, the 3D structure characteristics can not only avoid the self-aggregation of 2D nanosheets, but also benefit the removal, regeneration, and reuse of this composite in practical application by offering convenient operations. In consequence, the W-MoS 2 /NCF outperformed the most of MoS 2 -based composites in terms of mercury removal capacity, utilization efficiency of S, operation convenience, and recyclability. Taken together, the combination of the advantages of its excellent Hg(II) capture performance, facile and scalable synthesis process, the easy availability of raw materials, easy recyclability and reusability endowed the as-prepared W-MoS 2 /NCF with promising potential for being used as a highly effective scavenger to decontaminate Hg(II) contaminated wastewater. [Display omitted] • The W-MoS 2 /NCF was fabricated via a facile one-step hydrothermal method. • The 3D structure avoided the self-aggregation of 2D W-MoS 2 nanosheets and benefited the operation. • The vertical anchor of W-MoS 2 nanosheets on solid substrate enabled the full utilization of S atoms. • The W-MoS 2 /NCF exhibited high capacity (1206 mg·g−1) and good selectivity for Hg(II). • The residual Hg2+ in water samples were reduced from higher than 1000 μg·L-1 to < 2 μg·L-1. [ABSTRACT FROM AUTHOR]