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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]

Abstract Application of carbon nanomaterials to near-infrared light-mediated phototherapy has attracted great interest. However, their practical use in biological systems is severely limited by their poor water dispersibility, inevitable adsorption of plasma proteins, and their single therapeutic function. Herein, we prepared a phycocyanin (PC)-functionalized single-walled carbon nanohorns (PC@SWNHs) hybrid, where PC is used to preform a protein corona around the SWNHs through non-covalent interface interactions. In the PC@SWNHs, the preformed PC corona effectively improves the water dispersibility of the SWNHs and protects them from plasma protein adsorption. In addition, the excellent photodynamic activity of PC overcomes the inability of SWNHs to generate reactive oxygen species. The SWNHs not only give the hybrid a photothermal therapy (PTT) function, but they also enhance the photostability of PC. These characteristics of the PC@SWNHs are confirmed by in vitro and in vivo experiments, where synergistic photodynamic therapy (PDT)/PTT growth inhibition of tumors is achieved. The PC@SWNHs also act as a photoacoustic/thermal imaging agent to visualize the in vivo treatment process. Hence, this work not only paves the way to use the complementarity between SWNHs and proteins for multifunctional cancer theranostics, but it also allows for a better understanding of bio–nano interface interactions between them. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

The surface functionalization of carbon dots (CDs) can introduce an additional dimension for the control of their photoluminescence properties and effective promotion of the applications of CDs such as imaging, sensing, etc . In this study, a simple one-step carbonization using Tween 80 as the sole carbon source is described for directly synthesizing white-emitting CDs (WCDs) in high yield. The results revealed the presence of several long alkyl chains on the surface of the as-fabricated WCDs, which effectively suppress the aggregation-caused quenching (ACQ) effect and emit bright white luminescence under an UV illumination of 365 nm in the solution and solid states. Besides, together with the surface protection of long alkyl chains, WCDs preferentially interact with lipophilic fatty residues and are beneficial for the label-free imaging of latent fingerprints. This study provides a promising new method to not only effectively inhibit the intrinsic ACQ effect of CDs but also develop the surface engineering of functionalized white-emitting CDs for practical applications via facile synthesis. [ABSTRACT FROM AUTHOR]

Treatment in combination with real-time monitoring of dynamic organelle changes is of great significance for evaluating therapeutic efficacy. However, it remains highly challenging to realize such specific treatment and monitoring in organelles. Herein, we developed one kind of red emissive two-photon carbon dots (TP-CDs) via an N doping strategy for nucleolus-targeted treatment combined with real-time monitoring of dynamic changes in the nucleolus. In the TP-CD system, N doping endows TP-CDs with intrinsic two-photon excitation, red emission at 605 nm, and singlet oxygen (1O 2) production under 638 nm laser irradiation. More importantly, N heterocycles induced by doping offers significant affinity for TP-CDs toward RNA to realize specific self-targeting toward nucleolus and fluorescence variation during the photodynamic therapy (PDT) via the cleaving of RNA chain by 1O 2 to dissociate TP-CDs@RNA complex. By combining 1O 2 production, fluorescent variation during the PDT process, long-wavelength excitation and emission characteristics, as well as specific self-targetability of nucleolus, TP-CDs can be considered as a kind of "smart" CDs to realize treatment in combination of real-time dynamic changes in nucleolus for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]

It is of extreme importance to engineer the structural characteristics of carbon dots (CDs) to satisfy their practical applications in imaging and medical treatments. Here, Cu,N-doped CDs ( Cu,N -CDs) are a new class of near-infrared-(NIR) light-induced therapeutic agents that were prepared by a one-step hydrothermal method using EDTA·2Na and CuCl 2 . Specifically, Cu ΙΙ was located in the inner of Cu,N -CDs via N-Cu-N complexation, endowing NIR absorption for the production of heat and reactive oxygen species. The relationships between the hydrothermal temperature, NIR absorption, and intrinsic biological activity of the Cu,N -CDs were examined. The hydrothermal temperature significantly affected the latter two when the Cu content in the Cu,N -CDs was changed. The Cu,N -CDs at 180 °C were examined for cancer phototherapeutics in vitro and in vivo . The Cu,N -CDs markedly inhibited cancer via synergistic photothermal/photodynamic therapies. In addition, the Cu,N -CDs could also act as one kind of fluorescence cell-imaging agent and IR thermal imaging agent to visualize the in vitro and in vivo treatment process, respectively. Thus, the present study provides a promising new method to prepare CDs with NIR absorption feature for multifunctional cancer theranostic applications. [ABSTRACT FROM AUTHOR]

Wound is highly susceptible to bacterial infection, which can cause chronic wound and serial complications. However, timely treatment is hampered by the lack of real-time monitoring of wound status and effective therapeutic systems. Herein, in situ biosynthesis of functional conjugated polymer in artificial hydrogel was developed via the utilization of biological microenvironment to realize monitoring in real time of wound infection and inhibition of bacteria for the first time. Specially, an easily polymerizable aniline dimer derivative (N-(3-sulfopropyl) p-aminodiphenylamine, SPA) was artfully in situ polymerized into polySPA (PSPA) in calcium alginate hydrogel, which was initiated via the catalysis of hydrogen peroxide (H 2 O 2) overexpressed in infected wound to produce hydroxyl radical (•OH) by preloaded horseradish peroxidase (HRP). Benefitting from outstanding near infrared (NIR) absorption of PSPA, such polymerization can be ingeniously used for real-time monitoring of H 2 O 2 via naked-eye and photoacoustic signal, as well as NIR light-mediated photothermal inhibition of bacteria. Furthermore, combining the persistent chemodynamic activity of •OH, the in vivo experimental data proved that the wound healing rate was 99.03% on the 11th day after treatment. Therefore, the present work opens the way to manipulate in situ biosynthesis of functional conjugated polymer in artificial hydrogels for overcoming the issues on wound theranostics. [ABSTRACT FROM AUTHOR]