This study reports a family of photothermal materials, metal ion/tannic acid assemblies (MITAs). MITAs from Fe, V, and Ru afford excellent photothermal efficiency (η ≈ 40%). Sharply differing from the currently existing photothermal agents, MITAs are highlighted by merits including green synthesis, facile incorporation of diagnostic metal ions, and particularly topology-independent adhesion. Owing to the adhesion nature of MITAs, various kinds of MITA-based nanoengineerings are readily available via the self-adhesion of MITAs onto diverse templates, enabling MITAs well suited as a photothermal platform for versatile combination with other therapy approaches and imaging techniques. As a proof of concept, polymeric/inorganic nanoparticle/nanovesicle-supported Fe-tannic acid (FeTA) is fabricated. The photothermal effect is shown to be unaffected by the template origin and type and FeTA thickness on the templates. We validate the potency of nanovesicle-supported FeTA (PNV@FeTA) for tumor-specific photoactivated utilizations, including NIR photothermal therapy with complete tumor elimination, photothermal imaging (PTI), and photoacoustic imaging (PAI) in addition to T-MRI imaging. PNV@FeTA can be simultaneously equipped with functionalities, including T-MRI imaging by additionally doping Mn and NIR fluorescence imaging by encapsulating a hydrophilic NIR fluoroprobe. MITA demonstrates unparalleled superiority as a photothermal platform in engineering multimodal theranostics for advanced applications.

Constructing a tumor microenvironment stimuli activatable theranostic nanoparticle with simple components and preparation procedures for multimodality imaging and therapy remains a major challenge for current theranostic systems. Here we report a novel and simple glutathione (GSH)-responsive turn-on theranostic nanoparticle for dual-modal imaging and combination therapy. The theranostic nanoparticle, DHP, consisting of a disulfide-bond-linked hydroxyethyl starch paclitaxel conjugate (HES-SS-PTX) and a near-infrared (NIR) cyanine fluorophore DiR, is prepared with a simple one-step dialysis method. As DiR is encapsulated within the hydrophobic core formed by HES-SS-PTX, the fluorescence of DiR is quenched by the aggregation-caused quenching (ACQ) effect. Nonetheless, once DHP is internalized by cancer cells, the disulfide bond of HES-SS-PTX can be cleaved by intracellular GSH, leading to the synchronized release of conjugated PTX and loaded DiR. The released PTX could exert its therapeutic effect, while DiR could adsorb onto nearby endosome/lysosome membranes and regain its fluorescence. Thus, DHP could monitor the release and therapeutic effect of PTX through the fluorescence recovery of DiR. Remarkably, DHP can also be used as an in vivo probe for both fluorescent and photoacoustic imaging and at the same time achieves potent antitumor efficacy through chemo-photothermal combination therapy. This study provides novel insights into designing clinically translatable turn-on theranostic systems.

VD spiral exhibits a useful operating range, in the region of 25-30% under-sampling, for which CS reconstruction can be used to increase the sensitivity of fMRI to brain activity. Using CS, VD acquisitions achieve the same sensitivity as 2-shot Archimedean acquisitions, but require only a single shot.