AgS nanoparticles are increasingly important in biomedicine, such as in cancer imaging. However, there has been only limited success in the exploration of theranostic AgS nanoparticles for photoinduced cancer imaging and simultaneous therapy. Here we report size-dependent AgS nanodots (NDs) with well-defined nanostructure as a theranostic agent for multimodal imaging and simultaneous photothermal therapy. The NDs are precisely synthesized through carefully controlled growth of AgS in hollow human serum albumin nanocages. These NDs produce effective fluorescence in second near-infrared (NIR-II) region, distinct photoacoustic intensity, and good photothermal conversion in a size-dependent manner under light irradiation, thereby generating sufficient in vivo fluorescence and photoacoustic signals as well as potent hyperthermia at tumors. Moreover, AgS NDs possess ideal resistance to photobleaching, effective cellular uptake, preferable tumor accumulation, and in vivo elimination, thus facilitating NIR-II fluorescence/photoacoustics imaging with both ultrasensitivity and microscopic spatial resolution and simultaneous photothermal tumor ablation. These findings provide insight into the clinical potential of AgS nanodots for cancer theranostics.

Elemental tellurium (Te) nanoparticles are increasingly important in a variety of applications such as thermoelectricity, photoconductivity, and piezoelectricity. However, they have been explored with limited success in their biomedical use, and thus a tremendous challenge still exists in the exploration of Te nanoparticles that can treat tumors as an effective anticancer agent. Here, we introduce bifunctional Te nanodots with well-defined nanostructure as an effective anticancer agent for photo-induced synergistic cancer therapy with tumor ablation, which is accomplished using hollow albumin nanocages as a nanoreactor. Under near-infrared light irradiation, Te nanodots can produce effective photothermal conversion, as well as highly reactive oxygen species such as •O and dismutated •OH via a type-I mechanism through direct electron transfer, thereby triggering the potent in vivo hyperthermia and simultaneous intracellular reactive oxygen species at tumors. Moreover, Te nanodots possess perfect resistance to photobleaching, effective cytoplasmic translocation, preferable tumor accumulation, as well as in vivo renal elimination, promoting severe photo-induced cell damage and subsequent synergy between photothermal and photodynamic treatments for tumor ablation. These findings provide the insight of elemental Te nanodots for biomedical research.

Transition metal sulfide nanocrystals are developed as a theranostic platform through the protein-nanoreactor approach with facile functionalization for multimodal NIRF/PA/SPECT/CT imaging and photothermal tumor ablation.

Herpes simplex virus type 1 (HSV-1) establishes latency in neurons and can cause severe disseminated infection with neurological impairment and high mortality. This neurodegeneration is thought to be tightly associated with virus-induced cytoskeleton disruption. Currently, the regulation pattern of the actin cytoskeleton and the involved molecular mechanisms during HSV-1 entry into neurons remain unclear. Here, we demonstrate that the entry of HSV-1 into neuronal cells induces biphasic remodeling of the actin cytoskeleton and an initial inactivation followed by the subsequent activation of cofilin, a member of the actin depolymerizing factor family that is critical for actin reorganization. The disruption of F-actin dynamics or the modulation of cofilin activity by mutation, knockdown, or overexpression affects HSV-1 entry efficacy and virus-mediated cell ruffle formation. Binding of the HSV-1 envelope initiates the epidermal growth factor receptor (EGFR)-phosphatidylinositide 3-kinase (PI3K) signaling pathway, which leads to virus-induced early cofilin phosphorylation and F-actin polymerization. Moreover, the extracellular signal-regulated kinase (ERK) kinase and Rho-associated, coiled-coil-containing protein kinase 1 (ROCK) are recruited as downstream mediators of the HSV-1-induced cofilin inactivation pathway. Inhibitors specific for those kinases significantly reduce the virus infectivity without affecting virus binding to the target cells. Additionally, lipid rafts are clustered to promote EGFR-associated signaling cascade transduction. We propose that HSV-1 hijacks cofilin to initiate infection. These results could promote a better understanding of the pathogenesis of HSV-1-induced neurological diseases.

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Photothermal therapy (PTT) is of particular importance as a highly potent therapeutic modality in cancer therapy. However, a critical challenge still remains in the exploration of highly effective strategy to maximize the PTT efficiency due to tumor thermoresistance and thus frequent tumor recurrence. Here, a rational fabrication of the micelles that can achieve mutual synergy of PTT and molecularly targeted therapy (MTT) for tumor ablation is reported. The micelles generate both distinct photothermal effect from Cypate through enhanced photothermal conversion efficiency and pH-dependent drug release. The micelles further exhibit effective cytoplasmic translocation of 17-allylamino-17-demethoxygeldanamycin (17AAG) through reactive oxygen species mediated lysosomal disruption caused by Cypate under irradiation. Translocated 17AAG specifically bind with heat shock protein 90 (HSP90), thereby inhibiting antiapoptotic p-ERK1/2 proteins for producing preferable MTT efficiency through early apoptosis. Meanwhile, translocated 17AAG molecules further block stressfully overexpressed HSP90 under irradiation and thus inhibit the overexpression of p-Akt for achieving the reduced thermoresistance of tumor cells, thus promoting the PTT efficiency through boosting both early and late apoptosis of Cypate. Moreover, the micelles possess enhanced resistance to photobleaching, preferable cellular uptake, and effective tumor accumulation, thus facilitating mutually synergistic PTT/MTT treatments with tumor ablation. These findings represent a general approach for potent cancer therapy.