Immune responses stimulated by photodynamic therapy (PDT) and photothermal therapy (PTT) are a promising strategy for the treatment of advanced cancer. However, the antitumor efficacy by PDT or PTT alone is less potent and unsustainable against cancer metastasis and relapse. In this study, Gd3+ and chlorin e6 loaded single‐walled carbon nanohorns (Gd‐Ce6@SWNHs) are developed, and it is demonstrated that they are a strong immune adjuvant, and have high tumor targeting and penetration efficiency. Then, three in vivo mouse cancer models are established, and it is found that sequential PDT and PTT using Gd‐Ce6@SWNHs synergistically promotes systemic antitumor immune responses, where PTT stimulates dendritic cells (DCs) to secrete IL‐6 and TNF‐α, while PDT triggers upregulation of IFN‐γ and CD80. Moreover, migration of Gd‐Ce6@SWNHs from the targeted tumors to tumor‐draining lymph nodes sustainably activates the DCs to generate a durable immune response, which eventually eliminates the distant metastases without using additional therapeutics. Gd‐Ce6@SWNHs intervened phototherapies also generate durable and long‐term memory immune responses to tolerate and prevent cancer rechallenge. Therefore, this study demonstrates that sequential PDT and PTT using Gd‐Ce6@SWNHs under moderate conditions elicits cooperative and long‐lasting antitumor immune responses, which are promising for the treatment of patients with advanced metastatic cancers.
The morphologies of gold nanoparticles (NPs) affect their tumor accumulation through enhanced permeability and retention effect. However, detailed information and mechanisms of NPs' characteristics affecting tumor accumulation are limited. The aim of this study is to evaluate the effects of shape and active targeting ligands of theranostic NPs on tumor accumulation and therapeutic efficacy, and to elucidate the underlying mechanism.
Tumor combination therapy using nano formulations with multimodal synergistic therapeutic effects shows great potential for complete ablation of tumors. However, targeting tumor metastases with nano structures is a major obstacle for therapy. Therefore, developing a combination therapy system able to target both primary tumors and their metastases at distant sites with synergistic therapy is desirable for the complete eradication of tumors. To this end, a dual chemodrug-loaded theranostic system based on single walled carbon nanohorns (SWNHs) is developed for targeting both primary breast tumors and their lung metastases.
The emergence of multi‐drug resistant (MDR) pathogens is a major public health concern, posing a substantial global economic burden. Photothermal therapy (PTT) at mild temperature presents a promising alternative to traditional antibiotics due to its biological safety and ability to circumvent drug resistance. However, the efficacy of mild PTT is limited by bacterial thermotolerance. Herein, a nanocomposite, BP@Mn‐NC, comprising black phosphorus nanosheets and a manganese‐based nanozyme (Mn‐NZ) is developed, which possesses both photothermal and catalytic properties. Mn‐NZ imparts glucose oxidase‐ and peroxidase‐like properties to BP@Mn‐NC, generating reactive oxygen species (ROS) that induce lipid peroxidation and malondialdehyde accumulation across the bacterial cell membrane. This process disrupts unprotected respiratory chain complexes exposed on the bacterial cell membrane, leading to a reduction in the intracellular adenosine triphosphate (ATP) content. Consequently, mild PTT mediated by BP@Mn‐NC effectively eliminates MDR infections by specifically impairing bacterial thermotolerance because of the dependence of bacterial heat shock proteins (HSPs) on ATP molecules for their proper functioning. This study paves the way for the development of a novel photothermal strategy to eradicate MDR pathogens, which targets bacterial HSPs through ROS‐mediated inhibition of bacterial respiratory chain activity.
Multifunctional probes with high MRI sensitivity and high efficiency for cell labeling are desirable for MR cell imaging. Herein, we have fabricated fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (fmSiO4@SPIONs) for neural progenitor cell (C17.2) MR imaging. FmSiO4@SPIONs were discrete and uniform in size, and had a clear core–shell structure. The magnetic core size was about 10 nm and the fluorescent mesoporous silica coating layer was around 20 nm. Compared with fluorescent dense silica-coated SPIONs (fdSiO4@SPIONs) with a similar size, fmSiO4@SPIONs demonstrated higher MR sensitivity and cell labeling efficiency. When implanted into the right hemisphere of stroke mice, contralateral to the ischemic territory, a small amount of labeled cells were able to be tracked migrating to the lesion sites using a clinical MRI scanner (3 T). More impressively, even when administered intravenously, the labeled cells could also be monitored homing to the ischemic area. MRI observations were corroborated by histological studies of the brain tissues. Our study demonstrated that fmSiO4@SPIONs are highly effective for cell imaging and hold great promise for MRI cell tracking in future.