Ce doped polyaniline nanoparticles for absorption and photoacoustic imaging response to GSH in vitro and in vivo

Structural characteristics of a novel Bletilla striata polysaccharide and its activities for the alleviation of liver fibrosis

Liver fibrosis has proven to be the main predisposing factor for liver cirrhosis and liver cancer; however, an effective treatment remains elusive. Polysaccharides, with low toxicity and a wide range of bioactivities, are strong potential candidates for anti-hepatic fibrosis applications. For this study, a new low molecular weight neutral polysaccharide (B. striata glucomannan (BSP)) was extracted and purified from Bletilla striata. The structure of BSP was characterized and its activities for alleviating liver fibrosis in vivo were further evaluated. The results revealed that the structural unit of BSP was likely →4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-2ace-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-3ace-Manp-(1→, with a molecular weight of only 58.5 kDa. Additionally, BSP was observed to attenuate the passive impacts of liver fibrosis in a manner closely related to TLR2/TLR4-MyD88-NF-κB signaling pathway conduction. In summary, the results of this study provide theoretical foundations for the potential applications of BSP as an anti-liver fibrosis platform.

In situ synthesized nanozyme for photoacoustic-imaging-guided photothermal therapy and tumor hypoxia relief

Nanozymes have attracted extensive research interest due to their ideal enzymatic catalytic performance; however, uncontrollable activities and nonspecific accumulation limit their further clinical application. To overcome these obstacles, we proposed in situ synthesized nanozyme, and realized the concept through an intelligent nanosystem (ISSzyme) based on Prussian blue (PB) precursor. PB nanozyme was synthesized at the tumor sites through the interaction of ISSzyme with glutathione, which was demonstrated by comparing with conventional PB nanozyme. ISSzyme is capable of tumor-specific photoacoustic imaging (PAI) and photothermal therapy (PTT), reducing the false-positive signals of PAI and the treatment side effects of PTT. ISSzyme has catalase-like activities, resulting in tumor hypoxia relief and metastasis inhibition. More importantly, the in situ synthesized PB nanozyme has the favorable property of minimal liver accumulation. Considering the above advantages, ISSzyme is expected to shed light on the design of the next-generation artificial enzymes, with many new biomedical applications.

Copperphosphotungstate Doped Polyanilines Nanorods for GSH-Depletion Enhanced Chemodynamic/NIR-II Photothermal Synergistic Therapy

Introduction

The high concentration of glutathione (GSH) and hydrogen peroxide (H₂O₂) levels within the tumor microenvironment (TME) are the major obstacle to induce the unsatisfactory anticancer treatment efficiency. The synergistic cancer therapy strategies of the combination the GSH depletion enhanced chemodynamic therapy (CDT) with photothermal therapy (PTT) have been proved to be the promising method to significantly improve the therapeutic efficacy.

Methods

The copperphosphotungstate was incorporated into polyanilines to design copperphosphotungstate doped polyaniline nanorods (CuPW@PANI Nanorods) via chemical oxidant polymerization of aniline. The low long-term toxicity and biocompatibility were evaluated. Both in vitro and in vivo experiments were carried out to confirm the GSH depletion enhanced CDT/NIR-II PTT synergistic therapy.

Results

CuPW@PANI Nanorods feature biosafety and biocompatibility, strong NIR-II absorbance, and high photothermal-conversion efficiency (45.14%) in NIR-II bio-window, making them highly applicable for photoacoustic imaging and NIR-II PTT. Moreover, CuPW@PANI Nanorods could consume endogenous GSH to disrupt redox homeostasis and perform a Fenton-like reaction with H₂O₂ to produce cytotoxic •OH for the enhanced CDT. Furthermore, NIR-II photothermal-induced local hyperthermia accelerates •OH generation to enhance CDT, which realizes high therapeutic efficacy in vivo.

Conclusion

This study provides a proof of concept of GSH-depletion augmented chemodynamic/NIR-II photothermal therapy.

Biomimetic semiconducting polymer dots for highly specific NIR-II fluorescence imaging of glioma

Glioma with very short medium survival time consists of 80% of primary malignant types of brain tumors. The unique microenvironment such as the existence of the blood-brain barrier (BBB) makes the glioma theranostics exhibit low sensitivity in diagnosis, a poor prognosis and low treatment efficacy. Therefore, the development of multifunctional nanoplatform that can cross BBB and target the glioma is essential for the high-sensitivity detection and ablation of cancer cells. In this study, C6 cell membrane-coated conjugated polymer dots (Pdots-C6) were constructed for targeted glioma tumor detection. As a new kind of biomimetic and biocompatible nanoprobes, Pdots-C6 preserve the complex biological functions of natural cell membranes while possessing physicochemical properties for NIR-II fluorescence imaging of glioma. After encapsulating C6 cell membrane on the surface of conjugated Pdots, Pdots-C6 exhibited the most favorable specific targeting capabilities in vitro and in vivo. In particular, this pilot study demonstrates that biomimetic nanoparticles offer a potential tool to enhance specific targeting to the brain, hence improving glioma tumor detection accuracy.