Conjugation Linked PEDOT:PSS with Low Impedance and High Stretchability for Epidermal Electrophysiology.

Long-term epidermal recording of bioelectricity is of paramount importance for personal health monitoring. It requires stretchable and dry film electrodes that can be seamlessly integrated with skin. The simultaneous achievement of high conductivity and skin-like ductility of conducting materials is a prerequisite for reliable signal transduction at the dynamic interface, which is also the bottleneck of epidermal electrophysiology. Here, carbon nanotubes (CNTs) are introduced as "conjugation linkers" into a topologically plasticized conducting polymer (PEDOT:PSS). A thin-film electrode with high conductivity (≈3250 S cm-1) and high stretchability (crack-onset strain>100%) is obtained. In particular, the conjugation linker enables the high volumetric capacitance and the low film resistance, both of which synergically reduce the interfacial impedance. The capabilities of this electrode is further demonstrated in the precise recording of various electrophysiological signals.

Stepwise Aggregation Control of PEDOT:PSS Enabled High-Conductivity, High-Resolution Printing of Polymer Electrodes for Transparent Organic Phototransistors.

Electrohydrodynamic (EHD) jet printing is a widely employed technology to create high-resolution patterns and thus has enormous potential for circuit production. However, achieving both high conductivity and high resolution in printed polymer electrodes is a challenging task. Here, by modulating the aggregation state of the conducting polymer in the solution and solid phases, a stable and continuous jetting of PEDOT:PSS is realized, and high-conductivity electrode arrays are prepared. The line width reaches less than 5 µm with a record-high conductivity of 1250 S/cm. Organic field-effect transistors (OFETs) are further developed by combining printed source/drain electrodes with ultrathin organic semiconductor crystals. These OFETs show great light sensitivity, with a specific detectivity (D*) value of 2.86 × 1014 Jones. In addition, a proof-of-concept fully transparent phototransistor is demonstrated, which opens up new pathways to multidimensional optical imaging.

HClO-triggered interventional probe enabled early detection and intervention of atherosclerosis.

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of early atherosclerosis (AS). Targeting foam cell formation can be a promising approach for the early detection and prevention of AS. However, only a few studies have actually examined foam cells in vivo, and most methods combined nanotechnology with angiography, which is complex and could cause further damage to the endothelium. Herein, based on methylene blue, a biosafe NIR dye approved by the FDA, an interventional probe (HMB-NA@Mp) triggered by hypochlorous acid (HClO) was designed for imaging foam cells easily, safely, and effectively in the early stage of AS. Here, encapsulation of the probe by foam cells targeted platelet membrane (Mp) increased probe targeting and reduced toxicity. Cell and animal experimental results showed that the probe could accumulate at the lesion site and significantly enhance fluorescence in the early AS model group. Remarkably, at the same time, it could also release the metabolite niacin, which played a role in inhibiting atherosclerosis. Thus, HMB-NA@Mp is expected to be a powerful means for the early detection and timely intervention of early AS in the absence of clinical symptoms.

A deep tumor penetration nanoplatform for glycolysis inhibition and antimetastasis of breast cancer.

The poor penetration into deep tumor tissues of nanomedicines could not inhibit the production of lactic acid by deep tumor glycolysis, which leads to the accumulation of lactic acid and promotes tumor metastasis. In order to increase tumor penetration, it remains challenging to avoid tumor metastasis by the direct degradation of the extracellular matrix (ECM). Herein, in order to increase tumor penetration, a nano-platform, which can reduce extracellular matrix (ECM) production, and inhibit the glycolysis of deep tumors by releasing ethylenediaminetetraacetic acid (EDTA) is reported. In this design, EDTA and indocyanine green (ICG) are encapsulated in the liposome by a thin-film hydration method, and folic acid (FA) and the polyethyleneimine polymer (FA-PEI) are applied to coat the surface of liposomes through electrostatic interactions, and the FA-EDTA/ICG-Lip nanoparticles are obtained. FA-EDTA/ICG-Lip NPs can release EDTA and ICG in lysosomes (pH 4.5) to reduce ECM production by down-regulating transforming growth factor ß (TGF-ß) and activating an immune response by inducing tumor cell immunogenic cell death (ICD), respectively. Simultaneously, EDTA inhibits glycolysis of deep tumors by chelating Mg2+. By avoiding tumor metastasis, the strategy of indirectly reducing ECM production is demonstrated to enhance tumor penetration and inhibit deep tumor glycolysis.

A nano-detection system based on a chemical probe for early diagnosis of atherosclerosis in situ.

With the existing medical diagnostic technology, the diagnosis of atherosclerosis (AS) is mainly focused on the later stage of AS development rather than plaque imaging in the period before plaque formation. It is impractical to apply the existing theoretical methods for the purpose of early detection of AS. Herein, this study uses a naphthalimide-based fluorescent probe for recognition of cellular reactive oxygen species (ROS). A platelet membrane (Mp) with foam cell targeting was wrapped around the probes to prepare two vesicle structures TBNG@Mp and GNTB@Mp. The animal experiment results show that the screened nano-detection system TBNG@Mp could accumulate in the thoracic aorta of early AS rats. Under the effect of intracellular ROS, fluorescence signals can be observed. In addition, acute biological toxicity was not observed in pathological sections. Therefore, the foam cell targeting system TBNG@Mp with acceptable biocompatibility can realize the detection of AS one to two decades in advance as well as has a good application prospect.

Reshaping the tumor microenvironment for increasing the distribution of glucose oxidase in tumor and inhibiting metastasis.

The poor penetration of solid tumors hinders the development of hunger therapy represented by glucose oxidase (GOx). To address this limitation, we have constructed a GOx/Dex@ZIF-TA nanosystem consisting of tannic acid (TA), carrier ZIF-8, encapsulated GOx and dexamethasone (Dex). In this nanosystem, the loaded Dex can not only expand the pores of the nucleus to promote GOx to enter the nucleus, addressing the shortcomings of short life of reactive oxygen species, but also inhibit the production of collagen to reshape the tumor microenvironment and inhibit lung metastasis. In vivo experiments proved that Dex could inhibit the production of collagen, which increased the accumulation and penetration of the tumor tissues and inhibited lung metastasis. In addition, cell experiments showed that Dex could also enlarge the nuclear pores of the nucleus and promote the entry of drugs into the nucleus. More importantly, Dex is a broad anti-inflammatory drug, and the results of this study should be easily transformed to achieve clinical benefits. Together, this work provided a way to address the limitations of hunger distribution in tumor tissues.