Multifunctional Gold Nanozyme-Engineered Amphotericin B for Enhanced Antifungal Infection Therapy.

Chronic wounds of significant severity and acute injuries are highly vulnerable to fungal infections, drastically impeding the expected wound healing trajectory. The clinical use of antifungal therapeutic drug is hampered by poor solubility, high toxicity and adverse reactions, thereby necessitating the urgent development of novel antifungal therapy strategy. Herein, this study proposes a new strategy to enhance the bioactivity of small-molecule antifungal drugs based on multifunctional metal nanozyme engineering, using amphotericin B (AmB) as an example. AmB-decorated gold nanoparticles (AmB@AuNPs) are synthesized by a facile one-pot reaction strategy, and the AmB@AuNPs exhibit superior peroxidase (POD)-like enzyme activity, with maximal reaction rates (Vmax) 3.4 times higher than that of AuNPs for the catalytic reaction of H2O2. Importantly, the enzyme-like activity of AuNPs significantly enhanced the antifungal properties of AmB, and the minimum inhibitory concentrations of AmB@AuNPs against Candida albicans (C. albicans) and Saccharomyces cerevisiae (S. cerevisiae) W303 are reduced by 1.6-fold and 50-fold, respectively, as compared with AmB alone. Concurrent in vivo studies conducted on fungal-infected wounds in mice underscored the fundamentally superior antifungal ability and biosafety of AmB@AuNPs. The proposed strategy of engineering antifungal drugs with nanozymes has great potential for enhanced therapy of fungal infections and related diseases.

Chirality-Dependent Angiogenic Activity of MoS2 Quantum Dots toward Regulatable Tissue Regeneration.

Despite great advances in understanding the biological behaviors of chiral materials, the effect of chirality-configured nanoparticles on tissue regeneration-related biological processes remains poorly understood. Herein, the chirality of MoS2 quantum dots (QDs) is tailored by functionalization with l-/d-penicillamine, and the profound chiral effects of MoS2 QDs on cellular activities, angiogenesis, and tissue regeneration are thoroughly investigated. Specifically, d-MoS2 QDs show a positive effect in promoting the growth, proliferation, and migration of human umbilical vein endothelial cells. The expression of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), and fibroblast growth factor (FGF) in d-MoS2 QDs group is substantially up-regulated, resulting in enhanced tube formation activity. This distinct phenomenon is largely due to the higher internalization efficiency of d-MoS2 QDs than l-MoS2 QDs and chirality-dependent nano-bio interactions. In vivo angiogenic assay shows the expression level of angiogenic markers in newly-formed skin tissues of d-MoS2 QDs group is higher than that in l-MoS2 QDs group, leading to an accelerated re-epithelialization and improved skin regeneration. The findings of chirality-dependent angiogenesis activity of MoS2 QDs provide new insights into the biological activity of MoS2 nanomaterials, which also opens up a new path to the rational design of chiral nanomaterials for tissue regeneration application.

High-Throughput Colorimetric Analysis of Nanoparticle-Protein Interactions Based on the Enzyme-Mimic Properties of Nanoparticles.

While an in-depth understanding of the biological behavior of engineered nanoparticles (NPs) is of great importance for their various applications, it remains challenging to quantitatively characterize NP-protein interactions in a simple and high-throughput manner. In the present work, we propose a new, colorimetric approach capable of quantitatively analyzing the adsorption of proteins onto the surface of NPs by their distinct peroxidase-mimic properties. Taking cationic AuNPs as an example, we demonstrate that this colorimetric method is capable of evaluating NP-protein interactions in a simple and high-throughput manner in multiwell plates. Important binding parameters (e.g., the binding affinity) of three different serum proteins (bovine serum albumin, transferrin, and lysozyme) as well as human serum to AuNPs with three different sizes (average diameters of 5, 10, and 15 nm) have been obtained. Based on a quantitative analysis of NP-protein interactions, we observe that the binding affinity and the inhibition efficiency of the nanozyme activity of AuNPs are strongly affected by the characteristics of proteins as well as the sizes of NPs. These results illustrate the great potential of the present colorimetric method as a simple, low-cost, and high-throughput platform for quantitatively investigating NP-protein interactions.

Covalent organic framework isomers with divergent photocatalytic properties.

A pair of isomeric Py-BT-COFs with the same composition, but slightly different atomic arrangements, were designed and synthesized. The minute structural variations of the Py-BT-COF isomers generated significantly different redox and photophysical properties and correspondingly led to different photocatalytic manifestations in H2 evolution and rhodamine B degradation.

Heavy-to-light electron transition enabling real-time spectra detection of charged particles by a biocompatible semiconductor.

The current challenge of wearable/implantable personal dosimeters for medical diagnosis and radiotherapy applications is lack of suitable detector materials possessing both excellent detection performance and biocompatibility. Here, we report a solution-grown biocompatible organic single crystalline semiconductor (OSCS), 4-Hydroxyphenylacetic acid (4HPA), achieving real-time spectral detection of charged particles with single-particle sensitivity. Along in-plane direction, two-dimensional anisotropic 4HPA exhibits a large electron drift velocity of 5 × 105 cm s-1 at "radiation-mode" while maintaining a high resistivity of (1.28 ± 0.003) × 1012 Ω·cm at "dark-mode" due to influence of dense π-π overlaps and high-energy L1 level. Therefore, 4HPA detectors exhibit the record spectra detection of charged particles among their organic counterparts, with energy resolution of 36%, (µt)e of (4.91 ± 0.07) × 10-5 cm2 V-1, and detection time down to 3 ms. These detectors also show high X-ray detection sensitivity of 16,612 µC Gyabs-1 cm-3, detection of limit of 20 nGyair s-1, and long-term stability after 690 Gyair irradiation.

Central environmental protection inspector and stock price crash risk-evidence from polluting industries firms in China.

In recent years, under the background of vigorously promoting environmental governance, the implementation effect of the central environmental protection inspection is an issue of great concern to the government and the public. This paper systematically investigates the impact of central environmental protection inspection on the risk of stock price crash using a sample of listed firms in polluting industries. The results show that compared with non-supervised areas, central environmental protection inspection can reduce the polluting industries' firms' stock price crash risk by reducing stock price bubbles. After a series of robustness tests, the results still held. The above transmission mechanism is more effective in the samples of private enterprises, low information transparency and disclosure quality enterprises, non-national civilized urban areas, and high promotion incentive areas. Furthermore, this paper found that there were differences in the effects of central environmental protection inspection in different batches. Among the effects of central environmental protection inspection in different batches, the effect of environmental regulation in the second, third, and fourth batches was better, and the effect of central environmental protection inspection in different batches gradually deepened. Finally, by analyzing the environmental governance of the central environmental protection inspection, it is found that the central environmental protection inspection has significant short-term and long-term control effect in air pollution governance, and it is still necessary to strengthen the law enforcement in water pollution governance.

Highly biocompatible Ag nanocluster-reinforced wound dressing with long-term and synergistic bactericidal activity.

Clinical application of antibiotic-free agents like silver nanoparticle-derived materials remains a critical challenge due to their limited long-term antibacterial activity and potential system toxicity. Herein, a highly biocompatible Ag nanocluster-reinforced hydrogel with enhanced synergistic antibacterial ability has been developed. Specifically, bioactive curcumin was incorporated into lysozyme-protected ultrasmall Ag nanoclusters (LC-AgNCs) and further integrated with sodium alginate (Sa) hydrogel (LC-AgNCs@Sa) through multiple interaction forces. Due to the synergistic antibacterial activity, LC-AgNCs could effectively kill both S. aureus and E. coli bacteria with a concentration down to 2.5 µg mL-1. In-depth mechanism investigations revealed that the bactericidal effect of LC-AgNCs lies in their bacterial membrane destruction, reactive oxygen species (ROS) production, glutathione depletion and prooxidant-antioxidant system disruption ability. Curcumin can mediate the intracellular ROS balance to protect NIH 3T3 cells from oxidative stress and improve the biocompatibility of LC-AgNCs@Sa. LC-AgNCs@Sa with long-term antibacterial ability can effectively protect the wound from bacterial invasion in vivo, and significantly accelerate the wound healing process due to their distinctive functions of inhibiting inflammatory factor (TNF-α) production, promoting collagen deposit and facilitating re-epithelization. This study provides a new, versatile strategy for the design of high-performance antibacterial dressing for broad infectious disease therapy.

Acridine based metal-organic framework host-guest featuring efficient photoelectrochemical-type photodetector and white LED.

A novel metal-organic framework (MOF) host-guest material [Cd3(EtOIPA)4(HAD)2]·H2O has been successfully synthesized by the reaction of 5-ethoxyisophthalic acid (EtOIPA), acridine (AD) and Cd(II) salts under hydrothermal conditions. Structurally, the title MOF possesses a trinucleate Cd(II) based 2D double-layer with the protonated AD cations as the template encapsulated into the grids. The combination of experiments and theoretical calculations reveals that the orderly arrangement of EtOIPA dimers, protonated AD cations and trinucleate Cd(II) clusters generates highly delocalized π-electron channels with a prolonged exciton lifetime. The MOF powders show bright yellow emission with a long lifetime of 50.63 ns. Photoelectrochemical measurements reveal a high photocurrent density ratio of 290 between light and dark conditions at 0 V bias potential, making it a perfect self-driven photodetector. By coating the yellow phosphor on a commercially available blue LED, a high performance white LED with CIE, CCT and CRI values of (0.325, 0.336), 88.2 and 5844 K, respectively can be obtained.

Interactions of cationic gold nanoclusters with serum proteins and effects on their cellular responses.

Cationic nanoparticles (NPs) have shown great potential in biological applications owing to their distinct features such as favorable cellular internalization and easy binding to biomolecules. However, our current knowledge of cationic NPs' biological behavior, i.e., NP-protein interactions, is still rather limited. Herein, we choose ultrasmall-sized fluorescent gold nanoclusters (AuNCs) coated by (11-mercaptoundecyl) - N, N, N - trimethylammonium bromide (MUTAB) as representative cationic NPs, and systematically study their interactions with different serum proteins at nano-bio interfaces. By monitoring the fluorescence intensity of MUTAB-AuNCs, all proteins are observed to bind with roughly micromolar affinities to AuNCs and quench their fluorescence. Transient fluorescence spectroscopy, X-ray photoelectron spectroscopy and isothermal titration calorimetry are also adopted to characterize the physicochemical properties of MUTAB-AuNCs after the protein adsorption. Concomitantly, circular dichroism spectroscopy reveals that cationic AuNCs can exert protein-dependent conformational changes of these serum proteins. Moreover, protein adsorption onto cationic AuNCs can significantly influence their cellular responses such as cytotoxicity and uptake efficiency. These results provide important knowledge towards understanding the biological behaviors of cationic nanoparticles, which will be helpful in further designing and utilizing them for safe and efficient biomedical applications.

Red room temperature phosphorescence of lead halide based coordination polymer showing efficient angle-dependent polarized emission and photoelectric performance.

The development of organic-inorganic hybrid materials with long-lived room temperature phosphorescence (RTP) has attracted tremendous attention owing to their promising applications in the optoelectronic and anti-counterfeiting fields. In this work, by the selection of lead halide and electron-poor heteroaromatic molecule 1,10-phenanthroline (phen), a coordination polymer [Pb(phen)Cl2] has been synthesized under hydrothermal conditions. This complex shows an alternating arrangement of a long-range order of phen π-conjugated systems and lead halide inorganic chains as revealed by X-ray single-crystal structural analysis. This structural character and special chemical components endow this hybrid material with a rare example of red room temperature phosphorescence. Its electronic structure and electronic transition behavior were further examined by theoretical calculations. Meanwhile, the film of the complex features remarkable angle-dependent polarized emission and photoelectric performance.

Simultaneous regulation of optical properties and cellular behaviors of gold nanoclusters by pre-engineering the biotemplates.

Herein, we reported a new strategy to simultaneously regulate both the physicochemical properties and biological behaviors of fabricated nanomaterials. Upon precisely pre-tailoring the number of charged groups of bovine serum albumin (BSA), the resultant BSA-templated gold nanoclusters (BSA-AuNCs) exhibit remarkably different fluorescence properties and strong biotemplate-dependent cellular uptake behavior.