Genesis of electron deficient Pt1(0) in PDMS-PEG aggregates

Nanoparticle-Based Immunotherapy for Reversing T-Cell Exhaustion

T-cell exhaustion refers to a state of T-cell dysfunction commonly observed in chronic infections and cancer. Immune checkpoint molecules blockading using PD-1 and TIM-3 antibodies have shown promising results in reversing exhaustion, but this approach has several limitations. The treatment of T-cell exhaustion is still facing great challenges, making it imperative to explore new therapeutic strategies. With the development of nanotechnology, nanoparticles have successfully been applied as drug carriers and delivery systems in the treatment of cancer and infectious diseases. Furthermore, nanoparticle-based immunotherapy has emerged as a crucial approach to reverse exhaustion. Here, we have compiled the latest advances in T-cell exhaustion, with a particular focus on the characteristics of exhaustion that can be targeted. Additionally, the emerging nanoparticle-based delivery systems were also reviewed. Moreover, we have discussed, in detail, nanoparticle-based immunotherapies that aim to reverse exhaustion, including targeting immune checkpoint blockades, remodeling the tumor microenvironment, and targeting the metabolism of exhausted T cells, etc. These data could aid in comprehending the immunopathogenesis of exhaustion and accomplishing the objective of preventing and treating chronic diseases or cancer.

Cell-Based Micro/Nano-Robots for Biomedical Applications: A Review

Micro/nano-robots are powerful tools for biomedical applications and are applied in disease diagnosis, tumor imaging, drug delivery, and targeted therapy. Among the various types of micro-robots, cell-based micro-robots exhibit unique properties because of their different cell sources. In combination with various actuation methods, particularly externally propelled methods, cell-based microrobots have enormous potential for biomedical applications. This review introduces recent progress and applications of cell-based micro/nano-robots. Different actuation methods for micro/nano-robots are summarized, and cell-based micro-robots with different cell templates are introduced. Furthermore, the review focuses on the combination of cell-based micro/nano-robots with precise control using different external fields. Potential challenges, further prospects, and clinical translations are also discussed.

Advanced Strategies for Stabilizing Single-Atom Catalysts for Energy Storage and Conversion

Well-defined atomically dispersed metal catalysts (or single-atom catalysts) have been widely studied to fundamentally understand their catalytic mechanisms, improve the catalytic efficiency, increase the abundance of active components, enhance the catalyst utilization, and develop cost-effective catalysts to effectively reduce the usage of noble metals. Such single-atom catalysts have relatively higher selectivity and catalytic activity with maximum atom utilization due to their unique characteristics of high metal dispersion and a low-coordination environment. However, freestanding single atoms are thermodynamically unstable, such that during synthesis and catalytic reactions, they inevitably tend to agglomerate to reduce the system energy associated with their large surface areas. Therefore, developing innovative strategies to stabilize single-atom catalysts, including mass-separated soft landing, one-pot pyrolysis, co-precipitation, impregnation, atomic layer deposition, and organometallic complexation, is critically needed. Many types of supporting materials, including polymers, have been commonly used to stabilize single atoms in these fabrication techniques. Herein, we review the stabilization strategies of single-atom catalyst, including different synthesis methods, specific metals and carriers, specific catalytic reactions, and their advantages and disadvantages. In particular, this review focuses on the application of polymers in the synthesis and stabilization of single-atom catalysts, including their functions as carriers for metal single atoms, synthetic templates, encapsulation agents, and protection agents during the fabrication process. The technical challenges that are currently faced by single-atom catalysts are summarized, and perspectives related to future research directions including catalytic mechanisms, enhancement of the catalyst loading content, and large-scale implementation are proposed to realize their practical applications.

Graphical Abstract

Single-atom catalysts are characterized by high metal dispersibility, weak coordination environments, high catalytic activity and selectivity, and the highest atom utilization. However, due to the free energy of the large surface area, individual atoms are usually unstable and are prone to agglomeration during synthesis and catalytic reactions. Therefore, researchers have developed innovative strategies, such as soft sedimentation, one-pot pyrolysis, coprecipitation, impregnation, step reduction, atomic layer precipitation, and organometallic complexation, to stabilize single-atom catalysts in practical applications. This article summarizes the stabilization strategies for single-atom catalysts from the aspects of their synthesis methods, metal and support types, catalytic reaction types, and its advantages and disadvantages. The focus is on the application of polymers in the preparation and stabilization of single-atom catalysts, including metal single-atom carriers, synthetic templates, encapsulation agents, and the role of polymers as protection agents in the manufacturing process. The main feature of polymers and polymer-derived materials is that they usually contain abundant heteroatoms, such as N, that possess lone-pair electrons. These lone-pair electrons can anchor the single metal atom through strong coordination interactions. The coordination environment of the lone-pair electrons can facilitate the formation of single-atom catalysts because they can enlarge the average distance of a single precursor adsorbed on the polymer matrix. Polymers with nitrogen groups are favorable candidates for dispersing active single atoms by weakening the tendency of metal aggregation and redistributing the charge densities around single atoms to enhance the catalytic performance. This review provides a summary and analysis of the current technical challenges faced by single-atom catalysts and future research directions, such as the catalytic mechanism of single-atom catalysts, sufficiently high loading, and large-scale implementation.

Bi/Trinuclear Pt1&2Cu Clusters Assembly from Isolated Metal Atoms

We report a facile strategy in synthesizing uniform heterometallic bi/tri-atom clusters starting from mono-metallic atoms in liquid phase. Specifically, Pt1&2Cu bi/tri-atoms are prepared by reducing CuCl2 at preformed Pt1 atoms...

Deep learning enables fast and dense single-molecule localization with high accuracy

Single-molecule localization microscopy (SMLM) has had remarkable success in imaging cellular structures with nanometer resolution, but standard analysis algorithms require sparse emitters, which limits imaging speed and labeling density. Here, we overcome this major limitation using deep learning. We developed DECODE (deep context dependent), a computational tool that can localize single emitters at high density in three dimensions with highest accuracy for a large range of imaging modalities and conditions. In a public software benchmark competition, it outperformed all other fitters on 12 out of 12 datasets when comparing both detection accuracy and localization error, often by a substantial margin. DECODE allowed us to acquire fast dynamic live-cell SMLM data with reduced light exposure and to image microtubules at ultra-high labeling density. Packaged for simple installation and use, DECODE will enable many laboratories to reduce imaging times and increase localization density in SMLM.