Enzyme-instructed self-assembly leads to the activation of optical properties for selective fluorescence detection and photodynamic ablation of cancer cells.

Both fluorescence and photoactivity activatable probes are particularly valuable for cancer theranostics as they allow for sensitive fluorescence diagnosis and on-demand photodynamic therapy (PDT) against targeted cancer cells at the same time, which undoubtedly promote the diagnostic accuracy and reduce the side effects on normal tissues/cells. Here, we show that enzyme-instructed self-assembly (EISA) is an ideal strategy to develop a both fluorescence and reactive oxygen species (ROS) generation capability activatable probe with aggregation-induced emission (AIE) signature. As a proof-of-concept, we design and synthesize a precursor TPE-Py-FpYGpYGpY that consists of an AIE luminogen (TPE-Py) and a short peptide with three tyrosine phosphates (pY), which permits selective fluorescence visualization and PDT of alkaline phosphatase (ALP)-overexpressed cancer cells. TPE-Py-FpYGpYGpY has good aqueous solubility thanks to the hydrophilic phosphotyrosine residues and hence leads to weak fluorescence and negligible ROS generation ability. After ALP enzymatic dephosphorylation of the precursors, however, self-assembly of ALP-catalysed products occurs and the resultant nanostructures are activated to be highly emissive and efficiently produce ROS. Cellular studies reveal that TPE-Py-FpYGpYGpY is capable of differentiating cancer cells and normal cells, specifically pinpointing and suppressing ALP-overexpressed cancer cells. This study may inspire new insights into the design of advanced activatable molecular probes.

In vivo cancer research using aggregation-induced emission organic nanoparticles.

Exploration of a nanoplatform that benefits precise cancer diagnosis and treatment in vivo is particularly valuable. In recent years, aggregation-induced emission luminogens (AIEgens) have emerged as advanced fluorescent materials for the design and preparation of organic nanoparticles (NPs); they also have unique advantages in biomedical applications, especially in cancer diagnosis and theranostics. In this review, we summarize the current status of the development of AIEgen-based NPs for in vivo cancer research, including in vivo tumor diagnosis, drug delivery, and photodynamic therapy. We hope that our review will inspire more exciting research in cross-disciplinary fields, contributing to precise cancer diagnostics and therapeutics.

Biocompatible fluorescent supramolecular nanofibrous hydrogel for long-term cell tracking and tumor imaging applications.

Biocompatible peptide-based supramolecular hydrogel has recently emerged as a new and promising system for biomedical applications. In this work, Rhodamine B is employed as a new capping group of self-assembling peptide, which not only provides the driving force for supramolecular nanofibrous hydrogel formation, but also endows the hydrogel with intrinsic fluroescence signal, allowing for various bioimaging applications. The fluorescent peptide nanofibrous hydrogel can be formed via disulfide bond reduction. After dilution of the hydrogel with aqueous solution, the fluorescent nanofiber suspension can be obtained. The resultant nanofibers are able to be internalized by the cancer cells and effectively track the HeLa cells for as long as 7 passages. Using a tumor-bearing mouse model, it is also demonstrated that the fluorescent supramolecular nanofibers can serve as an efficient probe for tumor imaging in a high-contrast manner.

Supramolecular nanofibers of self-assembling peptides and proteins for protein delivery.

We report an efficient strategy for intracellular protein delivery by co-assembled supramolecular nanofibers of peptides and proteins.

[Research progress on wind erosion control].

Wind erosion is the main inducement and an important process of desertification, and also, a main environmental problem needed to be controlled in many countries and areas. Based on the formation mechanisms of wind erosion and some important research results, this paper reviewed the biological, chemical, and mechanical measures in wind erosion control, which could be applied individually or integrated together to decrease or prevent wind erosion. It was suggested that management should be strengthened to ensure a better effect in applying these measures to further improve ecological environment.

[Dynamics of carbon and nitrogen storages in plant-soil system during desertification process in Horqin sandy land].

Organic carbon and nitrogen storages in plant-soil system were measured at different desertification stages (potential, light, moderate, severe, and most-severe) in Horqin sandy land. From potential desertification to light, moderate, severe, and most-severe desertification, total biomass (aboveground and belowground) carbon storages decrease by 26.4%, 51.0%, 79.0%, and 91.0%, respectively, while total biomass nitrogen storages decrease by 33.6%, 66.9%, 87.4%, and 93.2%, soil organic carbon storages by 52.2%, 75.9%, 87.0% , and 90.1%, and soil nitrogen storages by 43.5%, 71.0%, 81.3%, and 82.7%, respectively. The carbon and nitrogen storages in plant-soil system are in the order: potential (C: 5 266 g x m(-2) and N: 534 g m(-2)) >light (C: 2619 g x m(-2) and N: 303 g x m(-2)) >moderate (C: 1368 g x m(-2) and N: 156 g x m(-2)) >severe (C: 715 g x m(-2) and N: 99 g x m(-2))>most severe (C: 517 g x x m(-2) and N: 91 g x m(-2)). The biomass carbon and nitrogen storages decline more rapidly at later desertification stage (from severe to most-severe) than initial stage (from potential to light), while soil carbon and nitrogen decline more rapidly at initial stage. There is a greater proportional decline in soil carbon than in nitrogen during desertification process. The biomass nitrogen storages decline more rapidly than carbon at initial stage, however, the case is reverse at later stage.