How different are the surfaces of semiconductor Ag2Se quantum dots with various sizes?

Dynamic Monitoring of Time-Dependent Evolution of Biomolecules Using Quantum Dots-Based Biosensors Assemblies

The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules that are part of cell membranes. Additionally, this paper describes and analyzes a quantum dots-based biosensor assembly, which is used to implement a fully functional color ECL visualization system that allows for cellular and biomolecular structures to be accurately visualized. The related nano-emitter allows the implementation of real-time bioimaging scenarios. Consequently, the proposed approach is thoroughly evaluated relative to the time-dependent evolution of biomolecules. It has been demonstrated that traditionally problematic structures, like the biomolecules that are part of cell membranes, can be studied and monitored relative to their time-dependent dynamic evolution using the proposed solution. The reported research process has been conducted in the realm of cooperation with a specialized biomedical engineering company, and the described results are expected to substantially support a better understanding of the biomolecules' time-dependent dynamic evolution.

Acid-Resistant Near-Infrared II Ag2Se Quantum Dots for Gastrointestinal Imaging

With the development of near-infrared II (NIR-II) fluorescence imaging, Ag2Se quantum dots (QDs) have become promising label candidates due to their negligible toxicity and narrow band gap. Despite their potential for gastrointestinal (GI) imaging, the application of Ag2Se QDs still presents significant challenges due to issues such as fluorescence extinction or poor stability in the complex digestive microenvironment. Herein, we have proposed a novel approach to the continuous production of Se precursors using glutathione (GSH) as the reductant under acidic conditions, realizing the continuous growth of water-dispersible Ag2Se QDs. The Ag2Se QDs emitting at 600-1100 nm have been successfully synthesized. Meanwhile, the silver-rich surface of the synthesized NIR-II Ag2Se QDs has been passivated well with the dense GSH, resulting in exceptional colloidal stability and photostability and endowing them with acid resistance. As a result, the obtained NIR-II Ag2Se QDs have exhibited remarkable stability in gastric acid, thus enabling their utilization for long-term real-time monitoring of GI peristalsis via NIR-II fluorescence imaging. Moreover, in contrast to conventional barium meal-based X-ray imaging, NIR-II fluorescence imaging with as-prepared NIR-II Ag2Se QDs can offer clearer visualization of fine intestinal structures, with a width as small as 1.07 mm. The developed strategy has offered a new opportunity for the synthesis of acid-resistant nanocrystals, and the acid-resistant, low-toxicity, and biocompatible NIR-II Ag2Se QDs synthesized in this work show a great promise for GI imaging and diagnosis of GI diseases in vivo.

Enhanced Proliferation of Visualizable Mesenchymal Stem Cell-Platelet Hybrid Cell for Versatile Intracerebral Hemorrhage Treatment

The intrinsic features and functions of platelets and mesenchymal stem cells (MSCs) indicate their great potential in the treatment of intracerebral hemorrhage (ICH). However, neither of them can completely overcome ICH because of the stealth process and the complex pathology of ICH. Here, we fabricate hybrid cells for versatile and highly efficient ICH therapy by fusing MSCs with platelets and loading with lysophosphatidic acid-modified PbS quantum dots (LPA-QDs). The obtained LPA-QDs@FCs (FCs = fusion cells) not only inherit the capabilities of both platelets and MSCs but also exhibit clearly enhanced proliferation activated by LPA. After systemic administration, many proliferating LPA-QDs@FCs rapidly accumulate in ICH areas for responding to the vascular damage and inflammation and then efficiently prevent both the primary and secondary injuries of ICH but with no obvious side effects. Moreover, the treatment process can be tracked by near-infrared II fluorescence imaging with highly spatiotemporal resolution, providing a promising solution for ICH therapy.