Peptide-Directed Synthesis of Aggregation-Induced Emission Enhancement-Active Gold Nanoclusters for Single- and Two-Photon Imaging of Lysosome and Expressed αvß3 Integrin Receptors.

This study explores the synthesis and characterization of aggregation-induced emission enhancement (AIEE)-active gold nanoclusters (AuNCs), focusing on their near-infrared luminescence properties and potential applications in biological imaging. These AIEE-active AuNCs were synthesized via the NaBH4-mediated reduction of HAuCl4 in the presence of peptides. We systematically investigated the influence of the peptide sequence on the optical features of the AuNCs, highlighting the role of glutamic acid in enhancing their quantum yield (QY). Among the synthesized peptide-stabilized AuNCs, EECEE-stabilized AuNCs exhibited the maximum QY and a pronounced AIEE effect at pH 5.0, making them suitable for the luminescence imaging of intracellular lysosomes. The AIEE characteristic of the EECEE-stabilized AuNCs was demonstrated through examinations using transmission electron microscopy, dynamic light scattering, zeta potential analysis, and single-particle imaging. The formation of the EECEE-stabilized AuNCs was confirmed by size-exclusion chromatography and mass spectrometry. Spectroscopic and electrochemical examinations uncover the formation process of EECEE-stabilized AuNCs, comprising EECEE-mediated reduction, NaBH4-induced nucleation, complex aggregation, and subsequent cluster growth. Furthermore, we demonstrated the utility of these AuNCs as luminescent probes for intracellular lysosomal imaging, leveraging their pH-responsive AIEE behavior. Additionally, cyclic arginylglycylaspartic acid (RGD)-modified AIEE dots, derived from cyclic RGD-linked peptide-induced aggregation of EECEE-stabilized AuNCs, were developed for single- and two-photon luminescence imaging of αvß3 integrin receptor-positive cancer cells.

Aptamer-based flares hybridized with single-stranded DNA-conjugated MoS2 nanosheets for ratiometric fluorescence sensing and imaging of potassium ions and adenosine triphosphate in human fluids and living cells.

Addressing the limitations observed in previous studies, where the quantitative range of nanoprobes for detecting K+ and adenosine triphosphate (ATP) did not cover concentrations found within living cells, the present study aimed to develop ratiometric nanoprobes that can accurately sense changes in K+ and ATP levels in living cells and quantify them in human fluids. The proposed nanoprobes consisted of recognition flares modified with 6-carboxyfluorescein (FAM) and 5-carboxytetramethylrhodamine (TAMRA), along with thiolate single-stranded DNA (ssDNA) and molybdenum disulfide nanosheets (MoS2 NSs). The thiolate ssDNA acts as a linker between the flares and the MoS2 NSs, directly forming a functional nanostructure at room temperature. The direct conjugation of labeled flares to the MoS2 NSs simplifies the fabrication process. In the absence of K+ and ATP, the hybridization of flares and thiolate ssDNA caused FAM to move away from TAMRA, suppressing the fluorescence resonance energy transfer (FRET) process. However, upon the introduction of K+ and ATP, the flares undergo a structural transformation via the formation of G-quadruplex formation and the generation of hairpin-shaped structures, respectively. This structural change leads to the release of the flares from the ssDNA-conjugated nanosheet surface. The release of the flares brings FAM and TAMRA into close proximity, allowing FRET to occur, leading to FRET and static quenching. By monitoring the ratio between the fluorescence intensities of FAM and TAMRA, the concentration of K+ (5-100 mM) and ATP (0.3-5 mM) can be accurately determined by the proposed nanoprobes. The advantages of these nanoprobes lie in their ability to provide ratiometric measurements, which enhance the accuracy and reliability of the quantification process. The proposed nanoprobes offer potential applications as ratiometric imaging probes for monitoring K+ and ATP-related reactions in living cells, providing valuable insights into cellular processes. Additionally, they can be employed for determining the levels of K+ and ATP in human fluids, offering potential diagnostic applications in various clinical settings.

Efficacy of natural products in preventing oral mucositis resulting from cancer therapies: A network meta-analysis of randomized controlled trials.

BACKGROUND: Oral mucositis significantly compromises the quality of life for patients undergoing cancer therapies. This study aimed to evaluate the effectiveness of natural products in either preventing or alleviating oral mucositis resulting from cancer treatments. METHODS: A systematic review and network meta-analysis were conducted, sourcing data from the Cochrane Library, PubMed, Embase, Airiti Library, and Wan Fang Data Knowledge Service Platform until August 2023. The study was registered in PROSPERO (CRD42021285433). Confidence in Network Meta-Analysis (CINeMA) and R software 4.1.3 were used for analysis. RESULTS: From 1556 identified articles, 36 randomized controlled trials (RCTs) were analyzed, involving 2083 patients. Honey, notably, was found to significantly reduce the overall incidence of oral mucositis compared to standard care, with a relative risk (RR) of 0.80 (95% CI: 0.67-0.96). It was particularly effective against moderate-to-severe oral mucositis (grade ≥ 2), reducing incidence with RR of 0.48 (95% CI: 0.30-0.75) versus placebo and 0.56 (95% CI: 0.34-0.93) against standard care. Other natural products, including propolis, chamomile, and P. major L., also demonstrated significant efficacy in reducing the incidence of oral mucositis. Regarding pain relief, honey, and P. major L. emerged as effective, significantly reducing pain severity with a mean difference (MD) of -2.96 (95% CI: -3.80 to -1.94) compared to placebo. CONCUSSION: This network meta-analysis supports the use of honey, propolis, chamomile, and P. major L. as effective natural products in the prevention and treatment of oral mucositis among cancer patients. Specifically, honey is highlighted for its significant impact on reducing both the overall incidence and the severity of moderate-to-severe oral mucositis. By leveraging their anti-inflammatory and antioxidant properties, integrating these natural products into the standard care regimen could markedly improve the well-being of individuals undergoing cancer therapy.