Supra-Fluorophores: Ultrabright Fluorescent Supramolecular Assemblies Derived from Conventional Fluorophores in Water.

Fluorescent organic nanoparticles (NPs) with exceptional brightness hold significant promise for demanding fluorescence bioimaging applications. Although considerable efforts are invested in developing novel organic dyes with enhanced performance, augmenting the brightness of conventional fluorophores is still one of the biggest challenges to overcome. This study presents a supramolecular strategy for constructing ultrabright fluorescent nanoparticles in aqueous media (referred to as "Supra-fluorophores") derived from conventional fluorophores. To achieve this, this course has employed a cylindrical nanoparticle with a hydrophobic microdomain, assembled by a cyclic peptide-diblock copolymer conjugate in water, as a supramolecular scaffold. The noncovalent dispersion of fluorophore moieties within the hydrophobic microdomain of the scaffold effectively mitigates the undesired aggregation-caused quenching and fluorescence quenching by water, resulting in fluorescent NPs with high brightness. This strategy is applicable to a broad spectrum of fluorophore families, covering polyaromatic hydrocarbons, coumarins, boron-dipyrromethenes, cyanines, xanthenes, and squaraines. The resulting fluorescent NPs demonstrate high fluorescence quantum yield (>30%) and brightness per volume (as high as 12 060 m-1 cm-1 nm-3). Moreover, high-performance NPs with emission in the NIR region are constructed, showcasing up to 20-fold increase in both brightness and photostability. This Supra-fluorophore strategy offers a versatile and effective method for transforming existing fluorophores into ultrabright fluorescent NPs in aqueous environments, for applications such as bioimaging.

Rational design of NIR-II molecule-engineered nanoplatform for preoperative downstaging and imaging-guided surgery of orthotopic hepatic tumor.

Orthotopic advanced hepatic tumor resection without precise location and preoperative downstaging may cause clinical postoperative recurrence and metastasis. Early accurate monitoring and tumor size reduction based on the multifunctional diagnostic-therapeutic integration platform could improve real-time imaging-guided resection efficacy. Here, a Near-Infrared II/Photoacoustic Imaging/Magnetic Resonance Imaging (NIR-II/PAI/MRI) organic nanoplatform IRFEP-FA-DOTA-Gd (IFDG) is developed for integrated diagnosis and treatment of orthotopic hepatic tumor. The IFDG is designed rationally based on the core "S-D-A-D-S" NIR-II probe IRFEP modified with folic acid (FA) for active tumor targeting and Gd-DOTA agent for MR imaging. The IFDG exhibits several advantages, including efficient tumor tissue accumulation, good tumor margin imaging effect, and excellent photothermal conversion effect. Therefore, the IFDG could realize accurate long-term monitoring and photothermal therapy non-invasively of the hepatic tumor to reduce its size. Next, the complete resection of the hepatic tumor in situ lesions could be realized by the intraoperative real-time NIR-II imaging guidance. Notably, the preoperative downstaging strategy is confirmed to lower the postoperative recurrence rate of the liver cancer patients under middle and advanced stage effectively with fewer side effects. Overall, the designed nanoplatform demonstrates great potential as a diagnostic-therapeutic integration platform for precise imaging-guided surgical navigation of orthotopic hepatic tumors with a low recurrence rate after surgery, providing a paradigm for diagnosing and treating the advanced tumors in the future clinical translation application.

Supramolecular peptide nanotubes as artificial enzymes for catalysing ester hydrolysis.

Peptide-based artificial enzymes are attracting significant interest because of their remarkable resemblance in both composition and structure to native enzymes. Herein, we report the construction of histidine-containing cyclic peptide-based supramolecular polymeric nanotubes to function as artificial enzymes for ester hydrolysis. The optimized catalyst shows a ca. 70-fold increase in reaction rate compared to the un-catalysed reaction when using 4-nitrophenyl acetate as a model substrate. Furthermore, the amphiphilic nature of the supramolecular catalysts enables an enhanced catalytic activity towards hydrophobic substrates. By incorporating an internal hydrophobic region within the self-assembled polymeric nanotube, we achieve a 55.4-fold acceleration in hydrolysis rate towards a more hydrophobic substrate, 4-nitrophenyl butyrate. This study introduces supramolecular peptide nanotubes as an innovative class of supramolecular scaffolds for fabricating artificial enzymes with better structural and chemical stability, catalysing not only ester hydrolysis, but also a broader spectrum of catalytic reactions.

Molecular Self-Assembly and Supramolecular Chemistry of Cyclic Peptides.

This Review focuses on the establishment and development of self-assemblies governed by the supramolecular interactions between cyclic peptides. The Review first describes the type of cyclic peptides able to assemble into tubular structures to form supramolecular cyclic peptide nanotubes. A range of cyclic peptides have been identified to have such properties, including α-peptides, ß-peptides, α,γ-peptides, and peptides based on δ- and ε-amino acids. The Review covers the design and functionalization of these cyclic peptides and expands to a recent advance in the design and application of these materials through their conjugation to polymer chains to generate cyclic peptide-polymer conjugates nanostructures. The Review, then, concentrates on the challenges in characterizing these systems and presents an overview of the various analytical and characterization techniques used to date. This overview concludes with a critical survey of the various applications of the nanomaterials obtained from supramolecular cyclic peptide nanotubes, with a focus on biological and medical applications, ranging from ion channels and membrane insertion to antibacterial materials, anticancer drug delivery, gene delivery, and antiviral applications.

Rational synthesis of hollow cubic CuS@Spiky Au core-shell nanoparticles for enhanced photothermal and SERS effects.

Hollow cubic CuS@Spiky Au core-shell nanoparticles (NPs) were rationally synthesized both for guided highly efficient damage to cancer cells by the photothermal effect and for the real-time monitoring of biochemical responses during cellular apoptosis, totally based on label-free SERS intracellular imaging.

[Construction and selection of the most efficient siRNA interfering plasmid specific to mouse Qa-1 gene].

This study was purposed to construct three siRNA eukaryotic expression vector specific to mouse Qa-1 gene, to investigate its silencing effect on Qa-1 gene and to select the most efficient siRNA plasmid specific to mouse Qa-1 gene. Three siRNA peptides specific to mouse Qa-1 through siRNA Web design tools of Ambion company were chosed. Jingsai Company helped to complete the siRNA eukaryotic expression vector. The mouse NIH3T3 cells cultured in RPMI 1640 medium with 10% fetal bovine serum were divided into four groups: three groups of the cells were transfected with lipofectamine 2000 reagent and three different siRNA eukaryotic expression vectors, while one group cells were transfected with lipofectamine 2000 reagent alone as negative control. Cells were collected at 24, 48, 72 hours after transfection; the RNA level of Qa-1 was detected by RT-PCR, and the expression position was examined with flow cytometry analysis by using anti-Qa-1 monoclonal antibody. The results indicated that the constructed three siRNA eukaryotic expression vectors were found to be specific to mouse Qa-1 gene. The sequence analysis showed that the sequence was identical to what chosed from web tools. NIH3T3 cells in vitro were adhered in culture that cell shape appeared to change after transfection. RT-PCR and flow cytometry analysis by using anti-Qa-1 monoclonal antibody approved that both Qa-1 RNA and the expression of Qa-1 on cell surface decreased. The decreased levels in the three groups were different. At 24, 48 and 72 hours, the expression of Qa-1 on NIH3T3 cells decreased as in the following: H2-T231: 60.9%, 81.9%, 43.6%; H2-T232: 64.5%, 73.9%, 61.1%; H2-T233: 61.9%, 71.2%, 47.5%. H2-T232 was most efficient one in all three time points. It is concluded that all three siRNA eukaryotic expression vectors selected can successfully suppress the expression of the Qa-1, and from them H2-T232 is most efficient.