Latest ArticlesMultifunctional bismuth sulfide (Bi2S3) nanomaterials exhibit significant potential as nanomedicines for the diagnosis and treatment of cancer. These nanomaterials act as excellent photothermal agents and radiation sensitizers for the treatment of tumors, and they can also act as contrast agents for computed tomography (CT) imaging, photoacoustic imaging (PA), and other forms of imaging to provide real-time tumor monitoring and testing guidance. Compared with other nanomaterials, Bi2S3 nanomaterials can readily adapt to different applications by virtue of the fact that they can be easily functionalized. However, these nanomaterials have some limitations that cannot be ignored and need to be addressed, such as poor biocompatibility, toxicity, and low chemical stability. It is widely believed that appropriate functionalization of Bi2S3 nanomaterials could remedy such defects and significantly improve performance. This review summarizes the ways in which Bi2S3 nanomaterials can be functionalized and discusses their applications in cancer theranostics over the last few years, focusing particularly on imaging and therapy. We also discuss issues relating to how Bi2S3 nanomaterials can be analyzed, including how we might be able to use these systems to inhibit and treat tumors and how current limitations might be overcome to improve treatment efficacy. Finally, we hope to provide inspiration and guidance as to how we might create a more optimized multifunctional nano-system for the diagnosis and treatment of tumors.
As a potential photochromic system, acylhydrazones exhibit many outstanding advantages including low cost, simple synthesis and high modifiability compared with some classic photochromic systems. However, the absorption wavelengths of acylhydrazones usually locate in ultraviolet region, which makes the band separation between the absorbance maxima of its irradiated and unirradiated forms cannot be observed by naked eyes and greatly limits their practical applications. In this work, a simple strategy for constructing acylhydrazone photochromic system with visible color/emission change is provided. Rhodamine 6G hydrazine-2-aldehyde-pyridine Schiff base (compound 3) is designed and synthesized by combining acylhydrazone with Rhodamine 6G structure. The introduction of Rhodamine 6G moiety to 3 not only makes it remain all the advantages of acylhydrazone photochromic system but also exhibits visible photo-induced color/emission changes both in solution and in a solid matrix. Moreover, 3 exhibits reversible photochromic property with good fatigue resistance, which makes it an excellent candidate for photo-patterning.
A novel upper-rim functionalized calix[4]squaramide organocatalyst bearing bis-squaramide and cyclohexanediamine scaffolds was designed and prepared to catalyse a serial of asymmetric Michael addition of 1, 3-dicarbonyl compounds to α, β-unsaturated carbonyl compounds in high yields (up to 99 %) and good to excellent enantiomeric excesses (up to 99% ee). The comparative experiments indicated that the cooperative effect between calixarenes cavitives and chiral catalytic centers on this calix[4]squaramide catalyst could promote these reactions. Moreover, this strategy also provides valuable and easy access to chiral chromene, naphthoquinone and acetylacetone derivatives, which are important skeletons in biological and pharmaceutical compounds.
An energy-saving and eco-friendly method for the efficient construction of various tri- and tetra-substituted pyrrolecarbonitriles through ultrasound-assisted multicomponent tandem reaction of readily available alkenes, TMSCN and N, N-disubstituted formamides within 40 min under metal-, solvent-free and mild conditions was developed. The dual role of iodine (catalyst and oxidant) notably simplified the reaction conditions and reduced the chemical waste generated.
Angiogenesis occurs during the process of tumor growth, invasion and metastasis, and is essential for the survival of solid tumors. As an integrin significantly overexpressed in human tumor vascular endothelial cells, αvβ3 is a suitable targeting site for anti-angiogenesis of tumor. We designed and prepared a selfassembling peptide (SAP) with the ability to targeting αvβ3 and self-assembly. SAP formed nanoparticles in solution and transformed into nanofibrous network once specifically binding to integrin αvβ3 on the surface of human umbilical vein endothelial cells (HUVECs). The SAP network stably anchored on HUVECs over 24 h, which consequently resulted in high-efficient inhibition of vascularization. In vitro anti-angiogenesis experiment displayed that the inhibition rate of tube-formation reached 94.9%. In vivo anti-angiogenesis array based on chick chorioallantoic membrane (CAM) model exhibited that the SAP had an inhibition rate up to 63.1%. These results indicated the outstanding anti-angiogenic ability of SAP, potentially for tumor therapy.
Chemo-photothermal treatment is one of the most efficient strategies for cancer therapy. However, traditional drug carriers without near-infrared absorption capacity need to be loaded with materials behaving photothermal properties, as it results in complicated synthesis process, inefficient photothermal effects and hindered NIR-mediated drug release. Herein we report a facile synthesis of a polyethylene glycol (PEG) linked liposome (PEG-liposomes) coated doxorubicin (DOX)-loaded ordered mesoporous carbon (OMC) nanocomponents (PEG-LIP@OMC/DOX) by simply sonicating DOX and OMC in PEG-liposomes suspensions. The as-obtained PEG-LIP@OMC/DOX exhibits a nanoscale size (600±15 nm), a negative surface potential (-36.70 mV), high drug loading (131.590 mg/g OMC), and excellent photothermal properties. The PEG-LIP@OMC/DOX can deliver loaded DOX to human MCF-7 breast cancer cells (MCF-7) and the cell toxicity viability shows that DOX unloaded PEG-LIP@OMC has no cytotoxicity, confirming the PEG-LIP@OMC itself has excellent biocompatibility. The NIR-triggered release studies demonstrate that this NIR-responsive drug delivery system enables on-demand drug release. Furthermore, cell viability results using human MCF-7 cells demonstrated that the combination of NIR-based hyperthermal therapy and triggered chemotherapy can provide higher therapeutic efficacy than respective monotherapies. With these excellent features, we believe that this phospholipid coating based multifunctional delivery system strategy should promote the application of OMC in nanomedical applications.
As balanced electron-rich P, C-chelating ligands, phosphine-phosphonium-ylides are considered for their ability to in situ promote palladium-catalysed direct C(sp2)-H arylation. Using methyl phosphonium salts of 2, 2'-bis(diphenylphosphino)-1, 1'-binaphtyl ("methyl-BINAPIUM") as ylide precursors under optimized reaction conditions, arylation of benzoxazole was found to proceed in moderate to high yield to give functional 2-aryl benzoxazoles. A strong anion effect of the non-salt free ylide was evidenced (TfO- > I- > PF6- ≈ salt-free). This first example of phosphonium ylides as ligands in catalytic C-H activation extends the prospect of their general implementation in homogeneous transition metal catalysis.
In this work, polymethacrylic acid (PMAA)-templated silver nanoclusters (Ag NCs) were developed as the fluorescent probe for the efficient and sensitive detection of adenosine triphosphate (ATP) in a wide range of pH values. The fluorescence intensity of the Ag NCs could keep stable with pH values ranging from 2.5 to 9.3. The detection of ATP was based on the quenching of the fluorescent Ag NCs in the presence of ATP. The fluorescence quenching of the Ag NCs with increasing ATP concentration was studied at pH 2.5, 4.5, 7.0 and 8.5 which involved a wide pH environment in body fluids. The limit of detection (LOD) for ATP was as low as 0.1 mmol/L in an acidic environment with pH of 2.5 and all the linear correlation coefficients were satisfactory under wide-span pH values from 2.5 to 8.5. In addition, the sensitive determination of ATP was also achieved by adding copper ions (Cu2+). The high selectivity and rapid detection process proved that the fluorescent probe had great potential to detect ATP in biological samples under different pH conditions.
A new copper-thiolate cluster assembled framework [Cu2(μ4-SCH3)Cl]n (1), has been solvothermally synthesized through in situ reaction viz., in situ ligand generation and metal reduction. Compound 1 represents the first 3D framework based on Atlas-sphere functionalized by single μ2-Cl- groups. DOS calculation reveals the interaction of electronic structures. It is found that the HOMO is mainly distributed on Cl, Cu and S bonding orbitals, while the LUMO is dominated by Cu-Cl antibonding orbitals.
Peptide self-assembled nanomaterials have attracted more and more attention due to their wide applications such as drug delivery, cell imaging, and real-time drug monitoring. However, the application of the peptide is still limited by its inherent optical properties. Here we proposed and prepared a series of fluorescent tripeptide nanoparticles (TPNPs) through π-π stacking and zinc coordination. The experimental results show that the nanoparticles (TPNPs1) formed by the self-assembly of the tripeptide tryptophan-tryptophan-tryptophan have the highest fluorescence intensity, uniform and appropriate size, and low cytotoxicity. Furthermore, there was fluorescence resonance between TPNPs1 and doxorubicin, which has been successfully applied for real-time cell imaging and drug release monitoring.