Metal-organic framework (MOF)/C-dots and covalent organic framework (COF)/C-dots hybrid nanocomposites: Fabrications and applications in sensing, medical, environmental, and energy sectors.

Developing new hybrid materials is critical for addressing the current needs of the world in various fields, such as energy, sensing, health, hygiene, and others. C-dots are a member of the carbon nanomaterial family with numerous applications. Aggregation is one of the barriers to the performance of C-dots, which causes luminescence quenching, surface area decreases, etc. To improve the performance of C-dots, numerous matrices including metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and polymers have been composited with C-dots. The porous crystalline structures, which are constituents of metal nodes and organic linkers (MOFs) or covalently attached organic units (COFs) provide privileged features such as high specific surface area, tunable structures, and pore diameters, modifiable surface, high thermal, mechanical, and chemical stabilities. Also, the MOFs and COFs protect the C-dots from the environment. Therefore, MOF/C-dots and COF/C-dots composites combine their features while retaining topological properties and improving performances. In this review, we first compare MOFs with COFs as matrices for C-dots. Then, the recent progress in developing hybrid MOFs/C-dots and COFs/C-dots composites has been discussed and their applications in various fields have been explained briefly.

Polysaccharide-based C-dots and polysaccharide/C-dot nanocomposites: fabrication strategies and applications.

C-dots are a new class of materials with vast applications. The synthesis of bio-based C-dots has attracted increasing attention in recent years. Polysaccharides being the most abundant natural materials with high biodegradability and no toxicity have been the focus of researchers for the synthesis of C-dots. C-dots obtained from polysaccharides are generally fabricated via thermal procedures, carbonization, and microwave pyrolysis. Small size, photo-induced electron transfer (PET), and highly adjustable luminosity behavior are the most important physical and chemical properties of C-dots. However, C-dot/polysaccharide composites can be introduced as a new generation of composites that combine the features of both C-dots and polysaccharides having a wide range of applications in biomedicines, biosensors, drug delivery systems, etc. This review demonstrates the features, raw materials, and methods used for the fabrication of C-dots derived from different polysaccharides. Furthermore, the properties, applications, and synthesis conditions of various C-dot/polysaccharide composites are discussed in detail.

Piperine from Black Pepper Decreased the Expression of Intercellular Adhesion Molecule-1 in Macrophages.

BACKGROUND: Macrophages are the main players involved in inflammation. Intercellular adhesion molecule-1 (ICAM-1) facilitates macrophage polarization prior to extravasation into inflamed tissue. Piperine, a natural product derived from black pepper, possesses useful biological and pharmacological activities. In the current study, the possible anti-inflammatory effect of piperine on the expression of ICAM-1 on J774.1 murine macrophage cell line was investigated. METHODS: Lipopolysaccharide (LPS)-stimulated J774.1 cells were cultured in the presence of different concentrations of piperine to examine the changes in ICAM-1 expression by real-time PCR and flow cytometry. RESULTS: We found that piperine decreased ICAM-1 gene expression level from 2.4 ± 0.25 RFC (relative fold change) in LPS-only treated cells to 0.85 ± 0.525 RFC at 1µg/ml (p<0.05), 0.43 ± 0.27 RFC at 10µg/ml (p<0.01), and 0.26 ± 0.25 RFC at 20µg/ml (p<0.01). In flow cytometry, piperine at all concentrations significantly decreased ICAM-1 surface expressions (P<0.05). The geometric mean fluorescence intensity (g-MFI) in LPS-only treated cells (792 ± 57.3) decreased to 482±70 g-MFI at 20 µg/ml piperine. CONCLUSION: According to the results of this study, by decreasing the expression of ICAM-1, piperine has been suggested to reduce inflammation and have the potential to provide therapeutic benefits for immune-mediated diseases.

Therapeutic Efficacy of Mesenchymal Stem Cells and Mesenchymal Stem Cells-derived Neural Progenitors in Experimental Autoimmune Encephalomyelitis.

BACKGROUND AND OBJECTIVES: The goal of treatment for MS is to reduce the inflammation and induce the regeneration of degenerated axons. Considering the anti-inflammatory and regenerative capacity of mesenchymal stem cell (MSCs), in this study the therapeutic efficacy of allogeneic MSCs and MSCs-derived neural progenitor cells (MSCs-NPs) was investigated in cellular therapy of chronic experimental autoimmune encephalomyelitis (EAE). METHODS AND RESULTS: MSCs, MSCs-NPs and MSCs＋MSCs-NP were administered intravenously to EAE mice on days 22, 29, and 36 post immunization. The levels of cytokines and PGE2 in sera or supernatant of in vitro cultured splenocytes derived from treated mice were measured by ELISA. The results of this study showed that in comparison to MSCs monotherapy, MSCs-NPs administration had a more profound capability of inhibiting the proliferation of pathogenic MOG35₋55-specific T cells, decreasing IFN-γ production and increasing anti-inflammatory IL-10 cytokine production. These findings could be explained by higher ability of in vitro cultured MSCs-NPs in production of PGE2 compared to MSCs. In line with these findings, while the administration of MSCs and MSCs-NPs significantly decreased the clinical scores of EAE in comparison with the untreated EAE group, MSCs-NPs were significantly more efficient in reducing clinical score compared to MSCs. Of interest, combined therapy with MSCs and MSCs-NPs did not provide any benefit over monotherapy with MSCs-NPs. CONCLUSIONS: In comparison to MSCs, allogenic MSCs-NPs are more potent in the attenuation of EAE.