Summary: Exosomes are extracellular vesicles released by the vast majority of cell types both in vivo and ex vivo, upon the fusion of multivesicular bodies (MVBs) with the cellular plasma membrane. Two main functions have been attributed to exosomes: their capacity to transport proteins, lipids and nucleic acids between cells and organs, as well as their potential to act as natural intercellular communicators in normal biological processes and in pathologies. From a clinical perspective, the majority of applications use exosomes as biomarkers of disease. A new approach uses exosomes as biologically active carriers to provide a platform for the enhanced delivery of cargo in vivo. One of the major limitations in developing exosome-based therapies is the difficulty of producing sufficient amounts of safe and efficient exosomes. The identification of potential proteins involved in exosome biogenesis is expected to directly cause a deliberate increase in exosome production. In this review, we summarize the current state of knowledge regarding exosomes, with particular emphasis on their structural features, biosynthesis pathways, production techniques and potential clinical applications.

Exosomes are lipid bilayer particles released from cells into their surrounding environment. These vesicles are mediators of near and long-distance intercellular communication and affect various aspects of cell biology. In addition to their biological function, they play an increasingly important role both in diagnosis and as therapeutic agents. In this paper, we review recent literature related to the molecular composition of exosomes, paying special attention to their role in pathogenesis, along with their application as biomarkers and as therapeutic tools. In this context, we analyze the potential use of exosomes in biomedicine, as well as the limitations that preclude their wider application.

A series of diclofenac N-derivatives (2, 4, 6, 8c, 9c, 10a-c) were synthesized in order to test their anti-cancer and anti-inflammatory effects. The anticarcinogen activity has been assayed against three cancer cell lines: HT29, human colon cancer cells; Hep-G2, human hepatic cells; and B16-F10, murine melanoma cells. First, we determined the cytotoxicity of the different compounds, finding that the most effective compound was compound 8c against all cell lines and both compounds 4 and 6 in human Hep-G2 and HT29 cell lines. Compounds 4 and 8c were selected for the percentage of apoptosis determination, cell cycle distribution, and mitochondrial membrane potential measure because these products presented the lowest IC50 values in two of the three cancer cell lines assayed (B16-F10 and HepG2), and were two of the three products with lowest IC50 in HT29 cell line. Moreover, the percentages of apoptosis induction were determined for compounds 4 and 8c, showing that the highest values were between 30 to 60%. Next, the effects of these two compounds were observed on the cellular cycle, resulting in an increase in the cell population in G2/M cell cycle phase after treatment with product 8c, whereas compound 4 increased the cells in phase G0/G1, by possible differentiation process induction. Finally, to determine the possible apoptosis mechanism triggered by these compounds, mitochondrial potential was evaluated, indicating the possible activation of extrinsic apoptotic mechanism. On the other hand, we studied the anti-inflammatory effects of these diclofenac (DCF) derivatives on lipopolysaccharide (LPS) activated RAW 264.7 macrophages-monocytes murine cells by inhibition of nitric oxide (NO) production. As a first step, we determined the cytotoxicity of the synthesized compounds, as well as DCF, against these cells. Then, sub-cytotoxic concentrations were used to determine NO release at different incubation times. The greatest anti-inflammatory effect was observed for products 2, 4, 8c, 10a, 10b, and 9c at 20 µg·mL−1 concentration after 48 h of treatment, with inhibition of produced NO between 60 to 75%, and a concentration that reduces to the 50% the production of NO (IC50 NO) between 2.5 to 25 times lower than that of DCF. In this work, we synthesized and determined for the first time the anti-cancer and anti-inflammatory potential of eight diclofenac N-derivatives. In agreement with the recent evidences suggesting that inflammation may contribute to all states of tumorigenesis, the development of these new derivatives capable of inducing apoptosis and anti-inflammatory effects at very low concentrations represent new effective therapeutic strategies against these diseases.