Showing 3 results for Ultracentrifugation
Najme Nikdel, Javad Baharara, Saeed Zakerbostanabad, Maryam Tehranipour,
Volume 8, Issue 1 (6-2021)
Abstract
Exosomes are secreted by different types of cells and known as biological packages. Exosomes have significant role in intercellular communications and involved in the development and progression of various diseases such as cancer. Inhibin B and anti-mullerian hormone (AMH) are markers of granulosa cell tumors (GCT) and due to the role of exosomes in the progression of cancer, in this experimental study, the effect of exosomes derived from human ovarian cancer cells on the secretion of Inhibin B and antimullerian hormone (AMH) by granulosa cells was investigated. First, A2780 human ovarian cancer cells were cultured, then the supernatant was collected to extract the exosomes by ultracentrifugation and subsequently, the extracted exosomes were checked out using dynamic light scattering (DLS) and Scanning electron microscopy (SEM). In addition, granulosa cells were isolated and cultured from the ovaries immature female Balb / C mice and treated with 25 μg/ml of exosomes derived from the ovarian cancer cell-line. Inhibin B and AMH hormones levels were then measured. The results showed the significant (P<0/05) increase of the level of inhibin B and AMH hormones in the treated cells in comparison with the control group. According to the results, exosomes increased the secretion of Inhibin B and AMH hormones and seems to be effective in the proliferation of granulosa cell tumors.
Mojtaba Cheravi, Javad Baharara, Parichehreh Yaghmaei, Nasim Hayati Roudbari,
Volume 8, Issue 4 (12-2021)
Abstract
Nowadays, researchers have made extensive efforts to find new treatments for nerve damage. Meanwhile, the role of exosomes in cell-cell communication is considered to be a new mechanism. Exosomes can act as suitable differentiating agents. The aim of this study was to investigate the differentiating effect of cerebrospinal fluid-derived exosomes on adipose mesenchymal stem cells in alginate hydrogel. Exosomes were extracted from the cerebrospinal fluid by ultracentrifugation and were then identified by atomic force microscopy (AFM), SEM and DLS technique. In addition, Adipose Mesenchymal Stem cells in alginate hydrogel were treated with different concentrations of exosomes. Cell survival was assessed by MTT and Acridine Orange/Ethidium Bromide methods. Cell differentiation was processed by immunocytochemistry and Real-Time PCR. Examinations confirmed the presence of exosomes with an approximate size of 70 nm. Cell survival results indicate that he ability of cells to survive and proliferate during 14 days. Also, the expression of MAP2 proteins (microtubule-associated protein 2) and Nestin (intermediate filament protein) was confirmed by immunocytochemistry. The results of Real Time - PCR showed that during the seventh and fourteenth days the expression level of MAP2 gene increased and the expression of Nestin gene showed a significant decrease compared to the control group. This study showed that exosomes extracted from cerebrospinal fluid can cause neuronal differentiation of Adipose mesenchymal stem cells in alginate hydrogel scaffolds.
Miss. Hanieh Ghandchi, Mrs. Reihaneh Ramezani, Mrs. Zahra Moosavinejad,
Volume 10, Issue 4 (12-2023)
Abstract
Recently, milk exosomes have attracted much attention from researchers due to their availability and efficiency in cosmetic products and also as drug delivery nanocarriers. Since it is very important to find a simple and efficient method to purify these vesicles, in this research some methods of exosome isolation from bovine milk such as ultracentrifugation, using PEG polymer and several commercial kits were discussed and characterized. Detection of exosomes has been done using DLS and electron microscopy.
In ultracentrifugation, as the most common method of exosome isolation, the number of particles in the electron microscope images was estimated to be very low (5 ± 2 particles), while in the microscopic images of the Exosun kit, a large number of exosomes (150 ± 30 particles) was visible. In PEG precipitation, the average diameter of the particles in DLS results was 263 nm and more than the ultracentrifugation, Exocib and Anaexo kit, where the diameter of the particles was 176 nm, 142 nm, and 123 nm, respectively. The average diameter of the particles in the microscopic images of the Exosun kit was 30-70±10 nm, and DLS results confirmed the small size of the isolated particles. Considering the large number of small particles (≥ 30nm) in the microscopic results of the exosun kit, other methods may not have been able to isolate these small particles. Finally, although all the studied methods were able to isolate exosome from milk, more extensive studies are necessary to make a more accurate comparison and to introduce a standard method for isolating exosome from bovine's milk.
