Avid Bioservices Inc (CDMO)

[biopharm]

the current techniques are particularly limited as they apply to tumor-derived extracellular microvesicle and exosomes. For example, the extra-corporeal removal of exosomes from the circulation of cancer patients has been proposed, in which patient's blood is pumped through a lectin-affinity column and then returned to the patient (U.S. Pat. No. 8,288,172). It has also been reported that tumor-derived exosomes can be purified using paramagnetic beads coated with antibodies against tumor-specific proteins such as HER2/neu (Koga et al., 2005). Kits using magnetic beads to capture specific exosomes are also available, such as Exo-Flow™ kits. In addition to the general drawbacks described above, such methods and kits are very limiting, requiring both advance knowledge of a particular exosome surface marker to be exploited in the antibody binding, as well as many detailed technical steps in the protocol, such as the preparation and use of biotinylated capture antibodies.

So a new patent and how many exosomes / surface markers are there?

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ExoCarta 2012: database of exosomal proteins, RNA and lipids

Exosomes are membraneous nanovesicles of endocytic origin released by most cell types from diverse organisms; they play a critical role in cell–cell communication. ExoCarta (www.exocarta.org) is a manually curated database of exosomal proteins, RNA and lipids. The database catalogs information from both published and unpublished exosomal studies. The mode of exosomal purification and characterization, the biophysical and molecular properties are listed in the database aiding biomedical scientists in assessing the quality of the exosomal preparation and the corresponding data obtained. Currently, ExoCarta (Version 3.1) contains information on 11?261 protein entries, 2375 mRNA entries and 764 miRNA entries that were obtained from 134 exosomal studies. In addition to the data update, as a new feature, lipids identified in exosomes are added to ExoCarta. We believe that this free web-based community resource will aid researchers in identifying molecular signatures (proteins/RNA/lipids) that are specific to certain tissue/cell type derived exosomes and trigger new exosomal studies.

INTRODUCTION

Exosomes are 40–100?nm diameter membrane vesicles of endocytic origin that are released by most cell types under normal and pathological conditions upon fusion of multivesicular bodies (MVBs) with the plasma membrane (PM) (1,2). Since the original observation of exosome secretion from reticulocytes (3,4), the release of these membrane particles in vitro into culture medium is reported in other cells (2,5–7). Exosomes have a cup shaped appearance as visioned by electron microscopy, a buoyant density in sucrose of 1.10–1.21?g/ml; and sediment at 100?000g. Exosomes harbor proteins/RNA/lipids that reflect the functionality of the host cell and posses molecular signatures or footprints resembling the diseased cell from which they were secreted (7). Recent studies have shown that exosomes can be isolated in vivo in bodily fluids such as blood (8), urine (9), breast milk (10), amniotic fluid (11), malignant ascites (12), bronchoalveolar lavage fluid (13) and synovial fluid (14). The accessibility of exosomes in bodily fluids makes them an ideal specimen for biomarker discovery.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3245025/

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