Why EVs Important 

​EVs contain a wide variety of macromolecular structures on their surface and within, including lipids such as flotillin, sphingomyelin, and cholesterol, and nucleic acids in the form of cell-free DNA, mitochondrial DNA, proteins, and various RNAs in the form of mRNA, miRNA, small non-coding RNA, structural RNA, and tRNA fragments. As such, EVs represent a unique heterogeneous mixture of biological moieties that contribute to the repertoire of molecules within the tumor microenvironment.

 

Why interstitial fluid extracellular vesicles?

Interstitial fluid is the plasma filtrate that surrounds and fills the space between and among cells of all tissues. It is constantly being produced at the level of the pre-capillary venule and capillaries. Interstitial fluid drains into the local lymphatic vasculature to become lymph.

 

Tumor tissue is known to have a higher level of interstitial pressure than normal tissue. The interstitial fluid and its contents such as extracellular vesicles, enters the lymphatic system and presents the main communication channel between the tumor and sentinel draining lymph node. This communication channel is known to facilitate immune evasion of the tumor or sensitization of the host immune system to recognize the tumor.

 

Tumor EVs are typically analyzed within blood plasma. However, EVs derived from tumors must go through an obstacle course of cellular barriers to get from the tumor to the blood stream. Therefore, the tumor EVs within the blood stream only represent a small component of the EVs directly made at the tumor source. Interstitial fluid EVs from the tissue are a direct snapshot of the tumor and microenvironment host cells.  

 

Previous studies have shown that interstitial fluid can be isolated from tumor tissue at a speed that does not disrupt the tissue or cellular morphology. However, these previous methods were applied to soluble components of the tumor tissue fluid, not extracellular vesicles. The present kit is optimized to prevent the binding of extracellular vesicle to the filtration matrix and enter the collection chamber. This maximizes the yield and partially purifies the EV component within the interstitial fluid.

 

The importance of the tumor microenvironment.

 

Tumor microenvironment is a population of interacting cells from the host and tumor. The tumor is heterogenous mixture of cell types from the cancer and from the host including tumor cells, suppressor cells, immune killing clls, blood vessels, lymphatics, stromal cells all communicating back and forth. the outcome of the communication can determine if the tumor grows or regresses. The tumor microenvironment can grow rapidly during exogenous, drug development, as the tumor progresses from pre-invasive, invasive, and metastatic.