Browsing by Subject "platelet"

The potential of extracellular vesicles (EVs) as diagnostic markers and drug delivery vehicles has been studied increasingly in recent years. One of the challenges in this field has been the isolation of EVs from complex biological fluids such as blood. The methods widely used for the isolation process include for example size exclusion chromatography (SEC) and ultracentrifugation (UC). As these methods use size and density of the particle, the have not been efficient enough in isolating EVs from certain particles such as lipoproteins. Due to the challenges related to these methods, other isolation methods have been sought to improve the efficiency of EV isolation. One of these methods is ion-exchange chromatography (IEC). From the two forms of IEC, anion-exchange chromatography has been studied more in EV isolation due to the negative net charge on EV particles. However, in this study the functionality and efficiency of cation-exchange chromatography (CEC) in EV isolation was studied as very little research has been done on this method. In this study, two CEC-resins were studied to define their applicability in EV isolation. A standard strong cation-exchange chromatographic resin SP Sepharose Fast Flow was compared to a strong tentacle-type resin. In addition to this, we studied the possibility to use a magnesium gradient to separate different forms of lipoproteins from EVs through dextran-sulfite precipitation. Tentacle-type CEC-resin was found to be more efficient in capturing EVs compared to the standard-type resin without magnesium. These EVs could then be eluted from the column with sodium chloride. The use of magnesium gradient allowed the separation of apolipoproteins in the samples. Higher concentrations of magnesium also reduced the number of lipoproteins in the samples altogether but resulted in the loss of EVs as well. These results were promising and showed that cation-exchange chromatography can be used in EV isolation. Tentacle-type resin seemed to be most efficient in removing impurities and capturing EVs. While more research is needed before these findings can be applied to clinical use, these results prove that cation-exchange chromatography can be used in EV isolation as a new, efficient and up scalable method.