Scalable high-throughput isoelectric fractionation platform for extracellular nanocarriers

A system for continuous isoelectric fractionation and isolation of a plurality of extracellular RNA (exRNA) nanocarriers with high resolution, the system comprising:

• a microfluidic device comprising:
• a plurality of chips formed from one or more materials comprising one or more of polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), polyimide (PI), or polyethersulphone (PES), the plurality of chips comprising:
• a first chip comprising:
• a water inlet;
• an ion-exchange membrane-based bipolar junction configured to dissociate water into H3O+ and OH− ions, the bipolar junction comprising one or more cation exchange membranes and one or more anion exchange membranes, a positive electrode, and a negative electrode, wherein each of the one or more cation exchange membranes and the one or more anion exchange membranes has a thickness of about 500 μm to about 600 μm;
• a first chip microchannel capillary network positioned downstream of the ion-exchange membrane-based bipolar junction and configured to partition the H3O+ and OH− ions;
• a first chip chamber comprising a trapezoidal-shaped geometry and configured to generate an initial coarse pH gradient running transverse to a fluid flow, wherein the first chip microchannel capillary network is connected to the first chip chamber through a first chip microchannel capillary network outlet and a first chip chamber inlet at an angle of about 45°, and wherein the initial coarse pH gradient is from about pH 0.5 to about 13.5;
• and
• one or more first chip outlets, fluidly connected to one or more subsequent separation chips via a separation chip inlet;
• and
• one or more subsequent separation chips comprising:
• one or more separation chip inlets fluidly connected to the one or more first chip outlets;
• a sample inlet fluidly connected to a separation chip chamber, the sample inlet being configured to load a biological sample containing the plurality of exRNA nanocarriers;
• the separation chip chamber fluidly connected to the one or more separation chip inlets and the sample inlet, the separation chip chamber comprising a trapezoidal-shaped geometry configured to generate a fine pH gradient running transverse to the fluid flow, wherein the fine pH gradient comprises a pH gradient encompassing a pH range between any two pH values from about 0.5 to about 13.5;
• a separation chip microchannel capillary network positioned downstream of the one or more separation chip inlets, fluidly connecting the one or more separation chip inlets and the separation chip chamber, and configured to partition the H3O+ and OH− ions;
• a positive electrode and a negative electrode configured to apply a current across the separation chip chamber;
• and
• one or more separation chip outlets, wherein the plurality of exRNA nanocarriers are fractionated into different separation chip outlets based on the specific isoelectric points of the plurality of exRNA nanocarriers;
• and
• fluid connections between the one or more first chip outlets and the one or more separation chip inlets for the transfer of select subset pH zones from the first chip to the one or more subsequent separation chips, wherein the fluid connections comprise silicone tubing, and wherein the select subset pH zones transferred from the first chip to the one or more subsequent separation chips are based on the specific isoelectric points of the plurality of exRNA nanocarriers;
• a voltage source configured to apply a voltage (V) of about 20 V to about 220 V to the microfluidic device;
• and
• a pump connected to the microfluidic device for inducing the fluid flow.