Methods and systems for cell labeling and imaging
The present disclosure provides methods and systems for cell processing, including delivery of imaging agents into cells. The methods and systems may comprise the use of a microfluidic device. The microfluidic device may comprise a channel comprising a compressive element. The compressive element may be configured to reduce a volume of the cell and facilitate the formation of one or more transient pores in a cell membrane of the cell. The one or more pores may permit one or more imaging agents to enter the cell. Also provided are modified cells produced using the disclosed methods and systems and methods of imaging the modified cells in a subject.
1 . A method for delivering a substance into a cell, comprising:
(a) providing a microfluidic device, wherein:
the microfluidic device comprises a channel that comprises a first wall comprising a first interior surface and a second wall comprising a second interior surface,
the first wall and the second wall extend along a flow direction,
the microfluidic device comprises a compressive element comprising a plurality of ridges connected to the first wall and extending towards the second interior surface,
each of the plurality of ridges comprises a ridge surface that forms a gap with the second interior surface,
each of the plurality of ridges comprises a material having a modulus from 1 to 100 kPa,
each of the plurality of ridges has a rectangular cross-sectional profile in a plane perpendicular to the first interior surface, and
the microfluidic device comprises a fluid within the microfluidic device, wherein the fluid comprises the cell and the substance, and wherein the substance is an imaging agent;
and
(b) subjecting the fluid to flow through the channel in contact with the compressive element, wherein:
a height of the gap is smaller than a diameter of the cell, causing the cell to compress as the cell passes through the gap, and
the contact causes formation of at least one pore in a membrane of the cell, wherein the at least one pore enables an entry of the substance into the cell.
2 . The method of claim 1 , wherein the cell is an animal cell.
3 . The method of claim 1 , wherein the gap between the ridge surface and the second interior surface of the channel is between about 2 μm and about 15 μm.
4 . The method of claim 1 , wherein the cell has a cell diameter, and wherein a gap between the compressive element and an interior surface of the channel is less than or equal to about 20% of the cell diameter.
5 . The method of claim 1 , wherein each of the plurality of ridges has a width of between 15 μm and 250 μm.
6 . The method of claim 1 , wherein the fluid flows through the channel at a rate of from about 100 μL/min to about 1,000 μL/min.
7 . The method of claim 1 , wherein the cell has a volume, and wherein the compressive element is configured to reduce the volume of the cell.
8 . The method of claim 1 , wherein the channel is defined by at least a first wall and a second wall, wherein the first wall and the second wall are substantially rigid.
9 . The method of claim 8 , wherein the first wall comprises a flexible material and a bracing material, and wherein the bracing material is positioned on an exterior surface of the first wall.
10 . The method of claim 8 , wherein the first wall or the second wall is prepared by injection molding.
11 . The method of claim 1 , wherein the channel does not comprise a diversion channel.
12 . The method of claim 11 , wherein the channel is defined by at least a first wall and a second wall, wherein the first wall and the second wall are substantially rigid.
13 . The method of claim 1 , wherein the microfluidic device comprises a sorting element.
14 . The method of claim 1 , wherein the imaging agent is a nanoparticle.
15 . The method of claim 1 , wherein the imaging agent is a magnetic imaging agent.
16 . The method of claim 1 , wherein surface roughness of the ridge surface may be configured to increase cell membrane poration.
17 . The method of claim 1 , wherein the microfluidic device further comprises a recovery space positioned between an adjacent pair of the plurality of ridges.
18 . The method of claim 17 , wherein the recovery space extends between the first wall and the second wall and has a height that is greater than the height of the gap.
19 . The method of claim 17 , wherein the recovery space extends between the first wall and the second wall and has a height that is greater than the diameter.
20 . The method of claim 17 , wherein the recovery space has a length, measured between the adjacent pair of the plurality of ridges, of between 200 μm and 500 μm.