Microfluidic method and system for isolating particles from biological fluid

• US 20110020459A1
• Filed: 05/13/2010
• Published: 01/27/2011
• Est. Priority Date: 05/14/2009
• Status: Active Grant

• Current Assignee: Genestream, Inc.
• Original Assignee: Genestream, Inc.
• Inventors: Sethu, Palaniappan, Achrol, Achal Singh
• Granted Patent: US 8,790,916 B2
• Time in Patent Office: Days
• US Class Current: 424/520
• CPC Class Codes: A61K 35/12 Materials from mammals; Compositions comprising non-specified tissues or cells; Compositions comprising non-embryonic stem cells; Genetically modified cells vaccines or medicinal preparations containing antigens or antibodies A61K39/00
• CPC Class Codes: A61K 35/14 Blood; Artificial blood perfluorocarbons A61K31/02; umbilical cord blood A61K35/51; haemoglobin A61K38/42
• CPC Class Codes: B01L 2200/0652 Sorting or classification of particles or molecules
• CPC Class Codes: B01L 2300/0883 Serpentine channels
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: B03C 2201/18 Magnetic separation whereby the particles are suspended in a liquid
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 27/745 for detecting magnetic beads used in biochemical assays concerning the assays G01N33/54326; sensors therefor G01R33/1269; automatic analysers therefor G01N35/0098
• CPC Class Codes: G01N 33/53 Immunoassay; Biospecific binding assay; Materials therefor
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 33/54333 Modification of conditions of immunological binding reaction, e.g. use of more than one type of particle, use of chemical agents to improve binding, choice of incubation time or application of magnetic field during binding reaction

Abstract

The invention relates to a system and method for isolating particles from a biological fluid, including: obtaining a sample of biological fluid from a source (e.g. a patient) in which the sample contains particles of multiple sample particle types; tagging particles in the sample with tagging agents, including mixing the sample with a solution of magnetic tagging agents that selectively bind to particles of at least one of the sample particle types, thereby forming a group of tagged particles in the sample; passing the sample through a magnetic conduit having a magnetic field that interacts with at least some of the tagged particles; sorting the particles of the sample into multiple groups based on the interaction between the tagged particles and the magnetic field; and optionally returning selected portions of the processed fluid back to its source with or without the addition of appropriate therapeutic agents.

Claims

1. A method for isolating particles from biological fluid of a patient, comprising the steps of:

obtaining a sample of biological fluid directly from a cannula coupled to the patient, wherein the sample contains particles of multiple sample particle types, each sample particle type being classified as a targeted particle or a non-targeted particle;

tagging particles in the sample with tagging agents, including mixing the sample with a solution of magnetic tagging agents that selectively bind to particles of at least one of the sample particle types, thereby forming a group of tagged particles and another group of untagged particles within the sample;

passing the sample through a magnetic conduit having a magnetic field that interacts with at least a portion of the tagged particles; and

sorting the particles of the sample into at least two groups based on the interaction between the tagged particles and the magnetic field.

2. The method of claim 1, wherein obtaining a sample of biological fluid includes obtaining a sample of at least one selected from the group consisting of:

blood, cerebrospinal fluid, and urine.

3. The method of claim 1, wherein mixing includes mixing the sample with a solution of tagging agents that selectively bind to at least one of the targeted particles.

4. The method of claim 1, wherein mixing includes selectively binding a magnetic bead functionalized with an antibody that is specific in its binding to at least one of the targeted particles.

5. The method of claim 1, wherein sorting the particles includes:

allowing at least some of the untagged particles to flow through a first outlet of the magnetic conduit, thereby forming a first group; and

diverting at least a first portion of the tagged particles to flow through a second outlet of the magnetic conduit, thereby forming a second group.

6. The method of claim 5, wherein sorting the particles further includes diverting at least a second portion of the tagged particles to flow through a third outlet of the magnetic conduit, thereby forming a third group.

7. The method of claim 6, wherein diverting the first portion of tagged particles includes diverting the first portion of tagged particles into a buffer stream separate from the sample.

8. The method of claim 6, wherein the steps of diverting the first and second portions of tagged particles are performed at substantially the same location along the magnetic conduit.

9. The method of claim 8, wherein diverting the first portion of the tagged particles includes allowing the magnetic field to repel the first portion of the tagged particles towards the second outlet, and diverting the second portion of the tagged particles includes allowing the magnetic field to attract the second portion of the tagged particles towards the third outlet.

10. The method of claim 6, wherein diverting the second portion of tagged particles is performed downstream of diverting the first portion of tagged particles.

11. The method of claim 1, wherein sorting the tagged particles includes:

allowing at least some of the untagged particles to flow through a first outlet of the magnetic conduit, thereby forming a first group; and

capturing at least a first portion of the tagged particles on a first surface of the magnetic conduit with magnetic force, thereby forming a second group.

12. The method of claim 11, wherein capturing the first portion of the tagged particles includes allowing the magnetic field to repel the first portion of the tagged particles toward the surface.

13. The method of claim 11, wherein capturing the first portion of the tagged particles includes allowing the magnetic field to attract the first portion of the tagged particles toward the surface.

14. The method of claim 11, wherein sorting the particles further includes capturing a second portion of the tagged particles on a second surface of the magnetic conduit with the magnetic field, thereby forming a third group.

15. The method of claim 14, wherein the steps of capturing the first and second portions of tagged particles are performed at substantially the same location along the magnetic conduit.

16. The method of claim 15, wherein capturing the first portion of tagged particles includes allowing the magnetic field to repel the first portion of the tagged particles towards the first surface and capturing the second portion of the tagged particles includes allowing the magnetic field to attract the second portion of the tagged particles towards the second surface.

17. The method of claim 14, wherein the step of capturing the second portion of tagged particles is performed downstream of capturing the first portion of tagged particles.

18. The method of claim 17, further comprising mixing with the sample a second solution of tagging agents that selectively bind to particles of at least one of the sample particle types, wherein mixing the second solution of tagging agents is performed downstream of mixing the first solution of tagging agents and upstream of capturing the second portion of tagged particles.

19. The method of claim 14, further comprising removing a first part of the magnetic field to release the first portion of tagged particles out of the conduit and removing a second part of the magnetic field to release the second portion of tagged particles out of the conduit.

20. The method of claim 19, wherein the step of removing a second part of the magnetic field is performed downstream of removing a first part of the magnetic field.

21. The method of claim 20, wherein the step of removing a second part of the magnetic field is performed before the step of removing a first part of the magnetic field.

22. The method of claim 1, further comprising mixing with the sample a second solution of tagging agents that selectively bind to particles of at least one of the sample particle types.

23. The method of claim 22, wherein mixing the second solution of tagging agents is performed downstream of mixing the first solution of tagging agents.

24. The method of claim 1, further comprising lysing at least some of the sample particles with a lytic solution that selectively lyses particles of at least one of the sample particle types and releasing intracellular particles.

25. The method of claim 24, further comprising repeating the steps of tagging, passing, and sorting, wherein in the repeated steps the particles are released intracellular particles.

26. The method of claim 1, further comprising capturing particles of at least one of the sample particle types, including passing the sample through a chamber having a surface with capture particles that selectively bind to and capture at least one of the sample particle types based on immunoaffinity between the capture particles and the sample particle types.

27. The method of claim 1, wherein at least some of the particles in the sample are cells having cell membranes, further comprising:

fixing the cell membranes of at least some of the cells in the sample with a fixation solution that rigidifies cell membranes in the sample; and

permeabilizing at least some of the fixed cell membranes with a permeabilization solution;

wherein the step of mixing includes binding a tagging agent to a type of intracellular particle.

28. The method of claim 27, wherein the step of mixing further includes binding another tagging agent to a type of extracellular particle.

29. The method of claim 1, further comprising recirculating at least a selected portion of the sample in the body of the patient.

30. The method of claim 1, further comprising enumerating at least one group of sorted particles.

31. The method of claim 30, further comprising administering a therapeutic agent to the patient based on the enumeration.

32. The method of claim 31, further comprising recirculating at least a selected portion of the sample in the body of the patient based on the enumeration, wherein the step of administering a therapeutic agent includes determining a selected amount of a therapeutic agent to administer to the patient and adding the selected amount of therapeutic agent to the recirculating portion of sample.

33. A microfluidic system for isolating particles from biological fluid of a patient, comprising:

a sampling module including a cannula coupled to the patient that obtains a sample of biological fluid from the patient, wherein the sample contains particles of multiple sample particle types;

a microfluidic tagging conduit, fluidly coupled to the sampling module at a point-of-care of the patient, having;

a first inlet that receives the sample;

a second inlet that receives a solution of magnetic tagging agents that selectively bind to and tag particles of at least one particle type; and

a textured surface that induces mixing of the particles and tagging agents; and

a microfluidic magnetic conduit, fluidly coupled to the tagging conduit and having at least one magnet providing a magnetic field that interacts with at least a portion of the tagged particles such that the particles in the sample are sorted into at least two groups based on the interaction between the tagged particles and the magnetic field.

34. The system of claim 33, wherein the textured surface of the tagging conduit includes herringbone structures.

35. The system of claim 33, wherein the tagging conduit is serpentine-shaped.

36. The system of claim 33, wherein the magnetic conduit includes a first outlet through which untagged particles flow to form a first group, and a surface, onto which the magnetic field captures at least a portion of the tagged particles to form a second group.

37. The system of claim 36, wherein the magnetic conduit includes a second surface onto which the magnetic field captures a second portion of the tagged particles to form a third group.

38. The system of claim 37, wherein the second surface is downstream of the first surface in the magnetic conduit.

39. The system of claim 33, wherein the magnetic conduit includes a first outlet through which untagged particles flow to form a first group, and a second outlet through which the magnetic field diverts a first portion of the tagged particles to form a second group.

40. The system of claim 39, wherein the second outlet is downstream of the first outlet.