# US 12,005,448 B2 · Systems and methods of using anisotropic nanostructures in microfluidic devices for binding and optional release of molecules and cells

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- Number: US 12,005,448 B2
- Document ID: US12005448B2
- Status: Granted
- Kind: B2
- Application number: 17/268,955
- Filed: 2019-08-16
- Published: 2021-10-07
- Granted: 2024-06-11
- Earliest claimed: 2018-08-17
- Assignees: The Regents of the University of California
- Applicants: The Regents of the University of California
- Inventors: Leonardo Scarabelli; Gail Vinnacombe; Liv Heidenreich; Naihao Chiang; Yao Gong; Paul S. Weiss; Steven J. Jonas
- Web page: https://patentgrep.com/patent/US12005448B2

## CPC

- B01L 3/502707: {characterised by the manufacture of the container or its components}
- B01L 3/50273: {characterised by the means or forces applied to move the fluids}
- B01L 3/502761: {specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules}
- C01G 7/00: Compounds of gold
- C12N 5/0693: {Tumour cells; Cancer cells}
- G01N 21/6458: {Fluorescence microscopy (fluorescence microscopes per se G02B21/0076 and G02B21/16)}
- G01N 21/658: {enhancement Raman, e.g. surface plasmons}
- G01N 33/54346: {Nanoparticles}
- G01N 33/5759: {involving compounds localised on the membrane of tumour or cancer cells}
- G02B 21/006: {focusing arrangements; selection of the plane to be imaged}
- G02B 21/16: adapted for ultraviolet illumination {; Fluorescence microscopes (G02B21/0076 takes precedence)}
- B01L 2300/0838: Capillaries
- B01L 2300/0896: Nanoscaled
- B01L 2300/168: Specific optical properties, e.g. reflective coatings
- B01L 2400/0478: pistons
- B82Y 35/00: Methods or apparatus for measurement or analysis of nanostructures
- C01P 2004/03: obtained by SEM
- C01P 2004/30: extending in three dimensions
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- G01N 2021/656: {Raman microprobe}
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

Systems and methods are disclosed that utilize metal nanostructures that are synthesized in situ along the internal surfaces of a microfluidic device. The nanostructures are formed by initial deposition of metallic seeds followed by flowing growth and reducing agent solutions into the capillaries/microfluidic channels to grow the nanostars. The nanostructures may optionally be functionalized with a capture ligand. The capture ligand may be used to selectively bind to certain cells (e.g., circulating tumor cells). The cells may be removed by a beam of light (e.g., laser beam) that induces localized heating at the surface location(s) containing the nanostructures. The plasmonic nature of the nanostructures can be used to heat the nanostructure(s) locally for the selective removal of one or certain cells. The nanostructures may be used to acquire Raman spectra of molecules or other small objects that are bound thereto for identification and quantification.

## Claims

### Claim 1

A microfluidic device for the selective capture and release of cells comprising:
one or more microfluidic channels or capillaries having one or more inner surfaces functionalized with a plurality of in-situ grown gold anisotropic nanostars disposed thereon, wherein the gold anisotropic nanostars exhibit plasmonic activity in one or more wavelength ranges and further comprise a capture ligands specific to a specific type of cell:
one or more pumps configured to pump a sample containing the cells through the one or more microfluidic channels or capillaries, wherein at least some of the cells adhere to the capture ligands; and
a light source configured to deliver a focused beam of light onto the one or more inner surfaces functionalized with the plurality of in-situ grown gold anisotropic nanostars, wherein the focused beam of light is configured to produce localized heating on the gold anisotropic nanostars, which is configured to cause conformation changes in the gold anisotropic nanostars to release the at least some of the cells that adhere to the capture ligands.

### Claim 2 (depends on 1)

The microfluidic device of claim 1, wherein one or more of wavelength ranges comprises the near-infrared wavelength range.

### Claim 3 (depends on 1)

The microfluidic device of claim 1, wherein the capture ligands comprise an antibody or aptamer.

### Claim 4 (depends on 1)

A system comprising the microfluidic device of claim 1, further comprising a Raman spectrometer or Raman microscope configured to obtain Raman spectra or to obtain Raman images of the cells that adhere to the capture ligands.

### Claim 5 (depends on 4)

The system of claim 4, wherein the Raman spectra, Raman images, or spectral data is enhanced by the gold anisotropic nanostars disposed on the inner surface of the one or more microfluidic channels or capillaries.

### Claim 6 (depends on 4)

The system of claim 4, further comprising a computing device, the computing device containing software executed thereon that identifies the cell type based on the Raman spectra, Raman images obtained by the Raman spectrometer or Raman microscope.

### Claim 7 (depends on 1)

A system comprising the microfluidic device of claim 1, further comprising an optical microscope configured to image the cells that adhere to the capture ligands.

### Claim 8 (depends on 7)

The system of claim 7, wherein the optical microscope comprises a fluorescent microscope.

### Claim 9 (depends on 7)

The system of claim 7, wherein the optical microscope comprises a confocal microscope.

### Claim 10 (depends on 1)

The microfluidic device of claim 1, wherein the light source comprises one or more of a laser, light emitting diode (LED), or laser diode.

### Claim 11 (depends on 1)

A method of using the microfluidic device of claim 1, comprising pumping the sample through the one or more microfluidic channels or capillaries having one or more cells, wherein one or more of the cells adheres to the gold anisotropic nanostars via the capture ligand.

### Claim 12 (depends on 11)

The method of claim 11, further comprising releasing one or more of the adherent cells from the gold anisotropic nanostars by increasing the local temperature with the focused beam of light from the light source directed at one or more target sites on the one or more microfluidic channels or capillaries.

### Claim 13 (depends on 12)

The method of claim 12, wherein the focused beam of light is scanned relative to the one or more inner surfaces functionalized with the plurality of in-situ grown gold anisotropic nanostars.

### Claim 14 (depends on 12)

The method of claim 12, wherein the focused beam of light is directed at one or more target sites while fluid is pumped through the one or more microfluidic channels or capillaries.