Selective lysing of cells using ultrasound

Abstract

Described are embodiments that employ ultrasonic energy to selectively lyse larger adipose cells in a suspension containing adipose cells of different sizes resulting in a suspension in which the only viable cells are the small adipose cells and stem cells. Embodiments provide for generating an acoustic standing wave field of sufficient intensity and proper geometry, that high shear stress is induced on the cell membranes of cells larger than a predetermined size. The remaining small adipose cells can be physically separated from the suspension after the suspension is subjected to the acoustic standing wave field.

1 - 8 . (canceled) 
     
     
         9 . An apparatus for lysing cells of greater than or equal to a predetermined diameter in a mixture of cells of a plurality of diameters, the apparatus comprising:
 a transducer that vibrates to generate an acoustic wave; and   a first surface connected to the transducer and positioned at a distance from a second surface, wherein the first surface transmits the acoustic wave generated by the transducer to the second surface and creates an acoustic standing wave field between the first surface and the second surface, the acoustic standing wave field having a wavelength that is no more than twice the predetermined diameter and the acoustic standing wave field exerting shear forces on exterior membranes of cells with a diameter equal to or greater than the predetermined diameter.   
     
     
         10 . The apparatus of  claim 9 , wherein the first surface is a curved surface. 
     
     
         11 . The apparatus of  claim 10 , wherein the first surface is an interior surface of a side wall of a cylinder. 
     
     
         12 . The apparatus of  claim 9 , wherein the first surface is a flat surface. 
     
     
         13 . The apparatus of  claim 12 , wherein the first surface is a bottom surface of a first plate and the transducer is coupled to a top surface of the first plate. 
     
     
         14 . The apparatus of  claim 13 , wherein the second surface is flat and is a top surface of a second plate that is substantially parallel to the first plate. 
     
     
         15 . The apparatus of  claim 9 , wherein the second surface is an interior surface of a container holding the mixture of cells. 
     
     
         16 . The apparatus of  claim 9 , wherein the distance is an integer multiple of the wavelength. 
     
     
         17 . The apparatus of  claim 9 , wherein the apparatus further comprises:
 a second transducer that vibrates to generate a second acoustic wave of a second wavelength that is less than the first wavelength, wherein the second wavelength is no more than twice a second predetermined diameter of adipose cells; and   a third surface connected to the second transducer and positioned at a second distance from a fourth surface, wherein the third surface transmits the acoustic wave generated by the transducer to the fourth surface and creates a second acoustic standing wave field between the third surface and the fourth surface, the second acoustic standing wave field exerting shear forces on exterior membranes of cells with a diameter equal to or greater than the second predetermined diameter.   
     
     
         18 . The apparatus of  claim 9 , wherein when a mixture of adipose cells of a plurality of diameters is subjected to the acoustic standing wave field, adipose cells with diameters equal to or greater than the predetermined diameter are selectively lysed compared to cells of a smaller diameter. 
     
     
         19 . An apparatus for lysing cells of greater than or equal to a predetermined diameter in a mixture of cells of a plurality of diameters, the apparatus comprising:
 a transducer that vibrates to generate an acoustic wave; and   a first surface connected to the transducer and positioned at a distance from a second surface, wherein the first surface transmits the acoustic wave generated by the transducer to the second surface and creates an acoustic standing wave field between the first surface and the second surface, the acoustic standing wave field having a wavelength that is no more than twice the predetermined diameter;   a cartridge configured to hold the mixture of cells, wherein the cartridge is positioned between the first surface and the second surface and, wherein at least a portion of the standing wave acoustic field is within an interior of the cartridge, the acoustic standing wave field exerting shear forces on exterior membranes of cells with a diameter equal to or greater than the predetermined diameter.   
     
     
         20 . The apparatus of  claim 19 , wherein the cartridge is disposable. 
     
     
         21 . The apparatus of  claim 19 , wherein the cartridge includes walls made of acoustically transparent material. 
     
     
         22 . The apparatus of  claim 21 , wherein the acoustically transparent material comprises a plastic material. 
     
     
         23 . The apparatus of  claim 19 , wherein when the mixture is subjected to the acoustic standing wave field, adipose cells with diameters equal to or greater than the predetermined diameter are selectively lysed compared to cells of a smaller diameter. 
     
     
         24 .- 27 . (canceled)