Patent Publication Number: US-2015079671-A1

Title: Device for performing biopsies on a vesicular object

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     1. This application is a division of application Ser. No. 13/986,029 filed Mar. 25, 2013, now U.S. Pat. No. ______ [fill in later], granted ______ [fill in later]. 
     2. This application also claims the benefit of PPA Ser. No. 61/686,025 filed Mar. 28, 2012 by the present inventor, which is incorporated by reference. 
    
    
     FEDERALLY SPONSORED RESEARCH 
     This invention was not made under a government contract and the government has no rights in it. 
     SEQUENCE LISTING OR PROGRAM 
     Not applicable. 
     BACKGROUND 
     Prior Art 
     The following is a tabulation of some prior art that presently appears relevant: 
     U.S. PATENTS 
       
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 PAT. NO. 
                 ISSUE DATE 
                 PATENTEE 
               
               
                   
                   
               
             
            
               
                   
                 8,394,033 
                 July 2006 
                 DiCarlo 
               
               
                   
                 8,376,957 
                 February 2013 
                 Hibner 
               
               
                   
                 20060200040 
                 September 2006 
                 Weikel 
               
               
                   
                 8,357,103 
                 January 2013 
                 Mark 
               
               
                   
                   
               
            
           
         
       
     
     BACKGROUND 
     The present method and device relates to a method and device for removing tissue or other cellular material (cellular material) from a vesicular object having a size typically in the neighborhood of 100-300 microns. This device has particular application for removing cellular material from mammalian embryos at the hatched blastocyst stage of development. This has not been possible with previous devices which have been mostly designed for biopsies of a much larger nature. 
     Removing material from the hatched blastocyst has been difficult because the blastocysts are spherical vesicular structures consisting of a thin double layer of living cells surrounding a relatively large central cavity that is filled with an aqueous fluid. The difficulty, and the failure of the prior art, arises because of the physical characteristics of the envelope of these living cells which is flimsy but resistant to puncture. For example, attempts to puncture a hatched blastocyst often simply compress the envelope of the embryo without puncturing it. With the present device there is no compression at all. 
     ADVANTAGES OF THE EMBODIMENT 
     The present device overcomes the above-described difficulties by providing a device wherein the object is firmly held, for example, by using a vacuum as described in application Ser. No. 13/374,195, the object is then pierced by the probe. An aperture, or biopsy port, on one side of the probe is then aligned with the material to be removed. A vacuum applied to the interior of the probe draws the cellular material into the probe itself for subsequent removal from the vesicular object. 
     An additional advantage lies in fact that the device leaves the object unharmed after the biopsy. As an example only, the puncture wound made in the surface of an expanding or hatched blastocyst by the biopsy probe will involve a very small percentage (less than 1%) of the surface. In a living embryo (blastocyst), this wound is surrounded by rapidly dividing cells on all sides. As soon as the probe is withdrawn, the wound closes tightly enough to prevent leakage of fluid into or out of the blastocoel space and will heal closed completely within a few hours. 
     A yet additional advantage is that smaller biopsy probes, down to 4 um outside diameter (OD) near the tip end, with biopsy ports at least as small as 2 um diameter, can be made at present. This is small enough to be used on certain large individual cells, resulting in the potential of removing or inserting cellular components. Smaller probes and biopsy ports are possible. 
     SUMMARY, CONCLUSION, RAMIFICATIONS, AND SCOPE 
     The above-described device punctures and allows removal of cellular material from a very specific location on a vesicular object. For example, an identifiable portion of the surface of a hatched blastocyst is the Inner Cell Mass, consisting of embryonic stem cells. This device has the potential to harvest embryonic stem cells without serious damage to the embryo. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the device may be clearly understood and readily carried into effect, a preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings wherein: 
         FIG. 1  is a drawing of a probe 20 microns in diameter at the location of the aperture, which is specified between 9 and 15 microns diameter. 
         FIG. 2 , is a drawing representing cellular material from the object&#39;s envelope of cells being drawn into the biopsy probe through the port. 
     
    
    
     REFERENCE NUMERALS 
     FIG. 1. 
     
         
           1 . Aperture. 
           2 . Sealed distal tip. 
           3 . Pipette&#39;s hollow center. 
       
    
     FIG. 2. 
     
         
           4 . Envelope of cells. 
           5 . Blastocoel fluid. 
           6 . Biopsy sample. 
       
    
     DETAILED DESCRIPTION OF AN EMBODIMENT 
     Elements 
     A device for performing biopsies on a vesicular object is shown in  FIGS. 1 . and  2 . In this embodiment the device includes a hollow pipette with a sealed tip at its distal end. Such pipette having an aperture ( 1 ) through the pipette wall (biopsy port) located only a few microns, typically 40 to 70 um, proximally from the sealed pipette&#39;s distal tip. ( 2 ). More specifically, the biopsy port is located on one sidewall of the pipette, at a right angle to the pipette&#39;s long axis, communicating with the pipette&#39;s hollow center and is created, as explained in more detail below, without damage to the pipette&#39;s far wall. 
     In the present embodiment, the diameter of the biopsy port is approximately one-half of the outside diameter of the pipette and the port is created in such a way as to leave the edges of the port sharp and capable of cutting or shearing cellular material from a target. 
     Such pipette, with the sealed distal tip and biopsy port, being referred to herein as a biopsy probe. 
     Method of Manufacture 
     A standard method of manufacture for the biopsy probe is first pulling a standard or thin-wall 1.5 mm OD (outside diameter) glass tube to a long taper, then scoring and breaking the thin glass tip at the desired diameter. This diameter has been, to date, typically between Bum and 25 um OD. Then, on a microforge at relatively low temperature, just hot enough to melt the glass, the tip end is touched to the molten glass bead, which seals it and draws the molten tip into a sharp spike. 
     The aperture, or biopsy port, on the formed probe is then drilled from the side using an appropriate device, for example only, a femtosecond laser. The laser must be tuned to make a clean hole of the desired diameter through only the near sidewall of the glass tube, without damage to the inside of the far sidewall. The position of the port is determined by the diameter of the probe near the tip. For example only, if the diameter is “x”, the port diameter is “0.5x” and the port is positioned “5x” to “7x” back from the sharp, and sealed, distal tip. This allows the biopsy port to be positioned (for use on an early embryo for example) at the level of the envelope of living cells when the sharp tip end is still inside the blastocoel space. The intended use of the probe, e.g. type and stage of development of an embryo to be biopsied and physical size of the cells to be captured, determines the specific position and size of the biopsy port. 
     Operation 
     A standard operation of the probe would include the following steps. The target is captured and held and the sharp and sealed distal tip of the biopsy probe is advanced, possibly as described in application Ser. No. 13/374,195. After penetrating a specific area of the object&#39;s surface, the biopsy probe&#39;s sealed distal tip ( 2 ) is advanced into the central space of the target ( 5 ) until the biopsy port ( 1 ) is aligned with the hole in the surface of the target made by the biopsy probe&#39;s sealed distal tip, or aligned in close proximity to the material to be removed from the interior of the object. A vacuum is then applied inside the biopsy probe and material is drawn into the biopsy probe through the port. ( 6 ) As the biopsy probe is withdrawn from the object, if the material is connected to the object, the material in the biopsy port is sheared, cut, or torn, away from the object leaving the object undamaged. 
     While the above description contains many specificities, these should not be construed as limitations on the scope of any embodiment, but as examples of various embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments without departing from the scope of the method and device disclosed above. 
     Thus the scope should be determined by the appended claims and their legal equivalents, and not by the examples given.