Device for performing biopsies on a vesicular object
A device for removing material from a vesicular object, said device being a pipette having a sealed tip at its distal end and an aperture whereby the distal tip of the device is inserted into the target object, the aperture aligned with the material to be removed from the object, vacuum applied to the inside of the device, such vacuum drawing the material into the aperture, and the device being removed from the object in such a manner as to cut or otherwise separate the material in the pipette from the object, the material remaining in the pipette, while leaving the object undamaged.
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 RESEARCHThis invention was not made under a government contract and the government has no rights in it.
SEQUENCE LISTING OR PROGRAMNot applicable.
BACKGROUND Prior ArtThe following is a tabulation of some prior art that presently appears relevant:
U.S. PATENTS
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 EMBODIMENTThe 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 SCOPEThe 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.
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:
- 1. Aperture.
- 2. Sealed distal tip.
- 3. Pipette's hollow center.
- 4. Envelope of cells.
- 5. Blastocoel fluid.
- 6. Biopsy sample.
A device for performing biopsies on a vesicular object is shown in
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 ManufactureA 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.
OperationA 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's surface, the biopsy probe'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'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.
Claims
1. A device for removing material from a vesicular object (object) said device being a pipette and having: whereby the distal tip of the device is inserted into the object, the aperture aligned with the material to be removed from the object, vacuum applied to the inside of the device, such vacuum drawing the material into the aperture, and the device being removed from the object in such a manner as to cut or otherwise separate the material in the pipette from the object, this material remaining in the pipette, while leaving the object undamaged.
- a, a sealed tip at its distal end (2), the distal tip being sharp enough to puncture the object;
- b, an aperture (1), both the specific location and size of the aperture being appropriate for the object and the material to be removed; and
- c, the aperture having edges sharp enough to cut or otherwise separate the material in the pipette from the object;
Type: Application
Filed: Nov 20, 2014
Publication Date: Mar 19, 2015
Inventor: Paul J. Taylor (Bozeman, MT)
Application Number: 14/544,087
International Classification: G01N 1/08 (20060101);