PHYSIOLOGICALLY ACTIVE IMPLANTABLE BIOMATERIALS HAVING ENGINEERED FUNCTIONAL SURFACES

Abstract

Wireless implantable medical devices, in particular stents, for operably coupling to and functionally interfacing with tissue, such as vascular tissue, adjacent to the implantable medical device, having integrally formed electronic circuitry configured to sense and/or stimulate tissue, such as nerves, adjacent to or in proximity to the situs of the implantable medical device and capable of transmitting signals from the stent to a remote receiver to interrogate conditions in the body or receive signals to stimulate tissue.

Claims

1. A wireless physiologically active implantable medical device, comprising a scaffold configured to be delivered to and implanted at a situs in a mammalian body, the scaffold further comprising a plurality of structural supports, at least one electronic circuit integrally formed as part of at least one structural support of the plurality of structural supports, at least one structural support of the plurality of structural supports further comprising at least one integrally formed region electrically coupling the at least one electronic circuit to tissue proximate the situs in a mammalian body.

2. The wireless physiologically active implantable medical device of claim 1, wherein the scaffold is a stent.

3. The wireless physiologically active implantable medical device of claim 2, wherein the plurality of structural supports form a tubular structure of the stent.

4. The wireless physiologically active implantable medical device of claim 3, wherein at least some structural supports of the plurality of structural supports further include at least one recess in an abluminal surface of the at least some structural supports of the plurality of structural supports.

5. The wireless physiologically active implantable medical device of claim 4, wherein the at least one electronic circuit is integrally formed within the at least one recess.

6. The wireless physiologically active implantable medical device of claim 4, wherein the at least one electronic circuit further comprises an integrated circuit.

7. The wireless physiologically active implantable medical device of claim 5, wherein the at least one integrally formed region configured to electrically couple the at least one electronic circuit to tissue at the situs further comprises a raised topography comprising a plurality of micro-needles.

8. The wireless physiologically active implantable medical device of claim 7, wherein the plurality of micro-needles is configured to receive electrical signals from the electronic circuit and communicate the electrical signals to tissue in the mammalian body.

9. The wireless physiologically active implantable medical device of claim 5, wherein the at least one electronic circuit is configured as at least one of an antenna, a transmitter, a power source and/or an electrode.

10. The wireless physiologically active implantable medical device of claim 6, wherein the integrated circuit further comprises an LC circuit.

11. The wireless physiologically active implantable medical device of claim 9, wherein the stent is an antenna operably coupled to the at least one electronic circuit.

12. The wireless physiologically active implantable medical device of claim 5, further comprising at least one electrode in electrical communication with the at least one electronic circuit.

13. The wireless physiologically active implantable medical device of claim 6, further comprising at least one electrode in electrical communication with the integrated circuit.

14. The wireless physiologically active implantable medical device of claim 5, wherein the at least one electronic circuit is positioned within a width and depth of the at least one structural support of the plurality of structural supports.

15. The wireless physiologically active implantable medical device of claim 1, wherein each structural support of the plurality of structural supports has a thickness less than or equal to 75 microns.

16. The wireless physiologically active implantable medical device of claim 15, wherein each structural support of the plurality of structural supports has a width less than or equal to 75 microns.

17. The wireless physiologically active implantable medical device of claim 7, wherein each micro-needle of the plurality of micro-needles has a height of less than or equal to about 10.0 microns.

18. A method of making a wireless physiologically active implantable medical device, comprising the steps of: a. Providing a substrate for forming the wireless physiologically active implantable medical device; b. Vacuum depositing a device forming material onto the substrate; c. Masking portions of the deposited device forming material to define recesses regions to be formed on the device forming material; d. Forming recesses in a surface of the device forming material; e. Depositing at least one electrical component layer of a plurality of electrical component layers into the recesses; and f. Forming surface features on a surface of at least some of the electrical component layers of the plurality of electrical component layers.

19. The method of claim 18, wherein step b further comprises the step of depositing a shape memory metal.

20. The method of claim 19, further comprising the step of depositing an electrically conductive layer coupling at least one electrical component layer of the plurality of electrical component layers to the device forming material.

21. The method of claim 20, further comprising the step of depositing an electrically conductive layer coupling at least one electrical component layer of the plurality of electrical component layers to another electrical component layer.

22. The method of claim 18, wherein step e further comprises 3D printing at least one electrical component layer of a plurality of electrical component layers into the recesses.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] In the accompanying figures, like elements are identified by like reference numerals among the several preferred embodiments of the present invention.

[0029] FIG. 1 is partial cross-sectional diagrammatic view of a stent or medical device illustrating integrally formed electronic circuitry in accordance with the present invention.

[0030] FIG. 2 is a process flow chart outlining the method of making the inventive physiologically active stent or medical device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The foregoing and other features and advantages of the invention are apparent from the following detailed description of exemplary embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.

[0032] The wireless physiologically active implantable medical device 10 of the present invention integrally and substantially monolithically combines a stent 12 with microelectronic components 14 and electrodes 26. The stent 12 is preferably formed by vacuum depositing a stent forming material onto a substrate. The stent-forming material is preferably a metal suitable for use as an antenna capable of transmitting and receiving radiofrequency or other electromagnetic signals across body tissue. Of course, because it is implantable, stent 12 must also be biocompatible. A shape memory metal, such as Nitinol, is well suited both as a stent material and as an antenna. Binary, ternary, quaternary or other metal alloys may be employed as the stent-forming (or device-forming) material. Non-limiting examples include NiTi, NiTiCo, NiTiPt, NiTiPd, NiTiHf, NiTiZr, NiTiAu, NiTiCr, NiTiW, NiTiCoZr, or NiTiCuPd.

[0033] Stent 12 is formed having a plurality of structural members and preferably formed with at least one recess in at least one structural member of the plurality structural members. The recess may be formed during the vacuum deposition of the stent material or formed by post-processing techniques, such as photolithography. The microelectronic components 14 and electrodes 26 are then formed in situ within the recesses by known microelectronic fabrication techniques used to manufacture such devices, including, for example, physical vapor deposition of the individual sub-layers and sub-components of the microelectronic components and patterning by photolithography and etching the sub-layers and sub-components of the microelectronic components 14 or electrodes 26.

[0034] For exemplary purposes only, FIG. 1 depicts microelectronic component 14 as an LC circuit comprising a plurality of inductors 16, capacitor layers 18, 20 and dielectric layers 22 that isolate the LC circuit.

[0035] Microelectronic component 14 may be configured as an LC circuit, an amplifier, a transmitter, filter, tuner, power supply, an analog-digital converter, memory, computer, sensor or any such other microelectronic component 14 as is capable of being formed integrally and substantially monolithically within the plurality of recesses in stent 12. Those skilled in the art of microelectronic fabrication will understand that the plurality of recesses function as packaging for the microelectronic component 14.

[0036] Similarly, electrode 26 is preferably formed by vacuum depositing metal capable of acting as an electrode into electrode recesses in the stent, and depositing onto stent 12 an electrically conductive layer 24 electrically coupling microelectronic component 14 to electrode 26. In this arrangement, electrical energy transmitted by microelectronic component 14 will be discharged by electrode 26 to tissue adjacent the stent 12.

[0037] To further facilitate electrically coupling of the stent 12, namely electrodes 26, to the tissue adjacent the stent 12, raised surface topographical features 28 may be provided on the surface of the electrodes 26 which will act as micro-needles and engage the tissue allowing for better electrical contact between the electrodes 26 and the tissue. In some embodiments, each micro-needle has a height of less than or equal to about 10.0 microns.

[0038] FIG. 2 is a process flow diagram depicting a method for fabricating the inventive physiologically active medical device 12 in accordance with the present invention.

[0039] A substrate is provided 100 and a device forming material, preferably metal, is vacuum deposited onto the substrate 102. Once the device forming material is deposited, it is patterned 104 with a pattern corresponding to the recesses to be formed in a surface of the device forming material. As is well known in photolithography, a photoresist is applied to the surface of the device forming material, and a positive or negative mask is applied to the photoresist and the photoresist is exposed to light through the mask. Alternatively, a positive or negative photoresist may be employed. The exposed photoresist is then developed to remove the exposed photoresist thereby uncovering patterned regions of the device forming material to be removed. Subsequent removal 106 of portions of the patterned regions of the device forming material defines the plurality of recesses in the surface of the device forming material. Removal may be by wet or dry etching, ablation, or laser cutting, or other equivalent processes that yield high resolution recess features in the surface of the device forming material.

[0040] With the plurality of recesses formed in the surface of the device, conventional microelectronic fabrication techniques may be followed to deposit and form electrical component layers 108 or traces within the recess along with forming the electrodes in the electrode recesses. The electrical component layers 108, traces and/or the electrodes may be also be formed by 3D printing into the plurality of recesses. Once the microelectronic circuitry and electrodes are formed, desired surface features on the electrodes, such as the tissue contact projections, may be formed 110 by deposition, photolithography and/or 3D printing or other processes adapted to form high resolution features on the surface of the device forming material.

[0041] Once the device is fully formed, it is released 112 from the substrate and any post-processing steps, such as validation, quality control, quality assurance, or the like may be undertaken on the device.

[0042] Finally, it will be understood that the wireless physiologically active medical device of the present invention may be formed as tubular cylinder, as with conventional radially expandable stents, or may be formed as a planar material that is capable of being coiled or folded for delivery and implantation into the body in its final device shape. The final device shape may cover all or a portion of the circumference of the body lumen at the situs of implantation.

[0043] Vacuum deposition onto both cylindrical and planar substrates is known in the art, as exemplified by U.S. Pat. Nos. 6,379,383 and 6,357,310, which are hereby incorporated by reference. Similarly, 3D printing onto cylindrical surfaces is also known in the art, as exemplified by WO 2011/011818, also incorporated by reference. 3D printing onto planar substrates is well known.

[0044] While the invention has been described in connection with various embodiments, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as, within the known and customary practice within the art to which the invention pertains.