DE202013003997U1 - System for targeted local heat ablation using nanoparticles - Google Patents

Abstract

A system for locally heating tissue within a body, comprising: an elongate device having attached thereto one or more nanoparticles and adapted to be inserted into a body; and a source of electromagnetic energy configured to emit electromagnetic radiation in the vicinity of the nanoparticles and thereby excite at least some of the nanoparticles.

Description

FIELD OF THE INVENTION

The present invention relates to devices for treating various dysfunctional body functions through the use of a targeted ablation that uses a combination of electromagnetic radiation and nanoparticles.

BACKGROUND OF THE INVENTION

Energy-induced ablation is a well-described and active field in medical practice. All applications have the common goal of reducing, eliminating, or otherwise altering living tissue, or altering the consequences of pathological processes, such as inflammation or abnormal or deleterious tissue growth.

The clinically important areas where ablation is used include gastrointestinal, urological and cardiac areas. Many other medical areas can also be treated with appropriate ablation techniques.

Currently used ablation technologies include the direct application of heat, focused radio frequency, laser or ultrasound or cryogenics and, in some cases, actual surgical ligature of the target tissue. These techniques have associated problems of ineffective control over the amplitude, duration and extent of ablation, resulting in collateral damage to nearby tissue. Furthermore, they typically can be used only once, with additional intervention requiring many more potential complications. Because of these limitations, these methods almost always deliver too much heat, energy or cold to the target area when attempting to ablate the tissue in the only available intervention.

Various new methods have been developed for locally heating tissue using relatively non-invasive techniques. Plasmonic Photothermal Therapy (PPTT) has demonstrated the ability to achieve localized heating in the required temperature range, confined to a confined space. However, PPTT is carried out by the injection of nanoparticles into a tissue to be ablated and the excitation of the nanoparticles by light, which causes the thermal ablation of the tissue. This method is problematic due to the need to inject the nanoparticles into the ablation site, which gives a treating physician no control over the deviation or position of the nanoparticles after they have been injected. Furthermore, the process is limited to specific types of nanoparticles.

Accordingly, there is a need for a gentle methodology for targeted heat application which has known tissue-reducing effects and which can be repeatedly administered to the target tissue as well as a mechanism by which fine-tuning of the ablative process can be achieved.

BRIEF SUMMARY OF THE INVENTION

The present invention describes devices for treating various dysfunctional body functions through the use of a targeted ablation that uses a combination of electromagnetic radiation and nanoparticles.

It is an object of some embodiments of the present teachings to provide devices in which nanoparticles and PPTT are used for localized tissue ablation wherein the nanoparticles are embedded in a device.

It is a further object of some embodiments of the present teachings to provide a device that uses nanoparticles and PPTT and that is not limited to the specific type of nanoparticles used for the PPTT process.

It is also an object of some embodiments of the present teachings to provide a controlled, effective tissue ablation method that limits the extent of ablation to what is therapeutically necessary and that is repeatable as often as necessary.

According to one aspect of some embodiments of the present teachings, there is provided a system for locally heating tissue in a body comprising an elongate device to which one or more nanoparticles are attached and which is adapted to be inserted into a body and a source of electromagnetic energy configured to emit electromagnetic radiation in the vicinity of the nanoparticles and thereby excite at least some of the nanoparticles.

In some embodiments, the nanoparticles have diameters in the range of 1 to 1000 nanometers (nm). In some embodiments, the nanoparticles are metallic. In some embodiments, the nanoparticles are magnetic. In some embodiments, the nanoparticles comprise metal shells at least either non-metallic core structures or non-metallic core-shell structures.

In some embodiments, the nanoparticles comprise fabricated nanostructures. In some of these embodiments, the nanoparticles are generated in a solution.

In some embodiments, the electromagnetic radiation is in the spectral range of 380 to 2000 nm. In some embodiments, the electromagnetic radiation is tuned to the plasmonic resonance frequency of the nanoparticles. In some embodiments, the electromagnetic energy source comprises a light source selected from a group consisting of a filtered lamp, a light emitting diode (LED), and a laser. In some embodiments, the electromagnetic energy source emits radiation in the infrared to radio frequency range.

In some embodiments, the nanoparticles are spherical. In some embodiments, the nanoparticles have a shape selected from the group consisting of nonspherical, asymmetric spheres, cubes, pyramids, and octahedrons.

In some embodiments, the nanoparticles are attached to the device using a method selected from a group consisting of physical deposition, chemical deposition, physical absorption, electrochemical bonding, and covalent bonding.

In some embodiments, the device is selected from a group consisting of a blank stent, a drug-coated stent, a catheter, and a vessel on a catheter. In some of these embodiments, the vessel is selected from the group consisting of a balloon and an inflatable polymer.

In some embodiments, the excited nanoparticles are configured to heat a target tissue in a body.

In some embodiments, the nanoparticles attached to the device have at least two characteristic resonances, and the source of electromagnetic energy is configured for multimodal excitation of the nanoparticles on the at least two characteristic resonances. In some of these embodiments, the nanoparticles are of a single species, and the at least two characteristic resonances are due to the geometry of the nanoparticles. In some of these embodiments, the nanoparticles are diverse.

In some embodiments, the nanoparticles having at least two characteristic resonances are spatially separated on the device. In some embodiments, the nanoparticles having at least two characteristic resonances are uniformly distributed on the device.

In some embodiments, the source of electromagnetic energy is configured to emit electromagnetic energy that excites the nanoparticles at different frequencies at different times.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. In case of doubt, the description, including the definitions, takes precedence.

As used herein, the terms "comprising," "including," "having," and their grammatical variants are to be construed as specifying the features of specifying integers, steps, or components, but excluding adding one or more additional features, integers, Steps, components, or groups of the same are not enough. These terms include the terms "consisting of" and "consisting essentially of".

As used herein, the indefinite article "a" means "at least one" or "one or more" unless the context clearly dictates otherwise.

The above and other aspects, features, and advantages of the present invention will become apparent from the following description when read in conjunction with the accompanying drawings, in which the same reference numerals designate the same elements, all of which are part of this description.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the present teachings may be obtained by reference to some embodiments set forth in the drawings of the accompanying drawings. Although the depicted embodiments are only examples of methods, structures, and compositions for carrying out the present teachings, both the organization and method of the invention may be broadly understood together with other objects and advantages thereof with reference to the drawings and the description below. The drawings are not intended to limit the scope of the present invention, which is set forth with particularity in the claims as appended or changed thereafter, but merely to illustrate and explain the invention.

For a more complete understanding of the present invention, reference is now made to the following drawings. Show it:

1 various types of plasmonic and infrared excitable nanoparticles that may be used in the embodiments of the present teachings;

2 in cross-section, one embodiment of an ablation system that utilizes uniform electromagnetic excitation of the nanoparticles disposed on a stent, according to an embodiment of the present teachings, from outside the body;

3 in cross-section, an embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a stent, according to an embodiment of the present teachings, from outside the body;

4 in cross-section, an embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a stent, in accordance with an embodiment of the present teachings, from within a body vessel;

5 in cross-section, one embodiment of an ablation system that utilizes directional and local electromagnetic excitation of nanoparticles disposed on the stent according to an embodiment of the present teachings from a catheter through a body vessel and through a stent;

6 in cross section, one embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a balloon according to an embodiment of the present teachings from a catheter threaded through a body vessel;

7 in cross section, one embodiment of an ablation system that utilizes directional and local electromagnetic excitation of nanoparticles disposed on a balloon according to an embodiment of the present teachings from a catheter threaded through a body vessel;

8th in cross-section an embodiment of a system that mimics Stretta engagement in accordance with one embodiment of the present teachings; and

9 in cross-section an embodiment of a medical device to which multimodal nanoparticles are attached according to an embodiment of the present teachings.

DETAILED DESCRIPTION OF THE INVENTION

The present invention describes devices for treating various dysfunctional body functions through the use of a targeted ablation that uses a combination of electromagnetic radiation and nanoparticles.

Reference will now be made in detail to several embodiments of the invention, which are illustrated in the accompanying drawings. Wherever possible, the same or similar reference numbers will be used throughout the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to scale. For convenience and clarity, directional terms such as top, bottom, top, bottom, above, and below may be used with reference to the drawings.

It will now be referred to 1 , which depicts various types of plasmonic and infrared excitable nanoparticles that may be used in the embodiments of the present teachings. As in 1 Various types of plasmonic and infrared excitable nanoparticles may be used in accordance with some embodiments of the present teachings. Such nanoparticles can comprise many different secondary species that can be excited by electromagnetic radiation.

The simplest variety of these nanoparticles is a metallic, plasmonic nanosphere 1 , which can be made of any metal that may have a plasmonic resonance in visible and / or infrared regions. Such metals include silver (Ag), gold (Au), platinum (Pt) and copper (Cu). Varying the size of these nanospheres from a few nanometers to dozens and hundreds of nanometers changes the resonant frequency of these structures. In some embodiments, the size of these nanospheres ranges from 1 to 200 nm.

A second subset of nanoparticles suitable for use in the present teachings are core-shell structures consisting of a metallic shell 3 that have an internal, dielectric, central core 2 coated, consist. Varying the thickness of the shell 3 changes the resonant frequency of the core-shell structure.

A nanotube 4 Typically, like a carbon nanotube, is another type of nanoparticles that are electromagnetically excitable, typically by infrared or radio frequency radiation. In some embodiments, the nanotube 4 a diameter of 1 to 5 nanometers (nm) and a length ranging from several dozen nanometers to several hundred micrometers. In some embodiments, the length is less than 1 micron. Changing the diameter and type of nanotube 4 can change the resonance frequency for an infrared excitation, whereas the radio frequency excitation is less affected by the structural change of the nanotube.

An asymmetric nanorod 5 having an elongated axis providing a resonant frequency and having a transverse axis providing a second resonant frequency may be used in accordance with an embodiment of the present teachings. Changing the aspect ratio and size of such nanorods or nanowires changes their respective resonant frequencies.

In some embodiments of the present teachings, electromagnetic radiation may be used, including monochromatic, filtered or even broadband frequencies 6 belong to one or more nanoparticles 7 of the species listed above. The type of radiation used is dependent on the specific resonance or resonance groups of the nanoparticle 7 dependent. When excited at the appropriate resonance, the nanoparticle shows 7 due to the oscillation of the electrons in the metal, a plasmonic behavior, which causes excessive heat development in the nanoparticle, which is then called thermal radiation 8th is emitted to the surrounding environment.

The nanoparticles can be spherical and non-spherical, metallic and non-metallic, core-shell structures and also nanoparticles that are produced directly on a device or prefabricated in a solution.

The wavelength resonances of the nanoparticles may be in the visible spectrum (i.e., 380 to 700 nanometers (nm)) and in the NIR spectrum (i.e., 700 to 2000 nm) and may include multi-resonant nanoparticles. In some embodiments, the wavelength for excitation of nanoparticles is in the NIR range, which has low absorption in human blood and tissue, so that the transmission of the excitation signal is maximized.

The size of the nanoparticles is selected to be suitable for the embodiment or application. In some embodiments, the dimensions of the nanoparticles range from 1 to 1000 nanometers. In some embodiments, the dimensions of the nanoparticles range from 1 to 200 nanometers.

It will now be referred to 2 , which depicts in cross section an embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a stent, according to an embodiment of the present teachings, from outside the body. As can be seen, is an external electromagnetic (EM) radiation source 9 which may comprise a lamp, a laser, a light emitting diode (LED), a microwave or radio frequency (RF) source, outside a body 11 positioned in a non-invasive way.

The ablation system off 2 includes a nanoparticle coated stent 14 which is located in an internal portion of the body, for example in a blood vessel 13 , Because the EM source 9 is outside the body, the distance can be 12 between the EM source 9 and the stent 14 be pretty big, z. B. in the range of a few millimeters to several centimeters. This range is a limiting factor for the system, allowing the functionality of the system of one wavelength 10 depends on the source of radiation 9 is emitted and used to form the nanoparticles 15 due to the weak penetration of the most visible light into the tissue.

The electromagnetic source 9 is applied externally so that the electromagnetic radiation emitted by it is the nanoparticles 15 isotropically excited without selectivity, and all nanoparticles 15 be stimulated the same. The excited nanoparticles 15 emit a thermal radiation, causing them to the walls of the vessel 13 next to the stent 14 thermally heat to cause ablation of the target tissue. This PPTT process is a local reaction that causes only cell tissue tissue to be ablated in the immediate vicinity of the excited nanoparticles. Typically, the stent remains 14 thermally inactive until the nanoparticles 15 be excited with a suitable wavelength.

The electromagnetic radiation coming from the source 9 depends on the exact nature of the nanoparticles used and is not limited to a specific segment of the spectrum.

The intensity and duration (pulsed or continuous) of the radiation coming from the source 9 is emitted, determine the temperature of which the nanoparticles 15 and reach the subsequent PPTT. Such irradiation is externally controlled and typically takes from a few seconds to a few minutes.

The PPTT behavior of the stent 14 is to thermally ablate only those cells that straddle the stent, or the platelets, the actual clot, or the old clot that adheres to the stent, causing the coagulation of the vessel 13 is prevented. This localized ablation has minimal effect on the intima layer of the vessel 13 , causing the vessel 13 heal and normal endothelialization is possible. For embodiments in which the stent 14 a drug-coated stent (DES), unwanted hyper-endothelialization can be resolved.

In some embodiments of the present teachings, the stent 14 a DES or a blank stent, such as a bare metal stent (BMS), and the PPTT effect of the nanoparticles 15 is from the mechanical and chemical purposes of the stent 14 separated. Thus, the PPTT may be at any time during or after implantation of the stent 14 be implemented.

The embodiment of 2 is particularly suitable for applications where the stent is in peripheral vasculature, and the external application of electromagnetic radiation is preferred because of the relative closeness of the vessels to the skin. This can be the case with congenital structural constriction, for example in infants with congenital heart disease (CHD), where the heart is very close to the skin and the required penetration depths are low.

It will now be referred to 3 , which depicts in cross-section an embodiment of an ablation that utilizes uniform electromagnetic excitation of nanoparticles disposed on a stent, according to an embodiment of the present teachings, from outside the body. As can be seen, there is an EM source 16 outside a body vessel 19 but within the body under a layer of external tissue 18 , The source 16 is through the outer fabric 18 , such as skin, through a relatively minor invasive process via a small puncture 21 used, so that the relative distance 20 between the source 16 and a stent 22 in the vessel 19 is positioned, reduced. By reducing the distance between the source 16 and the stent 22 is the penetration depth of the radiation 17 that from the source 16 is emitted, resulting in better excitation of the nanoparticles 23 on the stent 22 allows. In this embodiment, the excitation is isotropic and over the length of the stent 22 uniform, so that all nanoparticles 23 are stimulated to induce the PPTT.

It will now be referred to 4 , which depicts in cross-section an embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a stent, in accordance with an embodiment of the present teachings, from within a body vessel. As can be seen, becomes a catheter 25 into an existing stent 27 used in a container 24 lies. This can be done during insertion of the stent itself or at a later stage when thrombosis is detected. The catheter 25 can be used such that one end 26 a fiberglass the entire length of the stent 27 reached and the stent 27 from the inside by an electromagnetic radiation 28 isotropically and uniformly illuminated, thereby reducing the nanoparticles 29 be stimulated on the stent 27 are arranged.

The electromagnetic energy source 26 , which may be a glass fiber and / or an internally implanted light source, such as micro LEDs, may be placed using conventional and readily available catheters currently used for medical diagnostic and therapeutic procedures. This allows the PPTT to be implemented at later times, after surgical implantation of the stent 27 about a relatively simple catheter intervention that does not require complete removal of the stent. In some embodiments, the internal light source activates the PPTT in response to an external command without requiring the use of electrical wires.

The internal illumination source 26 can be in or near the stent 27 or at any other suitable internally located excitation site. For example, the excitation source for a cardiac stent may be inserted into the esophagus using the penetration depth of the light source to penetrate the implanted stent, similar to that previously described 3 described.

It will now be referred to 5 showing in cross-section an embodiment of an ablation system that provides directional and local electromagnetic excitation of Nanoparticles disposed on the stent, in accordance with one embodiment of the present teachings, used from a catheter through a body vessel and through a stent. As shown, there is a stent 33 in a vessel 30 , and an optical source on a catheter 31 with a directional head 32 is mounted in the stent 33 used. In this embodiment, the EM excitation 34 that from the directional head 32 is emitted, depending on the direction, leaving only nanoparticles 35 in a restricted section of the stent 33 be stimulated. The rest of the nanoparticles 36 on the stent 33 remains inactive.

The catheter 31 can be over the length of the stent 33 be moved to a PPTT behavior in specific desired areas of the stent 33 to accomplish. In this embodiment, all nanoparticles on the stent 33 or only the nanoparticles can be stimulated on a local area of the stent 33 be stimulated, reducing the ablation damage to healthy areas of the vessel 30 is reduced.

Yet another embodiment is disclosed in 6 which depicts in cross-section an embodiment of an ablation system that utilizes uniform electromagnetic excitation of nanoparticles disposed on a balloon according to an embodiment of the present teachings from a catheter threaded through a body vessel. Here is an inflatable balloon 40 shown on a catheter 38 is placed to a vessel 37 inflate. In some embodiments, the catheter is 38 placed in the damaged area, leaving the balloon 40 is aligned to the desired section. The catheter 38 /Balloon- 40 Device becomes of the ends 41 and 42 of the catheter 38 inflated ago, causing the balloon 40 is inflated over the necessary distance to the walls of the vessel 37 to touch.

In some embodiments, the catheter is 38 equipped with a radiation source (not shown) that passes through a fiber in the catheter 38 is coupled, so that the fiber is the nanoparticles 44 that attach to the outer edges of the balloon 40 are located, with an EM radiation 43 uniformly and isotropically illuminated. The nanoparticles 44 on the external section of the balloon 40 next to the tissue surface of the vessel 37 are positioned, thereby causing the PPTT.

It should be understood that the power source, such as an LED or a laser, may be attached to the catheter in some embodiments 38 and thus can be accurately directed to the area of interest on the balloon, thereby spatially controlling the area to be influenced by the PPTT.

In some embodiments, sensors (not shown), such as temperature sensors, may be placed adjacent to the light source so that the absorbed energy dose can be accurately monitored and controlled. For example, a therapist might choose to perform the PPTT as a secondary treatment used to prevent vascular growth following standard angioplasty, or the primary intervention may be PPTT. This method allows ablation to occur even when no stent is applied and allows ablation to be tracked if a previously inserted BMS slowly closes and / or if a failed DES requires treatment.

7 FIG. 10 depicts, in cross section, an embodiment of an ablation system that employs directional and local electromagnetic excitation of nanoparticles disposed on a balloon according to an embodiment of the present teachings from a catheter threaded through a body vessel. As can be seen, becomes a catheter 48 in a vessel 45 placed at a desired position, and a balloon 51 is inflated to a desired volume. The balloon 51 is from the seals 52 and 53 that attach to the two ends of the balloon 51 are held in place. In this embodiment, an EM radiation source 49 who have a directional head 50 has, on a catheter 48 placed so that the directional head 50 the nanoparticles 55 spatially and locally illuminate and stimulate, as indicated by the reference number 54 is specified. It will only be nanoparticles 55 excited, directly with the energy 54 be illuminated, and the rest of the nanoparticles 56 remains inactive.

In this embodiment, the nanoparticles can be applied to the entire balloon 51 about the source 49 be excited, or it may only be a local area of nanoparticles 55 on the balloon 51 be stimulated, which reduces the ablation damage to healthy areas of the vessel.

8th FIG. 10 depicts, in cross-section, one embodiment of a system that mimics a Stretta engagement in accordance with an embodiment of the present teachings and shows an intervention similar to the Stretta procedure for the treatment of GERD. This is the gastric-oesophageal connection 57 using a balloon 61 standing on a tube 58 placed and inserted into the esophagus, slightly inflated. The balloon 61 is at an open end 62 the tube 58 attached and is through a ring 63 kept in place. According to the present teachings, the balloon is 61 externally with nanoparticles 66 coated.

A catheter or similar device 59 which typically has a directional head which is a radiation source 60 includes, gets into the tube 58 used. The source 60 illuminates specific areas of the balloon 61 locally and spatially with energy 64 , producing only specific nanoparticles 65 be excited and the rest of the nanoparticles 66 remains inactive. The directional source 60 can be rotated and aligned to patterns of ablation areas along the lateral surface of the balloon 61 to create. It is understood that although it is not necessary, the nanoparticles on the balloon 61 uniformly stimulate, this can also be done.

Similarly, such balloons may be used for atrial fibrillation ablation, where the target area is typically the anterior portion of the balloon 61 instead of at the middle circumference of the balloon or in its vicinity. In this situation, a tip of the catheter 59 preferably used to locate the catheter and hold it in place.

Since most ablations are performed under fluoroscopic guidance in a cath lab, the openings on the pulmonary veins may not be visible. For larger vessels, the balloon may be oblong or a second smaller balloon may be positioned in front of the primary balloon to hold the catheter in a substantially centered position.

The nanoparticles may be embedded on the described devices, including stents, catheters, and balloons, using various techniques, including physical embedding, chemical bonding, or electroplating.

It is a particular feature of the present teachings that a balloon is attached to a catheter, such as the balloon 40 on the catheter 38 ( 6 ), when properly placed and expanded, requires minimal catheter positioning, exerts the same pressure on all contact points, and achieves better contact with all possible target points. A suitable placement would be, for example, in the lumen of the vessel or at an exit position where the vessel abuts a chamber such that the tip of the catheter is positioned through the vessel lumen and the body of the balloon, when expanded, contacts the chamber wall which surrounds the vessel opening. When used in this manner, the catheter is self-centering and self-locating. The self-centering and self-positioning catheter is also suitable when used with existing energy delivery methods, e.g. For example, excess heat, RF or cold.

Improved self-centering could also be achieved by using a two-stage balloon. The most distal part of the balloon would enter and expand the vessel to center the catheter inside the vessel lumen. A more proximal part of the balloon would attach to the opening of the vessel into the chamber. Such use achieves near perfect centering of the therapeutic heat-releasing balloon.

It will now be referred to 9 , which depicts in cross-section an embodiment of a medical device to which multimodal nanoparticles are attached in accordance with an embodiment of the present teachings. In one of the previously described embodiments, more than a single type of nanoparticles can be used on the same device. For example, as in 9 Shown are several different types of nanoparticles on a device 69 arranged. In such a device there is a tissue to be ablated 68 and the device 69 close to each other. A radiation source 67 that is external (not shown) or internal (shown) is used to excite the nanoparticles on the device. In 9 Three different types of nanoparticles are shown: nanospheres 70 , Core-shell nanostructures 71 and nanorods 72 , Preferably, each of the nanoparticles 70 . 71 and 72 its own particular resonant frequency on which it is excited and a PPTT behavior 76 generated. For example, the nanosphere 70 a resonant frequency hv ₁ 73 exhibit the core-shell nanosphere 71 can be a resonant frequency hv ₂ 74 exhibit, and the nanorod 72 may be a resonant frequency hv ₃ 75 exhibit.

In this multimodal behavior, the nanoparticles can optionally belong to the same subset, but with different resonance frequencies. For example, the nanoparticles can be nanospheres 70 be, which have different diameters, or nanorods 73 that have different aspect ratios. Each nanoparticle is then excited only when the appropriate resonant frequency is used, leaving the other nanoparticles inactive. Several types or sizes of resonant nanoparticles can be used, including nanoparticles of different sizes, compositions (solid or core-shell structures), and materials.

By changing the types of nanoparticles used and placing different nanoparticles on different segments of the device, different regions of the device can be excited by different excitation wavelengths, thereby allowing further ablation control by selectively controlling only some of the ablation control Fraction of the nanoparticles is brought to resonance by using only their resonant frequencies and creating a spatial separation of the ablation, even if they are unified by the source 67 be stimulated.

Alternatively, the different nanoparticles may be uniformly distributed along the device, thereby enabling multiple activation of the device using a different subset of nanoparticles and a different excitation frequency at each activation. In such embodiments, and when different nanoparticles are spatially distributed along the device, different nanoparticles can be excited by illuminating them at the correct wavelength at different times or in separate interventions. This can be used to cause the PPTT several times, or in the event that some of the nanoparticles are destroyed or otherwise rendered inactive, thereby increasing the number of possible reactions of the PPTT.

In addition, if the nanoparticles are damaged or destroyed by initial PPTT irradiation, secondary layers may permit additional PPTT treatments at later times and at different wavelengths.

Specific ablation techniques, as in the embodiments of 1 to 9 and described in the present teachings can be used for vascular ablation, esophageal ablation and many other types of medical treatments.

By using a balloon nanoparticle methodology, as in 6 to 8th It has been shown that it is possible to give a more accurate and less effective but perhaps even more effective energy for local tissue destruction. This would reduce complications, mainly scarring. Further, due to the delivery by the balloon, either using a conventional energy source or nanoparticles as a medium of energy delivery, ablation is both focally more precise and less likely to bypass the critical tissue.

Such methods of treatment are particularly useful for the treatment of Barrett's esophagus, asthma, dysplasia, sinus opening narrowing, stenosis, narrowing of the passages in the gastrointestinal tract, narrowing of the urogenital tracts or passageways, and excessive uterine bleeding. The urogenital tracts and passages include passages from the kidneys to the bladder, including the connecting areas, the passage from the bladder to the urethra, the fallopian tubes and passages from the ovary to the uterus.

All of these areas are examples of applications of the ablation techniques described using the stent of focused and local balloon and nanoparticle ablation procedures in accordance with the present teachings for which much better results are achievable.

The methods of the present teachings, and in particular the embodiment of 8th , can also be used with an esophageal catheter to perform localized and well-controlled ablation procedures. This will replace the traditional Stretta procedure for the treatment of esophageal reflux disease (GERD). When used for this purpose, the apparatus of the present teachings can replace the current Stretta procedure without the need for power lines and without the consequent residual damage to adjacent tissue. Other examples of gastrointestinal include ablation or lesion removal in the esophagus, in the gastro-oesophageal region, and the elimination of scarred local obstruction in the gut or gallbladder and its drainage system, the biliary tract. This includes other tubular structures, including the entire urogenital tracts, sinuses, and hearing, lung structures, and, more generally, any area of the body for which controlled focal ablation may be beneficial.

It should be understood that certain features of the invention, which have been described for purposes of clarity in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which for purposes of brevity have been described in connection with a single embodiment, may also be provided separately or in any suitable sub-combination, or as appropriate in any other described embodiment of the invention. Certain features described in connection with various embodiments are not to be considered as essential features of these embodiments unless the embodiment is not functional without these elements.

Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent that many alternatives, changes and variations will be apparent to those skilled in the art. Accordingly, it is to be understood that all alternatives, changes, and variations that fall within the scope of the appended claims are included.

The mention or identification of any reference in the present application is not to be taken as an admission that this reference is available as prior art for the invention.

The section titles are used here to facilitate the understanding of the description and are not to be considered as strictly limiting.

Claims (13)

A system for locally heating tissue within a body comprising: an elongated device to which one or more nanoparticles are attached and which is adapted to be inserted into a body; and a source of electromagnetic energy configured to emit electromagnetic radiation in the vicinity of the nanoparticles and thereby excite at least some of the nanoparticles. The system of claim 1, wherein the nanoparticles comprise fabricated nanostructures. The system of claim 1, wherein the electromagnetic radiation is tuned to the plasmonic resonance frequency of the nanoparticles. The system of claim 1, wherein the electromagnetic energy source comprises a light source selected from the group consisting of a filtered lamp, a light emitting diode (LED), and a laser. The system of claim 1, wherein the nanoparticles are magnetic. The system of claim 1, wherein the nanoparticles are attached to the device using a method selected from the group consisting of physical deposition, chemical deposition, physical absorption, electrochemical bonding, and covalent bonding. The system of claim 1, wherein the device is selected from the group consisting of a blank stent, a drug coated stent, a catheter and a vessel on a catheter. The system of claim 1, wherein the excited nanoparticles are configured to heat a target tissue within a body. The system of claim 1, wherein the nanoparticles attached to the device have at least two characteristic resonances, and the source of electromagnetic energy for multimodal excitation of the nanoparticles is configured on the at least two characteristic resonances. The system of claim 9, wherein the nanoparticles are of a single species and the at least two characteristic resonances are due to the geometry of the nanoparticles. The system of claim 9, wherein the nanoparticles having at least two characteristic resonances are spatially separated on the device. The system of claim 9, wherein the nanoparticles having at least two characteristic resonances are uniformly distributed on the device. The system of claim 1, wherein the source of electromagnetic energy is configured to emit electromagnetic energy configured to excite the nanoparticles at different frequencies at different times.

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