Surface modification of medical devices
Surface modification of blood pump components with bifunctional modifiers addresses the challenge of blood clotting by creating a pH-controlled microenvironment that inhibits clot formation, enabling heparin-free operation and improving pump safety.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-08
- Publication Date
- 2026-03-27
AI Technical Summary
Existing blood pumps face challenges with blood clotting due to the interaction of blood with pump components, particularly in designs that use purge fluids like dextrose or heparin, which may not be suitable for all patients, and there is a need for an alternative to prevent clotting without anticoagulants.
Surface modification of metal or ceramic components in blood pumps using bifunctional modifiers, such as functionalized aminosilanes, to create a microenvironment with a pH of 7.0 or higher, reducing protein denaturation and platelet activation, thereby delaying coagulation and minimizing clot formation.
The modified surfaces reduce the risk of blood clotting by creating a favorable microenvironment that inhibits fibrin formation and protein denaturation, allowing the use of heparin-free purge fluids and enhancing the safety and effectiveness of blood pumps.
Smart Images
Figure 2026510028000001_ABST
Abstract
Description
Technical Field
[0001] Cross - reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 450,998, filed Mar. 9, 2023, the entire content of which is incorporated herein by reference.
[0002] Technical Field The present disclosure relates to medical devices having a blood - contacting surface, such as a blood pump (e.g., an intravascular blood pump for assisting blood flow within a patient's blood vessel and for assisting a method of purging such a pump while it is operating while inserted into a patient).
Background Art
[0003] Background Different types of blood pumps are known, such as axial blood pumps, centrifugal blood pumps, or hybrid blood pumps, where blood flow is caused by both axial and radial forces. An example of a blood pump is the IMPELLA® line of blood pumps from Abiomed (Danvers, Mass.) (e.g., IMPELLA 2.5® blood pump, IMPELLA CP® blood pump, IMPELLA 5.5® blood pump, etc.). An intravascular blood pump can be inserted into a patient's blood vessel, such as the aorta, by a catheter.
[0004] In some pump designs, a purge fluid can be utilized to prevent blood from entering the mechanism and to reduce the effect of blood on the pump mechanism. The purge fluid can include an aqueous dextrose solution (e.g., D5). In some cases, such a purge fluid may also include an anticoagulant, such as heparin (typically the sodium salt of heparin), which is thought to prevent blood from clotting within the gap or clearance between pump components, such as an impeller shaft and the housing. In other examples, sodium bicarbonate has been introduced as an alternative to heparin. [Overview of the project] [Means for solving the problem]
[0005] overview In various embodiments, percutaneous blood pumps may be provided. A percutaneous blood pump may include a pumping device coupled to a catheter. The pumping device may include a motor section coupled to a pump section. The pump section may be configured to deliver blood from the blood inlet of the pumping device to the blood outlet of the pumping device.
[0006] The metal or ceramic surface of the pumping device may contain a bifunctional modifier. The bifunctional modifier may be a functionalized aminosilane. The functionalized aminosilane may be 4-aminobutyltriethoxysilane. The bifunctional modifier may be a functionalized aminosiloxane. The bifunctional modifier may also be a functionalized aminoalkylsilsequioxane. The functionalized aminosiloxane may be aminoethylaminopropyl / methylsilsesquioxane, aminopropyl / methylsilsesquioxane, aminopropylsilsesquioxane, and / or aminopropyl / vinylsilsesquioxane. The bifunctional modifier may be a functionalized silanetriol. The functionalized silanetriol may be a carboxyalkylsilanetriol. The carboxyalkylsilanetriol may include carboxyethylsilanetriol.
[0007] The bifunctional modifier may be selected to have (or form) a hydrate layer having a thickness of 1 nm or less from the metal or ceramic surface to be modified. The bifunctional modifier may have a pH of 10 to 11. The bifunctional modifier may have a viscosity of 3 to 15 cSt. The bifunctional modifier may have a molar percentage of functional groups in the bifunctional modifier of 60 to 75%.
[0008] Metallic or ceramic surfaces may be the surfaces of shafts, bearings, rotors, or stators. Metallic or ceramic surfaces may contain oxides. Metallic or ceramic surfaces may contain Cu, Fe, Al, Pb, Ti, Be, Ni, Si, Zr, Mn, Mo, Co, Bi, Zn, Mg, and / or Cr. Metallic or ceramic surfaces may define radial gaps and / or axial gaps within the motor section and / or pump section.
[0009] A percutaneous blood pump may be configured to have a purge fluid passing through at least a portion of the motor section and / or pump section (e.g., a radial or axial gap between two components of the motor section and / or pump section). The purge fluid may contain an anticoagulant. The purge fluid may not contain an anticoagulant.
[0010] In various embodiments, methods can be provided for creating a microenvironment for delaying the initiation of coagulation. The method may include providing a percutaneous blood pump, such as one disclosed herein. The percutaneous blood pump may include a metal or ceramic surface modified with a bifunctional modifier, such as one disclosed herein. The metal or ceramic surface may be configured to come into contact with blood. The method may include passing a purge fluid through at least a portion of the motor section and / or pump section of the percutaneous blood pump. The purge fluid may include an anticoagulant. The purge fluid may not include an anticoagulant.
[0011] Brief explanation of the drawing The present invention will be described below with reference to the attached drawings. The attached drawings are not intended to be drawn to scale. In the drawings, identical or substantially identical components shown in various drawings are represented by the same reference numerals. For clarity, not all components are reference-labeled in all drawings. [Brief explanation of the drawing]
[0012] [Figure 1]A diagram of a portion of the blood pump is shown. [Figure 2] This diagram shows a portion of the blood pump, with its distal end located in the right ventricle of the heart. [Figure 3A] This is a schematic diagram showing the bonding of the first modifier to the surface. [Figure 3B] This is a schematic diagram illustrating ionization in the blood that leads to localized alkalinization. [Figure 4A] This is the structure of a bifunctional modifier. [Figure 4B] This is the structure of a bifunctional modifier. [Figure 4C] This is the structure of a bifunctional modifier. [Figure 4D] This is the structure of a bifunctional modifier. [Figure 4E] This is a schematic diagram of the anhydrous deposition method for silane. [Figure 5A] This is a schematic diagram of ionization that occurs when a pH modifier is used. [Figure 5B] This illustration shows protection with NaHCO3 at pH < 7. [Figure 5C] This illustration shows protection by NaHCO3 at pH > 7. [Figure 6] This is a diagram of a part of the blood pump. [Figure 7] This is a diagram of a system including a blood pump. [Modes for carrying out the invention]
[0013] Please understand that the accompanying drawings are not necessarily to scale and present somewhat simplified representations of various features illustrating the basic principles of the present invention. Specific design features of the work sequences disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes of various illustrated components, are partly determined by the specific intended use and environment of operation. Certain features of the illustrated embodiments are enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustrative purposes.
[0014] Detailed Description As is known, a blood pump can be placed inside a patient who requires life-saving emergency treatment. A blood pump can also be used to assist in high-risk procedures. In some pump designs, a purge fluid can be utilized to prevent blood from entering the pump mechanism and to reduce the effect of blood on the pump mechanism. For example, the purge fluid can include an aqueous dextrose solution such as 5% dextrose in an aqueous solution (e.g., D5). In some cases, the purge fluid can also include an anticoagulant such as heparin (e.g., the sodium salt of heparin), which is thought to prevent blood from clotting within the gap between pump components such as an impeller shaft and the housing. As will be appreciated, heparin may not be suitable for all patients. In such cases, alternatives to heparin such as sodium bicarbonate have been recognized by the inventors.
[0015] The inventors recognize that a sodium bicarbonate purge fluid can provide environmental conditions that delay the onset of clotting and suppress fibrin formation. For example, the rate of thrombus formation is generally reduced at the location where the purge fluid and the anticoagulated blood mix throughout the axial gap. The inventors also recognize that the protective effect of sodium bicarbonate may be due to a decrease in the probability of protein denaturation and platelet activation due to an increase in pH (e.g., above 7.0, e.g., 7.8) and additional CO2 in the purge fluid / blood mixture. For example, a particular favorable microenvironment can be created.
[0016] As disclosed herein, the inventors further recognize the advantages of adjusting the pH of these surfaces (e.g., permanently) in order to achieve a favorable microenvironment when the metal or ceramic surface contacts blood. For example, such a microenvironment can delay the onset of coagulation, inhibit fibrin formation, and as a result, the blood clot formation rate can be reduced overall. The microenvironment can also be configured to reduce the probability of protein denaturation and platelet activation due to an increase in pH in the blood mixture within the microenvironment (e.g., above 7.0, such as 7.8). For example, as shown herein, the inventors recognize that at high pH, surface modification can provide a protective effect, e.g., reducing protein denaturation and platelet activation, and thus minimizing coagulation. The inventors also recognize that such surface modification can have an enzymatic effect on blood clot formation and blood clot dissolution.
[0017] As will be appreciated, in embodiments having a blood pump with such surface modification, the blood pump can still be used with a suitable purge fluid (e.g., dextrose).
[0018] In some embodiments, the surface can be modified with a bifunctional modifier. For example, in some embodiments, one function of the bifunctional modifier can be to covalently crosslink the modifier to the surface. As will be appreciated, in such cases, this can include a modifier having an affinity. In some embodiments, the first modifier can be selected based on the surface to be modified. For example, on some surfaces such as ceramic surfaces, the first modifier can include an alkoxy functional group, such as a methoxy functional group (-OCH3). On epoxy surfaces, the first modifier can include a carbide or an epoxide. Hydroxyl modifiers can be used for ceramics and metals. Carboxyl groups can also be used as modifiers.
[0019] An example of a first modifier (300) that binds to the surface is shown in Figure 3A. In Figure 3A, a solution of isopropanol at 60°C is used to promote the binding of the modifier to the surface. As can be seen, binding can also be promoted using other alcohol solutions at other suitable temperatures (e.g., 20°C to 120°C).
[0020] In some embodiments, the first modifier may be configured as a pH adjuster. As shown in Figures 3A and 3B, for example, the pH adjuster may contain NH2. Ionization that may result in blood is also shown in Figure 3B (where NH2 is replaced with NH3). + (converted to) and shown in Figures 5A-5C. In Figure 3B, the estimated ionization of the modifier in blood by hydrolysis (left side of Figure 3B) can result in local alkalization (right side of Figure 3B). In some embodiments, pH can reduce denaturation through surface modification, as it can maintain a negative charge on protein molecules. As shown in these drawings, the OH group can maintain a negative charge on proteins. In Figure 5A, the left side shows the charge of molecules at low pH (<7, e.g., D5 only), while the right side shows the charge at higher pH (>7, e.g., D5 and blood). Figures 5B and 5C show images of protection with NaHCO3 at lower pH (5B, pH<7) and higher pH (5C, pH>7).
[0021] In some embodiments, the bifunctional modifier may be a functionalized aminosilane. In some embodiments, the functionalized aminosilane is of the formula (EtO)3Si(CH2) n Functionalized triethoxysilanes having NH2 (wherein n=3 to 11) are possible. A non-limiting example of such an aminosilane is shown in Figure 4A: 4-aminobutyltriethoxysilane. Other non-limiting examples include 3-aminopropyltriethoxysilane, 5-aminopentyltriethoxysilane, 6-aminohexyltriethoxysilane, and 11-aminoundecyltriethoxysilane. In some embodiments, the functionalized aminosilane is of the formula R1R2R3Si(CH2) nThe functionalized silane may have NH2 (wherein n=3 to 11, R1, R2, and R3 are independently alkyl or alkoxy groups, where at least two of R1, R3, and R2 are alkoxy groups). The alkyl and alkoxy groups may have carbon chain lengths of 1 to 5. Such non-limiting examples include 3-aminopropyl(diethoxy)methylsilane and 4-aminobutyl(diethoxy)ethylsilane. The bifunctional modifier may also be a functionalized aminosiloxane. The bifunctional modifier may also be a functionalized aminoalkylsilsesquioxane. Non-limiting examples of such bifunctional modifiers are shown in Figures 4B to 4C, including aminoethylaminopropyl / methylsilsesquioxane (Figure 4B); and / or aminopropyl / methylsilsesquioxane (Figure 4C). Other functionalized aminosiloxanes include aminopropylsilsesquioxane and / or aminopropyl / vinylsilsesquioxane. The bifunctional modifier may be a functionalized silanetriol, such as a carboxyalkylsilanetriol, such as carboxyethylsilanetriol, or a silanetriol salt, such as a disodium carboxyethylsilanetriol salt (Figure 4D). An example of anhydrous deposition of silane is schematically shown in Figure 4E.
[0022] In some embodiments, the bifunctional modifier may be selected to have a high hydration layer. In some embodiments, the bifunctional modifier may be selected to have a hydration layer having a thickness of 1 nm or less from the underlying surface to be modified. For example, the thickness of the hydration layer may be 0.1 nm to 1 nm. The thickness of the hydration layer may be at least 0.1 nm, at least 0.2 nm, at least 0.3 nm, at least 0.4 nm, or at least 0.5 nm. The thickness of the hydration layer may be 0.3 nm or less, 0.4 nm or less, 0.5 nm or less, 0.6 nm or less, 0.8 nm or less, or 1.0 nm or less. As understood, the hydration layer may have other suitable thicknesses in other embodiments. In some embodiments, such a hydration layer may prevent or obstruct molecules (such as molecules in blood) from reaching the surface.
[0023] In some embodiments, the bifunctional modifier may have a pH of 10 to 11. In some embodiments, the bifunctional modifier may have a viscosity of 3 to 15 cSt. In some embodiments, the molar percentage of functional groups in the bifunctional modifier molecule may be 60 to 75%. In some embodiments, the bifunctional modifier may be provided in an aqueous solution.
[0024] Although advantages for high pH surface modification are disclosed herein, it will be understood that these advantages may, in some cases, be achieved by having low pH surface modification. In such cases, a suitable bifunctional modifier may be selected to create such an environment.
[0025] Referring here to Figure 1, a pump (100) is shown having a tubular member comprising a drive section (110) and a pump section (130), and a catheter 115 attached to the proximal end (120) of the drive section (110) (for example, the end of the drive section closer to the physician or the “posterior end” of the drive section) through which a line extends for supplying power to the drive section (110), the pump section (130) being fastened to the distal end (125) of the drive section. The drive section (110) may also include a motor housing (150) in which an electric motor (151) is housed, the motor shaft (160) of the electric motor exiting the drive section (110) and projecting distally into the pump section (130). The pump section (130) may also include a pump housing (165) (which may be a tubular pump housing) having an impeller (170) that rotates inside, the impeller resting on the end of a motor shaft (160) protruding from a motor housing (150). The motor shaft (160) may be mounted in two bearings (171, 172) that are maximally separated from each other within the motor housing to ensure true and precise guidance of the impeller (170) within the motor housing (150). Different pump designs may use different bearing types. As shown in Figure 1, bearing (171) may include a radial ball bearing, and bearing (172) may include an axial-radial sliding bearing. As shown in Figure 1, blood (140) may exit from the outflow cage of the pump housing (165). Otherwise, the blood that would enter the motor housing (150) can be further obstructed by the purge fluid (135) that passes through the motor housing and the impeller-side shaft seal bearing. Therefore, the purge fluid can pass through the gap of the impeller-side radial sliding bearing to prevent the blood from entering the housing. This can be done by having a purge fluid pressure higher than the pressure present in the blood.
[0026] As shown in Figure 1, the purge fluid (135) can fill the motor housing (150) of the pump and form a lubricating film within the pump bearings (171, 172). For example, as described in U.S. Patent Application Publication No. 2015 / 0051436, the purge fluid (135) can form a lubricating film within the bearing clearance (180) of the axial plain bearing of the pump. The purge fluid is supplied through a purge fluid supply line and is said to flow through the radial bearing clearance (173) located at the distal end of the motor housing (150), and then through the bearing clearance (180) of the axial plain bearing. The purge fluid thus supplied can contribute to hemodilution and reduce the blood residence time under the impeller (170).
[0027] Figure 2 shows the use of a blood pump to support the left ventricle in this particular example. As shown in this drawing, the blood pump may include a catheter (14) and a pumping device (10) attached to the catheter (14). The pumping device (10) may include a motor section (11) and a pump section (12), which are arranged coaxially anterior to posterior to each other, resulting in a rod-shaped structural form. The pump section (12) may include an extension in the form of a flexible suction hose (13), often called a "cannula". An impeller may be provided in the pump section (12) to generate blood flow from a blood inlet (20) through a portion of the pumping device and, for example, through a portion of the motor section and / or pump section to a blood outlet (21), and the rotation of the impeller is generated by an electric motor located in the motor section (11). The blood pump may be positioned primarily in the ascending aorta (6) leading to the aortic arch (5). When the aortic valve (18) is closed, it is positioned in contact with the outside of the pump section 12 or substantially within the left ventricle (17) and its suction hose (13). The blood pump having the suction hose (13) anteriorly may be advanced to the represented position by advancing the catheter (14) or optionally by using a guidewire. In this way, the suction hose (13) can pass retrogradely through the aortic valve (18), so that blood is drawn through the suction hose (13) and pumped into the aorta (16).
[0028] As should be understood, the use of the blood pump is not limited to the application shown in Figure 2, which is merely a typical example of its application. Therefore, the pump can also be inserted through other peripheral vessels, such as the subclavian artery. Alternatively, a reverse application to the right ventricle could be envisioned. Furthermore, as should be understood, other appropriate pump placement configurations may be used in other embodiments.
[0029] Figure 6 shows an embodiment illustrating the fluid flowing through the purge gap. As shown in this figure, the pump may include a first gap (290) and a second gap (292). In some embodiments, the first gap (290) may include a small radial gap (291) between the outer surface of the shaft (25) and the inner surface of the sleeve bearing (289), which can control the purge flow rate as the purge fluid (288) flows through the purge gap. As understood, metal or ceramic surfaces, such as the bearing surface around these gaps, may be surface modified (see the surface near "*" (295) in Figure 6). As understood, in other embodiments, the shaft may also be modified as described herein. In some embodiments, both the shaft and the bearing are surface modified. As further understood, the surfaces do not need to have the same modifier, but in some embodiments they may.
[0030] Furthermore, as can be understood, in some embodiments, any metal or ceramic surface of the blood pump may be modified. In some embodiments, the metal surface may be a surface that comes into contact with blood, as with the blood-contact bearings and shafts described herein. The metal surface may be any suitable metal. The metal may include oxides. For example, the metal may include Cu, Fe, Al, Pb, Ti, Be, Ni, Si, Zr, Mn, Mo, Co, Bi, Zn, Mg, and / or Cr, but other metallic materials may be used. Such surfaces may be readily modified as described herein or by other preferred methods (e.g., silanization).
[0031] In some embodiments, the small radial gap (291) may extend radially by 4 μm to 9 μm, for example, 5 to 6 μm in some pumps and 7 to 8 μm in others. In some embodiments, the first gap may mainly contain a purge fluid. In some embodiments, due to the mixing of flows, some blood components may reach the distal end of this gap. Due to the small size, heat, and high shear, the accumulation of biological material at this location may include denatured proteins, which may result in increased purge pressure, increased friction, and higher motor current. In such embodiments, the microenvironment may be configured to reduce the denaturation and adsorption of blood proteins within the gap by modifying one or more surfaces. In some embodiments, a purge fluid may be introduced. The purge fluid may be, for example, a saline purge fluid. The purge fluid may contain one or more anticoagulants, such as heparin or sodium bicarbonate. In some embodiments, the purge fluid may not contain anticoagulants. Although it is described as having a purging fluid, it will be understood that the purging fluid is not required in all medical devices, even though one or more surfaces may be modified to create the disclosed microenvironment. For example, in some embodiments, a blood pump may be configured to be purgeless (e.g., with only blood flowing), and the surface modification serves to create a microenvironment, for example, by reducing coagulation.
[0032] In one embodiment, surface modification can prevent protein aggregation by increasing the charge of serum proteins, and thus reduce the formation of biodeposition.
[0033] In some embodiments, the second gap (292) may include an axial gap (293) between the impeller (34) and the sleeve bearing (289). In some embodiments, the axial gap (293) may extend about 90 to 110 μm, for example, about 100 μm, in the axial direction (e.g., a distance (294) parallel to the axis (299) of the impeller shaft).
[0034] In some embodiments, the second gap may be a place where the purge fluid (if used) and blood can mix. The purge fluid flows toward the impeller, drawing in blood from the entire body into the gap, creating a clockwise flow pattern within this microenvironment.
[0035] The purge flow rate is typically in the range of approximately 2 mL / hour to 30 mL / hour. This results in a purge pressure of approximately 1100 mmHg to 300 mmHg. While the typical purge flow rate for some blood pumps is approximately 5 mL / hour to 20 mL / hour, certain models may have a purge flow rate of approximately 2 mL / hour to 10 mL / hour.
[0036] In surgical patients, surgeons prefer not to administer heparin during the first few days after surgery. For these patients, a heparin-free purge fluid is preferable.
[0037] Referring to Figure 7, the blood pump assembly (900) may include a blood pump (910) fluid-connected to a container (951) (such as a purge bag) containing the purge fluid disclosed herein, via a purge device (953). The blood pump assembly (900) may also include a controller (930) (e.g., the AUTOMATED IMPELLA CONTROLLER® (AIC) blood pump controller from Abiomed, Inc. (Danvers, MA)), a display (940), a connector cable (960), a plug (970), and a relocation unit (980). As shown, the controller (930) may include a display (940). The controller (930) can monitor and control the blood pump (910). During operation, the purge device (953) may deliver a purge fluid, as disclosed herein, to the blood pump (910) through first lines (950, 955) (e.g., tubing), through one or more components (956, 957, 958, 959), and through a catheter tube (917) to prevent blood from entering the motor (not shown) in the motor housing of the pump. A connector cable (960) may provide an electrical connection between the blood pump (910) and the controller (930). A plug (970) connects the catheter tube (917), the purge device (953), and the connector cable (960). In some embodiments, the plug (970) may include memory for storing operating parameters in case it is necessary to transfer the patient to a different controller. A relocation unit (980) may be used to relocate the blood pump (910). As shown in this figure, the fluid lines (950, 955) may be separate from the connector cable (960) which has one or more wires.
[0038] One or more metal or ceramic surfaces within a blood pump, for example, one or more ceramic and / or metal surfaces that may come into contact with blood (e.g., one or more surfaces of the shaft, bearings, rotor, stator, etc.), may be modified with a bifunctional modifier as disclosed herein.
[0039] In some embodiments, the method may involve operating a pump, which may include rotating the impeller of the pump. In this regard, the method may involve pumping a flow of blood from a blood inlet, through a portion of the pumping device, for example, through a portion of the motor section and / or pump section, to exit from a blood outlet. In such embodiments, the blood may pass over one or more of the modified surfaces (for example, through an axial gap disclosed herein). As described herein, such modified surfaces may create a microenvironment that can minimize and / or prevent protein aggregation as the blood passes over them.
[0040] In some embodiments, the method may also include flowing a purge fluid through a disclosed gap in the pump. This may be done by controlling a purge device (953) (which may include, for example, a positive displacement pump). This may include flowing a purge fluid through a blood pump, such as those disclosed herein, to allow the purge fluid to mix with the blood in the blood pump. This may include flowing the purge fluid through a first gap between a bearing and the outer surface of a rotatable shaft coupled to an impeller, where the bearing and gap are located within a lumen of a tubular member. In some embodiments, this may include flowing the fluid through a second gap after passing through the first gap, where the second gap is between the bearing and the surface of the impeller facing the bearing. In such embodiments, the blood and optionally the blood / purge fluid mixture may come into contact with a surface-modified metal or ceramic surface, such as those disclosed herein, to create a desired microenvironment as disclosed.
[0041] In some embodiments, the controller may be configured to control the flow rate of purge fluid into the pump based on the impeller speed. For example, at low impeller rotation speeds, the flow rate of purge fluid may be relatively low, and as the impeller speed increases, the fluid flow rate automatically increases to counteract, for example, the increase in pressure of blood trying to enter the pump gap.
[0042] In various embodiments, methods can be provided for creating a microenvironment to delay the initiation of coagulation. The method may include providing a percutaneous blood pump comprising a metal or ceramic surface modified with a bifunctional modifier, such as those disclosed herein. This may include operating the blood pump such that the blood flowing through it interacts with the bifunctional modifier on the surface.
[0043] Embodiments disclosed herein involve affecting the microenvironment of purge gaps (e.g., axial and / or radial gaps) within blood pumps (e.g., transcutaneous blood pumps), but such surface modifications may be used on blood-contacting surfaces and on other medical devices. For example, in some embodiments, high-pH surface modifications may be used on metal cables or cables having metal and / or ceramic components that pass through areas of a patient's skin and / or vascular structure. This may be used on the blood-contacting surface of a pacemaker. It may also be used to coat batteries and / or controllers that may be exposed to blood and / or susceptible to bacteria. As understood, in such examples, as described above, washing from the surface may also be performed to promote the prevention of microorganisms from adhering to the surface and forming biofilms.
[0044] While specific embodiments of the present technology have been described, it will be apparent to those skilled in the art that the present technology can be embodied in other specific forms without departing from its essential features. Therefore, these embodiments and examples should be considered in all respects as illustrative and not limiting. Furthermore, it will be understood that any reference in this specification to subject matter known in the art does not constitute an endorsement that such subject matter is generally known to those skilled in the art, unless otherwise indicated.
Claims
1. A percutaneous blood pump, A pumping device coupled to a catheter, wherein the pumping device includes a motor section coupled to a pump section, and the pump section is configured to pump blood from the blood inlet to the blood outlet of the pumping device. Includes, The metal or ceramic surface of the pumping device contains a bifunctional modifier, thereby providing a transcutaneous blood pump.
2. The percutaneous blood pump according to claim 1, wherein the metal or ceramic surface is the surface of a shaft, bearing, rotor, or stator.
3. The percutaneous blood pump according to claim 1 or 2, wherein the metal or ceramic surface contains an oxide.
4. The percutaneous blood pump according to any one of claims 1 to 3, wherein the metal or ceramic surface comprises Cu, Fe, Al, Pb, Ti, Be, Ni, Si, Zr, Mn, Mo, Co, Bi, Zn, Mg, and / or Cr.
5. A percutaneous blood pump according to any one of claims 1 to 4, wherein at least one metal or ceramic surface defines a radial gap and / or an axial gap in the motor section and / or the pump section.
6. A transcutaneous blood pump according to any one of claims 1 to 5, configured to have a purge fluid passing through at least a portion of the motor section and / or the pump section.
7. The percutaneous blood pump according to claim 6, wherein the purge fluid does not contain an anticoagulant.
8. The transcutaneous blood pump according to any one of claims 1 to 7, wherein the bifunctional modifier is a functionalized aminosilane.
9. The percutaneous blood pump according to claim 8, wherein the functionalized aminosilane is 4-aminobutyltriethoxysilane.
10. The transcutaneous blood pump according to any one of claims 1 to 9, wherein the bifunctional modifier is a functionalized aminosiloxane.
11. The transcutaneous blood pump according to claim 10, wherein the bifunctional modifier is a functionalized aminoalkylsilsesquioxane.
12. The transcutaneous blood pump according to claim 10, wherein the functionalized aminosiloxane is aminoethylaminopropyl / methylsilsesquioxane, aminopropyl / methylsilsesquioxane, aminopropylsilsesquioxane, and / or aminopropyl / vinylsilsesquioxane.
13. The percutaneous blood pump according to any one of claims 1 to 12, wherein the bifunctional modifier is a functionalized silanetriol.
14. The percutaneous blood pump according to claim 13, wherein the functionalized silanetriol is a carboxyalkylsilanetriol.
15. The transcutaneous blood pump according to claim 14, wherein the carboxyalkylsilanetriol comprises carboxyethylsilanetriol.
16. The percutaneous blood pump according to any one of claims 1 to 15, wherein the bifunctional modifier is selected to have a hydrate layer having a thickness of 1 nm or less from the metal or ceramic surface to be modified.
17. The bifunctional modifier has a pH of 10 to 11, as described in any one of claims 1 to 16, for the transcutaneous blood pump.
18. The percutaneous blood pump according to any one of claims 1 to 17, wherein the bifunctional modifier has a viscosity of 3 to 15 cSt.
19. The transcutaneous blood pump according to any one of claims 1 to 18, wherein the difunctional modifier has a molar percentage of functional groups in the difunctional modifier of 60 to 75%.
20. A method for creating a microenvironment that delays the onset of coagulation, To provide a transcutaneous blood pump containing a metal or ceramic surface modified with a bifunctional modifier. A method that includes this.
21. The method according to claim 20, wherein the metal or ceramic surface is configured to come into contact with blood.
22. The method according to claim 20 or 21, wherein the metal or ceramic surface is the surface of a shaft, bearing, rotor, or stator.
23. The method according to any one of claims 20 to 22, wherein the metal or ceramic surface includes an oxide.
24. The method according to any one of claims 20 to 23, wherein the metal or ceramic surface comprises Cu, Fe, Al, Pb, Ti, Be, Ni, Si, Zr, Mn, Mo, Co, Bi, Zn, Mg, and / or Cr.
25. The method according to any one of claims 20 to 24, wherein at least one metal or ceramic surface defines a radial gap and / or an axial gap in the motor section and / or pump section of the transcutaneous blood pump.
26. The method according to any one of claims 20 to 25, wherein the percutaneous blood pump is configured to have a purge fluid passing through at least a portion of the motor section and / or pump section of the percutaneous blood pump.
27. The method according to claim 26, wherein the purging fluid does not contain an anticoagulant.
28. The method according to any one of claims 20 to 27, wherein the bifunctional modifier is a functionalized aminosilane.
29. The method according to claim 28, wherein the functionalized aminosilane is 4-aminobutyltriethoxysilane.
30. The method according to any one of claims 20 to 29, wherein the bifunctional modifier is a functionalized aminosiloxane.
31. The method according to claim 30, wherein the bifunctional modifier is a functionalized aminoalkylsilsesquioxane.
32. The method according to claim 30, wherein the functionalized aminosiloxane is aminoethylaminopropyl / methylsilsesquioxane, aminopropyl / methylsilsesquioxane, aminopropylsilsesquioxane, and / or aminopropyl / vinylsilsesquioxane.
33. The method according to any one of claims 20 to 32, wherein the bifunctional modifier is a functionalized silanetriol.
34. The method according to claim 33, wherein the functionalized silanetriol is a carboxyalkylsilanetriol.
35. The method according to claim 34, wherein the carboxyalkylsilanetriol includes carboxyethylsilanetriol.
36. The method according to any one of claims 20 to 35, wherein the bifunctional modifier is selected to have a hydrate layer having a thickness of 1 nm or less from the modified metal or ceramic surface.
37. The method according to any one of claims 20 to 36, wherein the bifunctional modifier has a pH of 10 to 11.
38. The method according to any one of claims 20 to 37, wherein the bifunctional modifier has a viscosity of 3 to 15 cSt.
39. The method according to any one of claims 20 to 38, wherein the bifunctional modifier has a molar percentage of functional groups in the bifunctional modifier of 60 to 75%.