Micro-nano conical array intelligent drug delivery bandage based on AAO template

Abstract

The invention discloses a micro-nano conical array intelligent drug delivery bandage based on an AAO template, and aims to solve the problems of low drug delivery efficiency and insufficient precision in the prior art. The intelligent bandage comprises a bandage body, a power module, a sensor array, a medicine storage layer, a conical micro-nano hole array layer and an intelligent control module. And the bandage body is made of a breathable double-layer material with good biocompatibility, so that the wearing comfort and safety are ensured. The medicine storage layer is loaded with medicine to be conveyed and located below the conical micro-nano hole array layer prepared through the AAO template technology, the layer comprises a large number of evenly-distributed conical micro-nano holes, and directional conveying of the medicine under the action of an electric field is facilitated. And the requirements of different types of wounds can be met by adjusting the preparation process parameters of the AAO template. The intelligent control module integrates a microprocessor, an electric field generator and a sensor array, can monitor physiological parameters of wound tissues in real time, adjusts electric field output according to a preset program, and accurately controls the drug delivery rate and quantity. The power supply module adopts a miniaturized low-power-consumption design, and has the functions of quick charging and intelligent electric quantity monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a micro-nano conical array intelligent drug delivery bandage based on an anodic aluminum oxide (AAO) template. Background Art

[0002] In the medical field, especially for patients requiring localized drug delivery and wound management, traditional drug application methods such as direct application, oral administration, or intravenous injection often face challenges such as low drug utilization, difficulty controlling local concentrations, and poor patient compliance. These traditional methods are particularly limited in achieving precise, sustained, and efficient drug delivery for chronic wounds, burns, skin ulcers, and postoperative wounds.

[0003] In recent years, with the development of micro-nanotechnology and smart materials, smart bandages, as a new type of medical device, have attracted widespread attention due to their ability to automatically adjust drug release according to wound conditions, monitor healing progress, and provide necessary physical support. These smart bandages typically integrate sensors, micropumps, and adjustable drug storage units, aiming to achieve personalized treatment, improve treatment efficacy, and reduce patient discomfort and care burden.

[0004] In the existing technology, micro-nanostructures prepared based on anodic aluminum oxide (AAO) templates are widely used in drug carriers, tissue engineering, biosensors and other fields due to their good biocompatibility, high specific surface area and easily controllable pore structure. AAO templates can not only promote cell attachment and growth, but also achieve slow release of drugs through their special pore structure, thereby improving the bioavailability and duration of drug action. However, the combination of AAO template technology with smart bandages, especially in the preparation of smart bandages with conical array structures for precise drug delivery, is still in the initial exploratory stage.

[0005] For example, while existing smart bandages can regulate drug release to a certain extent, they often lack adaptability to changes in wound depth, shape, and healing stage. The design of a conical array structure, by simulating micro-nanostructures found in nature, such as plant roots or animal vascular networks, not only increases the surface area of the bandage-wound interface, promoting uniform distribution and deep penetration of drugs, but also optimizes the drug release rate and path by adjusting the array's geometric parameters (such as cone angle and array density), thereby better matching the wound's healing needs. Summary of the Invention

[0006] The purpose of the present invention is to provide a micro-nano conical array intelligent drug delivery bandage based on AAO template to address the technical defects in the prior art.

[0007] The technical solution adopted to achieve the purpose of the present invention is:

[0008] A micro-nano conical array intelligent drug delivery bandage based on an AAO template, comprising a bandage body, a power module, a sensor array, a drug storage layer, a conical micro-nanopore array layer, and an intelligent control module.

[0009] The bandage body is made of breathable and biocompatible materials, and is provided with a drug storage layer inside for loading the drug to be delivered. The drug molecules can be designed to be charged according to treatment needs;

[0010] The conical micro-nanopore array layer is fabricated using conductive materials using AAO template technology and is located above the drug storage layer. This layer contains a large number of evenly distributed conical micro-nanopores that gradually narrow from the drug storage layer downward, forming a unique conical structure. Microelectrodes are integrated on both sides of the layer to facilitate directional drug delivery under the action of an electric field.

[0011] The intelligent control module, integrated into the bandage itself, includes a microprocessor, an electric field generator, and a sensor array. The microprocessor receives data from the sensors and adjusts the output of the electric field generator according to a preset program to control the rate and amount of drug delivered through the tapered micro-nanopores.

[0012] The sensor array is located on the inner surface of the bandage body and can monitor key physiological parameters of wound exudate in real time;

[0013] The power module provides the necessary power for the entire system and adopts a miniaturized design to ensure the portability and endurance of the bandage;

[0014] In the above technical solution, the design of the tapered micro-nanopore array layer enables drugs to move directionally along the tapered channels under the action of an electric field, improving the efficiency and precision of drug delivery. Furthermore, the tapered structure enhances drug penetration, allowing drugs to more effectively penetrate wounds and reach deep lesions.

[0015] In the above technical solution, by adjusting the oxidation voltage, electrolyte type, electrolyte concentration, current density, oxidation time, temperature, and electrolyte component ratio, the pore size range, pore depth, inter-pore distance, shape and orderliness of the AAO template can be controlled to adapt to the needs of different wounds.

[0016] In this technical solution, the intelligent control module monitors the physiological changes of the wound in real time through a sensor array and automatically adjusts the electric field strength of the electric field generator according to a preset algorithm to control the release rate and amount of the drug from the tapered micro-nanopore array layer. This intelligent regulation mechanism ensures timely and effective drug delivery, avoiding drug waste and side effects.

[0017] In the above technical solution, the bandage body adopts a double-layer structure. The inner layer is made of a breathable and biocompatible material to ensure comfort and safety during long-term wear. The outer layer is made of a waterproof and breathable material, which can effectively prevent the intrusion of external contaminants and protect the wound from infection. Both the inner and outer layers are equipped with adhesive tape to adjust the tightness of the bandage to suit different wound locations.

[0018] In the above technical solution, the drug storage layer is made of degradable material, which can be naturally degraded after the drug delivery is completed, without the need for secondary removal, thereby reducing the burden on patients.

[0019] In this technical solution, the power module adopts a low-power design, combined with an efficient energy management system, to ensure the stability and reliability of the bandage during long-term use. Furthermore, the power module also features fast charging and intelligent power monitoring, allowing users to easily monitor the power status and charge the bandage at any time.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The AAO-based micro-nanoconical array intelligent drug delivery bandage of this invention utilizes a conical micro-nanopore array layer and automatically adjusts the electric field strength of the electric field generator according to a preset algorithm to control the release rate and amount of drugs from the conical micro-nanopore array layer, enabling efficient and precise drug delivery. This delivery method not only improves drug utilization but also reduces the occurrence of side effects, providing patients with a safer and more effective treatment option.

[0022] 2. The micro-nano conical array intelligent drug delivery bandage based on the AAO template of the present invention can control the pore size range, pore depth, pore distance, shape and orderliness by adjusting the oxidation voltage, electrolyte type, electrolyte concentration, current density, oxidation time, temperature, and electrolyte component ratio to adapt to the needs of different wounds.

[0023] 3. The intelligent control module in the AAO-based micro-nanoconical array smart drug delivery bandage can monitor physiological changes in the wound in real time and automatically adjust the drug delivery rate based on the actual situation, achieving intelligent and personalized drug delivery. This regulatory mechanism enables more precise treatment and promotes wound healing.

[0024] 4. The AAO template-based micro-nano conical array intelligent drug delivery bandage of the present invention can achieve precise targeting by clarifying the drug charging mechanism, directional electric field configuration and geometric optimization of the conical channel: the electric field direction strictly corresponds to the wound location to prevent drug diffusion to non-target areas; on-demand adjustment: by changing the electric field polarity to adapt to drugs with different charge properties, the range of therapeutic drug selection is expanded; efficient penetration: the local electric field enhancement effect of the conical channel increases the drug penetration depth, which is particularly suitable for chronic wounds or deep tissue infections. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Shown are the front view and cross-sectional view of the SEM image of the tapered micro-nanohole array layer based on the AAO template of the present invention.

[0026] Figure 2 Shown is a schematic diagram of the internal structure of the micro-nano conical array intelligent drug delivery bandage based on the AAO template of the present invention.

[0027] Figure 3 Shown is a schematic diagram of the middle structure of the micro-nano conical array intelligent drug delivery bandage based on the AAO template of the present invention.

[0028] Figure 4 Shown is a schematic diagram of the external structure of the micro-nano conical array intelligent drug delivery bandage based on the AAO template of the present invention.

[0029] Figure 5 Shown is a schematic diagram of the cross-sectional structure of the micro-nano conical array intelligent drug delivery bandage based on the AAO template of the present invention.

[0030] Figure 6 Shown is a diagram showing the working principle of the AAO template-based micro-nano conical array smart drug delivery bandage of the present invention.

[0031] Figure 7 Shown is a circuit block diagram of the AAO template-based micro-nano conical array smart drug delivery bandage of the present invention.

[0032] In the figure: 1-1 inner layer of the bandage body, 1-2 outer layer of the bandage body, 2-1 first adhesive tape, 2-2 second adhesive tape, 2-3 third adhesive tape, 2-4 fourth adhesive tape, 3-1 temperature sensor, 3-2 pH sensor, 3-3 NH4 + Sensor, 3-4 glucose sensor, 3-5 lactate sensor, 3-6 uric acid sensor, 3-7 reference electrode, 3-8 counter electrode, 4 drug storage layer, 5 conical micro-nanopore array layer, 6-1 conical micro-nanopore array layer lower electrode, 6-2 conical micro-nanopore array layer upper electrode, 7-1 first sensor array integrated circuit, 7-2 second sensor array integrated circuit, 8 intelligent control module, 9 power module, 10 skin. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Example 1

[0035] See also Figure 1-5 A micro-nano conical array intelligent drug delivery bandage based on an AAO template includes a bandage body, a sensor array, a drug storage layer 4, a conical micro-nanopore array layer 5, an intelligent control module 8, and a power module 9.

[0036] The inner layer 1-1 of the bandage body is made of a medical-grade elastic material with excellent breathability and comfort, ensuring that the bandage adheres to the skin 10 for a long time without causing discomfort. A drug storage layer 4 is provided on the inner surface of the inner layer 1-1. This layer is made of a hydrophilic polymer material that can store and maintain the stability of the drug.

[0037] The conical micro-nanopore array layer 5 is prepared by the AAO template method. First, a highly ordered AAO template is formed on an aluminum sheet by electrochemical anodization; then, a conductive material (such as metal or conductive polymer) is filled in the pores of the AAO template using chemical vapor deposition or physical vapor deposition technology to form a conductive conical micro-nanostructure; finally, a film with a conical micro-nanopore array is obtained by dissolving the AAO template. The film is fixed on the drug storage layer 4 of the inner layer 1-1 of the bandage body, and the tip of the conical micro-nanopore array layer 5 is facing the wound to facilitate drug penetration. Microelectrodes are integrated on both sides, wherein the upper electrode is located at the interface between the drug storage layer 4 and the conical layer, and the lower electrode is located at the contact surface between the conical array layer and the wound. The cone angle range of the conical micro-nanopore array layer 5 is 15°-60°, and the array density is 10 6 -10 9 Holes / cm 2The electrode spacing is 50-200 μm. The electric field direction is set by the intelligent control module 8 from the upper electrode (drug reservoir side) to the lower electrode (wound side), forming a directional electric field gradient throughout the tapered channel. By adjusting the electric field strength (0.1 V / cm to 10 V / cm) and polarity, the release direction and rate of positively or negatively charged drugs can be precisely controlled. The tapered geometry of the conical pore (pore size gradually decreases from 500nm on the drug reservoir side to 50nm on the wound side) optimizes the electric field distribution through the following mechanisms: 1) Local electric field enhancement: The reduced cross-sectional area in the narrow pore region increases the electric field line density, significantly enhancing the local electric field strength (up to 2-5 times that of the wide end), thereby enhancing the electrophoretic driving force for charged drug molecules; 2) Directed diffusion inhibition: The tapered structure restricts the random diffusion paths of drug molecules in the pore, forcing them to migrate along the electric field direction, reducing drug backflow; 3) Laminar flow synergy: The electric field-driven electroosmotic flow within the conical pore works synergistically with the pore size gradient to form a unidirectional fluid dynamics from the wide end to the narrow end, further improving drug delivery efficiency. The electric field-controlled response time is <100ms, and the electric field uniformity is ±5% (in the pore size >100nm region).

[0038] The intelligent control module 8 includes a microprocessor (model: STM32L4R5ZI, operating frequency 120MHz), a signal conditioning circuit (including an instrumentation amplifier and a low-pass filter, with a gain range of 1-1000 times and a cutoff frequency of 0.1-100Hz), an analog-to-digital converter (ADC, 16-bit resolution, sampling rate 1kSPS), an electric field generator (H-bridge drive circuit, output frequency adjustable from 10kHz to 1MHz, duty cycle 5% to 95%), and a wireless communication module (Bluetooth 5.2, transmission distance 10 meters). The circuit connection relationship is sensor array output terminal → signal conditioning circuit → ADC → microprocessor; microprocessor PWM output → H-bridge drive circuit → tapered micro-nanopore array layer electrodes (6-1, 6-2); the microprocessor is connected to the wireless module via an SPI interface.

[0039] The sensor (including reference electrode 3-7 and counter electrode 3-8) is used to monitor the temperature, pH, NH4 + , glucose, lactate and uric acid and other parameters, and transmit the data to the microprocessor. The sensor size is a circular sensor with a diameter of 0.5 cm. Its type and quantity can be adjusted according to actual conditions. The sensor array adopts a time-sharing multiplexing design: electrochemical sensors (pH, NH4 +The microprocessor controls the actuator (such as a micropump) to automatically adjust the electric field strength of the electric field generator based on the preset algorithm and the received data, and accurately adjusts the release rate and amount of the drug from the conical micro-nanopore array layer 5 to achieve efficient and accurate drug delivery. The pore size of the conical micro-nanopore array layer 5 ranges from 50nm to 500nm, the pore depth is from 1μm to 10μm, and the distance between pores is from 100nm to 1μm. The selection of these parameters is intended to optimize the penetration efficiency and delivery rate of the drug.

[0040] The power module 9 is a rechargeable lithium battery, which is connected to the intelligent control module 8 , has dimensions of 3cm×2cm×0.4cm, a capacity of 200mAh, and is arranged outside the inner layer 1 - 1 of the bandage body, on the right side of the intelligent control module 8 .

[0041] Example 2

[0042] Furthermore, by precisely adjusting the following key parameters, customized AAO templates that meet the needs of different wounds can be produced: By adjusting the voltage during the anodic oxidation process, the pore size of the AAO template can be effectively controlled. In this embodiment, the oxidation voltage range is set to 20V to 100V to generate micro-nano pores with different pore sizes from 50nm to 500nm; the selection of different types of electrolytes (such as sulfuric acid, oxalic acid, phosphoric acid, etc.) can affect the shape and orderliness of the pores. Oxalic acid is preferred as the electrolyte because it can generate a more regular and ordered pore structure; the concentration of the electrolyte directly affects the pore formation rate and the thickness of the pore wall. The electrolyte concentration is finely controlled between 0.1M and 3M to optimize the pore structure and stability; the depth and density of the pores can be further controlled by adjusting the current density. The current density range is set to 5mA / cm 2 Up to 50mA / cm 2 , to generate channels of different depths to adapt to wounds of different depths; the length of the oxidation time determines the integrity and depth of the channels. The oxidation time is set to 1 hour to 10 hours to ensure that the channels are fully formed without destroying the overall structure of the material; temperature control during the anodizing process is crucial to the orderliness and uniformity of the channels. The temperature is maintained between 0°C and 25°C to optimize the preparation effect of the AAO template; adding a small amount of additives (such as ethanol, glycerol, etc.) to a specific electrolyte can further regulate the shape and arrangement of the channels and improve the adaptability of the AAO template.

[0043] The drug release layer is coated on the AAO template layer and contains therapeutic drugs for specific wound types. The release rate and amount of the drugs from the tapered micro-nanopore array layer 5 are controlled by automatically adjusting the electric field strength of the electric field generator through the control actuator.

[0044] Example 3

[0045] Based on Example 1, the drug molecules loaded into the drug storage layer 4 can be designed to be charged, depending on the therapeutic needs. For example, antibiotics (negatively charged gentamicin) or growth factors (positively charged fibroblast growth factor) can directly utilize their inherent charge properties; neutral drug molecules (ibuprofen) can be given a surface charge by coating them with charged carriers (cationic liposomes, polyelectrolyte nanoparticles). The charged carriers bind to the drug through electrostatic adsorption or chemical bonding, ensuring directional migration under the action of the electric field.

[0046] The intelligent control module 8 includes a wireless communication module for exchanging data with a smartphone or remote medical center. Users can monitor the bandage's status, adjust drug release parameters, and receive remote medical advice via a smartphone app. The microprocessor in the intelligent control module 8 utilizes a low-power design to ensure sufficient battery life during extended use.

[0047] The power module 9 is a rechargeable solid-state lithium battery (rated voltage 3.7V, capacity 200mAh, cycle life >500 times), which integrates 1) a power management chip (TIBQ25619): supports 0.5A fast charging and overvoltage / overcurrent protection; 2) a voltage conversion circuit: 3.3V LDO (quiescent current <2μA) for digital circuits, ±5V DC-DC for sensors; 3) a power monitoring circuit (coulomb counter IC, accuracy ±1%); 4) a wireless charging coil (Qi standard, receiving power 2W).

[0048] Example 4

[0049] Based on Example 1, the edges of the inner layer 1-1 and the outer layer 1-2 of the bandage body are both provided with adhesive tape, and the bandage body can be flexibly adjusted according to the location and size of the wound to ensure that the AAO template layer and the wound are precisely fitted. The outer layer 1-2 of the bandage body uses a waterproof and breathable membrane to prevent external moisture from invading the interior of the bandage while maintaining the breathability and comfort of the bandage. In this embodiment, the waterproof and breathable membrane is made of a polymer material such as polytetrafluoroethylene and has excellent waterproof performance and breathability. At the same time, according to the size and location of the wound, different specifications of the tapered micro-nanopore array layer 5 can be customized to better cover the wound area to achieve the best therapeutic effect.

[0050] Example 5

[0051] Based on Examples 1-4, see Figure 6-7 The working process of a micro-nano conical array smart drug delivery bandage based on AAO template includes:

[0052] Step 1: Place the bandage body on the patient's skin 10 and fix it with adhesive tape, and turn on the power module 9.

[0053] Step 2, the intelligent control module 8 starts to control the temperature sensor 3-1, pH sensor 3-2, NH4 + Sensor 3-3, glucose sensor 3-4, lactate sensor 3-5 and uric acid sensor 3-6 monitor key physiological parameters of the wound.

[0054] In step 3, the microprocessor calculates and controls the actuator to automatically adjust the electric field strength of the electric field generator according to the preset algorithm and the received physiological parameter data, thereby controlling the release rate and amount of the drug from the conical micro-nanopore array layer 5 .

[0055] In step 4, the drug penetrates into the wound site through the conical micro-nanopore array layer 5 to exert a therapeutic effect.

[0056] In step 5, users can monitor the bandage's status, adjust drug release parameters, and receive telemedicine advice through a smartphone app.

[0057] For ease of explanation, spatial relative terms such as "upper", "lower", "inside", and "outside" are used in the embodiments to illustrate the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientation shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "above" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0058] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any actual relationship or order between these components.

[0059] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A micro-nano conical array intelligent drug delivery bandage based on AAO template, characterized in that: It includes a bandage body, a power module, a sensor array, a drug storage layer, a conical micro-nanopore array layer and an intelligent control module. The bandage body is made of breathable and biocompatible materials, and is provided with a drug storage layer inside for loading the drug to be delivered. The drug molecules can be designed to be charged according to treatment needs; The conical micro-nanopore array layer is fabricated using conductive materials using AAO template technology and is located above the drug storage layer. This layer contains a large number of evenly distributed conical micro-nanopores that gradually narrow from the drug storage layer downward, forming a unique conical structure. Microelectrodes are integrated on both sides of the layer to facilitate directional drug delivery under the action of an electric field. The intelligent control module, integrated into the bandage itself, includes a microprocessor, an electric field generator, and a sensor array. The microprocessor receives data from the sensors and adjusts the output of the electric field generator according to a preset program to control the rate and amount of drug delivered through the tapered micro-nanopores. The sensor array is located on the inner surface of the bandage body and can monitor key physiological parameters of wound exudate in real time; The power module provides the necessary electrical energy for the entire system and adopts a miniaturized design to ensure the portability and endurance of the bandage.

2. The AAO template-based micro-nano conical array smart drug delivery bandage according to claim 1, characterized in that: The design of the tapered micro-nanopore array layer enables drugs to move directionally along the tapered channels under the action of an electric field, improving the efficiency and precision of drug delivery. Furthermore, the tapered structure enhances drug penetration, allowing drugs to more effectively penetrate wounds and reach deep lesions.

3. The micro-nano conical array intelligent drug delivery bandage based on AAO template according to claim 1, characterized in that: By adjusting the oxidation voltage, electrolyte type, electrolyte concentration, current density, oxidation time, temperature, and electrolyte component ratio, the pore size range, pore depth, interpore distance, shape, and orderliness of the AAO template can be controlled to meet the needs of different wounds.

4. The AAO template-based micro-nano conical array smart drug delivery bandage according to claim 1, characterized in that: The intelligent control module monitors the physiological changes of the wound in real time through a sensor array and automatically adjusts the electric field strength of the electric field generator according to a preset algorithm to control the release rate and amount of the drug from the tapered micro-nanopore array layer. This intelligent regulation mechanism ensures timely and effective drug delivery, avoiding drug waste and side effects.

5. The AAO template-based micro-nano conical array smart drug delivery bandage according to claim 1, characterized in that: The bandage body features a two-layer structure. The inner layer is made of a breathable and biocompatible material, ensuring comfort and safety during prolonged wear. The outer layer is made of a waterproof, breathable material that effectively prevents the intrusion of external contaminants and protects the wound from infection. Both layers are equipped with adhesive tape for adjusting the tightness of the bandage to suit different wound locations.

6. The AAO template-based micro-nano conical array smart drug delivery bandage according to claim 1, characterized in that: The drug storage layer is made of degradable material and can be naturally degraded after the drug delivery is completed, without the need for secondary removal, thereby reducing the burden on patients.

7. The AAO template-based micro-nano conical array smart drug delivery bandage according to claim 1, characterized in that: The power module features a low-power design and an efficient energy management system to ensure the bandage's stability and reliability over extended use. Furthermore, the power module offers fast charging and intelligent power monitoring, allowing users to easily monitor battery status and charge the bandage at any time.

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