A programmable oxygenation device for wound oxygenation and a method of making the same

Abstract

The present application provides a programmable oxygenation device for wound oxygen supply and its preparation method and application, which comprises a one-way oxygen generation and transmission system and an oxygen storage type supramolecular hydrogel, the one-way oxygen generation and transmission system is arranged on the oxygen storage type supramolecular hydrogel, the one-way oxygen generation and transmission system is used for generating oxygen as an oxygen source to supply oxygen to the oxygen storage type supramolecular hydrogel, the oxygen storage type supramolecular hydrogel is used for storing the oxygen generated by the one-way oxygen generation and transmission system and slowly and continuously releasing the oxygen to the wound surface, so as to provide a long-time oxygen-rich microenvironment for the wound surface. The present application not only breaks through the obstacle of insufficient physical or chemical oxygen supply, but also has the characteristics of portability, safety, long-term storage and good tolerance, especially in a chronic wound model, and shows good wound healing ability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of programmable oxygen therapy devices, more particularly, to a programmable oxygenation device for wound oxygenation (GUFO) integrated with a one-way oxygen generation and transmission system and an oxygen storage hydrogel containing supermolecular assembly of perfluorinated hyperbranched polymer and a preparation method and application thereof. BACKGROUND

[0002] Oxygen plays a crucial role in the entire wound healing process. Hypoxia is a major cause of delayed wound healing, especially for chronic wounds. Widely used oxygen therapy methods to alleviate hypoxia include hyperbaric oxygen therapy (HBOT), topical oxygen therapy (TOT) and other therapies. Hyperbaric oxygen therapy and limb chamber topical oxygen therapy directly use gaseous oxygen to oxygenate wounds, but the oxygenation effect is limited and the oxygenation equipment is large in size, which is not suitable for portable treatment. In recent years, topical oxygen therapy dressings, which use hemoglobin, perfluorocarbon, peroxide, photosynthetic algae and other oxygen-dissolving oxygen-producing substances as oxygen carriers and add various chemicals that may affect wound healing as auxiliary, also have limitations in oxygenating wounds and promoting wound healing due to poor stability of oxygen carriers, toxic byproducts, insufficient oxygenation and other defects. Whether it is hyperbaric oxygen therapy or various topical oxygen therapy, there are a series of obstacles in achieving sustained relief of wound hypoxia. Therefore, it is necessary to develop a programmable oxygenation system that can controllably and continuously oxygenate wounds.

[0003] In addition, for chronic wound tissue regeneration, the structure of bioactive hydrogel matches the natural extracellular matrix, which not only can provide appropriate mechanical support as a scaffold material, but also can serve as an ideal oxygen reservoir and a buffering wet sponge to regulate the wound microenvironment, moisturize the wound and prevent potential oxygen burst. In view of this, the introduction of bioactive hydrogel into the wound oxygenation system is expected to improve the oxygen therapy effect. SUMMARY

[0004] The present application aims to overcome the shortcomings of the existing oxygenation technology, and provides a programmable, portable, controllable and long-term oxygenation device (GUFO) for wound oxygen supply and a preparation method and application thereof; the GUFO oxygenation device is composed of a unidirectional oxygen generation and transmission system (COGT-UTS) as an upper oxygen source and a supramolecular hydrogel (GUF) as a lower temporary oxygen storage library, wherein the unidirectional oxygen generation and transmission system (COGT-UTS) is prepared by encapsulating a controllable oxygen generation tablet (COGT) prepared on the basis of sodium percarbonate in a groove of a transparent polydimethylsiloxane (PDMS) disc, and then sealing the bottom of the disc by using a porous polydimethylsiloxane microneedle sponge (PPDMS-MNS); the supramolecular hydrogel (GUF) of the oxygen storage library is a supramolecular hydrogel (GUF) formed by using a perfluorinated supramolecular polymer (FHBP) as an oxygen carrier and a gelatin grafted with 2-ureido-4[1H]pyrimidinone (Geln-UPy) through multiple hydrogen bonds, hydrophobic interaction and other physical interactions.

[0005] The object of the present application is achieved by the following technical solutions.

[0006] A programmable oxygenation device (GUFO) for wound oxygen supply, comprising a unidirectional oxygen generation and transmission system (COGT-UTS) and an oxygen storage library type supramolecular hydrogel (GUF), wherein the unidirectional oxygen generation and transmission system (COGT-UTS) is arranged on the oxygen storage library type supramolecular hydrogel (GUF), the unidirectional oxygen generation and transmission system (COGT-UTS) is used to generate oxygen as an oxygen source to supply oxygen to the oxygen storage library type supramolecular hydrogel (GUF), and the oxygen storage library type supramolecular hydrogel (GUF) is used to store the oxygen generated by the unidirectional oxygen generation and transmission system (COGT-UTS) and slowly and continuously release oxygen to the wound, thereby providing a long-time oxygen-rich microenvironment for the wound.

[0007] The unidirectional oxygen generation and transmission system (COGT-UTS) comprises a controllable oxygen generation tablet (COGT), a polydimethylsiloxane (PDMS) disc and a porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), a groove is formed in the polydimethylsiloxane (PDMS) disc, the groove is used to place the controllable oxygen generation tablet (COGT), and the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) adopts a disc-shaped structure with one horizontal surface and the other surface uniformly distributed with microneedles, the horizontal surface is arranged on the surface of the polydimethylsiloxane (PDMS) disc, and the surface uniformly distributed with microneedles is inserted into the oxygen storage library type supramolecular hydrogel (GUF).

[0008] A preparation method of a programmable oxygenation device (GUFO) for wound oxygen supply, which is performed according to the following steps:

[0009] Step 1, Preparation of Controlled Oxygen Generating Tablets (COGT):

[0010] (1) Mix dimethyl sulfoxide, sodium percarbonate (SPC) and dopamine hydrochloride (DOPA) and stir for 20-32 h to achieve the purpose of modifying polydopamine (PDA) on the surface of sodium percarbonate (SPC) and finally obtain sodium percarbonate (SPC@PDA) modified with polydopamine.

[0011] (2) The prepared sodium percarbonate (SPC@PDA) modified with polydopamine surface is mixed with disodium hydrogen phosphate dodecahydrate (SPDD), placed in a circular mold for tableting, and after demolding, a round controllable oxygen-generating tablet (COGT) is obtained.

[0012] Step 2: Preparation of grooved polydimethylsiloxane (PDMS) discs: Mix polydimethylsiloxane (PDMS) and curing agent at a mass ratio of (10-20):1 to obtain mixture one. Add the above mixture one into a polytetrafluoroethylene mold with circular raised grooves. After vacuum degassing, cure at 70-90℃ for 20-40 minutes and then demold to obtain a grooved polydimethylsiloxane (PDMS) disc. The size of the circular raised grooves of the polytetrafluoroethylene mold matches the size of the controllable oxygen generating tablet (COGT), so that the controllable oxygen generating tablet (COGT) can be placed in the grooves of the polydimethylsiloxane (PDMS) disc. Both polydimethylsiloxane (PDMS) and curing agent are from silicone elastomer kit (Dow Corning 184).

[0013] Step 3: Preparation of breathable porous polydimethylsiloxane microneedle sponge (PPDMS-MNS): Polydimethylsiloxane and curing agent are mixed evenly at a mass ratio of (10-20):1. Then, sucrose particles with a size of 150-300 μm are added, and the mass ratio of polydimethylsiloxane (PDMS) to sucrose particles is 10:(1-5). This results in mixture two. Mixture two is then added to a polytetrafluoroethylene microneedle mold. After removing air bubbles under vacuum, the mixture is heated at 70-90℃. After curing for 20-40 minutes, the microneedles are demolded to obtain microneedles. The microneedles are then immersed in boiling water for 24 hours, followed by immersion in room temperature water overnight. After drying, porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) is obtained. The porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) has a circular structure with one side horizontal and the other side uniformly distributed with microneedles. The polydimethylsiloxane (PDMS) and curing agent are both from a silicone elastomer kit (Dow Corning 184).

[0014] Step 4: Assembly of the unidirectional oxygen generation and transport system (COGT-UTS): The controllable oxygen generation tablet (COGT) prepared in step 1 is encapsulated in the groove of the polydimethylsiloxane (PDMS) disc prepared in step 2, and finally encapsulated with the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) prepared in step 3, wherein the horizontal plane of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) faces the side of the polydimethylsiloxane (PDMS) disc groove, i.e. the unidirectional oxygen generation and transport system (COGT-UTS) is obtained.

[0015] Step 5: Synthesis of perfluorinated hyperbranched polymer (FHBP): N,N-dimethylformamide (DMF) is used as the solvent, polyethylene glycol diglycidyl ether (PEGEP) and octanediamine (ODA) are used as raw materials, and the reaction temperature is 60-90°C. After polymerization for 4-8h, 3-perfluoroalkyl-1,2-epoxy propane (PFCEP) is added to the reaction system and the reaction continues for 5-9h. Finally, the perfluorinated hyperbranched polymer (FHBP) is obtained. The perfluorinated hyperbranched polymer (FHBP) is dissolved in methanol, and then the methanol solution of the perfluorinated hyperbranched polymer (FHBP) is added dropwise into deionized water. After the methanol is volatilized, the perfluorinated hyperbranched polymer (FHBP) nanoparticle aqueous solution is obtained.

[0016] Step 6: Preparation of oxygen storage library type supramolecular hydrogel (GUF): The 2-ureido-4[1H]pyrimidinone (UPy) grafted gelatin (Geln-UPy) is dissolved in the perfluorinated hyperbranched polymer (FHBP) nanoparticle aqueous solution prepared in step 5 to obtain mixture three. The mixture three is heated to 45°C and dissolved with vigorous stirring. After ultrasonic degassing, the mixture three is gradually cooled to room temperature (20-25°C) to form a gel, which is the oxygen storage library type supramolecular hydrogel (GUF).

[0017] Step 7: Assembly of the programmable oxygenation device (GUFO): The porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) of the unidirectional oxygen generation and transport system (COGT-UTS) is inserted into the oxygen storage library type supramolecular hydrogel (GUF) prepared in step 6, and the side with microneedles is uniformly distributed, thereby obtaining the programmable oxygenation device (GUFO).

[0018] In step 1, the mass ratio of sodium percarbonate (SPC) to dopamine hydrochloride (DOPA) is 1:(1-2), the amount of dimethyl sulfoxide is 100-300mL, and the mass ratio of sodium percarbonate (SPC@PDA) to sodium phosphate dibasic (SPDD) after polydopamine surface modification is 1:(0.5-1.8). The diameter of the controllable oxygen generation tablet (COGT) is 10-45mm, and the height is 1-5mm.

[0019] In step 2, the mass ratio of polydimethylsiloxane (PDMS) and curing agent is 8-20:1, the outer diameter of the polydimethylsiloxane (PDMS) disc is 25-60 mm, the outer wall height is 1.5-5.5 mm, the inner diameter of the groove is 10-45 mm, and the height of the groove is 1-5 mm.

[0020] In step 3, the mass ratio of polydimethylsiloxane (PDMS) and curing agent is 8-20:1, the mass ratio of polydimethylsiloxane (PDMS) and sucrose particles is 10:2-5, the diameter of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) is 25-60 mm, and the thickness is 0.2-0.5 mm; the needle height of the microneedle distributed on the surface of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) is 1 mm, the diameter of the bottom of the microneedle is 0.5 mm, the spacing between adjacent microneedles is 0.5 mm, a hemispherical concave structure is formed at the top end of the microneedle, and the diameter of the hemispherical concave structure is 0.1 mm.

[0021] In step 5, the molar ratio of polyethylene glycol diglycidyl ether (PEGEP), octanediamine (ODA) and 3-perfluoroalkyl-1,2-epoxypropane (PFCEP) is 1:0.8:1.2, the reaction temperature of the ring-opening polymerization reaction is 65-80℃, and the total reaction time is 10-15h.

[0022] In step 6, the mass ratio of perfluorinated hyperbranched polymer (FHBP) to water is (5-10):100, and the mass ratio of 2-ureido-4[1H]pyrimidinone grafted gelatin (Geln-UPy) to water is (15-30):100.

[0023] The beneficial effects of the present application are: compared with the prior art, the programmable oxygenation device (GUFO) integrates a one-way oxygen generation and transmission system (COGT-UTS) as an upper oxygen source, containing an oxygen storage type supramolecular hydrogel (GUF) of perfluorinated hyperbranched polymer (FHBP) and 2-ureido-4[1H] pyrimidinone grafted gelatin (Geln-UPy) as a lower oxygen storage; the upper one-way oxygen generation and transmission system (COGT-UTS) triggers the oxygen production of the controllable oxygen production tablet (COGT) by near-infrared light (808nm) irradiation through the polydimethylsiloxane (PDMS) disc, due to the numerous voids in the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), its air permeability is much higher than that of the polydimethylsiloxane (PDMS) disc, so the gaseous oxygen can only pass through the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) and transmit oxygen to the oxygen storage type supramolecular hydrogel (GUF) located in the lower layer of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), and based on the hydrophobicity of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), the by-products such as hydrogen peroxide and hydroxyl ion transmitted through the water channel are effectively hindered; the oxygen storage type supramolecular hydrogel (GUF) located in the lower layer of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) introduces perfluorinated hyperbranched polymer (FHBP) nanoparticles, which can act as an oxygen carrier and a temporary oxygen storage, dissolve the gaseous oxygen transmitted from the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), and convert it into dissolved oxygen, and the wet environment of the oxygen storage type supramolecular hydrogel (GUF) provides a long-term oxygen-rich microenvironment for the hypoxic wound surface, reverses the adverse situation of wound hypoxia, and is used for the treatment of diabetic chronic hypoxia type wound (such as SD rats);

[0024] The controllable oxygen production tablet (COGT) located in the upper layer of the programmable oxygenation device (GUFO) can control the oxygen production rate through near-infrared, and the tablet system can be replaced at any time to further prolong the oxygenation time, and the size and shape of the tablet can be customized according to the area and geometry of the patient's wound surface to meet individual needs; the oxygen storage type supramolecular hydrogel (GUF) located in the lower layer of the programmable oxygenation device (GUFO) has good mechanical support, rapid self-healing ability, tissue adhesion and antioxidant property, and is used for long-term regulation of the microenvironment of the wound surface to promote wound healing;

[0025] The programmable oxygenation device (GUFO) not only breaks through the barrier of insufficient physical or chemical oxygen supply, but also has the characteristics of portability, safety, long-term storage and good tolerance, especially in the rat chronic wound model, the GUFO oxygen therapy device shows good wound healing ability. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 are the preparation and characterization diagrams of the controllable oxygen-generating tablet (COGT) in the present application, wherein (a) is a preparation flowchart of the COGT, (b) is a display diagram of the COGT and the OGT with different sizes, (c) is a display diagram of the COGT (diameter 10 mm, height 1 mm) after encapsulation, (d) is a temperature change diagram of the COGT (diameter 10 mm, height 1 mm) and the OGT (diameter 10 mm, height 1 mm) under 808 nm infrared light irradiation within 5 minutes, (e) is a photothermal heating / cooling curve of the COGT (diameter 10 mm, height 1 mm) after 4 cycles, (f) is the oxygen release amount of the COGT (diameter 10 mm, height 1 mm) under the conditions of near-infrared light irradiation and no infrared light irradiation and its fitting curve, (g) is the cumulative oxygen release amount of the COGT, the OGT, the SPC@PDA and the SPC under intermittent near-infrared light (5 min h -1 , 10 times / day) irradiation within 120 hours;

[0027] Figure 2 are the characterization diagrams of the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) used in the animal experiment in the present application, wherein (a-d) are macroscopic display diagrams of the PPDMS-MNS, and (e-g) are microscopic morphology diagrams of the PPDMS-MNS;

[0028] Figure 3 are the characterization diagrams of the perfluorinated hyperbranched polymer (FHBP) nanoparticle aqueous solution used in the animal experiment in the present application, wherein (a) is a preparation schematic diagram of the FHBP nanoparticle, (b) is a nuclear magnetic resonance hydrogen spectrum diagram of the FHBP, (c) is a nuclear magnetic resonance fluorine spectrum diagram of the FHBP, (d) is an observation diagram of the Tyndall effect phenomenon of the FHBP-5% nanoparticle aqueous solution, (e) is a hydration dynamic diameter of the FHBP-5% nanoparticle aqueous solution, (f) is an oxygen carrying amount diagram of the FHBP-5% nanoparticle aqueous solution, and (g) is an oxygen release diagram of the FHBP-5% nanoparticle aqueous solution;

[0029] Figure 4is a preparation and characterization diagram of oxygen storage library type supramolecular hydrogel (GUF) used in animal experiments in the application, wherein, (a) is an inverted gel forming picture of GUF-5 hydrogel, (b) is a knot stretching picture of GUF-5 hydrogel strip, (c) is a micro-morphology and element distribution picture of GUF-5 hydrogel, (d) is a tensile stress-strain curve of GUF-x (x = 0, 2.5, 5, 10, x is the grafting rate of UPy) hydrogel, (e) is a compressive stress-strain curve of GUF-x (x = 0, 2.5, 5, 10, x is the grafting rate of UPy) hydrogel, and (f) is an angular frequency scanning rheological curve of GUF-x (x = 0, 2.5, 5, 10, x is the grafting rate of UPy) hydrogel;

[0030] Figure 5 is a preparation and composition diagram of a programmable oxygenation device (GUFO) used in animal experiments in the application, wherein, (a) is a composition process diagram of the GUFO oxygenation device, the composition of the GUFO oxygenation device includes the COGT-UTS as the upper layer and the GUF hydrogel as the lower layer, (b) is a real picture of the GUFO oxygenation device, the scale: 10 mm, (c-d) are the top view and front view of the GUFO oxygenation device adhered to the pig skin and irradiated by 808 nm near-infrared light, the scale: 10 mm;

[0031] Figure 6 is a wound effect diagram and histological evaluation diagram of a programmable oxygenation device (GUFO) used in animal experiments in the application in repairing the wound surface in a SD rat diabetic chronic wound model, wherein, (a) is a wound surface closure situation picture of each group of wound surfaces on day 0, 3, 7, 12 and 18, (b) is a wound size change diagram of each group of wound healing processes, and (c) is an H&E staining result of each group of wound healing processes;

[0032] Figure 7 is a schematic diagram of the programmable oxygenation device (GUFO) of the application. DETAILED DESCRIPTION

[0033] The technical solutions of the application are further described below through specific examples.

[0034] A programmable oxygenation device (GUFO) for wound oxygen supply, comprising a one-way oxygen generation and transmission system (COGT-UTS) and an oxygen storage library type supramolecular hydrogel (GUF), the one-way oxygen generation and transmission system (COGT-UTS) is arranged on the oxygen storage library type supramolecular hydrogel (GUF), the one-way oxygen generation and transmission system (COGT-UTS) is used to generate oxygen as an oxygen source to supply oxygen to the oxygen storage library type supramolecular hydrogel (GUF), and the oxygen storage library type supramolecular hydrogel (GUF) is used to store the oxygen generated by the one-way oxygen generation and transmission system (COGT-UTS) and slowly and continuously release oxygen to the wound, providing a long-time oxygen-rich microenvironment for the wound.

[0035] The one-way oxygen generation and transmission system (COGT-UTS) comprises a controllable oxygen generation tablet (COGT), a polydimethylsiloxane (PDMS) disc and a porous polydimethylsiloxane microneedle sponge (PPDMS-MNS), a groove is formed in the polydimethylsiloxane (PDMS) disc, the groove is used to place the controllable oxygen generation tablet (COGT), and the porous polydimethylsiloxane microneedle sponge (PPDMS-MNS) adopts a disc-shaped structure with one horizontal surface and the other surface uniformly distributed with microneedles, the horizontal surface is arranged on the surface of the groove of the polydimethylsiloxane (PDMS) disc, and the surface uniformly distributed with microneedles is inserted into the oxygen storage library type supramolecular hydrogel (GUF).

[0036] A preparation method of a programmable oxygenation device (GUFO) for wound oxygen supply, which is prepared according to the following steps:

[0037] Step 1: 5g sodium percarbonate (SPC), 5g dopamine hydrochloride (DOPA) and 150mL dimethyl sulfoxide are added to a 250mL three-necked flask, and the reaction is stirred at room temperature for 24h. After the reaction is completed, the product is washed with anhydrous ethanol, filtered and vacuum dried to obtain SPC@PDA. 0.5g SPC@PDA and 0.5g disodium phosphate dodecahydrate (SPDD) are weighed and uniformly mixed, and then pressed into a tablet in a cylindrical mold with a diameter of 10mm to obtain a cylindrical COGT tablet with a diameter of 10mm and a height of 1mm.

[0038] The tablet obtained by pressing 0.5g sodium percarbonate (SPC) and 0.5g disodium phosphate dodecahydrate (SPDD) is named OGT and used as a control group.

[0039] As Figure 1(d) and (e) show that COGT has obvious photothermal phenomenon under 808 nm near-infrared light irradiation, and its surface temperature can be increased from 22℃ to 42℃ within 5 minutes, while OGT has no photothermal effect due to the lack of modification of SPC by polydopamine, and its surface temperature can only be increased to 29℃ under the same condition of near-infrared light irradiation; in addition, COGT can be rapidly heated to 42℃ in four consecutive near-infrared light on / off cycles, and the photothermal temperature does not decay, and it cools to the initial temperature immediately after the near-infrared light is turned off, showing good photothermal stability.

[0040] COGT was packaged in a needle tube, both ends of which were sealed with pistons. If COGT released oxygen, the oxygen would push the pistons to move outward, and the volume of oxygen released could be calculated according to the distance pushed by the pistons, and then the oxygen release amount was obtained. As shown in Figure 1 (f) shows that COGT releases oxygen under near-infrared irradiation, and the oxygen release rate gradually increases, reaches a maximum, and then gradually slows down, and finally reaches a platform; while without near-infrared light irradiation, COGT hardly releases oxygen, and the oxygen release amount remains at a very low level, therefore, near-infrared light can stimulate COGT to release oxygen, thereby achieving the control effect.

[0041] In order to further prove the near-infrared light controlled oxygen release effect of COGT and the indispensability of SPDD, COGT, OGT, SPC@PDA and SPC with the same oxygen release potential were placed under intermittent near-infrared light, and the oxygen release amount-time curve was obtained, i.e. Figure 1 (g), the results show that SPC@PDA and SPC cannot release any oxygen due to the lack of necessary catalyst provided by SPDD, while COGT and OGT can release oxygen. Whether during near-infrared light irradiation or without near-infrared light irradiation, OGT maintains a uniform oxygen release rate, while the oxygen release rate of COGT during near-infrared light irradiation is significantly higher than that during near-infrared light irradiation, indicating that near-infrared light can control the oxygen release of COGT.

[0042] Step 2: 4.5 g of the matrix of PDMS and 0.3 g of curing agent were mixed uniformly, and the mixture was added to a circular polytetrafluoroethylene mold (diameter 20 mm, height 2 mm) with a circular convex groove (diameter 11 mm, height 1.2 mm). After vacuum degassing, it was cured at 80℃ for 30 min, and then demolded to obtain a PDMS disc with a groove. It was soaked in 75% ethanol for disinfection and drying, ready for use, i.e. a PDMS disc.

[0043] Step 3: Mix 4.5g of PDMS matrix and 0.3g of curing agent evenly, then add 1.4g of 200μm sucrose particles. Mix the mixture evenly and add it to a circular polytetrafluoroethylene microneedle mold (inner diameter 30mm, inner height 0.4mm; conical microneedles: needle height 1.1mm, needle bottom diameter 800μm; needle tip hemispherical protrusion: diameter 200μm). Degas the mixture, cure at 80℃ for 30min, demold, immerse the obtained microneedle membrane in boiling water for 24h, then immerse it in room temperature water overnight, then sterilize it in 75% alcohol, and dry it for later use. This is PPDMS-MNS.

[0044] In steps 2 and 3, the matrix and curing agent of PDMS were both derived from a silicone elastomer kit (Dow Corning 184).

[0045] like Figure 2 As shown, PPDMS-MNS microneedles have a large number of pores on both the surface and inside, which provides a channel for oxygen to permeate.

[0046] Step 4: Dissolve 10 mmol of polyethylene glycol diglycidyl ether (PEGEP) and 7 mmol of 1,8-octanediamine in 100 mL of anhydrous N,N-dimethylformamide (DMF). After degassing under reduced pressure, heat the reaction system to 80 °C and stir at 1000 rpm / min for 6 h. Then, add 12 mmol of 3-perfluoroalkyl-1,2-epoxypropane (PFCEP) and continue stirring for 8 h. After the reaction is complete, cool the reaction system to room temperature, precipitate the product with ice-cold diethyl ether, extract, collect the lower layer of viscous liquid, and dry under vacuum to obtain the product FHBP. Weigh 0.05 g of dried FHBP, dissolve it in 2 mL of methanol, and then add it dropwise dropwise to a beaker containing 10 mL of deionized water and equipped with a stirrer using a syringe. After the addition is complete, continue stirring to evaporate the solvent, and make up to 10 mL to obtain a 5% concentration of FHBP nanoparticle aqueous solution.

[0047] Hydrophilic polyethylene glycol is linked to hydrophobic long alkyl chains via ring-opening polymerization of amino and epoxy groups, and then capped with perfluorinated groups to obtain the perfluorinated hyperbranched polymer FHBP.

[0048] exist Figure 3 In (b), the absorption peaks at 1.25-1.37 ppm and 2.14-2.51 ppm correspond to protons on the diamine alkyl chain, the proton peak at 3.33-3.51 ppm originates from the methylene group of polyethylene glycol, and the characteristic peak at 3.63 ppm originates from the protons on the tertiary carbon obtained by ring opening of epoxy.

[0049] Figure 3(c) The FHBP was shown to correspond to the fluorine signal of perfluorohexyl group, in which the absorption peak at -82.34pp was derived from the absorption vibration of trifluoromethyl group. The above results proved the successful synthesis of FHBP.

[0050] As shown in Figure 3 As shown in (d) and (e), the FHBP-5% aqueous solution showed obvious Tyndall phenomenon, indicating that the FHBP assembled into colloidal particles in water, and the dynamic light scattering results showed that the particle size was 269±6nm and the polydispersity index was less than 0.3, indicating that the FHBP particle size was uniform and the solution was stable.

[0051] As shown in Figure 3 As shown in (f), deionized water was deoxygenated as a blank group (H2O), and PFH-5%@F68 solution obtained by emulsifying perfluorohexyl (PFH) with FDA-approved emulsifier polyether F68 was used as a positive control group (PFH-5%@F68), and the dissolved oxygen of each group was measured by a pen-type dissolved oxygen meter. Compared with the oxygen-saturated H2O+O2 group, the oxygen-carrying capacity of the FHBP-5% solution was 3.19±0.16mg L -1 , which was higher than that of the perfluorinated emulsion PFH-5%@F68 group (2.61±0.35mg L -1 ).

[0052] As shown in Figure 3 (g), in order to further study the oxygen release behavior of the FHBP solution, the oxygen concentration of the oxygen-saturated deionized water group decreased rapidly within the first 8h, and then tended to be flat, while the oxygen-saturated PFH-5%@F68 and FHBP-5% solutions showed a relatively stable oxygen release rate and maintained a high oxygen concentration.

[0053] The above results show that the introduction of perfluorinated chains enables FHBP to have good oxygen-carrying and releasing capacity.

[0054] Step 5: Gelatin grafted with UPy groups (Geln-UPy) was synthesized according to the reference “Self-Healing Gelatin Hydrogels Cross-Linked by Combining Multiple Hydrogen Bonding and Ionic Coordination” (Macromol. Rapid Commun. 2017, 38, 1700018), and UPy-modified gelatin (Geln-UPy-5) with a theoretical grafting rate of 5% was used. 0.3 g of Geln-UPy-5 was dissolved in 1 mL of FHBP aqueous solution with a concentration of 5% prepared in step 4, heated to 45°C, and dissolved with the aid of vigorous stirring, and ultrasonic bubble removal. The mixture was poured into a round mold (diameter 10 mm, thickness 1 mm), cooled to form a gel, and demolded to obtain a GUF-5 hydrogel. Correspondingly, the pure Geln-UPy-5 gel without the introduction of FHBP was recorded as GU-5, as a control group. The obtained gel was irradiated under ultraviolet light for 12 h to sterilize, and then stored at low temperature under sterile conditions.

[0055] wherein the synthesis process of gelatin grafted with UPy groups (Geln-UPy) is as follows: 0.05 mol of 2-amino-4-hydroxy-6-methylpyrimidine is dissolved in 0.35 mol of hexamethylene-1,6-diisocyanate, heated at 100°C under nitrogen atmosphere for 16 h, and after reaction, pentane is added to the reaction mixture, and the obtained precipitate is filtered. The crude product is washed with pentane to remove residual hexamethylene-1,6-diisocyanate, and finally the purified product is dried in a vacuum oven for 48 hours to obtain isocyanate-modified UPy monomer (UPy-NCO). 4.75 g of gelatin is dissolved in 40 mL of dimethyl sulfoxide, and then 0.25 g of UPy-NCO is added. After stirring for 24 h, the reaction mixture is precipitated in ethanol, and filtered to obtain gelatin grafted with UPy groups (Geln-UPy).

[0056] As shown in Figure 4 (a)-(c), the GUF-5 gel prepared above was freeze-dried, observed using a scanning electron microscope, and subjected to energy spectrum scanning. The results showed that the internal structure of the hydrogel was a porous network structure, and the hydrogel network contained elements such as F, N, O, and S.

[0057] As shown in Figure 4 (d) and (e), the GUF-5 hydrogel showed the best mechanical properties in terms of both tensile properties and compression properties.

[0058] As shown in Figure 4 (f), the storage modulus (G’) of the hydrogel was higher than the loss modulus (G”), which confirmed the stable structure of the hydrogel from the perspective of rheology.

[0059] Step 6: Put the COGT tablets prepared in step 1 into the PDMS disc groove prepared in step 2, and then encapsulate from the bottom with PPDMS-MNS prepared in step 3, to obtain a one-way oxygen generation and transmission system (COGT-UTS), and then insert the side of the COGT-UTS with evenly distributed microneedles into the GUF-5 hydrogel prepared in step 5, to obtain an oxygenation device GUFO, as shown in Figure 5 .

[0060] The wound repair ability of the programmable oxygenation device (GUFO) prepared for wound oxygen supply was tested and verified as follows:

[0061] Male SD rats aged 4 to 6 weeks and weighing 180 to 200 g were selected for the study of the effect of hydrogel on the repair of diabetic wounds.

[0062] All rats were fasted for 12 h, and then intraperitoneally injected with 55 mg / kg of streptozotocin (STZ). Seven to 14 days after injection, the fasting blood glucose was continuously monitored, and 40 rats with blood glucose higher than 16.7 mmol / L were selected for the subsequent experiment. The rats were punctured on the back by a 10 mm diameter puncher to cause full-thickness skin defects, and a diabetic wound model was obtained.

[0063] The 40 model rats were randomly and evenly divided into PBS, GU, GUF, and GUFO treatment groups. In the PBS group, 200 μL of sterile PBS was added to the wound with a syringe. In the GU, GUF, and GUFO treatment groups, the wounds were treated with GU-5 gel, GUF-5 gel, and GUFO oxygenation device, respectively. The GUFO oxygenation device was equipped with near-infrared light irradiation (808 nm, 5 min / time, 2 times / day). All wounds were covered with 3M medical dressing (Tegaderm TM ) to reduce the loss of liquid or hydrogel; after treatment, the wound was photographed every day, and the wound area was measured by ImageJ software; 18 days after treatment, the rats were euthanized, and the wound tissues were dissected and placed in a 4% paraformaldehyde solution for 24 h, followed by paraffin sectioning and H&E staining.

[0064] Figure 6are the wound effect pictures and histological evaluation pictures of the GUFO oxygenation device in the SD rat diabetic chronic wound model, the group using only PBS to clean the wound is set as the PBS group, the group using GU-5 hydrogel to treat is set as the GU group, the group using GUF-5 hydrogel to treat is set as the GUF group, and the group using the GUFO oxygenation device equipped with near-infrared light irradiation to treat is set as the GUFO group, wherein (a) is the wound closure condition picture of each group on the 0th, 3rd, 7th, 12th and 18th day, and (b) is the wound size change picture of each group in the wound healing process. Through observation and software statistics, the wound closure speed of the GUFO group is higher than that of the other control groups. Through H&E staining of paraffin sections, it can be seen that the GUFO group has been completely epithelialized on the 18th day; while the epithelial tissue of the control group still has a large gap, as shown in (c), the above results consistently prove the pro-healing effect of the programmable oxygenation device (GUFO) for wound oxygen supply. Figure 6

[0065] The above has exemplarily described the present application, and it should be noted that any simple modification, change or other equivalent replacement without creative labor of those skilled in the art without departing from the core of the present application falls within the protection scope of the present application.​

Claims

1. A method for preparing a programmable oxygenation device for wound oxygen supply, characterized in that: Follow these steps: Step 1, Preparation of controllable oxygen-generating tablets: (1) Mix dimethyl sulfoxide, sodium percarbonate and dopamine hydrochloride and stir for 20-32 h to achieve the purpose of modifying polydopamine on the surface of sodium percarbonate, and finally obtain sodium percarbonate modified with polydopamine. (2) The prepared sodium percarbonate modified with polydopamine is mixed with disodium hydrogen phosphate dodecahydrate, placed in a circular mold for tableting, and after demolding, a round controllable oxygen-generating tablet is obtained. Step 2: Preparation of grooved polydimethylsiloxane (PDMS) discs: Mix polydimethylsiloxane and curing agent evenly at a mass ratio of (10-20):1 to obtain mixture one. Add the above mixture one into a polytetrafluoroethylene mold with circular raised grooves. After vacuum degassing, cure at 70-90℃ for 20-40 minutes and then demold to obtain a grooved polydimethylsiloxane (PDMS) disc. The size of the circular raised grooves of the polytetrafluoroethylene mold matches the size of the controllable oxygen-generating tablet, so that the controllable oxygen-generating tablet can be placed in the grooves in the polydimethylsiloxane disc. The polydimethylsiloxane and curing agent are both from a silicone elastomer kit, model Dow Corning 184. Step 3: Preparation of breathable porous polydimethylsiloxane microneedle sponge: After mixing polydimethylsiloxane and curing agent at a mass ratio of (10-20):1, sucrose particles with a size of 150-300μm are added to the mixture. The mass ratio of polydimethylsiloxane to sucrose particles is 10:(1-5). The mixture is then mixed evenly to obtain mixture two. Mixture two is added to a polytetrafluoroethylene microneedle mold. After removing air bubbles under vacuum, the mixture is cured at 70-90℃ for 20-40 minutes and then demolded to obtain microneedles. The obtained microneedles are then soaked in boiling water for 24 hours and then soaked in room temperature water overnight. After drying, porous polydimethylsiloxane microneedle sponge is obtained. The porous polydimethylsiloxane microneedle sponge has a circular structure with one side horizontal and the other side uniformly distributed with microneedles. Both polydimethylsiloxane and curing agent are from a silicone elastomer kit, model Dow Corning 184. Step 4: Assembly of the one-way oxygen generation and transport system: The controllable oxygen-generating tablet prepared in Step 1 is encapsulated in the groove of the polydimethylsiloxane disk prepared in Step 2. Finally, the porous polydimethylsiloxane microneedle sponge prepared in Step 3 is used for encapsulation, wherein the horizontal surface of the porous polydimethylsiloxane microneedle sponge faces the groove of the polydimethylsiloxane disk, thus obtaining the one-way oxygen generation and transport system. Step 5: Synthesis of perfluorinated hyperbranched polymer: Using N,N-dimethylformamide as solvent, polyethylene glycol diglycidyl ether and octanediamine as raw materials, a ring-opening polymerization reaction was carried out at a reaction temperature of 60-90℃ for 4-8 hours. Then, 3-perfluoroalkyl-1,2-epoxypropane was added to the reaction system and the reaction was continued for 5-9 hours to finally obtain the perfluorinated hyperbranched polymer. The prepared perfluorinated hyperbranched polymer was dissolved in methanol, and then the methanol solution of the perfluorinated hyperbranched polymer was added dropwise to deionized water. After the methanol was evaporated, an aqueous solution of perfluorinated hyperbranched polymer nanoparticles was obtained. Step 6: Preparation of oxygen reservoir type supramolecular hydrogel: Dissolve 2-ureido-4[1H]pyrimidinone grafted gelatin in the aqueous solution of perfluorinated hyperbranched polymer nanoparticles prepared in step 5 to obtain mixture three. Heat the above mixture three to 45°C, stir vigorously to assist dissolution, remove bubbles by sonication, and then gradually cool the mixture three to room temperature of 20-25°C to form a gel, which is the oxygen reservoir type supramolecular hydrogel. Step 7: Assembly of the programmable oxygenation device: Insert the side of the porous polydimethylsiloxane microneedle sponge with microneedles evenly distributed on it into the oxygen storage supramolecular hydrogel prepared in step 6 to obtain the programmable oxygenation device.

2. The method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 1, the mass ratio of sodium percarbonate to dopamine hydrochloride is 1:(1-2), the amount of dimethyl sulfoxide is 100-300 mL, the mass ratio of sodium percarbonate modified with polydopamine to disodium hydrogen phosphate dodecahydrate is 1:(0.5-1.8), and the diameter of the controllable oxygen-generating tablet is 10-45 mm and the height is 1-5 mm.

3. The method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 2, the mass ratio of polydimethylsiloxane to curing agent is 15:

1.

4. The method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 2, the outer diameter of the polydimethylsiloxane disk is 25-60 mm, the outer wall height is 1.5-5.5 mm, the inner diameter of the groove is 10-45 mm, and the height of the groove is 1-5 mm.

5. A method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 3, the mass ratio of polydimethylsiloxane (PDMS) to curing agent is (8-20):1, and the mass ratio of polydimethylsiloxane (PDMS) to sucrose granules is 10:(2-5).

6. A method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 3, the porous polydimethylsiloxane microneedle sponge has a diameter of 25-60 mm and a thickness of 0.2-0.5 mm; the microneedles distributed on the surface of the porous polydimethylsiloxane microneedle sponge have a needle height of 1 mm, a bottom diameter of 0.5 mm, and a spacing of 0.5 mm between adjacent microneedles. A hemispherical concave structure is formed at the top of the microneedle, and the diameter of the hemispherical concave structure is 0.1 mm.

7. A method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 5, the molar ratio of polyethylene glycol diglycidyl ether, octanediamine and 3-perfluoroalkyl-1,2-epoxypropane is 1:0.8:1.2, the reaction temperature of the ring-opening polymerization reaction is 65-80℃, and the total reaction time is 10-15h.

8. A method for preparing a programmable oxygenation device for wound oxygen supply according to claim 1, characterized in that: In step 6, the mass ratio of the perfluorinated hyperbranched polymer to water is (5-10):100, and the mass ratio of the 2-ureido-4[1H]pyrimidinone-grafted gelatin to water is (15-30):

100.

9. A programmable oxygenation device for wound oxygenation prepared using the method described in any one of claims 1-8, characterized in that: The invention includes a one-way oxygen generation and transport system and an oxygen reservoir-type supramolecular hydrogel. The one-way oxygen generation and transport system is disposed on the oxygen reservoir-type supramolecular hydrogel. The one-way oxygen generation and transport system is used to generate oxygen as an oxygen source to supply oxygen to the oxygen reservoir-type supramolecular hydrogel. The oxygen reservoir-type supramolecular hydrogel is used to store the oxygen generated by the one-way oxygen generation and transport system and slowly and continuously release oxygen to the wound, providing a long-term oxygen-rich microenvironment for the wound. The unidirectional oxygen generation and transport system includes a controllable oxygen-generating tablet, a polydimethylsiloxane disk, and a porous polydimethylsiloxane microneedle sponge. A groove is formed in the polydimethylsiloxane disk to hold the controllable oxygen-generating tablet. The porous polydimethylsiloxane microneedle sponge has a circular structure with one side horizontal and the other side uniformly distributed with microneedles. The horizontal side is encapsulated in the groove of the polydimethylsiloxane disk, while the side with uniformly distributed microneedles is inserted into the oxygen reservoir-type supramolecular hydrogel.

10. The application of the programmable oxygenation device for wound oxygen supply as described in claim 9 in the preparation of wound repair materials.

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