Method for in-situ rapid growth of double-network hydrogel coating on surface of substrate and application of double-network hydrogel coating

Abstract

The invention discloses a method for in-situ rapid growth of a dual-network hydrogel coating on the surface of a base material by a one-step method, which comprises the following steps: putting the base material with an adhesion initiation layer on the surface into a hydrogel precursor solution, and carrying out in-situ polymerization for 0.1-10 minutes under light irradiation, wherein the adhesion initiation layer comprises an adhesive compound based on a catechol group and a first photoinitiator, and the hydrogel precursor solution comprises a natural polymer containing tyrosine, an acrylic monomer, a cross-linking agent and a second photoinitiator, and wherein the first photoinitiator and the second photoinitiator are different from each other and are independently selected from a divalent ruthenium compound and a persulfate. Compared with the prior art, the natural / synthetic polymer double-network gel coating with biological activity and mechanical property can grow on the surfaces of different substrates more quickly and efficiently through a one-step method; and the base material, the surface of which is modified by the in-situ grown double-network hydrogel coating, obtained by the method can be applied to in-vivo medical apparatuses and instruments.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomedical materials, and more particularly to a method for in-situ rapid growth of a double-network hydrogel coating on the surface of a substrate and applications thereof. BACKGROUND

[0002] With the proposal of smart medicine, the development of medical level and the combination of medical, nursing and health care industry, the demand for various medical devices used in the body is increasingly urgent. Hydrophilic and lubricious hydrogel coatings are widely used to improve the biocompatibility of the surface of interventional devices, reduce the sense of intervention, and reduce blood disturbance and damage to surrounding tissues. Hydrogel is a high molecular material with an endogenous three-dimensional cross-linked network, which has the advantages of hydrophilicity, lubricity, biocompatibility, etc., and various physical and chemical means can be used to modify the hydrogel lubricating coating to the surface of medical devices. For example, some scholars use dopamine-rich adhesive glue as a bonding-initiating layer, and through the use of the adhesive properties of catechol, the coordination ability of metal ions and the oxidation-reduction activity of dopamine, a polyacrylic acid hydrogel coating is grown in-situ on the surface of different materials (for example, see CN 114163925 A; Angew. Chem. Int. Ed. 2022, 61, e202209741; Adv. Mater. 2022, 34, 2108889). In addition, some scholars graft dopamine to the end of four-armed polyethylene glycol (PEG), and through the adhesion of dopamine, four-armed PEG is adsorbed to the surface of metals, silicon, glass, polymers and other materials, forming an enhanced circular PEG hydrogel coating (for example, see ACS Macro letter 2022, 11, 805-12). However, the above-mentioned work only forms a single network of synthetic hydrogel on the surface of the material, which has poorer biological activity than the hydrogel formed by natural polymers, or the hydrogel formed only by natural polymers has poor mechanical properties and is insufficient for application in hydrogel coatings. Therefore, it is difficult to obtain high mechanical properties and biological activity through a single network of hydrogel coating.

[0003] In the field, a double-network hydrogel formed by natural polymers and synthetic polymers has been proposed to solve the above problems. For example, some scholars have grown a layer of hyaluronic acid hydrogel on the surface of the material based on the catalytic cross-linking of horseradish peroxidase, and then immersed it in a hydrogel precursor solution (acrylamide monomer, cross-linking agent, initiator) for 15 hours, finally cross-linking to form a double-network hydrogel with biological activity and high mechanical properties (for example, see Adv. Funct. Mater. 2024, 34, 2312465). However, the double-network hydrogel in this technology needs to be prepared by a two-step method, which is time-consuming and cannot be prepared quickly, and the biological enzymes used in the process are prone to inactivation and high in cost.

[0004] In addition, CN116808305A discloses a cartilage matrix-based hydrogel and its preparation method and application, wherein methylacrylated hyaluronic acid and a visible light crosslinking system are used, and the visible light promotes the formation of a CdECM and HAMA composite hydrogel through a photo initiator chloro tris(2,2'-bipyridine) ruthenium(II) and sodium persulfate (Ru / SPS); at the same time, chemical crosslinking between the CdECM component in the hydrogel and the surrounding tissue is induced to form tyrosine, so that the hydrogel has tissue adhesion. However, this document is not used for in-situ growth of a hydrogel on a substrate, and more not for forming a double network hydrogel; more importantly, the use of two photo initiators chloro tris(2,2'-bipyridine) ruthenium(II) and sodium persulfate (Ru / SPS) together in this document is also impossible to form a double network hydrogel.

[0005] Therefore, there is a need in the art to develop a new method for in-situ rapid growth of a double network hydrogel coating on the surface of a substrate. SUMMARY

[0006] Therefore, there is a need in the art to develop a new method for in-situ rapid growth of a double network hydrogel coating on the surface of a substrate.

[0007] To this end, the present application provides a method for in-situ rapid growth of a double network hydrogel coating on the surface of a substrate by one-step, which comprises: placing a substrate having an adhesion initiation layer on the surface into a hydrogel precursor solution and in-situ polymerizing under light irradiation for a time period of 0.1-10 min, thereby obtaining a substrate modified by a double network hydrogel coating grown in-situ on the surface, wherein the adhesion initiation layer comprises an adhesion agent compound based on catechol groups and a first photo initiator, the hydrogel precursor solution comprises a natural polymer containing tyrosine, an acrylic monomer, a crosslinking agent and a second photo initiator, and wherein the first photo initiator and the second photo initiator are different from each other and independently selected from a divalent ruthenium compound and a persulfate salt.

[0008] In a preferred embodiment, the adhesion initiation layer is formed by dissolving the adhesion agent compound based on catechol groups and the first photo initiator in an organic solvent at room temperature, then depositing the obtained solution onto the surface of the substrate and preliminarily drying to remove most of the organic solvent.

[0009] In a preferred embodiment, in the obtained solution described above, the mass concentration of the adhesion agent compound based on catechol groups is 1-20 mass %.

[0010] In a preferred embodiment, the temperature of the in-situ polymerization is -20-40°C, and the light irradiation is performed using visible light with a wavelength of 350-500 nm.

[0011] In a preferred embodiment, the catechol-based adhesive compound is selected from one or more of dopamine hydrochloride, dopamine analogs, and methacryloyl dopamine copolymers.

[0012] In a preferred embodiment, the dopamine analogue is selected from one or more of tannic acid, catechol-gallic acid, and gallic acid.

[0013] In a preferred embodiment, the methacrylamide dopamine copolymer is a copolymer formed by methacrylamide dopamine and one or more comonomers selected from acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, thioctic acid, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate and dimethylaminoethyl methacrylate.

[0014] In a preferred embodiment, the tyrosine-containing natural polymer is selected from one or more of gelatin, collagen, silk fibroin, or decellularized matrix.

[0015] In a preferred embodiment, the acrylic monomer is selected from one or more of acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate, and dimethylaminoethyl methacrylate.

[0016] In a preferred embodiment, the crosslinking agent is one or more selected from N,N'-methylenebisacrylamide, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol diacrylate.

[0017] In a preferred embodiment, in the hydrogel precursor solution, the mass concentration of the tyrosine-containing natural polymer is 1-10% by mass, the mass concentration of the acrylic monomer is 5-20% by mass, and the mass concentration of the crosslinking agent is 0.01-1% by mass.

[0018] In a preferred embodiment, the first photoinitiator is a divalent ruthenium compound, and the second photoinitiator is a persulfate.

[0019] In a preferred embodiment, the mass concentration of the first photoinitiator is 0.001 to 5% by mass, and the mass concentration of the second photoinitiator is 0.1 to 15% by mass.

[0020] Furthermore, the present invention also provides the application of a substrate with a surface modified by an in-situ grown dual-network hydrogel coating obtained according to the above method in an in vivo medical device.

[0021] This invention enables the growth of natural / synthetic polymer dual-network hydrogel coatings with both bioactivity and mechanical properties on different substrate surfaces in a one-step process, which is significantly faster and more efficient than existing technologies. By controlling the growth process, hydrogel coatings with different mechanical properties and bioactivity can be obtained. Therefore, substrates modified with in-situ grown dual-network hydrogel coatings obtained by the method of this invention can be used in in vivo medical devices. Attached Figure Description

[0022] Figure 1 A schematic diagram of the method of the present invention for forming a dual-network hydrogel coating is shown.

[0023] Figure 2 These are optical photographs taken before and after the growth of a double-network hydrogel coating on the inorganic glass surface in Example 1.

[0024] Figure 3 This is a thickness curve of the double-network hydrogel coating on the glass surface at different times in Example 2.

[0025] Figure 4 These are optical photographs of different substrate surfaces before and after the growth of dual-network hydrogel coatings in Example 3. Detailed Implementation

[0026] Based on in-depth and extensive research, the inventors have discovered that using divalent ruthenium compounds and persulfates as first and second photoinitiators, respectively, and placing them respectively in an adhesion initiation layer on the surface of a substrate and in a hydrogel monomer solution for immersing the substrate with the adhesion initiation layer, as shown in the figure... Figure 1 The diagram illustrates a schematic of the formation of a dual-network hydrogel coating using the method of the present invention. On one hand, when a divalent ruthenium compound (containing divalent ruthenium ions Ru) is selected and used... 2+ When used as a photoinitiator, under light irradiation (e.g., ultraviolet or visible light), the divalent ruthenium ions Ru... 2+ It loses electrons to transform into an excited-state trivalent ruthenium ion Ru, capable of oxidizing tyrosine residues. 3+ It can convert tyrosine residues in tyrosine-containing natural polymers into free radicals, which then rapidly couple to form dityrosine bonds, thereby forming a stable first hydrogel network within seconds. On the other hand, when persulfate (containing persulfate S2O8) is selected and used... 2- When used as a photoinitiator, under light irradiation conditions (e.g., ultraviolet or visible light), the persulfate ions S2O8 in it... 2- It gains electrons to form sulfate (SO4). 2- ) and sulfate radicals (SO4) ·- ), and the sulfate radical SO4 in it ·-A second hydrogel network can be formed by the co-polymerization of acrylic hydrogel monomers and crosslinking agents within seconds to minutes, thereby enabling rapid in-situ growth of a dual-network hydrogel on the material surface in one step. Furthermore, the modified dual-network hydrogel coating possesses both bioactivity and mechanical properties. More importantly, the inventors unexpectedly discovered that when the two different photoinitiators are spatially separated on the substrate surface during the polymerization of the hydrogel monomer (sometimes also called hydrogel precursors) (e.g., by placing them in different upper and lower deposition layers or deposition solutions on the substrate surface), a hydrogel monomer solution containing a tyrosine-containing natural polymer, acrylic monomers, and a crosslinking agent can rapidly and efficiently grow a dual-network hydrogel coating with both bioactivity and mechanical properties in-situ on the substrate surface. Conversely, if the two different photoinitiators are present together during the polymerization of the hydrogel monomer (i.e., in the same deposition layer or deposition solution), although a dual-network hydrogel can be formed rapidly, all hydrogel precursors will form a dual-network hydrogel instead of growing in a controlled in-situ on the material surface, thus failing to meet the requirement of in-situ growth of a dual-network hydrogel on the material surface.

[0027] Based on the above findings, the present invention provides a one-step method for rapidly growing a dual-network hydrogel coating in situ on a substrate surface, comprising: placing a substrate having an adhesion initiation layer on its surface in a hydrogel precursor solution and polymerizing it in situ under light irradiation, thereby obtaining a substrate whose surface is modified by an in-situ grown dual-network hydrogel coating.

[0028] As used herein, the term "one-step" means that the desired dual-network hydrogel is formed or grown simultaneously in one step, rather than formed or grown separately in different steps or at different times.

[0029] As used herein, the term "in situ" means that the desired hydrogel network is formed or grown at a predetermined location on the substrate surface.

[0030] As used herein, the term "rapid" means that the desired dual-network hydrogel is formed within seconds to minutes (typically less than 10 minutes), for example, within 0.1 to 10 minutes. Unlike conventional methods, this invention adds the monomers / polymers, initiators, and crosslinking agents required for the formation of the dual-network hydrogel to the hydrogel precursor solution. More specifically, for example, a divalent ruthenium compound (containing divalent ruthenium ions Ru) serves as the first initiator. 2+ When Ru is exposed to light (such as ultraviolet or visible light), 2+ It loses electrons to transform into an excited-state trivalent ruthenium ion Ru, capable of oxidizing tyrosine residues. 3+It can convert tyrosine residues in tyrosine-containing natural polymers into free radicals, which then rapidly couple to form dityrosine bonds, thereby forming a stable first hydrogel network within seconds. Simultaneously, the persulfate ions (S₂O₈) in the persulfate, acting as the second initiator, [further details needed]. 2- It gains electrons to form sulfate (SO4). 2- ) and sulfate radicals (SO4) ·- ), including sulfate radicals SO4 ·- The acrylic hydrogel monomers and crosslinking agents can be co-polymerized within seconds to minutes to form a second hydrogel network, thereby enabling rapid in-situ growth of a dual-network hydrogel on the material surface in one step. Those skilled in the art will appreciate that the formation of the dual-network hydrogel of this invention within 0.1 to 10 minutes is unexpected and represents a significant advancement, possessing immense practical value, compared to the reaction time typically of at least tens of hours in existing technologies.

[0031] As used herein, the term "dual-network hydrogel" means that the formed hydrogel network includes not only the natural polymer network formed by the polymerization of tyrosine contained in natural polymers under light irradiation through a first photoinitiator to generate dimer tyrosine, but also the synthetic polymer network formed by the photopolymerization of acrylic monomers in the presence of a second photoinitiator and a crosslinking agent.

[0032] As used herein, the term "adhesion initiation layer" means a surface deposit or liquid deposit that is adhesive to a substrate surface (i.e., adheres to the substrate surface so that the desired dual network can grow or form in situ on the substrate surface) and contains a first photoinitiator.

[0033] In this invention, there are no particular restrictions on the substrate used. Preferably, it can be a substrate that is commonly used in medical devices, such as various metal materials, inorganic non-metallic materials, organic materials, etc. Examples include, but are not limited to, pure titanium metal plates, pure aluminum metal plates, titanium alloy plates, iron plates, aluminum alloy plates, copper plates, as well as polymethyl methacrylate (PMMA) plates, polyethylene terephthalate (PET) plates, polyvinyl chloride (PVC) plates, polycarbonate (PC) plates, and polypropylene (PP) plates.

[0034] In this invention, the adhesion initiation layer used comprises a catechol-based adhesive compound and a first photoinitiator. As used herein, the expression "catechol-based adhesive compound" means that the adhesive compound (which includes polymers and is therefore sometimes referred to as an adhesive polymer) contains catechol groups (typically containing multiple catechol groups), and its adhesion to the substrate surface (especially in an aqueous environment) is achieved based on these catechol groups, and it has the strong adhesion typically required for substrate surface modification coatings.

[0035] In this invention, preferably, the adhesive compound based on the catechol group can be one or more selected from dopamine hydrochloride, dopamine analogs, and methacrylamide dopamine copolymers. More preferably, the dopamine analog can be one or more selected from tannic acid, catechol-gallic acid, and gallic acid; and the methacrylamide dopamine copolymer can be a copolymer formed by methacrylamide dopamine and one or more comonomers selected from acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, lipoic acid, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate, and dimethylaminoethyl methacrylate. Particularly preferred, the adhesive compound based on the catechol group is a methacrylamide copolymer, such as poly(methacrylamide-co-methacrylamide) (P(MEA-co-DMA)) obtained by copolymerizing methacrylamide (DMA) with methoxyethyl acrylate (MEA) or a terpolymer (P(MEA-co-DMA-co-LA)) obtained by copolymerizing methacrylamide (DMA) monomer, lipoic acid (LA) monomer and methoxyethyl acrylate (MEA) monomer.

[0036] In this invention, preferably, the adhesion initiation layer can be formed by dissolving a catechol-based adhesive compound and a first photoinitiator in an organic solvent, such as methanol, at room temperature, then depositing the resulting solution onto the surface of a substrate using methods known in the art and preliminarily drying it to remove most of the organic solvent, for example, more than 50%, 60%, 75%, 85%, or even more than 90%. As used herein, the expression "preliminary drying" means, for example, allowing most of the solvent to evaporate or volatilize at room temperature, without the need for complete removal of the organic solvent. In other words, the deposited layer obtained after preliminary drying is preferably still in a wetted state, rather than completely dried into a dry film state. The applicant has found that such preliminary drying can more advantageously promote the formation of interlocking double-network hydrogels by photopolymerization.

[0037] In this invention, preferably, the mass concentration of the adhesive compound based on the catechol group in the solution obtained by dissolving the catechol group adhesive compound and the first photoinitiator can be 1 to 20% by mass. The inventors have found that using such a mass concentration has advantages including, but not limited to, the following aspects: (1) Optimized adhesion and uniform coating: In the concentration range of 1 to 20% by mass, the adhesive has moderate adhesion, which can provide sufficient bonding strength, while ensuring the uniformity and fluidity of the coating, avoiding excessively high concentrations that lead to excessively thick or uneven adhesive layers; (2) Control of drying rate and layer thickness: This concentration range helps to regulate the drying rate of the coating, so that the catechol group can better participate in the crosslinking reaction and form a stable adhesive layer, while excessively high concentrations may lead to excessively fast drying or incomplete solvent evaporation, affecting the adhesion effect; and (3) Better physical properties and operability: In this concentration range, the obtained adhesive layer has appropriate flexibility and strength, which can effectively withstand external stress, and is not prone to cracking or peeling, and is easy to operate and control in practical applications.

[0038] In this invention, the hydrogel precursor solution used comprises a tyrosine-containing natural polymer, an acrylic monomer, a crosslinking agent, and a second photoinitiator. As used herein, the expression "tyrosine-containing natural polymer" means a substance existing as a natural polymer that contains a tyrosine monomer or tyrosine residue capable of photopolymerization (e.g., forming a dityrosine bond via photopolymerization). As used herein, the term "acrylic monomer" means a monomer having an allyl carbonyl group (-C=CC(O)-).

[0039] In this invention, preferably, the natural polymer containing tyrosine residues used can be one or more selected from gelatin, collagen, silk fibroin, or decellularized matrix, wherein the tyrosine residues are covalently linked to and suspended from the natural polymer backbone. Preferably, in the hydrogel precursor solution used, the mass concentration of the tyrosine-containing natural polymer can be 1-10% by mass. The inventors have discovered that with such a mass concentration, the tyrosine residues can effectively bind to the natural polymer backbone, enhancing the stability of the material while retaining the flexibility and biocompatibility of the natural polymer. Furthermore, a moderate mass concentration of tyrosine ensures that it acts as an effective functional unit in the reaction, avoiding overpolymerization or uneven crosslinking problems caused by excessively high concentrations, while also ensuring sufficient reactivity to promote the desired chemical reaction.

[0040] In this invention, preferably, the acrylic monomer used can be one or more selected from acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate, and dimethylaminoethyl methacrylate. In this invention, preferably, the mass concentration of the acrylic monomer in the hydrogel precursor solution is 5-20% by mass. The inventors have discovered that with such a mass concentration, the acrylic monomer can effectively participate in the cross-linking reaction of the hydrogel, forming a three-dimensional network structure with good mechanical properties, maintaining the softness of the hydrogel while enhancing its compressive strength and stability. This concentration range allows for a moderate gelation rate during the hydrogel formation process, avoiding uneven structure caused by excessively rapid solidification, and preventing incomplete gelation due to excessively low concentration, ensuring consistent performance of the final product. Furthermore, a moderate concentration of acrylic monomer ensures that the hydrogel has high water absorption capacity while maintaining certain mechanical strength and toughness, making it suitable for applications such as medical dressings and absorbent materials requiring high water absorption and good structure.

[0041] In this invention, preferably, the crosslinking agent used can be one or more selected from N,N'-methylenebisacrylamide, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol diacrylate. This crosslinking agent can undergo free radical polymerization with acrylic monomers to form a hydrogel network. Preferably, in the hydrogel precursor solution used in this invention, the mass concentration of the crosslinking agent can be 0.01~1% by mass. The inventors have discovered that using such a mass concentration can achieve moderate crosslinking, forming a hydrogel network with a certain degree of flexibility and appropriate mechanical strength. This allows the hydrogel to maintain good deformability and water absorption while possessing sufficient structural stability, making it suitable for various applications. Excessively high crosslinking agent concentrations can lead to an overly dense network, limiting the hydrogel's water absorption capacity and extensibility, thus affecting its functionality.

[0042] In this invention, preferably, the first photoinitiator used is a divalent ruthenium compound, and the second photoinitiator used is persulfate. The inventors have discovered that when a divalent ruthenium compound is present as the first photoinitiator in an adhesion initiation layer on the substrate surface and persulfate is present as the second photoinitiator in a hydrogel monomer solution, in-situ growth or growth of the desired dual-network hydrogel on the substrate surface can be achieved more rapidly and efficiently. This initiator combination can be activated and generate free radicals under different light conditions, thus exhibiting strong applicability to different types of hydrogel monomers and substrates, and can be widely applied to in-situ coating and hydrogel modification of various material surfaces. Furthermore, by controlling the light exposure time and initiator concentration, the crosslinking density and network structure of the dual-network hydrogel can be precisely adjusted, thereby optimizing its mechanical properties, water absorption, and biocompatibility to meet different application requirements.

[0043] In this invention, preferably, the first photoinitiator is a divalent ruthenium compound, and its mass concentration is more preferably 0.001 to 5% by mass, in the solution obtained by dissolving the adhesive compound with catechol groups and the first photoinitiator. The inventors have discovered that with such a mass concentration, the initiator can be efficiently activated under appropriate light conditions, ensuring the smooth progress of the photoinitiation reaction. Too low a concentration of initiator may lead to insufficient reaction efficiency, while too high a concentration may trigger over-reaction, producing byproducts or causing unnecessary polymerization. Therefore, this concentration range helps to balance reaction efficiency and stability. Furthermore, excessive initiator may lead to excessive free radical generation, triggering unnecessary chain reactions or degradation reactions, which not only affects the quality of the product but may also impair the physical properties of the final adhesive layer.

[0044] In this invention, preferably, the second photoinitiator in the hydrogel precursor solution is persulfate, and its mass concentration is more preferably 0.1-15% by mass. The inventors have discovered that with such a mass concentration, the initiator can be efficiently activated under appropriate light conditions, ensuring the smooth progress of the photoinitiation reaction. Too low a concentration of initiator may lead to insufficient reaction efficiency, while too high a concentration may trigger over-reaction, producing byproducts or causing unnecessary polymerization. Therefore, this concentration range helps to balance reaction efficiency and stability. Furthermore, excessive initiator may lead to excessive free radical generation, triggering unnecessary chain reactions or degradation reactions, which not only affects the quality of the product but may also impair the physical properties of the final adhesive layer.

[0045] In this invention, examples of divalent ruthenium compounds that can be used as photoinitiators include, but are not limited to, tris(2,2-bipyridine)ruthenium dichloride. Such divalent ruthenium compounds are commercially available or can be prepared in the laboratory using methods well known in the art.

[0046] In this invention, examples of persulfates that can be used as photoinitiators include, but are not limited to, sodium persulfate (SPS). Such persulfates are commercially available or can be prepared in the laboratory by methods well known in the art.

[0047] In this invention, preferably, the temperature for in-situ polymerization can be -20 to 40°C, more preferably at room temperature. As used herein, the term "room temperature" generally refers to a temperature of 10 to 30°C. In this invention, the light used for irradiation can be ultraviolet light or visible light, preferably visible light with a wavelength of 350 to 500 nm. Because this invention can be conveniently carried out at room temperature using visible light, it is less costly and environmentally friendly, while also enabling large-scale production.

[0048] In this invention, a natural / synthetic polymer dual-network hydrogel coating with both bioactivity and mechanical properties is grown or formed in situ on the surface of a substrate using the above method. This allows for the application or modification of dual-network hydrogel coatings on different substrate surfaces without altering the properties of the substrate itself. Therefore, substrates modified with such in-situ grown dual-network hydrogel coatings can be used in in vivo medical devices. Natural polymers such as gelatin and decellularized matrix form a hydrogel network rich in amino acids and peptide bonds, exhibiting excellent biocompatibility and biodegradability. Their structure allows for interaction with biomolecules in vivo, promoting cell attachment, growth, and differentiation, demonstrating good bioactivity. Natural macromolecular materials such as gelatin have low immunogenicity and good biodegradability in vivo, reducing immune responses caused by the material and avoiding rejection reactions that may occur with long-term implantation. Therefore, they are particularly suitable for medical devices, especially implantable devices. Synthetic networks formed by free radical polymerization of acrylic monomers possess excellent mechanical strength, elasticity, and stability, making them less prone to breakage or loss of their original shape during long-term use in vivo, exhibiting appropriate toughness and durability. This is particularly important for medical devices, which need to withstand prolonged physical stresses such as friction, stretching, and compression during use. The dual-network hydrogel coating developed in this invention, combining natural macromolecules with a synthetic polymer network, provides excellent bioactivity and mechanical properties, giving the material the ideal characteristics required for medical devices. It not only supports tissue repair and cell growth but also ensures good stability, durability, and safety during in vivo use.

[0049] To further understand the present invention, the present invention will be described in detail below with reference to embodiments.

[0050] Unless otherwise specified, all medicines used below can be purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0051] Example

[0052] Example 1 : In-situ growth of double network hydrogel on inorganic glass surface

[0053] (I) Preparation of glass slides with adhesive initiation layer

[0054] First, poly(methoxyethyl acrylate-co-methacrylamide dopamine) (P(MEA-co-DMA)) was synthesized: (1) Preparation of MEA monomer: 100-200 mesh neutral alumina was packed into a 1 cm diameter, 15 cm long chromatography column. 50 mL of MEA monomer (purchased from Shanghai Aladdin Biochemical Technology, catalog number E102687-250g) was added to the chromatography column. The column was pressurized using a double-strand ball pressurizing device and collected in a solvent drying bottle. o C. Store in the dark for later use; (2) Preparation of DMA monomer: In a 500 mL three-necked flask, 20 g sodium tetraborate and 8 g sodium bicarbonate were dissolved in 200 mL deionized water, and oxygen in the system was removed by bubbling under 99.99% high-purity nitrogen from a nitrogen cylinder for 20 min. Then, 10 g dopamine hydrochloride was quickly weighed and added to the reaction system, and then the pH was adjusted to 8.5 with 1N sodium hydroxide solution. Then, in a constant pressure funnel, 9.14 g methacrylic anhydride was dissolved in 50 mL tetrahydrofuran, and after being added dropwise to the above system through a constant pressure funnel, the reaction was carried out at room temperature in the dark for 12 h. Then, methanol was added to quench the reaction, followed by washing twice with 100 mL ethyl acetate, then adjusting the pH to 2 with concentrated hydrochloric acid, and finally extracting three times with 100 mL ethyl acetate. The ethyl acetate layers were collected and combined, then dried with anhydrous sodium sulfate to remove water, and then extracted at 60 °C. o C was subjected to rotary evaporation to remove a large amount of ethyl acetate solvent. The resulting concentrated DMA ethyl acetate solution was added to 450 mL of refrigerated hexane, and then... o After standing at 4°C for 6 hours, the solid product was collected in centrifuge tubes and vacuum dried in a vacuum oven at room temperature. o C. Store in the dark for later use; (3) Synthesis of P(MEA-co-DMA): In the reaction tube, 5 g of MEA monomer, 1.345 g of DMA monomer in a molar ratio of 85:15 and 6.34 mg of azobisisobutyronitrile (AIBN) as polymerization initiator were added sequentially to 20 mL of tetrahydrofuran (THF) as organic solvent. After three cycles of "liquid nitrogen freezing for 3 minutes - vacuuming for 2 minutes - thawing at room temperature" to remove oxygen from the system and seal it, the mixture was then heated to 65°C. o The reaction was carried out at C under light-protected conditions for 24 hours. Afterward, methanol was added to quench the reaction, and the reaction product was precipitated with petroleum ether. After three cycles, the product was filtered under negative pressure by a water pump to obtain the copolymer product, which was a yellow solid.

[0055] Next, in a 10 mL brown sample vial, at room temperature, more than 100 mg of synthesized poly(methoxyethyl acrylate-co-methacrylamide dopamine) and 0.74 mg of tris(2,2-bipyridine) ruthenium dichloride were dissolved in 2 mL of methanol under magnetic stirring and atmospheric atmosphere to obtain an adhesion initiation layer precursor solution. An 8*8*1 mm glass slide was washed three times with methanol and water and then air-dried. 20 μL of this adhesion initiation layer precursor solution was then deposited onto the surface of the glass slide using a 1-20 μL pipette and pre-dried at room temperature (approximately 70% of the solvent evaporated, leaving the glass surface still wet), thus obtaining a glass slide with an adhesion initiation layer.

[0056] In a 20 mL brown sample vial, 0.5 g gelatin, 1 g acrylamide, 10 mg N,N'-methylenebisacrylamide, and 11.9 mg sodium persulfate were dissolved in deionized water under magnetic stirring at room temperature, and the volume was adjusted to 10 mL. After the polymer and monomers were completely dissolved, a transparent homogeneous solution was obtained. Then, a glass slide with the adhesion initiation layer prepared above was immersed in this homogeneous solution and irradiated under 405 nm visible light for 2 min, thereby growing a dual-network hydrogel coating in situ on the glass slide surface. The thickness of the dual-network hydrogel coating on the glass slide surface obtained in Example 1 was measured using an electron microscope, and it was found to be approximately 126 μm thick.

[0057] Optical photographs were taken of the glass slides in Example 1 before and after the growth of the dual-network hydrogel coating using a conventional mobile phone. The results are as follows: Figure 2 As shown. From Figure 2 As can be seen, the dual-network hydrogel can grow uniformly onto the glass slide surface. After immersing the glass slide with the hydrogel grown in deionized water at room temperature for 24 hours, the hydrogel layer still adheres stably to the glass slide surface, indicating that the hydrogel layer has stable adhesion to the glass slide surface. In addition, after the growth of the dual-network hydrogel, the coating contains natural polymers, namely gelatin. Gelatin is rich in amino acids and peptide bonds, exhibiting excellent biocompatibility and biodegradability, and can provide excellent biological activity.

[0058] Examples 2-7: Double network hydrogel coatings with different growth time (i.e. light irradiation time)

[0059] The growth process of the dual-network hydrogel coating was the same as in Example 1, except that the visible light irradiation time was changed to 15 s, 30 s, 45 s, 60 s, 90 s, and 180 s, respectively, in Examples 2-7. The thickness of the dual-network hydrogel coating on the glass slide surface obtained in Examples 2-7 was measured using an electron microscope, and the results are as follows: Figure 3 As shown. From Figure 3It can be seen that, on the one hand, as the visible light irradiation time increases, the monomers and natural polymers in the system continuously cross-link, and the thickness of the hydrogel coating increases uniformly, confirming the controllability and uniformity of the two cross-linking reactions and the controllable growth of the dual-network hydrogel coating; on the other hand, as the time further increases, the increase in the thickness of the dual-network hydrogel coating gradually slows down, and the inventors have found in experiments that when the light irradiation time is extended to 600 s (i.e. 5 min) or longer, the thickness of the dual-network hydrogel coating reaches a plateau and no longer increases.

[0060] Examples 8-18: In-situ growth of double network hydrogel coatings on different substrate surfaces

[0061] The growth process of the dual-network hydrogel coating is the same as that in Example 1, except that in Examples 8-18, commercially available pure titanium metal plates, pure aluminum metal plates, titanium alloy plates, iron plates, aluminum alloy plates, copper plates, polymethyl methacrylate (PMMA) plates, polyethylene terephthalate (PET) plates, polyvinyl chloride (PVC) plates, polycarbonate (PC) plates, and polypropylene (PP) plates with dimensions of 8*8*1 mm are used instead of the glass plates in Example 1 as substrates, and dual-network hydrogel coatings are grown on their surfaces.

[0062] Optical photographs were taken of the substrates before and after the growth of the dual-network hydrogel coating in these embodiments, and the results are as follows: Figure 4 As shown. From Figure 4 As can be seen, the method of the present invention can rapidly and in situ grow uniform dual-network hydrogel coatings on different substrate surfaces, thus proving the universality of the method of the present invention.

[0063] Examples 19-21 : Growth of double network hydrogel on different medical device surfaces

[0064] The growth process of the dual-network hydrogel coating is the same as in Example 1, except that the dual-network hydrogel coating is grown on the surface of injection needles, PVC catheters and silicone catheters used as medical devices. The results are similar to those in Examples 8-18 above. That is, the method of the present invention can be used to grow dual-network hydrogel coatings with both bioactivity and mechanical properties in situ and rapidly on the surface of different medical devices.

[0065] Example 22: In-situ growth of double network hydrogel on inorganic glass surface

[0066] In a 10 mL amber sample vial, 10 mg of dopamine hydrochloride and 3.7 mg of tris(2,2-bipyridine) ruthenium dichloride were dissolved in 10 mL of commercially available pH 8.5 Tris-HCl buffer solution under atmospheric pressure with magnetic stirring to obtain the adhesion initiation layer precursor solution. An 8*8*1 mm glass slide was washed three times with methanol and water and then air-dried. 20 μL of this adhesion initiation layer precursor solution was then deposited onto the surface of the glass slide using a 1-20 μL pipette and allowed to react at room temperature in the dark for 12 hours. After rinsing the glass surface with deionized water, a glass slide with an adhesion initiation layer was obtained.

[0067] The process of in-situ growing a dual-network hydrogel coating on the glass slide surface with the adhesion initiation layer obtained above is the same as in Example 1. As a result, it is similar to Example 1, that is, the dual-network hydrogel can be uniformly grown to the glass slide surface. After immersing the glass slide with the hydrogel grown in deionized water at room temperature for 24 hours, the hydrogel layer still adheres stably to the glass slide surface, indicating that the hydrogel layer has a stable adhesion to the glass slide surface.

[0068] Example 23: In-situ growth of double network hydrogel on inorganic glass surface

[0069] The process for obtaining the glass slide with the adhesion initiation layer is the same as in Example 22, except that in Example 23, dopamine hydrochloride is replaced with tannic acid. The process for in-situ growing a dual-network hydrogel coating on the surface of the glass slide with the adhesion initiation layer obtained above is the same as in Example 1. As a result, it is similar to Example 1, i.e., the dual-network hydrogel can grow uniformly onto the glass slide surface. After immersing the glass slide with the grown hydrogel in deionized water at room temperature for 24 hours, the hydrogel layer still stably adheres to the glass slide surface, indicating that the hydrogel layer has a stable adhesive force to the glass slide surface.

[0070] Example 24: In-situ growth of double network hydrogel on inorganic glass surface

[0071] The growth process of the dual-network hydrogel coating is the same as in Example 1, except that in Example 24, gelatin is replaced with silk fibroin. As a result, it is similar to that in Example 1, that is, the dual-network hydrogel can grow uniformly onto the glass slide surface. After the glass slide on which the hydrogel is grown is immersed in deionized water at room temperature for 24 hours, the hydrogel layer still adheres stably to the glass slide surface, indicating that the hydrogel layer has a stable adhesion to the glass slide surface.

[0072] Examples 25-26: In-situ growth of double network hydrogel on inorganic glass surface

[0073] The growth process of the dual-network hydrogel coating was the same as in Example 1, except that in Examples 25-26, the acrylamide monomer was replaced with hydroxyethyl methacrylate and glycidyl acrylate, respectively. As a result, it was similar to Example 1, i.e., the dual-network hydrogel could grow uniformly onto the glass slide surface. After immersing the glass slide with the hydrogel grown in deionized water at room temperature for 24 hours, the hydrogel layer remained stably adhered to the glass slide surface, indicating that the hydrogel layer had stable adhesion to the glass slide surface.

[0074] Example 27: In-situ growth of double network hydrogel on inorganic glass surface

[0075] The growth process of the dual-network hydrogel coating was the same as in Example 1, except that N,N'-methylenebisacrylamide was replaced with polyethylene glycol diacrylate in Example 27. As a result, it was similar to that in Example 1, i.e., the dual-network hydrogel could grow uniformly onto the glass slide surface. After immersing the glass slide with the hydrogel grown in deionized water at room temperature for 24 hours, the hydrogel layer remained stably adhered to the glass slide surface, indicating that the hydrogel layer and the glass slide surface had stable adhesion.

[0076] Example 28: In-situ growth of double network hydrogel on inorganic glass surface

[0077] The growth process of the dual-network hydrogel coating was the same as in Example 1, except that in Example 28, 2.38 mg of sodium persulfate was used as the first photoinitiator and dissolved in 2 mL of methanol along with other substances, and 3.7 mg of tris(2,2-bipyridine)ruthenium dichloride was used as the second photoinitiator and dissolved in 10 mL of deionized water along with other substances. As a result, it was similar to Example 1, i.e., the dual-network hydrogel could grow uniformly onto the glass slide surface. After immersing the glass slide with the hydrogel grown in deionized water at room temperature for 24 hours, the hydrogel layer remained stably adhered to the glass slide surface, indicating that the hydrogel layer and the glass slide surface had stable adhesion.

[0078] Comparative Example 1 : Without using acrylic monomer

[0079] The growth process of the hydrogel coating was the same as in Example 1, except that the hydrogel precursor solution used did not contain any acrylic monomers such as acrylamide. As a result, only a single network hydrogel coating was formed on the inorganic glass surface.

[0080] Comparative Example 2: Without using any natural polymer

[0081] The growth process of the hydrogel coating was the same as in Example 1, except that the hydrogel precursor solution used did not contain any natural polymers such as gelatin. As a result, only a single network hydrogel coating was formed on the inorganic glass surface.

[0082] Comparative Example 3: Without using natural polymer containing tyrosine

[0083] The growth process of the hydrogel coating was the same as in Example 1, except that hyaluronic acid was used instead of the gelatin used in Example 1. As a result, only a single network hydrogel coating was formed on the inorganic glass surface.

[0084] Comparative Example 4: Both first and second photoinitiators in the adhesion initiation layer

[0085] In a 10 mL brown sample vial, at room temperature, more than 100 mg of synthesized poly(methoxyethyl acrylate-co-methacrylamide dopamine), 0.74 mg of tris(2,2-bipyridine) ruthenium dichloride, and 2.38 mg of sodium persulfate were dissolved in 2 mL of methanol under magnetic stirring and atmospheric atmosphere to obtain an adhesion initiation layer precursor solution, which was stored in the dark. An 8*8*1 mm glass slide was washed three times with methanol and water and then air-dried. 20 μL of the adhesion initiation layer precursor solution was then deposited onto the surface of the glass slide using a 1-20 μL pipette and pre-dried at room temperature (approximately 70% of the solvent evaporated, leaving the glass surface still wet), thus obtaining a glass slide with an adhesion initiation layer, which was stored in the dark throughout the process.

[0086] In a 20 mL brown sample vial, 0.5 g gelatin, 1 g acrylamide, and 10 mg N,N'-methylenebisacrylamide were dissolved in deionized water under magnetic stirring at room temperature and the volume was adjusted to 10 mL. After complete dissolution of the polymer and monomers, a transparent homogeneous solution was obtained. Then, a glass slide with the aforementioned adhesive initiation layer was immersed in this homogeneous solution and irradiated under 405 nm visible light for 2 min, thereby growing a double-network hydrogel coating in situ on the glass slide surface. As a result, compared to Examples 1 and 28, the hydrogel coating could not stably form on the glass surface due to the absence of an initiator in the hydrogel precursor.

[0087] Comparative Example 5: Both first and second photoinitiators in the hydrogel precursor solution

[0088] In a 10 mL brown sample vial, at room temperature, more than 100 mg of synthesized poly(methoxyethyl acrylate-co-methacrylamide dopamine) was dissolved in 2 mL of methanol under magnetic stirring and atmospheric conditions to obtain an adhesion layer precursor solution, which was stored in the dark. An 8*8*1 mm glass slide was washed three times with methanol and water and then air-dried. 20 μL of the adhesion layer precursor solution was then deposited onto the surface of the glass slide using a 1-20 μL pipette and pre-dried at room temperature (approximately 70% of the solvent evaporated, leaving the glass surface still wet), thus obtaining a glass slide with an adhesion layer, which was stored in the dark throughout the process.

[0089] In a 20 mL brown sample vial, at room temperature, 0.5 g gelatin, 1 g acrylamide, 10 mg N,N'-methylenebisacrylamide, 3.7 mg tris(2,2-bipyridine)ruthenium chloride, and 11.9 mg sodium persulfate were dissolved in deionized water and the volume was adjusted to 10 mL. After the polymer and monomers were completely dissolved, a clear homogeneous solution was obtained. Then, the glass slide with the adhesive layer prepared above was immersed in this homogeneous solution and irradiated under 405 nm visible light for 2 min. As a result, compared to Examples 1 and 28, due to the presence of two initiators in the hydrogel precursor, all hydrogel precursors irradiated with 405 nm visible light polymerized to form a double-network hydrogel, rather than forming only on the surface of the glass slide with the adhesive layer.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for rapid in-situ growth of a dual-network hydrogel coating on a substrate surface in a one-step process, characterized in that, The method includes: A substrate with an adhesion initiation layer on its surface is placed in a hydrogel precursor solution and polymerized in situ under light irradiation for 0.1–10 min, thereby obtaining a substrate whose surface is modified with an in-situ grown dual-network hydrogel coating. The adhesion initiation layer comprises an adhesive compound based on a catechol group and a first photoinitiator, the hydrogel precursor solution comprises a tyrosine-containing natural polymer, an acrylic monomer, a crosslinking agent, and a second photoinitiator, wherein the first photoinitiator and the second photoinitiator are different from each other and are independently selected from divalent ruthenium compounds and persulfates.

2. The method according to claim 1, characterized in that, The adhesion initiation layer is formed by dissolving the catechol-based adhesive compound and the first photoinitiator in an organic solvent at room temperature, then depositing the resulting solution onto the surface of the substrate and pre-drying it to remove most of the organic solvent.

3. The method according to claim 2, characterized in that, In the resulting solution, the mass concentration of the catechol-based adhesive compound is 1 to 20 by mass.

4. The method according to claim 1, characterized in that, The in-situ polymerization temperature is -20~40℃, and the light irradiation is performed using visible light with a wavelength of 350~500 nm.

5. The method according to claim 1, characterized in that, The adhesive compound based on the catechol group is selected from one or more of dopamine hydrochloride, dopamine analogs, and methacrylamide dopamine copolymers, wherein the dopamine analogs are selected from one or more of tannic acid, catechol gallic acid, and gallic acid, and the methacrylamide dopamine copolymer is a copolymer formed by methacrylamide dopamine and one or more comonomers selected from acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, lipoic acid, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate, and dimethylaminoethyl methacrylate.

6. The method according to claim 1, characterized in that, The tyrosine-containing natural polymer is selected from one or more of gelatin, collagen, silk fibroin, or decellularized matrix; the acrylic monomer is selected from one or more of acrylic acid, acrylamide, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, methyl acrylate, methoxyethyl acrylate, N-isopropylacrylamide, glycidyl acrylate, and dimethylaminoethyl methacrylate; and the crosslinking agent is selected from one or more of N,N'-methylenebisacrylamide, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol diacrylate.

7. The method according to claim 6, characterized in that, In the hydrogel precursor solution, the mass concentration of the tyrosine-containing natural polymer is 1-10% by mass, the mass concentration of the acrylic monomer is 5-20% by mass, and the mass concentration of the crosslinking agent is 0.01-1% by mass.

8. The method according to claim 1, characterized in that, The first photoinitiator is a divalent ruthenium compound, and the second photoinitiator is a persulfate.

9. The method according to claim 8, characterized in that, The mass concentration of the first photoinitiator is 0.001 to 5% by mass, and the mass concentration of the second photoinitiator is 0.1 to 15% by mass.

10. The application of a substrate with a surface modified by an in-situ grown dual-network hydrogel coating obtained by any one of claims 1-9 in an in vivo medical device.

Images