Hydrogel with inflammation treatment and detection effects as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biomedical engineering and biological materials, and relates to hydrogel with inflammation treatment and detection effects as well as a preparation method and application of the hydrogel. The preparation method comprises the following steps: co-dissolving a first polymer and an ROS-responsive substance, adding a photoinitiator and a nanofiber-based diagnosis and treatment element, dispersing, and activating through EDC and NHS to obtain a first solution; mixing the second polymer with an anti-inflammatory drug to obtain a second solution; the two solutions are mixed and then subjected to ultraviolet curing to form the hydrogel. According to the application, the hydrogel is coated on a surface modified absorbable suture line, and the hydrogel coating intestinal anastomosis suture line with treatment and detection functions is prepared. The hydrogel disclosed by the invention is resistant to acid and alkali and swelling in an intestinal environment, drug release depends on ROS response instead of swelling, and the accuracy is high; the detection mode is realized through urine fluorescence, no complex equipment is needed, the cost is low, the biocompatibility is good, and a new scheme is provided for in-situ treatment and non-invasive monitoring of intestinal anastomotic stoma inflammation.

Description

Technical Field

[0001] This invention belongs to the fields of biomedical engineering and biomaterials technology, and relates to a hydrogel with both anti-inflammatory and detection functions, its preparation method and application. Background Technology

[0002] Inflammatory bowel disease (IBD) is a chronic inflammatory bowel disease affecting more than 7 million people worldwide. Over 40% of these patients require bowel resection surgery due to poor response to medication. Absorbable sutures are a crucial material for intestinal anastomosis surgery, but their traditional design focuses solely on mechanical closure, exhibiting significant limitations in adapting to the unique physiological environment of the intestine and the treatment of inflammation.

[0003] To improve the therapeutic effect of sutures, existing technologies often utilize hydrogel coatings to achieve drug loading. For example, patent CN113101264B discloses a ROS-responsive hydrogel, its preparation method, and its application. This hydrogel forms a network by crosslinking catechol-modified chitosan with cystamine, utilizing the redox responsiveness of disulfide bonds to release drugs within the atherosclerotic microenvironment. However, the intestinal environment exhibits complex pH fluctuations (5.5-7.5) and varying reactive oxygen species (ROS) concentrations. Traditional hydrogel coatings lack specific design for this environment, generally suffering from insufficient acid and alkali resistance and uncontrolled swelling behavior. This results in drug release depending on hydrogel swelling, failing to achieve precise drug release matched to the degree of inflammation.

[0004] In the field of inflammation detection, traditional non-invasive detection technologies mainly include PET imaging, magnetic resonance imaging (MRI), molecular diagnostics, and microneedle patch technology. PET imaging involves injecting specific probes (such as CD45-PET probes) and utilizing the binding properties of these probes to inflammatory markers, then using positron emission tomography (PET) to image and detect the inflamed area. MRI uses a magnetic field to induce resonance in hydrogen atoms within human tissue, combined with techniques such as hyperpolarized carbon-13, to monitor the metabolic processes of inflamed tissue. Molecular diagnostics typically involves collecting biological samples such as blood and feces, and using methods like real-time quantitative PCR to detect and analyze inflammation-related genes or proteins. Microneedle patch technology involves microneedles penetrating the stratum corneum of the skin, allowing tissue fluid to come into contact with sensors on the patch, thereby enabling the detection of inflammatory markers.

[0005] However, PET imaging and MRI rely on large specialized equipment and operators, resulting in high testing costs and complex procedures; molecular diagnostic technologies require the collection of biological samples, have poor testing timeliness, and are cumbersome to operate; although microneedle patch technology attempts to be minimally invasive, it carries the risk of skin tissue damage, and the cytotoxicity problem has not been completely solved, making it particularly difficult to apply to sensitive physiological environments such as the gut.

[0006] In summary, existing technologies face two major technical bottlenecks in the treatment and detection of intestinal inflammation: first, the lack of dual-functional hydrogel designs targeting the intestinal pH and ROS microenvironment makes it impossible to achieve precise drug release; second, inflammation detection technologies struggle to balance convenience, low cost, and biocompatibility. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the prior art and to provide a hydrogel that has both anti-inflammatory and diagnostic effects, as well as its preparation method and application.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A hydrogel with both anti-inflammatory and diagnostic functions is mainly composed of water and a polymer network. The polymer network is an interpenetrating network formed by the interpenetration of a first cross-linked network and a second cross-linked network. The interpenetrating network is loaded with nanofiber-based diagnostic and therapeutic elements and anti-inflammatory drugs.

[0010] The first cross-linking network does not have ROS-responsive properties. The first cross-linking network and nanofiber-based therapeutic elements are used to inhibit excessive swelling of hydrogels in the intestinal environment, thereby preventing the release of anti-inflammatory drugs through swelling.

[0011] The second cross-linked network has ROS-responsive properties, meaning that upon contact with ROS, covalent bonds break, releasing nanofiber-based therapeutic elements and anti-inflammatory drugs.

[0012] Nanofiber-based diagnostic and therapeutic elements mainly consist of short nanofibers and fluorescein-labeled MMPs (matrix metalloproteinases) responsive peptides grafted onto them. The MMPs responsive peptides are one or more of MMP-1, MMP-2, MMP-3, and MMP-9 responsive peptides. MMPs can specifically react with fluorescein-labeled MMPs responsive peptides, cleaving fluorescein-labeled amino acid fragments in the peptides. When inflammation occurs in vivo, the concentration of MMPs varies, resulting in different amounts of fluorescein-labeled amino acid fragments released, and thus different fluorescence intensities. Therefore, it can be used to quantitatively determine the degree of anastomotic inflammation.

[0013] As a preferred technical solution:

[0014] The hydrogel described above, which combines the functions of inflammation treatment and detection, has nanofibers with an average length of 10–50 μm and an average diameter of 300–800 nm.

[0015] As described above, a hydrogel that combines the functions of inflammation treatment and detection uses nanofibers as a third polymer, which may be polyvinyl formal (PVF), polycarbonate (PC), polyvinylidene fluoride (PVDF), polyvinyl alcohol-ethylene copolymer (PVA-co-PE), polylactic acid-glycolic acid copolymer (PLGA), polystyrene (PS), polylactic acid (PLA), or polyamide 6 (PA6).

[0016] The preparation process of nanofibers is as follows: First, electrospinning is performed on the spinning solution containing the third polymer to obtain a nanofiber membrane. Then, the nanofiber membrane is immersed in a mixed solution (composed of 1.5g NN-disuccinimidyl carbonate, 0.08mL triethylamine, and 15mL 1,4-dioxane) for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane is then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 10000-15000rpm, time 30-90min), centrifuged (speed 10000rpm, time 15min), and freeze-dried to obtain nanofibers.

[0017] The process parameters for electrospinning include: voltage 10-30kV, receiving distance 10-20cm, and spinning speed 0.3-4mL / h.

[0018] The preparation process of the nanofiber-based diagnostic and therapeutic element, as described above, is as follows: Fluorescently labeled MMPs-responsive peptides are dissolved in PBS (phosphate-buffered saline) and incubated with short nanofibers. After incubation, the nanofibers are removed and washed with PBS to remove free fluorescein-labeled MMPs-responsive peptides. The nanofibers are then blocked with bovine serum albumin solution (this blocking step reduces non-specific fluorescence background to below 5%, improving the signal-to-noise ratio of fluorescence microscopy by 3-5 times, ensuring the accuracy of inflammation detection), followed by freeze-drying to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMPs-responsive peptides to short nanofibers is 0.1–3:1–15. Bovine serum albumin can cover the surface of the short nanofibers, filling the sites not occupied by fluorescein-labeled MMPs-responsive peptides. This reduces the non-specific binding of other substances to the short nanofibers, so the fluorescence signal observed under a fluorescence microscope will mainly come from the specifically bound fluorescein-labeled MMPs-responsive peptides, rather than background fluorescence caused by non-specific adsorption.

[0019] The hydrogel described above, which combines the functions of inflammation treatment and detection, contains one or more of the following anti-inflammatory drugs: ibuprofen sodium, diclofenac sodium, ethacridine, dexamethasone sodium phosphate, hydrocortisone sodium phosphate, curcumin, and artemisinin.

[0020] As described above, a hydrogel that combines the functions of inflammation treatment and detection has a first cross-linking network formed by the cross-linking of a first polymer itself; and a second cross-linking network formed by the cross-linking of a ROS-responsive substance and a second polymer.

[0021] The hydrogel described above, which combines the functions of inflammation treatment and detection, wherein the first polymer is one or more of polyethylene glycol diacrylate (PEGDA), poly-N-isopropylacrylamide (PNIPAM), tetra-armed polyethylene glycol-mercapto (4Arm-PEG-SH), tetra-armed polyethylene glycol succinimide glutarate (4Arm-PEG-SG), polyethylene glycol dimethacrylate (PEGDMA), and tetra-armed polyethylene glycol acrylate (4Arm-PEG-Ac);

[0022] ROS-responsive substances are one or more of sulfur-based ROS-responsive substances and selenium-based ROS-responsive substances;

[0023] The second polymer is one or more of polylysine, gelatin, hyaluronic acid, and carboxymethyl chitosan.

[0024] This invention also provides a method for preparing a hydrogel with both anti-inflammatory and diagnostic functions as described above, comprising the following steps:

[0025] (a) The first polymer and the ROS-responsive substance are co-dissolved in PBS and stirred for 10-30 min until homogeneous. Then, a photoinitiator (one or more of the following: 1-hydroxycyclohexylphenyl ketone, phenyl-2,4,6-trimethylbenzoyl phosphate lithium salt, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylbenzophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenyl bis(2,4,6-trimethylbenzoylmethyl)phosphine oxide, methyl benzoylformate, 4-diethylaminobenzoyl diphenylphosphine oxide, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropanone) is added. The pH is adjusted to 5-7. After adding the nanofiber-based therapeutic element, it is uniformly dispersed using an ultrasonic cell disruptor (power 200-400W, 3s operation, 2s stop, total processing time 5-10 min, to ensure that the nanofiber-based therapeutic element has a dispersion particle size D50 ≤ 200nm in the mixture) to obtain the mixture.

[0026] (b) EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide) and NHS (N-hydroxysuccinimide) were added to a mixture and reacted for 40-90 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution. During this process, EDC first reacted with the carboxyl groups of the ROS-responsive substance to generate an O-acylisourea intermediate. The O-acylisourea intermediate then exchanged with NHS to generate a stable NHS-active ester intermediate (-CO-O-NHS), while releasing EDC byproducts.

[0027] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0028] (d) Mix the first solution and the second solution and vortex for 30-60s to obtain the hydrogel precursor solution. During this process, the NHS-active ester intermediate undergoes a nucleophilic substitution reaction with the amino group of the second polymer to form an amide bond, thereby crosslinking to form a second crosslinked network. This reaction is an irreversible covalent bond formation, which ensures the stability of the hydrogel network. If the components are directly blended, the reaction rate between the carboxyl group of the ROS-responsive substance and the amino group of the second polymer is slow and incomplete, and a uniform crosslinked network cannot be formed. By stepwise activation to generate the NHS-active ester intermediate, the reaction efficiency can be significantly improved, and the uniformity and mechanical properties of the interpenetrating network can be guaranteed.

[0029] (e) Irradiate the hydrogel precursor solution under a UV lamp with a wavelength of 365 nm and a power of 45 W for 5 to 40 min to form a hydrogel.

[0030] As a preferred technical solution:

[0031] As described above, in the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 5–20 wt%, 2–10 wt%, 0.5–4 wt%, and 0.1–1 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 0.5–3:0.1–2:0.08–1; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 2–8 wt% and 1–6 wt%, respectively; and in step (d), the volume ratio of the first solution to the second solution is 1–2:1–2.

[0032] The present invention also provides a hydrogel-coated intestinal anastomosis suture, comprising an absorbable suture and a hydrogel coating applied to its surface, wherein the hydrogel coating is made of the same material as the hydrogel described above that has both anti-inflammatory and diagnostic functions.

[0033] Existing technologies typically involve orally administering hydrogels to patients, allowing them to adhere to the intestines and respond to ROS (Reactive Oxygen Species) reactions, or using hydrogel microspheres to achieve ROS responses. However, orally administered hydrogels often struggle to form a broad and uniform viscous coating on the convoluted surface of the intestines. Furthermore, due to the motility of the gastrointestinal tract, orally administered hydrogels have a short retention time within the intestines, limiting the duration of drug efficacy. In addition, the fluid content and acidity within the digestive tract vary significantly (gastric pH 1.5, intestinal pH 6.15-7.88), making traditional electrostatically driven composite coagulation layers susceptible to damage from pH / salt changes (see "A Gel Factor, Hydrogel, Preparation Method and Application of Anti-inflammatory Drug Loading," CN117567554B). This significantly restricts the development and application of liquid coagulation layers as oral drug delivery carriers. This invention uses sutures as a carrier, integrating the therapeutic efficacy of hydrogels into the suture, ensuring colonization at the site of intestinal inflammation and inflammatory diagnosis.

[0034] As a preferred technical solution:

[0035] The hydrogel-coated intestinal anastomosis suture described above has an absorbable suture diameter of 0.307–0.336 mm (3-0 specification), which conforms to the specifications for intestinal sutures. The average breaking strength is not less than 24.3 N, meeting the requirements of industry standard YY1116-2020 for 3-0 absorbable sutures.

[0036] The hydrogel-coated intestinal anastomosis suture described above is an absorbable suture that has undergone surface modification. The surface modification steps are as follows:

[0037] (a) Immerse absorbable sutures (made of one or more of the following materials: poly(glycolic acid-lactide) (PGLA), poly(glycolic acid-caprolactone) (PGCL), poly(glycolic acid) (PGA), poly(p-dioxanone) (PPDO), poly(p-dioxanone) (PDO), poly(p-dioxanone) (PDS), and polytrimethylene carbonate (PTMC), the degradation period of these materials being longer than the healing period of intestinal anastomosis, to ensure that inflammation detection and treatment are carried out throughout the entire tissue repair process) in a solution of dopamine (DA) in Tris HCl at a concentration of 1-5 mg / mL, shake at 20-50°C for 20-36 h, and then dry;

[0038] (b) The product from step (a) is immersed in an ethanol solution of benzophenone (BP) with a concentration of 4-18 wt% for 10-30 min and then dried to complete the surface modification.

[0039] The hydrogel-coated intestinal anastomosis suture described above has a hydrogel coating thickness of 1–10 μm.

[0040] The preparation method of the hydrogel-coated intestinal anastomosis suture as described above is as follows: after immersing the absorbable suture in a hydrogel precursor solution, it is taken out and rotated and irradiated under a UV lamp with a wavelength of 365nm and a power of 45W for 5 to 40 minutes.

[0041] This invention constructs a dual-functional interpenetrating hydrogel with "anti-swelling-ROS response" properties and coats it onto the surface of absorbable sutures to achieve precise treatment and non-invasive detection of intestinal anastomotic inflammation. The specific principle is as follows:

[0042] The first cross-linking network is composed of non-ROS-responsive materials and inhibits excessive swelling of the hydrogel in the intestinal environment with a pH of 5.5-7.5 through its acid and alkali resistant network structure. This network works synergistically with nanofiber-based therapeutic elements to control the swelling rate of the hydrogel and prevent the sudden release of drugs due to changes in intestinal osmotic pressure.

[0043] The second cross-linked network is formed by cross-linking a ROS-responsive substance with a second polymer. Its covalent bonds can break under the influence of high concentrations of ROS at the site of inflammation, causing the network to collapse and release the loaded anti-inflammatory drug and nanofiber-based therapeutic elements. This design makes the drug release positively correlated with the degree of inflammation; the higher the degree of inflammation, the higher the ROS concentration, which in turn leads to a higher release of anti-inflammatory drugs.

[0044] The detection principle of nanofiber-based diagnostic and therapeutic elements is as follows:

[0045] When inflammation occurs at the intestinal anastomosis, the local concentration of MMPs increases, specifically cleaving peptides and releasing fluorescently labeled amino acid fragments. These released fragments enter the urine via the bloodstream, and the degree of inflammation at the anastomosis can be quantitatively reflected by detecting the fluorescence intensity in the urine. This method requires no large equipment, only urine samples, making it low-cost and easy to operate. It solves the problem of tissue damage caused by the reliance on specialized equipment and microneedle patches in traditional techniques such as PET imaging and MRI.

[0046] By using dopamine-benzophenone-modified absorbable sutures as a carrier for the hydrogel coating, the mechanical support function of the sutures is retained while drug loading and inflammation detection are achieved through the hydrogel coating. The hydrogel coating forms an integrated "treatment-detection" system at the intestinal anastomosis site. Simultaneously, in response to ROS, anti-inflammatory drugs are released, and nanofiber-based therapeutic elements release fluorescein-labeled amino acid fragments into the urine, enabling simultaneous monitoring of treatment efficacy and inflammation progression, thus solving the problem of separation between treatment and detection in existing technologies.

[0047] Beneficial effects:

[0048] 1. This invention designs an interpenetrating network hydrogel composed of a first cross-linked network and a second cross-linked network. The first cross-linked network inhibits excessive swelling of the hydrogel in the intestinal environment, and the second cross-linked network undergoes covalent bond breakage upon contact with ROS, thereby changing the drug release driver from swelling release to ROS-responsive release, effectively improving the precision of drug treatment. At the same time, the interpenetrating network is structurally stable in the intestinal pH environment of 5.5-7.5 and is resistant to acids and alkalis, solving the problems of uncontrolled swelling and sudden drug release of traditional hydrogels in the complex intestinal environment.

[0049] 2. This invention loads nanofiber-based diagnostic and therapeutic elements in an interpenetrating network, with fluorescein-labeled MMPs-responsive peptides grafted onto their surface. When inflammation occurs in vivo, changes in MMP concentration cleave the peptides and release fluorescein-labeled amino acid fragments with different fluorescence intensities into the urine. The degree of anastomotic inflammation can be quantitatively determined by detecting the urine fluorescence. This detection method does not require complex equipment or professional personnel; it only requires the collection of urine samples. It has the advantages of convenient operation and low cost. Compared with technologies such as microneedle patches, it has good biocompatibility and low cytotoxicity, avoiding additional inflammatory reactions or tissue damage.

[0050] 3. This invention coats an interpenetrating network hydrogel onto a surface-modified absorbable suture. The dopamine-benzophenone modification process enhances the bonding force between the suture and the hydrogel, resulting in a uniform coating that does not affect the mechanical properties of the suture. This hydrogel-coated suture can achieve integrated "treatment-detection" at the intestinal anastomosis site, releasing anti-inflammatory drugs through ROS response and dynamically monitoring inflammation progression through urine fluorescence signals, thus solving the problem of separation between treatment and detection in existing technologies. Attached Figure Description

[0051] Figure 1 The experimental results verify the anti-swelling function of the first cross-linked network; the small figures from left to right correspond to PBS solutions containing 1 mM H2O2 (which belongs to ROS), PBS solutions containing 0.5 mM H2O2, PBS solutions containing 0.25 mM H2O2, PBS solutions containing 0.1 mM H2O2, and PBS alone.

[0052] Figure 2 Experimental results verifying the ROS-responsive precise drug release function of the second cross-linked network; where (a): pH = 7.4; (b): pH = 6.8; (c): pH = 5.5;

[0053] Figure 3 Experimental results verifying the inflammatory response detection function of nanofiber-based diagnostic and therapeutic elements; where (a) is the fluorescence image of the immersion solution and (b) is the fluorescence spectrum of the immersion solution. Detailed Implementation

[0054] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0055] Tensile strength: The tensile strength and elongation of the sample (absorbable suture) were tested using a multi-functional tensile tester. During the test, a knot was tied in the middle of the sample with a spacing of 70 mm and a tensile speed of 140 mm / min. The break point at the knot was recorded as valid data. Each group of samples was tested 5 times and the average value was taken.

[0056] To ensure that the properties of the substances used in this invention are fully disclosed, this invention specifies the specific information or sources of the substances (as shown in Table 1). Products from other manufacturers that conform to the limitations of this invention are also applicable.

[0057] Table 1

[0058]

[0059]

[0060] Example 1

[0061] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0062] (1) Preparation of materials;

[0063] Spinning solution: solute is PVF, solvent is DMF (N,N-dimethylformamide), concentration is 15wt%;

[0064] The mixed solution consists of 1.5 g N,N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane.

[0065] Deionized water;

[0066] MMP-1-responsive peptide labeled with fluorescein isothiocyanate;

[0067] PBS;

[0068] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0069] First polymer: 4Arm-PEG-SH;

[0070] ROS-responsive substance: 3,3'-(propane-2,2-diylbis(thionyl))dipropionic acid;

[0071] Photoinitiator: 4-Diethylaminobenzoyldiphenylphosphine oxide;

[0072] EDC;

[0073] NHS;

[0074] Second polymer: Polylysine;

[0075] Anti-inflammatory drugs: ibuprofen sodium;

[0076] Absorbable sutures: 0.315 mm in diameter, with an average breaking strength of 25.2 N;

[0077] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 1 mg / mL;

[0078] The ethanol solution of benzophenone has a concentration of 4 mg / mL.

[0079] (2) Preparation of short nanofibers;

[0080] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 11000rpm, time 30min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 30μm and an average diameter of 600nm were obtained.

[0081] The electrospinning process parameters are: voltage 10kV, receiving distance 10cm, and spinning speed 2mL / h.

[0082] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0083] A 0.01 wt% solution of fluorescein-labeled MMP-1 responsive peptide was obtained by dissolving fluorescein-labeled MMP-1 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-1 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-1 responsive peptide to short nanofibers was 0.1:7, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:4.

[0084] (4) Preparation of hydrogel precursor solution;

[0085] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 10 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 5, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0086] (b) Add EDC and NHS to the mixture and react for 40 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0087] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0088] (d) Mix the first solution with the second solution and vortex for 30 seconds to obtain the hydrogel precursor solution;

[0089] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 5 wt%, 2 wt%, 1 wt%, and 0.5 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 0.5:0.1:0.08; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 2 wt% and 1 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1:1.

[0090] (5) Surface modification of absorbable sutures;

[0091] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 20°C for 20 h, and then dry;

[0092] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 10 minutes and then dry it to complete the surface modification.

[0093] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0094] After immersing the absorbable suture in a hydrogel precursor solution, it is removed and rotated under a UV lamp for 5 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0095] The final hydrogel coating of the intestinal anastomosis suture was 1 μm thick. The hydrogel mainly consisted of water and a polymer network. The polymer network was an interpenetrating network formed by the interpenetration of a first cross-linked network and a second cross-linked network. The interpenetrating network loaded nanofiber-based therapeutic elements and anti-inflammatory drugs. The first cross-linked network was formed by the self-crosslinking of the first polymer. The second cross-linked network was formed by the cross-linking of ROS-responsive substances with the second polymer. The first cross-linked network did not have ROS-responsive properties. The first cross-linked network and the nanofiber-based therapeutic elements were used to inhibit the excessive swelling of the hydrogel in the intestinal environment, thereby preventing the anti-inflammatory drugs from being released outward through swelling. The second cross-linked network had ROS-responsive properties, that is, upon contact with ROS, covalent bonds would break, releasing the nanofiber-based therapeutic elements and anti-inflammatory drugs within it.

[0096] Example 2

[0097] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0098] (1) Preparation of materials;

[0099] Spinning solution: solute is PC, solvent is DMF, concentration is 17wt%;

[0100] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0101] Deionized water;

[0102] MMP-3-responsive peptides labeled with fluorescein isothiocyanate;

[0103] PBS;

[0104] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0105] First polymer: PEGDA;

[0106] ROS-responsive substance: 3,3'-diselenodipropionic acid;

[0107] Photoinitiator: Phenylene bis(2,4,6-trimethylbenzoylmethyl)phosphine oxide;

[0108] EDC;

[0109] NHS;

[0110] Second polymer: hyaluronic acid;

[0111] Anti-inflammatory drugs: curcumin;

[0112] Absorbable sutures: 0.322 mm in diameter, with an average breaking strength of 30.6 N;

[0113] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 3 mg / mL;

[0114] An ethanolic solution of benzophenone with a concentration of 10 mg / mL;

[0115] (2) Preparation of short nanofibers;

[0116] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 15000rpm, time 60min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 20μm and an average diameter of 550nm were obtained.

[0117] The process parameters for electrospinning are: voltage 18kV, receiving distance 12cm, and spinning speed 0.7mL / h.

[0118] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0119] A 0.02 wt% solution of fluorescein-labeled MMP-3 responsive peptide was obtained by dissolving fluorescein-labeled MMP-3 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-3 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-3 responsive peptide to short nanofibers was 0.9:13, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:1.

[0120] (4) Preparation of hydrogel precursor solution;

[0121] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 20 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 6, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0122] (b) Add EDC and NHS to the mixture and react for 60 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0123] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0124] (d) Mix the first solution with the second solution and vortex for 45s to obtain the hydrogel precursor solution;

[0125] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 17 wt%, 6 wt%, 2 wt%, and 0.1 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 2:1.5:0.6; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 6 wt% and 4 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1:1.5.

[0126] (5) Surface modification of absorbable sutures;

[0127] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 35°C for 28 h, and then dry;

[0128] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 20 minutes and then dry it to complete the surface modification.

[0129] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0130] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 20 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0131] The final hydrogel coating of the intestinal anastomosis suture was 4 μm thick.

[0132] Example 3

[0133] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0134] (1) Preparation of materials;

[0135] Spinning solution: solute is PVDF, solvent is acetone, concentration is 12wt%;

[0136] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0137] Deionized water;

[0138] MMP-2-responsive peptides labeled with fluorescein isothiocyanate;

[0139] PBS;

[0140] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0141] First polymer: 4Arm-PEG-SG;

[0142] ROS-responsive substance: 2,2'-(propane-2,2-diylbis(thio)yl)diacetic acid;

[0143] Photoinitiator: Lithium phenyl-2,4,6-trimethylbenzoyl phosphate;

[0144] EDC;

[0145] NHS;

[0146] Second polymer: gelatin;

[0147] Anti-inflammatory drugs: Diclofenac sodium;

[0148] Absorbable sutures: diameter 0.336 mm, average breaking strength 34.1 N;

[0149] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 5 mg / mL;

[0150] The ethanol solution of benzophenone has a concentration of 18 mg / mL.

[0151] (2) Preparation of short nanofibers;

[0152] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 12000rpm, time 70min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 40μm and an average diameter of 500nm were obtained.

[0153] The process parameters for electrospinning are: voltage 18kV, receiving distance 15cm, and spinning speed 0.4mL / h.

[0154] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0155] A 0.04 wt% fluorescein-labeled MMP-2 responsive peptide solution was obtained by dissolving fluorescein-labeled MMP-2 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-2 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-2 responsive peptide to short nanofibers was 3:11, and the mass ratio of short nanofibers to bovine serum albumin solution was 2:3.

[0156] (4) Preparation of hydrogel precursor solution;

[0157] (a) The first polymer and ROS-responsive substance were co-dissolved in PBS and stirred for 15 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 6, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0158] (b) Add EDC and NHS to the mixture and react for 90 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0159] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0160] (d) Mix the first solution with the second solution and vortex for 40 seconds to obtain the hydrogel precursor solution;

[0161] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 15 wt%, 7 wt%, 0.5 wt%, and 0.7 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 1.5:1:0.31; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 5 wt% and 3 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 2:1.

[0162] (5) Surface modification of absorbable sutures;

[0163] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 50°C for 36 h, and then dry;

[0164] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 30 minutes and then dry it to complete the surface modification.

[0165] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0166] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 40 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0167] The final hydrogel coating of the intestinal anastomosis suture was 10 μm thick.

[0168] Example 4

[0169] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0170] (1) Preparation of materials;

[0171] Spinning solution: solute is PVA-co-PE, solvent is isopropanol, concentration is 8wt%;

[0172] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0173] Deionized water;

[0174] MMP-9-responsive peptide labeled with fluorescein isothiocyanate;

[0175] PBS;

[0176] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0177] First polymer: PEGDA;

[0178] ROS-responsive substance: 2,2'-(propane-2,2-diylbis(thio)yl)diacetic acid;

[0179] Photoinitiator: 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone;

[0180] EDC;

[0181] NHS;

[0182] Second polymer: Carboxymethyl chitosan;

[0183] Anti-inflammatory drugs: Dexamethasone sodium phosphate;

[0184] Absorbable sutures: diameter 0.311 mm, average breaking strength 28.5 N;

[0185] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 2 mg / mL;

[0186] An ethanolic solution of benzophenone with a concentration of 10 mg / mL;

[0187] (2) Preparation of short nanofibers;

[0188] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 10000rpm, time 90min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 50μm and an average diameter of 800nm ​​were obtained.

[0189] The electrospinning process parameters are: voltage 22kV, receiving distance 20cm, and spinning speed 4mL / h;

[0190] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0191] A 0.02 wt% solution of fluorescein-labeled MMP-9 responsive peptide was obtained by dissolving fluorescein-labeled MMP-9 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-9 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-9 responsive peptide to short nanofibers was 0.2:5, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:2.

[0192] (4) Preparation of hydrogel precursor solution;

[0193] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 20 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 6, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0194] (b) Add EDC and NHS to the mixture and react for 60 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0195] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0196] (d) Mix the first solution with the second solution and vortex for 30 seconds to obtain the hydrogel precursor solution;

[0197] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 10 wt%, 4 wt%, 1 wt%, and 0.5 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 1:0.25:0.17; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 4 wt% and 1.5 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1:1.

[0198] (5) Surface modification of absorbable sutures;

[0199] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 37°C for 24 h, and then dry;

[0200] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 15 minutes and then dry it to complete the surface modification.

[0201] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0202] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 30 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0203] The final hydrogel coating of the intestinal anastomosis suture was 8 μm thick.

[0204] Example 5

[0205] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0206] (1) Preparation of materials;

[0207] Spinning solution: solute is PLGA, solvent is tetrahydrofuran, concentration is 14.5wt%;

[0208] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0209] Deionized water;

[0210] MMP-2-responsive peptides labeled with fluorescein isothiocyanate;

[0211] PBS;

[0212] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0213] First polymer: PNIPAM;

[0214] ROS-responsive substance: L-selenocysteine;

[0215] Photoinitiator: 1-Hydroxycyclohexylphenyl ketone;

[0216] EDC;

[0217] NHS;

[0218] Second polymer: Polylysine;

[0219] Anti-inflammatory drugs: artemisinin;

[0220] Absorbable sutures: diameter 0.307 mm, average breaking strength 24.3 N;

[0221] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 4 mg / mL;

[0222] The ethanol solution of benzophenone has a concentration of 12 mg / mL.

[0223] (2) Preparation of short nanofibers;

[0224] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 12000rpm, time 90min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 40μm and an average diameter of 700nm were obtained.

[0225] The process parameters for electrospinning are: voltage 16kV, receiving distance 12cm, and spinning speed 0.9mL / h.

[0226] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0227] A 0.06 wt% solution of fluorescein-labeled MMP-2 responsive peptide was obtained by dissolving fluorescein-labeled MMP-2 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-2 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-2 responsive peptide to short nanofibers was 1.6:13, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:3.

[0228] (4) Preparation of hydrogel precursor solution;

[0229] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 30 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 7, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0230] (b) Add EDC and NHS to the mixture and react for 50 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0231] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0232] (d) Mix the first solution with the second solution and vortex for 60s to obtain the hydrogel precursor solution;

[0233] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 10 wt%, 6 wt%, 4 wt%, and 0.6 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 1.5:1:0.27; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 8 wt% and 6 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1:2.

[0234] (5) Surface modification of absorbable sutures;

[0235] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 30°C for 30 h, and then dry;

[0236] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 15 minutes and then dry it to complete the surface modification.

[0237] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0238] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 35 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0239] The final hydrogel coating of the intestinal anastomosis suture was 5 μm thick.

[0240] Example 6

[0241] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0242] (1) Preparation of materials;

[0243] Spinning solution: solute is PS, solvent is tetrahydrofuran, concentration is 20wt%;

[0244] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0245] Deionized water;

[0246] MMP-9-responsive peptide labeled with fluorescein isothiocyanate;

[0247] PBS;

[0248] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0249] First polymer: PEGDMA;

[0250] ROS-responsive substance: 3,3'-(propane-2,2-diylbis(thionyl))dipropionic acid;

[0251] Photoinitiator: 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone;

[0252] EDC;

[0253] NHS;

[0254] Second polymer: Carboxymethyl chitosan;

[0255] Anti-inflammatory drug: hydrocortisone sodium phosphate;

[0256] Absorbable sutures: diameter 0.311 mm, average breaking strength 28.5 N;

[0257] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 3 mg / mL;

[0258] The ethanol solution of benzophenone has a concentration of 15 mg / mL.

[0259] (2) Preparation of short nanofibers;

[0260] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 15000rpm, time 45min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 30μm and an average diameter of 800nm ​​were obtained.

[0261] The electrospinning process parameters are: voltage 24kV, receiving distance 20cm, and spinning speed 0.318mL / h;

[0262] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0263] A 0.03 wt% fluorescein-labeled MMP-9 responsive peptide solution was obtained by dissolving fluorescein-labeled MMP-9 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-9 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-9 responsive peptide to short nanofibers was 1.7:15, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:2.

[0264] (4) Preparation of hydrogel precursor solution;

[0265] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 20 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 7, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0266] (b) Add EDC and NHS to the mixture and react for 45 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0267] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0268] (d) Mix the first solution with the second solution and vortex for 45s to obtain the hydrogel precursor solution;

[0269] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 16 wt%, 10 wt%, 4 wt%, and 1 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 1:1:0.18; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 3 wt% and 2 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1:1.

[0270] (5) Surface modification of absorbable sutures;

[0271] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 40°C for 24 h, and then dry;

[0272] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 25 minutes and then dry it to complete the surface modification.

[0273] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0274] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 25 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0275] The final hydrogel coating of the intestinal anastomosis suture was 3 μm thick.

[0276] Example 7

[0277] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0278] (1) Preparation of materials;

[0279] Spinning solution: solute is PLA, solvent is dichloromethane, concentration is 8wt%;

[0280] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0281] Deionized water;

[0282] MMP-9-responsive peptide labeled with fluorescein isothiocyanate;

[0283] PBS;

[0284] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0285] First polymer: 4Arm-PEG-Ac;

[0286] ROS-responsive substance: 3,3'-dithiodipropionic acid;

[0287] Photoinitiator: Phenylene bis(2,4,6-trimethylbenzoylmethyl)phosphine oxide;

[0288] EDC;

[0289] NHS;

[0290] Second polymer: hyaluronic acid;

[0291] Anti-inflammatory drug: ethacridine;

[0292] Absorbable sutures: diameter 0.334 mm, average breaking strength 28.6 N;

[0293] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 2 mg / mL;

[0294] The ethanol solution of benzophenone has a concentration of 6 mg / mL.

[0295] (2) Preparation of short nanofibers;

[0296] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 10000rpm, time 60min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 10μm and an average diameter of 300nm were obtained.

[0297] The process parameters for electrospinning are: voltage 20kV, receiving distance 15cm, and spinning speed 1mL / h.

[0298] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0299] A 0.04 wt% fluorescein-labeled MMP-9 responsive peptide solution was obtained by dissolving fluorescein-labeled MMP-9 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-9 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based diagnostic and therapeutic element. The mass ratio of fluorescein-labeled MMP-9 responsive peptide to short nanofibers was 2:11, and the mass ratio of short nanofibers to bovine serum albumin solution was 2:5.

[0300] (4) Preparation of hydrogel precursor solution;

[0301] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 15 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 5, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0302] (b) Add EDC and NHS to the mixture and react for 80 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0303] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0304] (d) Mix the first solution with the second solution and vortex for 50 seconds to obtain the hydrogel precursor solution;

[0305] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 20 wt%, 10 wt%, 3 wt%, and 1 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 3:2:1; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 4 wt% and 2 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1.5:1.

[0306] (5) Surface modification of absorbable sutures;

[0307] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 37°C for 36 h, and then dry;

[0308] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 30 minutes and then dry it to complete the surface modification.

[0309] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0310] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 20 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0311] The final hydrogel coating of the intestinal anastomosis suture was 6 μm thick.

[0312] Example 8

[0313] A method for preparing a hydrogel-coated intestinal anastomosis suture, comprising the following specific steps:

[0314] (1) Preparation of materials;

[0315] Spinning solution: solute is PA6, solvent is formic acid, concentration is 13wt%;

[0316] Mixed solution: composed of 1.5 g N-N-disuccinimidyl carbonate, 0.08 mL triethylamine, and 15 mL 1,4-dioxane;

[0317] Deionized water;

[0318] MMP-3-responsive peptides labeled with fluorescein isothiocyanate;

[0319] PBS;

[0320] Bovine serum albumin solution: solvent is PBS, concentration is 1 wt%;

[0321] First polymer: 4Arm-PEG-SH;

[0322] ROS-responsive substance: 3,3'-diselenodipropionic acid;

[0323] Photoinitiator: Methyl benzoylformate;

[0324] EDC;

[0325] NHS;

[0326] Second polymer: gelatin;

[0327] Anti-inflammatory drugs: Dexamethasone sodium phosphate;

[0328] Absorbable sutures: diameter 0.316 mm, average breaking strength 27.8 N;

[0329] Dopamine tris(hydroxymethyl)aminomethane hydrochloride solution: concentration 4 mg / mL;

[0330] The ethanol solution of benzophenone has a concentration of 11 mg / mL.

[0331] (2) Preparation of short nanofibers;

[0332] First, the spinning solution was electrospun to obtain a nanofiber membrane. Then, the nanofiber membrane was immersed in a mixed solution for pretreatment (temperature 37℃, time 2h). The pretreated nanofiber membrane was then cut into fragments, dispersed in deionized water, homogenized and crushed (speed 13000rpm, time 60min), and centrifuged (speed 10000rpm, time 15min). After freeze-drying, short nanofibers with an average length of 20μm and an average diameter of 750nm were obtained.

[0333] The process parameters for electrospinning are: voltage 30kV, receiving distance 10cm, and spinning speed 0.3mL / h;

[0334] (3) Preparation of nanofiber-based diagnostic and therapeutic elements;

[0335] A 0.03 wt% fluorescein-labeled MMP-3 responsive peptide solution was obtained by dissolving fluorescein-labeled MMP-3 responsive peptide in PBS. This solution was then incubated with short nanofibers. After incubation, the nanofibers were removed and washed with PBS to remove free fluorescein-labeled MMP-3 responsive peptide. The nanofibers were then blocked with bovine serum albumin solution and freeze-dried to obtain the nanofiber-based therapeutic element. The mass ratio of fluorescein-labeled MMP-3 responsive peptide to short nanofibers was 0.3:1, and the mass ratio of short nanofibers to bovine serum albumin solution was 1:4.

[0336] (4) Preparation of hydrogel precursor solution;

[0337] (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred for 30 min until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 5, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture.

[0338] (b) Add EDC and NHS to the mixture and react for 70 min to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution;

[0339] (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution;

[0340] (d) Mix the first solution with the second solution and vortex for 30 seconds to obtain the hydrogel precursor solution;

[0341] In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 10 wt%, 4 wt%, 1 wt%, and 0.5 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 2:0.45:0.27; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 5 wt% and 3 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 2:1.

[0342] (5) Surface modification of absorbable sutures;

[0343] (a) Immerse absorbable sutures in a solution of dopamine tris(hydroxymethyl)aminomethane hydrochloride, shake at 20°C for 20 h, and then dry;

[0344] (b) Immerse the product from step (a) in an ethanol solution of benzophenone for 15 minutes and then dry it to complete the surface modification.

[0345] (6) Preparation of hydrogel-coated intestinal anastomosis sutures;

[0346] After immersing the absorbable suture in a hydrogel precursor solution, it was removed and rotated under a UV lamp for 15 minutes to obtain a hydrogel-coated intestinal anastomosis suture.

[0347] The final hydrogel coating of the intestinal anastomosis suture was 9 μm thick.

[0348] To demonstrate the anti-swelling function of the first cross-linked network, the precise drug release function of the second cross-linked network in response to ROS, and the inflammatory response detection function of the nanofiber-based therapeutic element, and to verify the design principle of the "anti-swelling-ROS response" dual-network synergy and integrated diagnostic and therapeutic system, this invention was verified through the following experiments:

[0349] (1) Experimental verification of the anti-swelling function of the first cross-linked network;

[0350] Experiment: First, a hydrogel with both anti-inflammatory and detection functions was prepared. The preparation steps were basically the same as steps (2) to (4) in Example 4. The only difference was that step (e) was performed after step (d) in step (4): the hydrogel precursor solution was irradiated under a UV lamp for 30 minutes to form a hydrogel with both anti-inflammatory and detection functions (hereinafter referred to as hydrogel). All materials were the same as in Example 4. Then, different pH conditions were set (covering the pH range of the intestine), and PBS solutions containing different concentrations of H2O2 were prepared under each pH condition (simulating different ROS concentration environments during intestinal inflammation). At the same time, a simple PBS group was set as a control. Subsequently, the same mass of hydrogel was placed in the above-mentioned solution environments with different pH values ​​and different H2O2 concentrations. The changes in the appearance and morphology of the hydrogel were observed and recorded at 0d, 1d, 2d, 3d, 4d, and 7d.

[0351] The experimental results are as follows Figure 1 As shown, from Figure 1 As can be seen, under different pH values ​​(5, 6, 7), the hydrogel remained relatively stable in morphology and with controllable swelling degree in the low H2O2 concentration (0.1mM, 0.25mM, 0.5mM) and PBS groups over time (0-7d) with different pH values ​​(5, 6, 7). However, in the 1mM H2O2 group, the hydrogel showed a more obvious degradation trend over time, indicating that the first cross-linking network can inhibit excessive swelling of the hydrogel and maintain the stability of the three-dimensional framework within the intestinal pH range through its acid and alkali resistant network structure. At the same time, the second cross-linking network can respond to high concentrations of H2O2 (simulating an inflammatory environment) and undergo degradation, which fits the "anti-swelling-ROS response" dual network design. This verifies the anti-swelling function of the first cross-linking network and the principle of its synergistic effect with the second cross-linking network, ensuring that drug release is dominated by "ROS response" and avoiding drug burst release caused by fluctuations in the intestinal environment.

[0352] (2) Experimental verification of the precise drug release function of the second cross-linked network in response to ROS;

[0353] Experiment: The hydrogel-coated intestinal anastomosis suture prepared in Example 4 was used to set up different simulated intestinal pH environments (covering the pH range under physiological and inflammatory states of the intestine). In each pH environment, PBS solutions containing different concentrations of H2O2 were prepared, and a PBS-only group was set up as a control. Subsequently, the hydrogel-coated intestinal anastomosis suture was immersed in PBS solutions with different pH values ​​and different H2O2 concentrations at different time points, and the cumulative release of anti-inflammatory drugs (dexamethasone sodium phosphate) in the solution was detected and recorded. The cumulative drug release-time curve was plotted.

[0354] The experimental results are as follows Figure 2 As shown, from Figure 2 As can be seen, under different pH conditions, the cumulative drug release in the high-concentration H2O2 (1mM) group was significantly higher than that in the low-concentration H2O2 (0.5mM) and PBS groups over time. Moreover, under all pH conditions, drug release showed a trend of "increasing with increasing H2O2 concentration", indicating that the second cross-linking network can respond to different pH environments in the intestine, triggering covalent bond breakage through high-concentration H2O2 at the inflammatory site, and achieving a positive correlation between drug release and the degree of inflammation. This verifies its ROS-responsive precise drug release function, ensuring that the drug is released in a controllable manner according to the inflammatory state, which is in line with the principle of "ROS-responsive drug release dominance" in the "anti-swelling-ROS-responsive" dual network design.

[0355] (3) Experimental verification of the inflammatory response detection function of nanofiber-based diagnostic and therapeutic elements;

[0356] Experiment: The hydrogel-coated intestinal anastomosis sutures prepared in Example 4 were used to prepare PBS solutions containing different concentrations of MMP-9. A PBS-only group was set up as a control (simulating the MMPs level of the intestinal anastomosis under non-inflammatory conditions). Subsequently, the hydrogel-coated intestinal anastomosis sutures of the same length were immersed in the above-mentioned PBS solutions of different concentrations of MMP-9. After incubation for a certain period of time, the soaking solution was collected, and the fluorescence images and fluorescence spectra of the soaking solution were collected to detect the changes in fluorescence intensity.

[0357] The experimental results are as follows Figure 3 As shown, from Figure 3 As can be seen from Figure a, the fluorescence intensity of the hydrogel-coated intestinal anastomosis suture soaking solution treated with PBS solution containing 20 ng / mL MMP-9 was significantly higher than that of the 10 ng / mL group and the PBS group; from Figure 3As shown in Figure b, the fluorescence intensity of the 20 ng / mL MMP-9 group at approximately 520 nm was significantly stronger than that of the 10 ng / mL group and the PBS group, and the fluorescence intensity increased with increasing MMP-9 concentration. This indicates that the nanofiber-based therapeutic element of the hydrogel-coated intestinal anastomosis suture can specifically respond to changes in MMP-9 concentration (the concentration of MMPs increases when simulating anastomotic inflammation) in a simulated intestinal environment. When inflammation occurs, the MMP-9 concentration increases, which specifically cleaves the peptide, causing the release of fluorescein-labeled amino acid fragments into the soaking solution (simulating the signal transmission of blood circulation-urine), making the fluorescence intensity positively correlated with the MMP-9 concentration. This verifies that the element can convert the degree of intestinal anastomotic inflammation into a detectable fluorescent signal, supporting non-invasive inflammation monitoring. This aligns with the design of an integrated "treatment-detection" system, solving the drawbacks of traditional detection relying on large equipment and invasive operations, and achieving deep integration of inflammation detection and therapeutic carriers.

[0358] Sequence list information:

[0359] DTD Version: V1_3

[0360] Filename: TSIP-100.xml

[0361] Software Name: WIPOSequence

[0362] Software version: 2.3.0

[0363] Generation Date: 2025-07-24

[0364] Basic Information:

[0365] Current application / applicant file name: TSIP-100

[0366] Applicant's Name or Title: Donghua University

[0367] Applicant's name or title / language:zh

[0368] Invention Title: Hydrogel with both anti-inflammatory and diagnostic functions, its preparation method and application (zh)

[0369] Total number of sequences: 4

[0370] sequence:

[0371] Serial Number (ID): 1

[0372] Length: 14

[0373] Molecular type: AA

[0374] Feature location / qualifier:

[0375]

[0376] residues:

[0377] GCDSGRMSMP VSDX 14 Serial Number (ID): 2

[0378] Length: 8

[0379] Molecular type: AA

[0380] Feature location / qualifier:

[0381]

[0382]

[0383] residues:

[0384] GPLGVRGX 8

[0385] Serial Number (ID): 3

[0386] Length: 12

[0387] Molecular type: AA

[0388] Feature location / qualifier:

[0389]

[0390] residues:

[0391] GVPLSLTMGX GG 12

[0392] Serial Number (ID): 4

[0393] Length: 9

[0394] Molecular type: AA

[0395] Feature location / qualifier:

[0396]

[0397] residues:

[0398] RSWMGLPGX 9

Claims

1. A hydrogel with both anti-inflammatory and diagnostic functions, mainly composed of water and a polymer network, characterized in that, The polymer network is an interpenetrating network formed by the interpenetration of a first cross-linked network and a second cross-linked network, and the interpenetrating network is loaded with nanofiber-based therapeutic elements and anti-inflammatory drugs. The first cross-linking network does not have ROS-responsive properties. The first cross-linking network and nanofiber-based therapeutic elements are used to inhibit excessive swelling of hydrogels in the intestinal environment, thereby preventing the release of anti-inflammatory drugs through swelling. The second cross-linked network has ROS-responsive properties, meaning that upon contact with ROS, covalent bonds break, releasing nanofiber-based therapeutic elements and anti-inflammatory drugs. Nanofiber-based therapeutic elements are mainly composed of short nanofibers and fluorescently labeled MMPs-responsive peptides grafted onto them.

2. The hydrogel with both anti-inflammatory and diagnostic functions according to claim 1, characterized in that, The average length of the short nanofibers is 10–50 μm, and the average diameter is 300–800 nm.

3. The hydrogel with both anti-inflammatory and diagnostic functions according to claim 1, characterized in that, The nanofibers are made of a third polymer, which may be polyvinyl alcohol formaldehyde, polycarbonate, polyvinylidene fluoride, polyvinyl alcohol-ethylene copolymer, polylactic acid-glycolic acid copolymer, polystyrene, polylactic acid, or polyamide 6.

4. The hydrogel with both anti-inflammatory and diagnostic functions according to claim 3, characterized in that, The preparation process of nanofiber-based diagnostic and therapeutic elements is as follows: Fluorescently labeled MMPs-responsive peptides are dissolved in PBS and incubated with short nanofibers. After incubation, the nanofibers are removed and washed with PBS to remove free fluorescein-labeled MMPs-responsive peptides. The nanofibers are then blocked with bovine serum albumin solution and freeze-dried to obtain nanofiber-based diagnostic and therapeutic elements. The mass ratio of fluorescein-labeled MMPs-responsive peptides to short nanofibers is 0.1–3:1–15.

5. The hydrogel with both anti-inflammatory and diagnostic functions according to claim 1, characterized in that, The anti-inflammatory drugs are one or more of the following: ibuprofen sodium, diclofenac sodium, ethacridine, dexamethasone sodium phosphate, hydrocortisone sodium phosphate, curcumin, and artemisinin.

6. A hydrogel with both anti-inflammatory and diagnostic functions according to any one of claims 1 to 5, characterized in that, The first cross-linking network is formed by the cross-linking of the first polymer itself; the second cross-linking network is formed by the cross-linking of the ROS-responsive substance and the second polymer.

7. A hydrogel with both anti-inflammatory and diagnostic functions according to claim 6, characterized in that, The first polymer is one or more of polyethylene glycol diacrylate, poly(N-isopropylacrylamide), tetra-armed polyethylene glycol-mercapto, tetra-armed polyethylene glycol succinimide glutarate, polyethylene glycol dimethacrylate, and tetra-armed polyethylene glycol acrylate; the ROS-responsive substance is one or more of sulfur-based ROS-responsive substances and selenium-based ROS-responsive substances. The second polymer is one or more of polylysine, gelatin, hyaluronic acid, and carboxymethyl chitosan.

8. A method for preparing a hydrogel with both anti-inflammatory and diagnostic functions as described in claim 7, characterized in that, Includes the following steps: (a) The first polymer and the ROS-responsive substance were co-dissolved in PBS and stirred until homogeneous. Then, a photoinitiator was added, the pH was adjusted to 5-7, and the nanofiber-based therapeutic element was added and dispersed evenly to obtain a mixture. (b) Add EDC and NHS to the mixture to activate the carboxyl groups of the ROS-responsive substance to obtain the first solution; (c) Dissolve the second polymer in PBS, add an anti-inflammatory drug, and obtain a second solution; (d) Mix the first solution with the second solution and vortex to obtain the hydrogel precursor solution; (e) The hydrogel precursor solution is irradiated under a UV lamp to form a hydrogel.

9. The method according to claim 8, characterized in that, In the mixture of step (a), the concentrations of the first polymer, ROS-responsive substance, photoinitiator, and nanofiber-based therapeutic element are 5–20 wt%, 2–10 wt%, 0.5–4 wt%, and 0.1–1 wt%, respectively; the molar ratio of EDC, NHS, and ROS-responsive substance in step (b) is 0.5–3:0.1–2:0.08–1; in the second solution of step (c), the concentrations of the second polymer and anti-inflammatory drug are 2–8 wt% and 1–6 wt%, respectively; in step (d), the volume ratio of the first solution to the second solution is 1–2:1–2.

10. A hydrogel-coated intestinal anastomosis suture, characterized in that, It includes absorbable sutures and a hydrogel coating applied to their surface, the hydrogel coating being made of the same material as the hydrogel described in any one of claims 1 to 7, which has both anti-inflammatory and diagnostic functions.

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