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CN-121714756-B - Exudate responsive self-shedding core-shell microgel powder for burn and scald wound surface and preparation method thereof

CN121714756BCN 121714756 BCN121714756 BCN 121714756BCN-121714756-B

Abstract

The invention provides a self-shedding core-shell microgel powder with exudate responsiveness for burn and scald wounds and a preparation method thereof, belonging to the technical field of medical materials. The core-shell microgel powder provided by the invention can quickly absorb a large amount of exudates and form attached hydrogel in situ after being applied to a wound surface, provides ideal wet environment and physical protection for wound surface healing, has the exudate response characteristic, not only can intelligently release active ingredients to actively regulate and control inflammation and promote repair, but also can realize the moderate self-falling of dressing in the later healing period, and greatly improves patient experience and treatment compliance. The product combines efficient seepage management, active therapeutic intervention and humanized painless removal, and provides a brand new and integrated solution for clinical care of complicated seepage wound surfaces such as burns and scalds.

Inventors

  • ZHANG LI
  • YANG HAO
  • HE MIAOMIAO

Assignees

  • 四川大学

Dates

Publication Date
20260508
Application Date
20260225

Claims (10)

  1. 1. The core-shell microgel powder is characterized in that the microgel powder has a core-shell structure, and the core in the core-shell structure is a calcium ion pretreated polyacrylamide microsphere; the shell in the core-shell structure is a sodium alginate layer loaded with hydrogen donor nano sheets, and the hydrogen donor nano sheets are dispersed in the sodium alginate layer.
  2. 2. The core-shell microgel powder according to claim 1 wherein the hydrogen donor nanoplatelets are magnesium silicide nanoplatelets or calcium silicide nanoplatelets; the surface of the hydrogen donor nano-sheet is coated with a polyvinylpyrrolidone layer; the mass percentage of the hydrogen donor nano-sheet in the core-shell microgel powder is 10% -20%; The particle size of the polyacrylamide microspheres is 180-280 microns; The whole particle size of the core-shell microgel powder is 280-360 microns.
  3. 3. A method for preparing the core-shell microgel powder according to claim 1 or 2, comprising the steps of: S1, immersing polyacrylamide microspheres in an ethanol solution containing calcium ions, and then drying to obtain polyacrylamide microspheres pretreated by the calcium ions; S2, mixing the calcium ion pretreated polyacrylamide microsphere with a sodium alginate aqueous solution containing hydrogen donor nano sheets, and performing an ionic crosslinking reaction to form a sodium alginate shell layer loaded with the hydrogen donor nano sheets on the surface of the microsphere to obtain core-shell structure gel particles, wherein the microgel powder has a core-shell structure, the core in the core-shell structure is the calcium ion pretreated polyacrylamide microsphere, the shell in the core-shell structure is a sodium alginate layer loaded with the hydrogen donor nano sheets, and the hydrogen donor nano sheets are dispersed in the sodium alginate layer; s3, separating, washing and freeze-drying the core-shell structure gel particles to obtain the core-shell microgel powder.
  4. 4. The preparation method according to claim 3, wherein in the step S1, the polyacrylamide microsphere is prepared by a water-in-oil emulsion polymerization method, and the water-in-oil emulsion polymerization method comprises the steps of adding an aqueous phase containing an acrylamide monomer, a cross-linking agent and an initiator dropwise to an oil phase containing an emulsifier for polymerization; Or the polyacrylamide microspheres are prepared by a precipitation polymerization method, wherein the precipitation polymerization method comprises the steps of polymerizing an acrylamide monomer in a mixed solvent of ethanol and water under the protection of nitrogen; Or, the polyacrylamide microsphere is prepared by a dispersion polymerization method, wherein the dispersion polymerization method comprises the step of polymerizing an acrylamide monomer in a mixed solvent of ethanol and water containing a dispersing agent polyvinylpyrrolidone.
  5. 5. The method according to claim 3, wherein in the step S1, the concentration of calcium ions in the ethanol solution containing calcium ions is 40 mg/ml to 60 mg/ml, and the soaking time is 20 hours to 28 hours; In the step S2, the mass volume concentration of sodium alginate in the sodium alginate aqueous solution containing the hydrogen donor nano-sheets is 0.1-0.3%, the doping amount of the hydrogen donor nano-sheets in the sodium alginate aqueous solution containing the hydrogen donor nano-sheets is 80-120% of the mass of sodium alginate, and the ionic crosslinking reaction is carried out at room temperature for 0.5-1.5 hours; in the step S3, the freeze-drying temperature is-60 ℃ to-40 ℃ and the drying time is 40-56 hours.
  6. 6. The preparation method of the water-in-oil emulsion polymerization method according to claim 4, wherein the oil phase comprises cyclohexane and span-based emulsifier, the volume ratio of the water phase to the oil phase is 1:2-3, the span-based emulsifier comprises span 20 and span 80, the mass ratio of the span 20 to the span 80 is 1.5-2.5:1, the speed of dropwise adding the water phase into the oil phase is 50-70 drops/min in the water-in-oil emulsion polymerization method, the polymerization reaction is carried out at 60-70 ℃, the stirring speed is 250-350 revolutions/min, and the reaction time is 2-4 hours; In the precipitation polymerization method, the volume ratio of the ethanol to the water in the mixed solvent of the ethanol and the water is 3-5:1, the polymerization reaction is carried out at 30-40 ℃, the stirring speed is 250-350 rpm, and the reaction time is 20-28 hours; In the dispersion polymerization method, the volume ratio of the ethanol to the water in the mixed solvent of the ethanol and the water is 3-5:1, the mass of the dispersing agent polyvinylpyrrolidone in the dispersion polymerization method is 0.5% -1.5% of the total mass of the solvent, the polymerization reaction is carried out at 65-75 ℃, the stirring speed is 250-350 rpm, and the reaction time is 20-28 hours.
  7. 7. The preparation method according to claim 3, wherein in the step S2, the mass-to-volume ratio of the calcium ion-pretreated polyacrylamide microsphere to the sodium alginate aqueous solution containing the hydrogen donor nanoplatelets is 0.05 g/100 ml to 0.15 g/100 ml.
  8. 8. The method according to claim 3, wherein in the step S3, the separation is performed by centrifugation at 4000 rpm to 6000 rpm for 3 minutes to 8 minutes; In the step S1, the drying is carried out at 35-45 ℃ for 1-3 hours; the hydrogen donor nanoplatelets are prepared by an ultrasound-assisted exfoliation method.
  9. 9. Use of the core-shell microgel powder according to any one of claims 1 to 2 or prepared by the preparation method according to any one of claims 3 to 8 for the preparation of a medical dressing for promoting wound healing.
  10. 10. The use according to claim 9, wherein the wound is a burn wound.

Description

Exudate responsive self-shedding core-shell microgel powder for burn and scald wound surface and preparation method thereof Technical Field The invention relates to the technical field of medical materials, in particular to a self-shedding core-shell microgel powder with exudate responsiveness for burn and scald wounds and a preparation method thereof. Background Skin burns and scalds, especially deep secondary and above injuries, are one of the clinically common severe wounds. The wound surface can lead to a great deal of tissue exudates to be lost due to serious damage of skin barriers, and is extremely easy to cause infection, thus forming a complex and fragile pathological microenvironment. How to effectively manage the seepage, control the infection and promote the tissue regeneration is a key challenge in the treatment of burns and scalds. In the development process of the wound dressing, the powdery dressing always occupies a place because of the advantages of high specific surface area, good liquid absorption, convenient use, easy fitting of irregular wound surfaces and the like. Conventional powder dressings, such as certain polysaccharide or inorganic salt powders, manage the leakage of fluids primarily by physical absorption. However, they tend to be single-acting, lack active biological effects, and can scab, harden after imbibition, and adhere to new granulation tissue easily when removed, resulting in secondary injury and severe pain. With the popularity of wet healing theory, hydrogel dressings have received great attention for their ability to provide a sustained moist environment, alleviating pain. However, some hydrogel dressings have poor initial adhesion, limited absorption of large amounts of exudates, or suffer from adhesion problems when removed. In recent years, strategies to load active therapeutic ingredients (e.g., antibacterial agents, growth factors, etc.) into a dressing to achieve "active therapy" have become a focus of research. For example, materials capable of releasing nitric oxide, hydrogen and other gas signal molecules are applied to dressing materials so as to regulate wound inflammation and promote angiogenesis, and have good potential. However, how to design a material, which not only can realize intelligent absorption and management of hypertonic liquid amount, but also can accurately and continuously release therapeutic components, and finally realize noninvasive and painless soft removal, is still a systematic problem to be solved in a fusion way in the field. Disclosure of Invention The invention aims to provide a self-shedding core-shell microgel powder with exudate responsiveness for a burn and scald wound surface and a preparation method thereof, which solve the problems that the traditional burn and scald dressing is easy to cause secondary injury and pain when being removed, and the function is single and the high inflammatory exudate wound surface cannot be intelligently managed. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides core-shell microgel powder, which has a core-shell structure, wherein the core in the core-shell structure is a polyacrylamide microsphere pretreated by calcium ions; the shell in the core-shell structure is a sodium alginate layer loaded with hydrogen donor nano sheets, and the hydrogen donor nano sheets are dispersed in the sodium alginate layer. Preferably, the hydrogen donor nanoplatelets are magnesium silicide nanoplatelets or calcium silicide nanoplatelets; the surface of the hydrogen donor nano-sheet is coated with a polyvinylpyrrolidone layer; the mass percentage of the hydrogen donor nano-sheet in the core-shell microgel powder is 10% -20%; The particle size of the polyacrylamide microspheres is 180-280 microns; The whole particle size of the core-shell microgel powder is 280-360 microns. The invention also provides a preparation method of the core-shell microgel powder, which comprises the following steps: S1, immersing polyacrylamide microspheres in an ethanol solution containing calcium ions, and then drying to obtain polyacrylamide microspheres pretreated by the calcium ions; S2, mixing the calcium ion pretreated polyacrylamide microsphere with a sodium alginate aqueous solution containing hydrogen donor nano sheets, and performing an ionic crosslinking reaction to form a sodium alginate shell layer loaded with the hydrogen donor nano sheets on the surface of the microsphere to obtain core-shell structure gel particles, wherein the microgel powder has a core-shell structure, the core in the core-shell structure is the calcium ion pretreated polyacrylamide microsphere, the shell in the core-shell structure is a sodium alginate layer loaded with the hydrogen donor nano sheets, and the hydrogen donor nano sheets are dispersed in the sodium alginate layer; s3, separating, washing and freeze-drying the core-shell structure gel particles to obtain th