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CN-122005905-A - Tea tree essential oil gel dressing and preparation method thereof

CN122005905ACN 122005905 ACN122005905 ACN 122005905ACN-122005905-A

Abstract

The invention discloses a tea tree essential oil gel dressing and a preparation method thereof. The gel dressing is prepared from oxidized hyaluronic acid, carboxymethyl chitosan and tea tree essential oil nanoemulsion, wherein aldehyde groups on the oxidized hyaluronic acid and amino groups on the carboxymethyl chitosan react through Schiff base to form a dynamic cross-linked hydrogel network, and the tea tree essential oil nanoemulsion is dispersed in the hydrogel network in a physical embedding manner. The tea tree essential oil nanoemulsion is prepared by emulsifying tea tree essential oil with an aqueous phase solution containing castor oil polyoxyethylene ether, polyethylene glycol and deionized water. The Schiff base imine bond in the gel dressing is kept stable under the pH of normal tissues, and the hydrolysis is accelerated under the weak acid microenvironment of the infected wound surface, so that the pH response intelligent release of tea tree essential oil is realized. The invention also provides a preparation method of the dressing, which has mild preparation process conditions and simple and convenient operation. The dressing has antibacterial, antiinflammatory and repair promoting effects, and is suitable for the management of infection wound surface.

Inventors

  • YANG GENSHENG
  • LI HUIJIE

Assignees

  • 湖州健行济世生物科技有限公司

Dates

Publication Date
20260512
Application Date
20260325

Claims (10)

  1. 1. The tea tree essential oil gel dressing is characterized by being prepared from oxidized hyaluronic acid, carboxymethyl chitosan and tea tree essential oil nanoemulsion, wherein aldehyde groups on the oxidized hyaluronic acid and amino groups on the carboxymethyl chitosan form a dynamic cross-linked hydrogel network through Schiff base reaction, the tea tree essential oil nanoemulsion is dispersed in the hydrogel network in a physical embedding manner, the tea tree essential oil nanoemulsion is prepared by emulsifying tea tree essential oil and aqueous phase solution, and the aqueous phase solution comprises 2 parts of castor oil polyoxyethylene ether, 1 part of polyethylene glycol and 0.5 part of deionized water according to the mass ratio.
  2. 2. The tea tree essential oil gel dressing according to claim 1, wherein the concentration of the oxidized hyaluronic acid solution is 3% -5% w/v, and the concentration of the carboxymethyl chitosan solution is 3% -5% w/v.
  3. 3. The tea tree essential oil gel dressing according to claim 1 or 2, wherein the oxidation degree of the oxidized hyaluronic acid is 70% -80%, and the tea tree essential oil gel dressing is prepared by oxidizing sodium hyaluronate with a molecular weight of 10-20 Da with sodium periodate.
  4. 4. The tea tree essential oil gel dressing according to claim 1 or 2, wherein the substitution degree of carboxymethyl chitosan is 70% -80%.
  5. 5. The tea tree essential oil gel dressing according to claim 1, wherein the molecular weight of polyethylene glycol is 400, and the particle size of the tea tree essential oil nanoemulsion is 50-100 nm.
  6. 6. The tea tree essential oil gel dressing according to claim 1, wherein the mass ratio of the oxidized hyaluronic acid to the carboxymethyl chitosan to the tea tree essential oil is 1:1:6.
  7. 7. A method of preparing a tea tree essential oil gel dressing according to claim 1, comprising the steps of: (1) Dissolving sodium hyaluronate in deionized water at 30-50 ℃, cooling to room temperature, adding sodium periodate solution with the concentration of 0.4mol/L, stirring and reacting for 12 hours at room temperature in a dark condition, adding ethylene glycol to terminate the reaction, dialyzing, purifying and freeze-drying to obtain oxidized hyaluronic acid powder with the oxidation degree of 70-80%; (2) The preparation of the tea tree essential oil nanoemulsion comprises the steps of mixing castor oil polyoxyethylene ether, polyethylene glycol with the molecular weight of 400 and deionized water according to the mass ratio of 2:1:0.5 to prepare an aqueous phase solution, placing the aqueous phase solution in a constant-temperature water bath with the temperature of 50-60 ℃, magnetically stirring the aqueous phase solution to be homogeneous at the rotating speed of 600r/min, adding tea tree essential oil drops into the aqueous phase solution at the speed of 0.5mL/min, and continuously emulsifying for 5 minutes at the temperature of 50-60 ℃ and the temperature of 600r/min after the dripping is finished to obtain the tea tree essential oil nanoemulsion with the particle size of 50-100 nm; (3) The preparation of the composite gel dressing comprises the steps of dissolving oxidized hyaluronic acid powder obtained in the step (1) in deionized water at 50 ℃, filtering the solution by a 0.22 mu m sterile filter membrane to obtain an oxidized hyaluronic acid solution with the concentration of 3% -5% w/v, dissolving carboxymethyl chitosan in the deionized water, filtering the solution by the 0.22 mu m sterile filter membrane, regulating the pH value to 6.5-7.0 by using a 0.1mol/LNaOH solution to obtain a carboxymethyl chitosan solution with the concentration of 3% -5% w/v, mixing the oxidized hyaluronic acid solution with the carboxymethyl chitosan solution in equal volume, uniformly stirring, adding the tea tree essential oil nanoemulsion obtained in the step (2), continuously stirring for 10 minutes, and standing and crosslinking for 12 hours at room temperature and in a dark condition to obtain the tea tree essential oil gel dressing.
  8. 8. The preparation method of the aqueous solution of sodium hyaluronate according to claim 7, wherein in the step (1), the molecular weight of the sodium hyaluronate is 10-20 Da, 1.0g of sodium hyaluronate is dissolved in 100mL of deionized water, 5.0mL of sodium periodate solution with the concentration of 0.4mol/L is added for oxidation reaction, and 1mL of ethylene glycol is added for termination reaction.
  9. 9. The method according to claim 7 or 8, wherein in the step (1), the dialysis is performed by filling the reaction solution into a dialysis bag having a molecular weight cut-off of 3500Da, dialyzing in deionized water for 48 hours, changing the dialysis solution every 12 hours, and the freeze-drying time is 48 hours.
  10. 10. The method according to claim 7, wherein in the step (3), the mass ratio of the oxidized hyaluronic acid, the carboxymethyl chitosan and the tea tree essential oil is 1:1:6.

Description

Tea tree essential oil gel dressing and preparation method thereof Technical Field The invention relates to the technical field of medical polymer materials and drug delivery, in particular to a tea tree essential oil gel dressing and a preparation method thereof. Background Bacterial infection is a serious challenge in clinical wound management, and pathogenic bacteria represented by staphylococcus aureus can cause local suppurative infection, so that wound persistence is not even further caused to cause systemic septicemia. At present, silver ions, silver nano particles or traditional antibiotics are mainly used as active ingredients of the commercial antibacterial dressing, but non-targeted release of the silver ions in the acidic microenvironment of the wound surface can cause toxicity to healthy tissue cells, and long-term use of the antibiotics directly promotes generation and diffusion of drug-resistant strains. Hydrogels have become an important direction of wound dressing research due to their high water content, good biocompatibility and tissue-like elasticity. In recent years, a dynamic crosslinked hydrogel system constructed by a schiff base reaction of carboxymethyl chitosan and oxidized hyaluronic acid has been widely focused, and has been used for loading various active ingredients such as taurine, stem cell exosomes, tobramycin and the like. The tea tree essential oil is used as a natural plant-derived broad-spectrum antibacterial agent, the terpene compound which is rich in the tea tree essential oil plays an antibacterial role through a multi-target synergistic mechanism, bacterial drug resistance is not easy to induce, and the tea tree essential oil has the potential of replacing the traditional antibiotics. However, the prior art still faces multiple technical bottlenecks in terms of effectively loading tea tree essential oil into a hydrogel dressing and achieving intelligent delivery. Tea tree essential oils are highly volatile and highly hydrophobic, with about 90% of the TTO rapidly evaporating from the epidermis, and they have a severe tendency to phase separate in aqueous gel matrices, resulting in uneven dispersion and rapid loss of active ingredient. The traditional medicine release of the medicine-carrying hydrogel dressing mainly depends on passive diffusion driven by concentration gradient, and lacks intelligent response capability for realizing on-demand release according to the pH change of an infected microenvironment. The existing hydrogel system loaded with tea tree essential oil nanoemulsion adopts a synthetic polymer material and photopolymerization crosslinking mode, has poor biodegradability, needs special equipment and does not have pH responsiveness, and the scheme of only staying at the nanoemulsion preparation level lacks the attaching, moisturizing and sustained-release functions required by wound dressing. In addition, most existing functional dressings focus on only a single antimicrobial or anti-inflammatory function, and it is difficult to simultaneously achieve multiple demands of antimicrobial, anti-inflammatory and pro-repair in the same system, and optimization of the balance between the cross-linking density of schiff base gel and drug loading capacity is still a major problem. Therefore, development of a novel wound dressing capable of efficiently and stably loading tea tree essential oil into a natural polysaccharide hydrogel network with a pH response intelligent drug release function and simultaneously achieving multiple functions of resisting bacteria, resisting inflammation and promoting repair is needed. Disclosure of Invention The invention provides a tea tree essential oil gel dressing which is prepared from oxidized hyaluronic acid, carboxymethyl chitosan and tea tree essential oil nanoemulsion, wherein aldehyde groups on the oxidized hyaluronic acid and amino groups on the carboxymethyl chitosan react through Schiff base to form a dynamic cross-linked hydrogel network, the tea tree essential oil nanoemulsion is dispersed in the hydrogel network in a physical embedding mode, the tea tree essential oil nanoemulsion is prepared by emulsifying tea tree essential oil and aqueous phase solution, and the aqueous phase solution comprises 2 parts of castor oil polyoxyethylene ether, 1 part of polyethylene glycol and 0.5 part of deionized water according to a mass ratio. As a preferable scheme, the concentration of the oxidized hyaluronic acid solution is 3% -5% w/v, and the concentration of the carboxymethyl chitosan solution is 3% -5% w/v. As a preferable scheme, the oxidation degree of the oxidized hyaluronic acid is 70% -80%, and the oxidized hyaluronic acid is prepared by oxidizing sodium hyaluronate with the molecular weight of 10-20 Da by sodium periodate. As a preferable scheme, the substitution degree of the carboxymethyl chitosan is 70% -80%. As a preferable scheme, the molecular weight of the polyethylene glycol is 400, and the grain diameter