Polyamino acid, preparation method thereof, polyamino acid hydrogel and application of polyamino acid hydrogel

Abstract

The invention relates to hydrogel design in the field of wound repair, in particular to polyamino acid, a preparation method of the polyamino acid, polyamino acid hydrogel and application of the polyamino acid hydrogel. The hydrogel prepared from polyamino acid provided by the invention is used for reactive oxygen species (ROS) regulation and hair follicle repair for efficient healing of chronic wounds, and compared with other clinically used wound dressings, the hydrogel can effectively reduce the ROS level of the wounds and provide a proper microenvironment for wound repair, so that cells are protected, and the healing effect of the wounds is improved. The traditional Chinese medicine composition can promote cell migration and proliferation, regulate the wound healing process, accelerate the conversion from the inflammation stage to the proliferation stage, promote vascular function reconstruction, collagen deposition and reepithelization, and solve the problem that chronic wounds are difficult to heal; moreover, the hair follicle generation promoting effect is achieved, and the problem that hair follicles are lost or generated slowly after wound healing can be solved.

Description

Technical Field

[0001] This invention relates to the field of wound repair material synthesis and application technology, specifically to polyamino acids, their preparation methods, and polyamino acid hydrogels and their applications. Background Technology

[0002] During the healing process of diabetic wounds, high blood sugar and persistent inflammation often lead to a large production of reactive oxygen species (ROS), resulting in excessive ROS accumulation in the wound. Excessive ROS can exceed the cell's antioxidant capacity, damaging normal cells and disrupting the extracellular matrix, thus preventing the wound from transitioning from the inflammatory phase to the proliferative phase, ultimately leading to chronic wound formation. Therefore, maintaining intracellular redox balance, i.e., effectively achieving antioxidant protection, holds promise for preventing abnormal cell growth and immune response disorders.

[0003] Furthermore, wounds are often accompanied by damaged or missing hair follicles, and abnormal hair follicle formation can impair basic skin functions such as perspiration and metabolism. With people's growing need for a better life, higher demands are being placed on wound repair materials, requiring not only high antioxidant capacity and repair-promoting effects, but also the ability to promote hair follicle growth. However, research and development on such wound repair materials is currently very limited, and there are no relevant research guidelines. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide polyamino acids, their preparation methods, polyamino acid hydrogels and their applications. The hydrogels made of polyamino acids provided by the present invention not only have high antioxidant capacity and strong repair-promoting effects, but also have the effect of promoting hair follicle generation.

[0005] This invention provides a polyamino acid having the structure of Formula 1;

[0006]

[0007]

[0008] Wherein, R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C6 straight-chain or branched alkyl groups, substituted or unsubstituted selenide C1-C6 straight-chain or branched alkyl groups, substituted or unsubstituted thioide C1-C6 straight-chain or branched alkyl groups, preferably selected from substituted or unsubstituted C3-C5 straight-chain or branched alkyl groups, substituted or unsubstituted selenide mono-hetero-hetero-C3-C5 straight-chain or branched alkyl groups, and substituted or unsubstituted thioide mono-hetero-C3-C5 straight-chain or branched alkyl groups;

[0009] n1, n2, and n3 are independently the number of structural units.

[0010] Specifically, in this invention, n1 is an integer from 20 to 200; n2 is an integer from 5 to 40; and n3 is an integer from 5 to 40. Preferably, n1 is an integer from 30 to 50; n2 is an integer from 20 to 30; and n3 is an integer from 20 to 30. More preferably, n1 is an integer from 43 to 45; n2 is an integer from 24 to 26; and n3 is an integer from 24 to 26.

[0011] In some embodiments of the present invention, the polyamino acid provided by the present invention has a structure of formula 1-a or formula 2-a;

[0012]

[0013] Wherein, y1, y2 and y3 are independently integers from 1 to 4, preferably 1 or 2;

[0014] X1, X2, and X3 are independently selected from methylene, thioether, or selenide bonds;

[0015] The terms n1, n2, and n3 are the same as those described above and will not be repeated here.

[0016] In other embodiments of the present invention, the polyamino acid provided by the present invention has a structure of formula 1-b or formula 2-b;

[0017]

[0018] X1, X2, and X3 are independently selected from methylene, thioether, or selenide bonds;

[0019] The terms n1, n2, and n3 are the same as those described above and will not be repeated here.

[0020] The present invention also provides a method for preparing any of the polyamino acids described above, comprising the following steps:

[0021] A ring-opening polymerization reaction is carried out between a methoxy polyethylene glycol amine having the structure of formula a-1 or a polyethylene glycol amine having the structure of formula a-2 and an acid anhydride monomer to obtain a polyamino acid.

[0022] The anhydride monomer is selected from one or more of the following: anhydride monomers having the structure of formula b-1, anhydride monomers having the structure of formula b-2, and anhydride monomers having the structure of formula b-3.

[0023]

[0024] Specifically, under an inert gas atmosphere, a dried methoxy polyethylene glycolamine having the structure of formula a-1 or a polyethylene glycolamine having the structure of formula a-2 is subjected to a ring-opening polymerization reaction with the acid anhydride monomer. The product obtained from the reaction is precipitated, filtered, dried, and purified to obtain polyamino acids. In some embodiments of the present invention, under a nitrogen atmosphere, a dried methoxy polyethylene glycolamine having the structure of formula a-1 or a polyethylene glycolamine having the structure of formula a-2 is subjected to azeotropic dehydration with toluene to remove toluene and water. Then, dried N,N-dimethylformamide is added to the mixture, and a ring-opening polymerization reaction is carried out with the acid anhydride monomer. The product obtained from the reaction is precipitated with ice-cold ether, centrifuged, and then dissolved in an appropriate amount of DMF. The product is placed in a 2000 Da to 3500 Da dialysis bag and dialyzed in deionized water for 3 days, followed by freeze-drying to obtain polyamino acids.

[0025] In the methoxy polyethylene glycol amine having the structure of formula a-1 and the polyethylene glycol amine having the structure of formula a-2 described in this invention, n1 is the same as described above; R1 in the acid anhydride monomer having the structure of formula b-1 is the same as described above; R2 in the acid anhydride monomer having the structure of formula b-2 is the same as described above; and R3 in the acid anhydride monomer having the structure of formula b-3 is the same as described above, and will not be repeated here. The mass ratio of one of the methoxy polyethylene glycol amine having the structure of formula a-1 or the polyethylene glycol amine having the structure of formula a-2 to the acid anhydride monomer described in this invention is 1:(1.5~3.5). The ring-opening polymerization reaction temperature described in this invention is 15℃~35℃, and the ring-opening polymerization reaction time is 2 days~5 days. Preferably, the ring-opening polymerization reaction temperature described in this invention is 15℃~30℃, and the ring-opening polymerization reaction time is 2.5 days~3.5 days.

[0026] The azeotropic dehydration temperature described in this invention is 120℃~140℃, and the azeotropic dehydration time is 1h~3h. Preferably, the azeotropic dehydration temperature is 120℃~130℃, and the azeotropic dehydration time is 2h~3h.

[0027] The methoxylated polyethylene glycol amine having the structure of formula a-1 described in this invention is prepared by the following method:

[0028] Methoxy polyethylene glycol having the structure of formula c-1 was reacted sequentially with p-toluenesulfonyl chloride and ammonium chloride to obtain methoxy polyethylene glycol amine having the structure of formula a-1.

[0029]

[0030] Specifically, in this invention, methoxy polyethylene glycol having the structure of formula c-1 and p-toluenesulfonyl chloride are reacted in a solvent at room temperature for 6 to 8 days, preferably 7 days, under potassium hydroxide conditions. The mixture is then precipitated in ice-cold ether, filtered, and dried to obtain a white solid product. The obtained white solid product and ammonium chloride are reacted in ammonia water at room temperature for 6 to 8 days, preferably 7 days, to obtain methoxy-polyethylene glycol-p-toluenesulfonyl, i.e., methoxy polyethylene glycol amine having the structure of formula a-1. The room temperature is preferably 15°C to 30°C. The mass ratio of methoxy polyethylene glycol having the structure of formula c-1, p-toluenesulfonyl chloride, and potassium hydroxide in this invention is 25:(9-10):(2.5-3), preferably 25:9.5:5.6. The volume of ammonia water used in this invention is 9 to 11 times that of methoxy-polyethylene glycol-p-toluenesulfonyl; the mass of ammonium chloride used is the same as that of the obtained white solid product. The solvent used in this invention is preferably selected from dichloromethane.

[0031] The polyethylene glycolamine having the structure of formula a-2 described in this invention is prepared by the following method:

[0032] Polyethylene glycol having the c-2 structure was reacted sequentially with p-toluenesulfonyl chloride and ammonium chloride to obtain a polyethylene glycol amine having the a-2 structure;

[0033]

[0034] The specific preparation process is the same as that of the methoxy polyethylene glycol amine with the structure of formula a-1, except that the methoxy polyethylene glycol with the structure of formula c-1 is replaced with polyethylene glycol with the structure of formula c-2, and finally p-toluenesulfonyl-polyethylene glycol, that is, polyethylene glycol amine with the structure of formula a-2, is obtained.

[0035] The anhydride monomer of the present invention is prepared by the following method: reacting an amino acid having the structure of formula d-1 with triphosgene to obtain an anhydride monomer having the structure of formula b-1.

[0036]

[0037] Specifically, when R1 in formula d-1 is selected from substituted or unsubstituted thiazo C1-C6 straight-chain or branched alkyl groups, the preparation method of the anhydride monomer having the structure of formula b-1 according to the present invention includes: reacting an amino acid having the structure of formula d-1 and triphosgene in a solvent at 45°C-50°C for 0.8h-1.2h under an inert gas atmosphere, then stopping the reaction, increasing the nitrogen flow rate to enrich the product, and allowing it to settle to obtain the monomer having the structure of formula b. In some embodiments of the present invention, under a nitrogen atmosphere, reacting an amino acid having the structure of formula d-1 and triphosgene in tetrahydrofuran at 48°C for 1h, then stopping the reaction, increasing the nitrogen flow rate to enrich the product, precipitating it with ice-cold n-hexane, continuously and rapidly stirring during the precipitation process, and then filtering or discarding the upper liquid to obtain the monomer having the structure of formula b-1. The ratio of amino acid with formula d-1, triphosgene, and solvent in this invention is (14-16)g:(14-16)g:(250-350)mL, preferably 15g:15g:300mL.

[0038] When R1 in formula d-1 is selected from substituted or unsubstituted selenide C1-C6 straight-chain or branched alkyl groups, the preparation method of the monomer having the structure of formula b-1 according to the present invention includes: reacting an amino acid having the structure of formula d-1 and triphosgene in a solvent at room temperature for 1.8 h to 2.2 h, quenching the triphosgene, and separating and purifying to obtain the monomer having the structure of formula b-1. In some embodiments of the present invention, the amino acid having the structure of formula d-1 and triphosgene are reacted in propylene oxide and tetrahydrofuran at room temperature for 2 h, washed three times with ice-saturated brine, the triphosgene is quenched, the upper liquid is retained, and then the upper liquid is successively dried, filtered, further concentrated by rotary evaporation and precipitated, and then the lower liquid obtained after precipitation is dissolved in ice-cold ethyl acetate, connected to a cold trap, and the solvent is removed by an oil pump to obtain the monomer having the structure of formula b-1. The ratio of propylene oxide, amino acid with formula d-1, triphosgene and solvent in this invention is (15-20) mL: (7-9) g: (7-9) g: (260-360) mL, preferably 16 mL: 8 g: 8 g: 320 mL.

[0039] The anhydride monomers of the present invention, wherein the anhydride monomer having the b-2 structure is prepared by reacting an amino acid having the d-2 structure with triphosgene to obtain the anhydride monomer having the b-2 structure; and the anhydride monomer having the b-3 structure is prepared by reacting an amino acid having the d-3 structure with triphosgene to obtain the anhydride monomer having the b-3 structure.

[0040]

[0041] The specific preparation process of the acid anhydride monomers with the b-2 structure and the acid anhydride monomers with the b-3 structure described in this invention is the same as the specific preparation process of the acid anhydride monomers with the b-1 structure described above. The only difference is that the amino acid raw materials are different, and will not be described again.

[0042] The present invention also provides a polyamino acid hydrogel, which is obtained by gelling polyamino acids obtained by any of the above-described polyamino polymers or by any of the above-described preparation methods.

[0043] This invention also provides the application of any of the aforementioned polyamino acid hydrogels as medical dressings with hair follicle repair and / or chronic wound repair functions. Specifically, this invention also provides a medical dressing with hair follicle repair and / or chronic wound repair functions, comprising the aforementioned polyamino acid hydrogel and optional medical additives, wherein the medical additives may or may not be added. The aforementioned polyamino acid hydrogel is a polyamino acid hydrogel for efficient healing of chronic wounds by regulating ROS and repairing hair follicles. Based on the effects of the aforementioned polyamino acid hydrogel, the medical dressing provided by this invention can not only reduce the high ROS level at the wound site, alleviate wound inflammation, and promote vascular function reconstruction, collagen deposition, and skin re-epithelialization, effectively solving the problem of prolonged and difficult healing of chronic wounds; it can also promote hair follicle generation at the wound site.

[0044] This invention provides polyamino acids, their preparation methods, polyamino acid hydrogels, and their applications. The polyamino acid hydrogel provided by this invention is a ROS-regulating and hair follicle repair hydrogel for efficient healing of chronic wounds. Compared to other wound dressings used clinically, it can effectively reduce the level of reactive oxygen species (ROS) in the wound, providing a suitable microenvironment for wound repair, thereby protecting cells, promoting cell migration and proliferation, regulating the wound healing process, and accelerating the transition from the inflammatory phase to the proliferative phase, thus promoting vascular function reconstruction, collagen deposition, and epithelialization, and solving the problem of difficult healing of chronic wounds. Furthermore, it also promotes hair follicle repair, addressing the problem of hair follicle loss or slow hair follicle regeneration after wound healing. Attached Figure Description

[0045] Figure 1 The NCA monomers prepared in Examples 1-3 1 H NMR spectrum;

[0046] Figure 2 The mPEG prepared in Example 1 2k -b-Met 25 Polyamino acid hydrogels 1 H NMR spectrum;

[0047] Figure 3 The mPEG prepared in Example 22k -b-SeMet 25 Polyamino acid hydrogels 1 H NMR spectrum;

[0048] Figure 4 The mPEG prepared in Example 3 2k -b-Nle 25 Polyamino acid hydrogels 1 H NMR spectrum;

[0049] Figure 5 The graph shows the phase transition test results of the polyamino acid hydrogels prepared in Examples 1-3;

[0050] Figure 6 The rheological test results of the polyamino acid hydrogels prepared in Examples 1-3 are shown in the figure.

[0051] Figure 7 The mPEG prepared in Example 1 2k -b-Met 25 Figure showing the test results of the scavenging ability of polyamino acid hydrogels against different concentrations of H2O2;

[0052] Figure 8 The mPEG prepared in Example 2 2k -b-SeMet 25 Figure showing the test results of the scavenging ability of polyamino acid hydrogels against different concentrations of H2O2;

[0053] Figure 9 The graphs show the cell-killing ability of different concentrations of hydrogen peroxide and the protective ability of the polyamino acid hydrogels prepared in Examples 1-3.

[0054] Figure 10 The images show H&E slices of the polyamino acid hydrogels prepared in Examples 1-3. Detailed Implementation

[0055] This invention discloses polyamino acids, their preparation methods, polyamino acid hydrogels, and their applications. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0056] The method for preparing polyamino acid hydrogels provided by this invention first synthesizes mPEG-NH2 and NCA, wherein the synthesis reaction equation for mPEG-NH2 is as follows:

[0057]

[0058] The reaction equation for the synthesis of NCA is as follows:

[0059]

[0060] In the above NCA synthesis reaction equation, R is a substituted or unsubstituted C1-C6 straight-chain or branched alkyl group, a substituted or unsubstituted selenide C1-C6 straight-chain or branched alkyl group, or a substituted or unsubstituted thiamethoxam C1-C6 straight-chain or branched alkyl group.

[0061] Then, a polyamino acid hydrogel was prepared using mPEG-NH2 and NCA. The synthesis reaction equation is as follows:

[0062] The present invention will be further described below with reference to the embodiments:

[0063] Example 1

[0064] mPEG 2k -b-Met 25 Synthesis:

[0065] First, we synthesize methoxylated polyethylene glycol amine. Here we will use 25.0 g mPEG 2k Dissolve the polymer completely in 250 mL of dichloromethane. Add 9.5 g of p-toluenesulfonyl chloride (PTSC) and 5.6 g of potassium hydroxide (KOH) sequentially. Stir for 7 days, then pour into a separatory funnel. Wash 6-8 times with ice-cold saturated sodium chloride solution in small, frequent washes to ensure the lower organic phase is as clear as possible. After separation, dry the lower phase overnight at room temperature with anhydrous magnesium sulfate (MgSO4). The next day, filter off the magnesium sulfate using a sintered glass funnel, concentrate by rotary evaporation, precipitate the liquid with ice-cold diethyl ether, stir for 15 minutes, filter using a Buchner funnel, and vacuum dry at room temperature for 12 hours to obtain the polymer. Dissolve the obtained polymer completely in ammonia water at a volume equal to 10 times its mass. Add an equal mass of ammonium chloride and react at room temperature for 7 days. Extract the organic phase with dichloromethane, wash 2-3 times with ice-cold saturated sodium chloride solution, and dry overnight at room temperature with anhydrous MgSO4. The following day, magnesium sulfate was filtered off using a sintered glass funnel, followed by precipitation with ice-cold ether, drying under vacuum using a Buchner funnel, and finally vacuum drying at room temperature to obtain the final product mPEG. 2k -NH2.

[0066] Next, NCA was synthesized. To synthesize Met NCA: Prepare an anhydrous, dry three-necked round-bottom flask, purge with nitrogen, add 300 mL of tetrahydrofuran (THF), weighing 15.00 g. L -Methionine ( L 15.00 g of triphosgene (Bis(trichloromethyl)carbonate, BTC) was added to a flask and incubated in an oil bath at 48°C for 1 hour until the liquid became clear. The nitrogen flow rate was then increased to remove as much THF as possible. When 20–30 mL of THF remained, the mixture was settled with ice-cold n-hexane with continuous rapid stirring. The upper colorless liquid was discarded. The solid was then dissolved in ethyl acetate and washed three times with ice-cold saturated sodium chloride solution. The solution was transferred to an Erlenmeyer flask, and an appropriate amount of anhydrous magnesium sulfate was added. The mixture was dried overnight at -20°C. The next day, the mixture was filtered through a G4 sintered glass funnel. The filtrate was connected to a cold trap, and the solvent was removed using a vacuum pump to obtain the final product. L -Methionine-N-carboxycyclic anhydride ( L -Met NCA).

[0067] Finally, the ring-opening polymerization of NCA was initiated using mPEG-NH2 to synthesize polyamino acids. The process is as follows: 1.00 g of mPEG-NH2 was added to 200 mL of dry toluene, and the mixture was azeotropically heated at 125 °C for 2 h to remove water. The toluene was then dried under vacuum. 40 mL of dry anhydrous N,N-dimethylformamide (DMF) and 2.17 g of [unspecified ingredient] were then added sequentially. L -Met NCA was reacted at room temperature for 3 days, with nitrogen purging three times. The mixture was settled with ice-cold diethyl ether, filtered through a Buchner funnel, and dried under vacuum to obtain a pale yellow polymer, which was weighed. The solid was dissolved in an appropriate amount of DMF and placed in a 2000 Da dialysis bag. After dialyzing in deionized water for 3 days, it was lyophilized to obtain mPEG. 2k -b-Met 25 ,PMet.

[0068] Example 2

[0069] mPEG 2k -b-SeMet 25 Synthesis:

[0070] First, methoxylated polyethylene glycol amines or polyethylene glycol amines were synthesized. The final product mPEG was obtained following the same steps as in Example 1. 2k -NH2.

[0071] Next, NCA was synthesized. To synthesize SeMet NCA: Prepare a pressure-resistant bottle, add 320 mL of tetrahydrofuran, add 16 mL of propylene oxide, and weigh 8.00 g. L -Selenomethionine ( L(-SeMet) and 8.00 g of triphosgene were added to a pressure-resistant flask and reacted at room temperature for 2 hours to obtain a pale yellow transparent liquid. The mixture was washed three times with ice-saturated brine to quench the triphosgene, and the supernatant was retained. The supernatant was dried overnight with anhydrous magnesium sulfate. The next day, the mixture was filtered through a G4 sintered glass funnel to remove the solid magnesium sulfate. The solvent was removed by rotary evaporation until 10–20 mL of liquid remained. Ice-saturated n-hexane was used to settle the supernatant, and the lower yellowish-brown viscous liquid was removed. The liquid was then transferred to an ampoule, connected to a cold trap, and the solvent was removed using an oil pump to obtain the final product. L -Selenomethionine-N-carboxycyclic anhydride ( L -SeMet NCA).

[0072] Finally, the ring-opening polymerization of NCA was initiated using mPEG-NH2 to synthesize polyamino acids. The process is as follows: 1.00 g of mPEG-NH2 was added to 200 mL of dry toluene, and the mixture was azeotropically heated at 125 °C for 2 h to remove water. The toluene was then dried under vacuum, and 40 mL of dry anhydrous N,N-dimethylformamide and 2.78 g of [unspecified ingredient] were added sequentially. L -SeMet NCA was reacted at room temperature for 3 days, with nitrogen purging three times. The mixture was settled with ice-cold diethyl ether, filtered through a Buchner funnel, and dried under vacuum to obtain a pale yellow polymer, which was then weighed. The solid was dissolved in an appropriate amount of DMF and placed in a 2000 Da dialysis bag. After dialyzing in deionized water for 3 days, it was lyophilized to obtain mPEG. 2k -b-SeMet 25 ,PSeMet.

[0073] Example 3

[0074] mPEG 2k -b-Nle 25 Synthesis:

[0075] First, methoxylated polyethylene glycol amines or polyethylene glycol amines were synthesized. The final product mPEG was obtained following the same steps as in Example 1. 2k -NH2.

[0076] Next, NCA was synthesized. Synthesis of Nle NCA: Prepare an anhydrous, dry three-necked round-bottom flask, purge with nitrogen, add 300 mL of tetrahydrofuran, and weigh 15.00 g. L -Leucine ( L -Norleucine, L-Nle) and 15.00 g of triphosgene were added to a flask and incubated in an oil bath at 48°C. After 1 hour, the liquid became transparent. The nitrogen flow rate was increased to purge as much THF as possible. When 20-30 mL of THF remained, it was precipitated with ice-cold n-hexane with continuous rapid stirring during the precipitation process. The mixture was then filtered using a sintered glass funnel to obtain a solid product. The solid was then dissolved in an appropriate amount of ice-cold ethyl acetate, washed three times with anhydrous saturated sodium chloride solution, and added to an Erlenmeyer flask. An appropriate amount of anhydrous magnesium sulfate was added, and the mixture was dried overnight at -20°C. The next day, the mixture was filtered using a G4 sintered glass funnel. The filtrate was connected to a cold trap, and the solvent was removed using a vacuum pump to obtain the final product. L -Leucine-N-carboxycyclic anhydride ( L -Nle NCA).

[0077] Finally, the ring-opening polymerization of NCA was initiated using mPEG-NH2 to synthesize polyamino acids. The process is as follows: 1.00 g of mPEG-NH2 was added to 200 mL of dry toluene and azeotropically dried at 125 °C for 2 h. The toluene was then dried under vacuum. 40 mL of dry anhydrous N,N-dimethylformamide and 1.96 g of L-Nle NCA were added sequentially, and the reaction was carried out at room temperature for 3 days, with nitrogen purging three times. The mixture was settled with ice-cold ether, filtered through a Buchner funnel, and vacuum dried to obtain a white polymer, which was weighed. The solid was dissolved in an appropriate amount of DMF and placed in a 2000 Da dialysis bag. After dialyzing in deionized water for 3 days, the mixture was lyophilized to obtain mPEG. 2k -b-Nle 25 ,PNle.

[0078] The polyamino acid hydrogels prepared in Examples 1-3 above were analyzed by 1H NMR spectroscopy, and the results are as follows: Figures 1-4 As shown, where Figure 1 The NCA monomers prepared in Examples 1-3 1 H NMR spectrum Figure 2 The mPEG prepared in Example 1 2k -b-Met 25 Polyamino acid hydrogels 1 H NMR spectrum Figure 3 The mPEG prepared in Example 2 2k -b-SeMet 25 Polyamino acid hydrogels 1 H NMR spectrum Figure 4 The mPEG prepared in Example 3 2k -b-Nle 25 Polyamino acid hydrogels 1 H NMR spectrum.

[0079] Phase transition tests were performed on the polyamino acid hydrogels prepared in Examples 1-3 above, and the results are as follows: Figure 5 As shown, Figure 5The graph shows the phase transition test results of the polyamino acid hydrogels prepared in Examples 1-3.

[0080] The polyamino acid hydrogels prepared in Examples 1-3 above were subjected to rheological tests to determine their gelation properties. The results are as follows: Figure 6 As shown, Figure 6 The rheological test results of the polyamino acid hydrogels prepared in Examples 1-3 are shown in the figure.

[0081] mPEG 2k -b-Met 25 and PEG 2k -b-SeMet 25 The reaction mechanism equation for the scavenging of H2O2 by polyamino acid hydrogels is as follows:

[0082]

[0083] The mPEG prepared above 2k -b-Met 25 and PEG 2k -b-SeMet 25 The NMR characterization of polyamino acid hydrogels with different concentrations of H2O2 was performed, and the test results were analyzed. The results are as follows: Figure 7 and Figure 8 As shown, Figure 7 The mPEG prepared in Example 1 2k -b-Met 25 The graph shows the test results of the scavenging ability of polyamino acid hydrogels against different concentrations of H2O2. Figure 8 The mPEG prepared in Example 2 2k -b-SeMet 25 Figure showing the test results of the scavenging ability of polyamino acid hydrogels against different concentrations of H2O2.

[0084] First, the cell-killing ability of different concentrations of hydrogen peroxide was investigated. Then, the cell-protective ability of the polyamino acid hydrogels prepared in Examples 1-3 was investigated. The results are as follows: Figure 9 As shown, Figure 9 The graphs show the killing effect of different concentrations of hydrogen peroxide on L929 cells and the protective effect of the polyamino acid hydrogels prepared in Examples 1-3. Figure 9 Table A shows the screening of hydrogen peroxide concentrations, while B-D show the cell survival rates of different polyamino acid materials and at a hydrogen peroxide concentration of 300 μmol / L.

[0085] To investigate the effects of the polyamino acid hydrogels prepared in Examples 1-3 on hair regeneration and wound regeneration, a type 1 diabetic mouse model was first constructed: SPF-grade C57BL / 6 mice were fasted for 12 hours prior to the experiment. Then, 2.10 g of citric acid was accurately weighed and dissolved in 100 mL of Milli-Q ultrapure water, labeled as solution A. Next, 2.94 g of sodium citrate was accurately weighed and dissolved in 100 mL of Milli-Q water, labeled as solution B. Solution A and solution B were then mixed at a 1:1 volume ratio. The pH was measured, and solution A or B was added to stabilize the final pH at 4.2-4.5, yielding a citric acid-sodium citrate buffer solution. Finally, streptozotocin (STZ) was dissolved at a mass fraction of 1.0% in the prepared buffer solution. Before injecting STZ solution into mice, each mouse must be accurately weighed using a precision balance. Based on the weight of each mouse, the drug is administered at a dose of 150.0 mg / kg. One week after STZ injection, blood samples are collected from the tail of the mice, and blood glucose levels are measured using a glucometer. If the measured blood glucose level is greater than or equal to 16.7 mmol / L... -1 If the blood glucose level does not reach the target value, the mice can be considered successfully modeled as having type 1 diabetes. If the blood glucose level does not reach the target value, the mice need to be injected with the same dose of STZ solution as the initial injection. One week after the second injection, blood glucose is measured again from the tail of the mice until the blood glucose level reaches the target value for successful modeling. Finally, the successfully modeled mice are divided into four groups: PBS group, PNle group, PMet group, and PSeMet group, with six mice in each group.

[0086] After successfully establishing a type 1 diabetic mouse model, a full-thickness skin resection model was created. First, mice were anesthetized with isoflurane, and their dorsal hair was shaved. Then, an 8.0 mm diameter full-thickness skin defect was constructed on the mouse's back, and a silicone gasket was fixed to the wound edge with bio-adhesive to prevent contraction. Finally, 200 μL of experimental material was injected into the center of the silicone gasket. Once the material's fluidity decreased, it was covered with sterile gauze and secured with a bandage. Vital signs were closely monitored. Photography was taken on days 0, 3, 7, 10, and 14 of treatment.

[0087] The results are as follows Figure 10 As shown, Figure 10 The images show H&E slices of the polyamino acid hydrogels prepared in Examples 1-3. Figure 10 The results show that the number of hair follicles in the wounds treated with the polyamino acid hydrogels prepared in Examples 1-3 increased, further demonstrating that the polyamino acid hydrogels provided by the present invention not only have a good wound regeneration effect, but also a good hair follicle repair effect, and that PSeMet has the best repair effect.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A polyamino acid, characterized in that, It has the structure of formula 1 or formula 2; Wherein, R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C6 straight-chain or branched alkyl groups, substituted or unsubstituted selenide C1-C6 straight-chain or branched alkyl groups, and substituted or unsubstituted thiamethoxam C1-C6 straight-chain or branched alkyl groups. n1, n2, and n3 are independently the number of structural units.

2. The polyamino acid according to claim 1, characterized in that, The n1 is an integer between 20 and 200; The n2 is an integer from 5 to 40; The n3 is an integer from 5 to 40.

3. The polyamino acid according to claim 1, characterized in that, It has the structure of formula 1-a or formula 2-a; Wherein, y1, y2 and y3 are independently integers from 1 to 4; X1, X2, and X3 are independently selected from methylene, thioether, or selenide bonds.

4. The polyamino acid according to claim 1, characterized in that, It has a structure of formula 1-b or formula 2-b; Wherein, X1, X2 and X3 are independently selected from methylene, thioether, or selenide bonds.

5. The method for preparing the polyamino acid according to any one of claims 1 to 4, characterized in that, Includes the following steps: A ring-opening polymerization reaction is carried out between a methoxy polyethylene glycol amine having the structure of formula a-1 or a polyethylene glycol amine having the structure of formula a-2 and an acid anhydride monomer to obtain a polyamino acid. The anhydride monomer is selected from one or more of the following: anhydride monomers having the structure of formula b-1, anhydride monomers having the structure of formula b-2, and anhydride monomers having the structure of formula b-3.

6. The preparation method according to claim 5, characterized in that, The ring-opening polymerization reaction is carried out at a temperature of 15°C to 30°C for 2 to 5 days.

7. The preparation method according to claim 5, characterized in that, The methoxylated polyethylene glycol amine having the structure of formula a-1 is prepared by the following method: Methoxy polyethylene glycol having the structure of formula c-1 was reacted sequentially with p-toluenesulfonyl chloride and ammonium chloride to obtain methoxy polyethylene glycol amine having the structure of formula a-1. The polyethylene glycolamine having the structure of formula a-2 is prepared by the following method: Polyethylene glycol having the c-2 structure was reacted sequentially with p-toluenesulfonyl chloride and ammonium chloride to obtain a polyethylene glycol amine having the a-2 structure; 8. The preparation method according to claim 5, characterized in that, The anhydride monomer having the structure of formula b-1 is prepared by the following method: An amino acid having the d-1 structure is reacted with triphosgene to obtain an anhydride monomer having the b-1 structure. The anhydride monomer having the b-2 structure is prepared by the following method: An amino acid having the d-2 structure is reacted with triphosgene to obtain an anhydride monomer having the b-2 structure. The anhydride monomer having the structure of formula b-3 is prepared by the following method: An amino acid having the d-3 structure is reacted with triphosgene to obtain an anhydride monomer having the b-3 structure.

9. A polyamino acid hydrogel, characterized in that, It is obtained by gelling polyamino acids obtained by any of the polyamino acids described in claims 1 to 4 or by any of the preparation methods described in claims 5 to 8.

10. The use of the polyamino acid hydrogel of claim 9 as a medical dressing with hair follicle repair and / or chronic wound repair functions.

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