CN117004036A - A kind of hyperbranched polylysine quaternary ammonium salt and its preparation method and application - Google Patents

Abstract

The invention provides a hyperbranched polylysine quaternary ammonium salt and its preparation method and application. Specifically, the hyperbranched polylysine quaternary ammonium salt has a structure shown in formula I or II. The present invention quaternizes hyperbranched polylysine or obtains hyperbranched polylysine quaternary ammonium salt by copolymerizing lysine quaternary ammonium salt and lysine, which can not only effectively inhibit multi-drug resistant Gram-negative bacteria, The sterilization kinetics results show that the sterilization rate is significantly improved and it has good antiviral effect.

Description

A hyperbranched polylysine quaternary ammonium salt and its preparation method and application

Technical Field

The invention relates to the technical field of antibacterial materials, and in particular to a hyperbranched polylysine quaternary ammonium salt and a preparation method and application thereof.

Background Art

In recent years, with the gradual emergence of various bacteria, especially multidrug-resistant bacteria, it has posed an extremely serious threat to human health.

According to the different antibacterial methods, the current antibacterial agents are mainly divided into release-type antibacterial agents and contact-type antibacterial agents. Release-type antibacterial agents mainly include inorganic and organic small molecule antibacterial agents, and contact-type antibacterial agents mainly include polymer antibacterial agents. Since polymer antibacterial agents are based on the contact process rather than the release of active substances to fight bacteria, they have stable antibacterial properties, long-lasting effects, and greatly improved safety of use. This makes them very popular and has developed rapidly in recent years.

Polymeric antimicrobial agents mainly include antimicrobial peptide antimicrobial agents, quaternary ammonium salt antimicrobial agents, etc. Antimicrobial peptides mainly kill pathogenic bacteria by physical means, reducing the possibility of drug resistance. Antimicrobial peptide mimetics with similar structures have become the focus of antimicrobial peptide development. Quaternary ammonium salt antimicrobial materials are a type of polycationic antimicrobial agent, which has been widely studied and applied due to its broad-spectrum antibacterial and antiviral properties.

However, there are currently few polymer antibacterial materials and quaternary ammonium salt antibacterial materials that can show antibacterial properties against multi-drug resistant Gram-negative bacteria. Hyperbranched polylysine has broad-spectrum antibacterial properties, but it also does not have anti-multi-drug resistant Gram-negative bacteria properties and antiviral properties. The development of new antibacterial drugs that can fight multi-drug resistant bacterial infections has become an urgent problem to be solved.

Summary of the invention

In view of this, the technical problem to be solved by the present invention is to provide a hyperbranched polylysine quaternary ammonium salt and a preparation method and application thereof, wherein the hyperbranched polylysine quaternary ammonium salt can effectively inhibit multidrug-resistant Gram-negative bacteria.

The present invention provides a hyperbranched polylysine quaternary ammonium salt having a structure shown in Formula I or Formula II:

m ₁ , m ₂ , m ₃ , m ₄ , n ₁ , n ₂ , x ₁ , x ₂ , x ₃ , x ₄ , y ₁ , y ₂ are the degrees of polymerization;

Wherein, R ₁ and R ₂ are independently selected from H or and R ₁ and R ₂ are not H at the same time;

R ₃ , R ₄ , R ₅ and R ₆ are independently selected from substituted or unsubstituted C1-C10 alkyl groups;

a and b are independently selected from integers of 0-21.

The above R ₃ , R ₄ , R ₅ and R ₆ are independently more preferably substituted or unsubstituted C1-C6 alkyl groups, and further preferably substituted or unsubstituted C1-C3 alkyl groups.

Preferably, the substituent of the C1-C10 alkyl group is selected from one or more of hydroxyl and phenyl groups, and more preferably phenyl groups.

The substituents of the C1-C6 alkyl group and the C1-C3 alkyl group are the same as above.

Preferably, R ₃ , R ₄ , R ₅ and R ₆ are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl or benzyl.

The a and b are independently selected from integers of 0 to 21, preferably integers of 7 to 15, and more preferably integers of 9 to 13.

In the present invention, when a is 0, it means that a methyl group is connected to the N atom to which R ₅ and R ₆ are connected.

When b is 0, it means that a methyl group is connected to the N atom to which R ₃ and R ₄ are connected.

The anion group of the hyperbranched polylysine quaternary ammonium salt is selected from at least one of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a chloride ion, a bromide ion, and an iodide ion.

Preferably, the anionic group is selected from at least one of chloride ion, bromide ion and iodide ion.

In Formula I, _m1 , _m2 , _n1 , _x1 , _x2 and _y1 are the degrees of polymerization, _m1 , _m2 , _x1 and _x2 are preferably integers of 0 to 60, and _m1 and _x1 are not 0 at the _same time, and _n1 and _y1 are preferably integers of 1 to 40; and 10≤m1+ _m2 + _n1 + _x1 + _x2 + _y1≤100 , _preferably , 15≤m1+ _m2 + _n1 + _x1 + _x2 + _y1≤50 ; 0.35≤( _m1 +m2)/( _m1 + _m2 + _n1 + _x1 + _x2 + _y1 ) _≤0.95 , preferably, 0.5≤( _m1 +m2)/( _m1 +m2+ _n1 + _x1 + _x2 + _y1 ) _≤0 . ₁ )≤0.8.

In formula II, _m3 , _m4 , _n2 , _x3 , _x4 and _y2 are the degrees of polymerization, _m3 , _m4 , _x3 and _x4 are preferably integers of 0 to 60, and _m3 and _x3 are _not 0 at the same time, _n2 and _y2 are preferably integers of 1 to 40; and 10≤m3+ _m4 + _n2 + _x3 + _x4 + _y2≤100 , _preferably , 15≤m3+ _m4 + _n2 + _x3 + _x4 + _y2≤50 ; 0.35≤( _m3 + _m4 )/( _m3 + _m4 +n2+ _x3 + _x4 + _y2 )≤0.95, preferably, 0.5≤( _m3 + _m4 )/( _m3 + _m4 + _n2 + _x3 + _x4 + _y2 ) ₂ )≤0.8.

In formula I or II, the repeating units may be arranged in order or in disorder.

The quaternary ammonium salt functionality of the hyperbranched polylysine quaternary ammonium salt is preferably 1%-50%, more preferably 5%-25%.

The test results show that the antibacterial properties of the quaternary ammonium salt can be adjusted by adjusting the length and functionality of the carbon chain on the quaternary ammonium salt. When the carbon chain length is 8 to 16 and the functionality is 5% to 25%, the antibacterial properties are more excellent. The present invention does not specifically limit the preparation method of the hyperbranched polylysine quaternary ammonium salt, and can be a quaternization method well known to those skilled in the art, including but not limited to the following two approaches: 1) quaternization is performed by Michael addition reaction of a quaternary ammonium salt containing a double bond with an amino group on hyperbranched polylysine; 2) quaternization reaction is directly performed on the amino group on the hyperbranched polylysine to obtain a quaternary ammonium salt.

The hyperbranched polylysine quaternary ammonium salt prepared by the present invention can firstly quaternize lysine monomers, and then copolymerize the lysine quaternary ammonium salt with lysine to prepare the hyperbranched polylysine quaternary ammonium salt, and the quaternization degree of the hyperbranched polylysine quaternary ammonium salt is adjusted by adjusting the ratio of the lysine quaternary ammonium salt to lysine.

Specifically, the present invention provides a method for preparing the hyperbranched polylysine quaternary ammonium salt, comprising the following steps:

S1) preparing hyperbranched polylysine by a condensation polymerization method;

S2) quaternizing the hyperbranched polylysine;

or

SⅠ) quaternizing lysine to obtain lysine quaternary ammonium salt;

SⅡ) Use lysine quaternary ammonium salt to copolymerize with lysine.

The present invention provides application of the hyperbranched polylysine quaternary ammonium salt in preparing an antibacterial agent.

Preferably, the antibacterial agent is an antibacterial agent against multi-drug resistant Gram-negative bacteria. Further preferably, the multi-drug resistant Gram-negative bacteria are multi-drug resistant Escherichia coli, multi-drug resistant Pseudomonas aeruginosa, etc.

The invention provides an antibacterial agent, comprising the hyperbranched polylysine quaternary ammonium salt.

The bactericidal rate of the hyperbranched polylysine quaternary ammonium salt can reach 99% when the concentration is 12-96 μg/mL, and it has the characteristics of low minimum inhibitory concentration and fast bactericidal speed.

Compared with the prior art, the present invention provides a hyperbranched polylysine quaternary ammonium salt having a structure shown in Formula I or Formula II. The hyperbranched polylysine is quaternized to obtain a hyperbranched polylysine quaternary ammonium salt, which can not only effectively inhibit multi-drug resistant Gram-negative bacteria, but also has a significantly improved bactericidal rate as shown by the bactericidal kinetic results, and has a good antiviral effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a hydrogen nuclear magnetic spectrum of the hyperbranched polylysine quaternary ammonium salt HPL-QA1 prepared in Example 2;

Figure 2 is a morphological diagram of Escherichia coli (left), standard drug-resistant Escherichia coli (middle) and Staphylococcus aureus (right) before and after treatment with the hyperbranched polylysine quaternary ammonium salt HPL-QA1 prepared in Example 2;

FIG3 is a time-killing curve of the hyperbranched polylysine quaternary ammonium salt HPL-QA1 prepared in Example 2 against multidrug-resistant Escherichia coli;

FIG. 4 shows the anti-H1N1 virus effect of the hyperbranched polylysine quaternary ammonium salt prepared in Example 2.

DETAILED DESCRIPTION

In order to further illustrate the present invention, the hyperbranched polylysine quaternary ammonium salt provided by the present invention and its preparation method and application are described in detail below in conjunction with embodiments.

Example 1

Synthesis of Hyperbranched Polylysine

90g of lysine hydrochloride and 25g of KOH were added to a 500mL reaction bottle, a water separator was connected, nitrogen was replaced three times, a nitrogen atmosphere was maintained, the reaction was stirred and heated at 180°C for 4h, heating was stopped, the reaction was cooled to room temperature, the polymer was dissolved in methanol and precipitated in ether, and 62g of hyperbranched polylysine (HPL) was obtained. HPL with different molecular weights (1000-15000g/mol) can be obtained by changing the reaction temperature and reaction time.

Example 2

Synthesis of Hyperbranched Polylysine Quaternary Ammonium Salt

Using small molecule quaternary ammonium salts, (2-acrylamideethyl)ammonium bromide with different substituents on N, ( R ₅ and R ₆ are independently substituted or unsubstituted C1-C10 alkyl groups, and a is an integer of 0-21) and hyperbranched polylysine through Michael addition reaction to prepare hyperbranched polylysine quaternary ammonium salt. The structure of the hyperbranched polylysine quaternary ammonium salt is adjusted by changing the length of the alkyl carbon chain (C1-C22) on the small molecule quaternary ammonium salt, or the types of the R ₅ and R ₆ groups. The grafting rate of the quaternary ammonium salt is adjusted by changing the ratio of the small molecule quaternary ammonium salt to the hyperbranched polylysine, and the grafting rate is calculated by measuring the amine value.

1) 5g dimethyldodecyl (2-acrylamideethyl) ammonium bromide Dissolved in 200 mL of deionized water, added 10 g of hyperbranched polylysine, reacted at 40 ° C for 24 h, the reaction mixture was precipitated in ether, centrifuged to obtain a yellow solid, dissolved in water and freeze-dried to obtain a yellow powdery hyperbranched polylysine quaternary ammonium salt 1 (HPL-QA1), whose nuclear magnetic hydrogen spectrum is shown in Figure 1. The quaternary ammonium salt grafting rate was calculated to be 20% by measuring the amine value.

2) According to the method of 1) above, the R ₅ and R ₆ groups are adjusted to ethyl, n-propyl, n-butyl, benzyl or other reactive groups, and the carbon chain length (C1-C22) on the small molecule quaternary ammonium salt is adjusted, and the reaction with hyperbranched polylysine can obtain quaternary ammonium salts with different carbon chain lengths. By adjusting the ratio of the small molecule quaternary ammonium salt to the hyperbranched polylysine, quaternary ammonium salts with different grafting rates can be obtained. The details are shown in Table 1 below:

Table 1 Synthesis of hyperbranched polylysine quaternary ammonium salt

Example 3

Example of direct quaternization

1) 2 g of HPL prepared in Example 1 was dissolved in 20 mL of methanol, 0.5 g of paraformaldehyde and 2 equivalents of sodium cyanoborohydride were added, the reaction was carried out at room temperature for 10 h, the solvent was evaporated under reduced pressure, 5 mL of deionized water was added, and the mixture was extracted 3 times with 10 mL of ethyl acetate. The organic phases were combined and dried to obtain a solid. The obtained solid was dissolved in 20 mL of DMF, 1 g of 10-bromodecane and 2 equivalents of potassium carbonate were added, the reaction was stirred at 90 ° C for 12 h, the heating was stopped and the mixture was cooled to room temperature, and the mixture was precipitated in ethyl acetate to obtain a hyperbranched polylysine quaternary ammonium salt HPL-QA40.

2) 2 g HPL was dissolved in 20 mL DMF, 4.5 g benzyl bromide and 2 g potassium carbonate were added, and the mixture was stirred at 120° C. for 12 h. 2 g 14-iodotetradecane and 2 equivalents of K ₂ CO ₃ were added, and the mixture was stirred at 90° C. for 12 h. The mixture was cooled to room temperature after heating was stopped, and precipitated in ether to obtain hyperbranched polylysine quaternary ammonium salt HPL-QA41.

3) 5 g of N(e)-Boc-L-lysine, 1.2 g of paraformaldehyde and 2.6 g of sodium cyanoborohydride were dissolved in 30 mL of methanol, reacted at room temperature for 12 h, the solvent was evaporated, 10 mL of deionized water was added, extracted three times with 15 mL of ethyl acetate, the organic phases were combined and spin-dried, the resulting product was reacted with 2 equivalents of 12-bromodecane and 2 equivalents of potassium carbonate at 90 degrees for 12 h, purified by silica gel column with n-hexane/ethyl acetate as developing solvent to obtain N(e)-Boc-L-lysine quaternary ammonium salt, the BOC protecting group was removed with a TFA/DCM mixed solution, and then copolymerized with lysine to obtain hyperbranched polylysine quaternary ammonium salt 45.

According to the above methods 1) and 2), quaternary ammonium salts of different structures can be obtained by quaternizing the amino group with different reactants. By adjusting the ratio of reactants to hyperbranched polylysine, quaternary ammonium salts with different grafting rates can be obtained. According to the above method 3), hyperbranched polylysine quaternary ammonium salts of different structures can be obtained by copolymerizing lysine quaternary ammonium salts with lysine. Specific examples are shown in Table 2 below:

Table 2. Synthesis of hyperbranched polylysine quaternary ammonium salts

Comparative Example 1 Synthesis of Hyperbranched Polylysine

80 g of lysine hydrochloride and 24.5 g of KOH were added to a 500 mL reaction bottle, connected to a water separator, and nitrogen was replaced three times. The nitrogen atmosphere was maintained, and the reaction was stirred and heated at 170 ° C for 6 h. The heating was stopped and cooled to room temperature. The polymer was dissolved in methanol and precipitated in ether to obtain 51 g of hyperbranched polylysine (HPL-1) with a molecular weight of 2600 g/mol.

Comparative Example 2 Synthesis of α-polylysine quaternary ammonium salt

Anhydrous DMSO-dichloromethane mixed solution in which ε-benzyloxycarbonyl-L-lysine-N-carboxyl-cyclic anhydride (ZLL-NCA) was dissolved was added to the reaction flask, and the initiator propylamine was added to initiate the ring-opening polymerization, and then deprotected with TFA/HBr, dialyzed, and freeze-dried to obtain α-polylysine. 2g of α-polylysine was mixed with 0.5g of dimethyldodecyl (2-acrylamideethyl) ammonium bromide. The product was dissolved in 10 mL of deionized water and reacted at 40 °C for 24 h. The reaction mixture was precipitated in ether and centrifuged to obtain a light yellow solid α-polylysine quaternary ammonium salt (αPL-QA).

Example 4 Antibacterial Performance Test

Minimum inhibitory concentration (MIC ₉₉ ) (the lowest concentration of polymer required to completely inhibit 99% microbial growth) test:

The various standard strains used in the following examples were purchased from Shanghai Luwei Technology Co., Ltd., and the clinical multidrug-resistant strains were from the Bethune First Hospital of Jilin University.

The hyperbranched polylysine quaternary ammonium salt prepared in Examples 2-3, the hyperbranched polylysine prepared in Comparative Example 1, and the α-polylysine quaternary ammonium salt prepared in Comparative Example 2 were respectively taken, and 10 polymer solutions with different concentration gradients of 12, 6, 3, 1.5, 0.75, 0.375, 0.188, 0.094, 0.048, and 0.024 mg/mL were prepared by a two-fold dilution method.

The antibacterial performance of the polymer was tested according to the broth dilution method described in the American Clinical and Laboratory Standards Institute (CLSI) antimicrobial susceptibility test standard M07-A9.

Bacterial growth rate (%) = (A _sample - A _{negative control} ) / (A _{positive control} - A _{negative control} ) × 100

Wherein, A _sample , A _{negative control} , A _{positive control} represent the absorbance values of polymer experimental group, negative control group and positive control group at 600nm respectively. Minimum inhibitory concentration (MIC ₉₉ ) is defined as the lowest concentration of polymer required to completely inhibit 99% microbial growth compared with the control group.

The minimum inhibitory concentration (MIC ₉₉ ) results are shown in Table 3 below:

Table 3 Comparison of MIC values of different antimicrobial polymers against different bacteria

Figure 2 shows the SEM images of HPL-QA1 anti-E. coli (left), resistant E. coli (middle) and Staphylococcus aureus (right) before (top) and after (bottom) treatment. It can be seen that the morphology of E. coli and resistant E. coli without polymer treatment is uniform rod-shaped, and Staphylococcus aureus is spherical, all with complete surfaces and in large quantities. After being treated with HPL-1 or HPL-QA1, E. coli, resistant E. coli and Staphylococcus aureus all showed obvious morphological changes. E. coli and resistant E. coli treated with polymers showed obvious collapse, shrinkage and holes on the surface, indicating that their cell membranes have been severely damaged; after being treated with polymers, the surface of Staphylococcus aureus is no longer smooth, and wrinkles and depressions appear, which also shows that the integrity of its cell membrane has been destroyed.

Example 5 Sterilization Speed Detection

According to the suspension quantitative killing test method in 2.1.1.7 of the "Technical Specifications for Disinfection" (2002 Edition), add 0.5ml of the test bacterial suspension and 0.5mL of organic interfering substances into a sterile test tube, then add 4.0ml of antibacterial polymer solution (100μg/mL) (PBS for positive control), and mix thoroughly. After the action reaches the predetermined time, take 0.5ml of the sample solution and add it to 4.5ml of the sterilized neutralizer, and mix well. After the neutralization action for 10 minutes, 1.0ml of the sample solution was inoculated and cultured, and the number of surviving bacteria was determined by the live bacteria culture counting method, and the average killing logarithm was calculated. The test was repeated 3 times.

The sterilization speed test results of HPL-QA1 prepared in Example 2, HPL-1 prepared in Comparative Example 1, and αPL-QA prepared in Comparative Example 2 are shown in Table 4 below:

Table 4

Example 6

Test of bacterial killing rate in culture medium

The bactericidal kinetics of the material were tested using Escherichia coli (E.coli), standard drug-resistant E.coli (EIEC), and clinically isolated multidrug-resistant E.coli (E1). The bacteria were cultured at 37°C to mid-logarithmic growth using LB broth medium and washed three times with PBS buffer. The bacterial solution was diluted to 10 ⁶ CFU/mL in fresh MH broth medium, and 100 μL of polymer solution was added to ensure that its concentration was 24 μg/mL (1×MIC ₉₉ ). 100 μL of PBS solution was used as a control. 20 μL of the mixed solution was diluted to the appropriate concentration using PBS at 0, 0.5, 1, 2, 3, 4, 5, and 6 hours after treatment, and then 100 μL was evenly spread on the LB plate, and the number of colonies was counted after incubation in a 37°C incubator for 24 hours.

The results are shown in Figure 3. HPL-1 can only reduce the concentration of E. coli, EIEC, and E1 by 2 orders of magnitude within 6 hours of action, while HPL-QA1 can reduce the concentration of bacteria in the culture medium by 6 orders of magnitude within 3 hours of action, achieving a complete killing effect on E. coli, EIEC, and E1.

Example 7 Antiviral Performance Test

The antiviral performance of the material was tested using influenza virus H1N1: A/PR/8/34 (ATCC VR-1469) according to the method in the "Technical Specifications for Disinfection" (2002 edition). The specific method is as follows: the virus was inoculated into a cell bottle covered with a monolayer of MDCK cells, cultured at 37°C, and the virus was harvested when 75% of the cells showed pathological changes. 100μL of 3% bovine serum albumin was mixed with 100μL of virus stock solution, and it was placed in a 20±1°C water bath for 5 minutes, and then 0.8mL of polymer solution was added and the time was immediately started. After 2 hours of action, 0.1mL was immediately taken out and mixed with a neutralizer. Deionized water was used instead of polymer solution as a positive control. The virus titer was determined using the endpoint dilution method. The sample was serially diluted 10 times with cell maintenance culture medium, and samples of different dilutions were titrated in a 96-well plate containing host cells, and placed at 37°C for 1-2 hours to ensure that all residual viruses were adsorbed on the cells. Replace the cell maintenance medium and continue to culture in a carbon dioxide incubator (37°C, 5% CO ₂ ). Observe the cytopathic effect under a microscope for 3 consecutive days and record the cytopathic effect. The virus infection titer is expressed as half of the cell infection agent (TCID ₅₀ ). The average logarithmic inactivation value is calculated as follows:

Average logarithmic inactivation value = logN ₀ -logN _x

Wherein, _N0 is the average virus infection titer ( _TCID50 ) of the positive control group, and _Nx is the average virus infection titer ( _TCID50 ) of the test group.

The killing effect of the antibacterial polymer on influenza A virus H1N1 after 2 hours of treatment at a concentration of 100 μg/mL is shown in Figure 4. HPL-1 has no killing effect on the virus, and the hyperbranched polylysine quaternary ammonium salt has a good killing effect on the H1N1 virus, with a virus killing rate of 89.8%-99.99%.

The above antibacterial test shows that the hyperbranched polylysine quaternary ammonium salt provided by the present invention can effectively inhibit multidrug-resistant Gram-negative bacteria, and has the characteristics of low minimum inhibitory concentration and fast bactericidal speed, which provides a new treatment method for combating multidrug-resistant bacterial infection.

The above embodiments are only used to help understand the method and core idea of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims (10)

1. A hyperbranched polylysine quaternary ammonium salt, characterized in that the hyperbranched polylysine quaternary ammonium salt has a structure shown in formula I or formula II: m ₁ , m ₂ , m ₃ , m _{4 ,} n ₁ , n 2 , x ₁ , x ₂ , x ₃ , x ₄ , y ₁ , y ₂ are the degree of polymerization; Among them, R ₁ and R ₂ are independently selected from H or And R ₁ and R ₂ are not H at the same time; R ₃ , R ₄ , R ₅ , and R ₆ are independently selected from substituted or unsubstituted C1 to C10 alkyl groups; a and b are independently selected from integers from 0 to 21. 2. The hyperbranched polylysine quaternary ammonium salt according to claim 1, characterized in that the substituent of the C1-C10 alkyl group is selected from one or more of hydroxyl and phenyl. 3. The hyperbranched polylysine quaternary ammonium salt according to claim 1, characterized in that, the R ₃ , R ₄ , R ₅ and R ₆ are independently selected from methyl, ethyl, n-propyl, Isopropyl, n-butyl, isobutyl, tert-butyl or benzyl. 4. The hyperbranched polylysine quaternary ammonium salt according to claim 1, characterized in that said a and b are independently selected from integers of 7-15. 5. The hyperbranched polylysine quaternary ammonium salt according to claim 1, wherein the m ₁ , m ₂ , m ₃ , m ₄ , x ₁ , x ₂ , x ₃ , and x ₄ are respectively An integer from 0 to 60, and m ₁ and x ₁ are not 0 at the same time, and m ₃ and x ₃ are not 0 at the same time; n ₁ , n ₂ , y ₁ , and y ₂ are respectively integers from 1 to 40; Formula I satisfies the following conditions: 10≤m ₁ +m ₂ +n ₁ +x ₁ +x ₂ +y ₁ ≤100，0.35≤(m ₁ +m ₂ )/(m ₁ +m ₂ +n ₁ +x ₁ +x ₂ +y ₁ )≤0.95; Formula II satisfies the following conditions: 10≤m ₃ +m ₄ +n ₂ +x ₃ +x ₄ +y ₂ ≤100，0.35≤(m ₃ +m ₄ )/(m ₃ +m ₄ +n ₂ +x ₃ +x ₄ +y ₂ )≤0.95. 6. The hyperbranched polylysine quaternary ammonium salt according to claim 1, characterized in that the quaternary ammonium salt functionality of the hyperbranched polylysine quaternary ammonium salt is 1%-50%. 7. The preparation method of the hyperbranched polylysine quaternary ammonium salt according to any one of claims 1 to 6, comprising the following steps: S1) Preparation of hyperbranched polylysine using condensation polymerization method; S2) Quaternization treatment of hyperbranched polylysine; or SⅠ) quaternizing lysine to obtain lysine quaternary ammonium salt; SⅡ) Utilize lysine quaternary ammonium salt and lysine to copolymerize. 8. Application of the hyperbranched polylysine quaternary ammonium salt according to any one of claims 1 to 6 in the preparation of antibacterial agents. 9. The application according to claim 8, characterized in that the antibacterial agent is an antibacterial agent against multidrug-resistant Gram-negative bacteria. 10. An antibacterial agent, comprising the hyperbranched polylysine quaternary ammonium salt according to any one of claims 1 to 6.