CN110354303A - A kind of antibacterial method of modifying of metallic titanium surface - Google Patents

Abstract

The invention discloses a kind of antibacterial method of modifying of metallic titanium surface.It include: that (1) Titanium particle successively uses deionized water, ethyl alcohol, acetone, deionized water ultrasonic cleaning, drying is for use；(2) γ-aminopropyl triethoxysilane solution is prepared, solvent is second alcohol and water；It is put into Titanium particle, 50-55 DEG C of heating water bath, 5-6h is reacted, triethylamine is added, react 10-12h, take out, wash, dry, drying；It (3) will be on the polypeptide grafted Titanium to surface amination.The present invention is modified by the method for covalence graft using Titanium as base material, and bacteriostatic peptide is accessed metallic titanium surface, to achieve the purpose that surface modification is antibacterial.

Description

A kind of antibacterial method of modifying of metallic titanium surface

Technical field

The present invention relates to biomedical material technologies, further say, are to be related to a kind of antibacterial of metallic titanium surface Method of modifying.

Background technique

1. infection caused by orthopaedics implant

Implantation material infection is one of the complications of bone surgery such as joint replacement (TJA) most serious.Document report, fracture Interior fixation is respectively 5%~20% and 0.5%~2% with the infection rate after prosthetic replacement, and has the complexity greater than 20% Skeleton animation art is due to caused by TJA postoperative infection.It is infected relative to other visual area surrounding tissues, TJA postoperative infection consequence is more Add serious, it is often necessary to remove prosthese, spacious to set joint, the second phase overhauls, or even fusion joint, amputation cause deformity.Patient is come It says, not only causes a large amount of medical burden, extend the pain of patient, and expand disease incidence, even result in death.

The prevention most common method of TJA postoperative infection is that postoperative systematicness is oral or injection of antibiotics, but local concentration compared with It is low, it is also easy to lead to bacterial drug resistance problem.The scheme of clinical treatment has debridement, phase displacement, second phase displacement, Long-term Oral Antibiotic repeatedly overhauls treatment nonresponder or even needs amputation.Wherein second phase displacement is most common treatment method, needs first to move Except infection prosthese, then after 4-8 weeks even more prolonged antibiotic treatment, then it is implanted into new prosthese.And it is postoperative also normal It need to continue antibiotic treatment 6 months or so.But incidence is still up to 3.2-5.6% to the infection after even twice replaced again.

2.TJA postoperative infection main cause-bacterial biof iotalm

A large amount of research confirms in recent years, and implantation material infection is related with implantation material surface formation bacterial biof iotalm.Bacterium Biomembrane (Bacterial biofilm, BF) refers to that bacterial adhesion in contact surface, secretes polysaccharide matrix, fibrin and rouge Its own wrapping is wherein formed a large amount of bacterial accumulation film sample objects by matter albumen etc..

The bacterium being grown in BF, no matter its morphosis, physio-biochemical characteristics and to sensibility of antibacterials etc. all Dramatically different with the cell of planktonic growth, pathogenic characteristic is also different.BF can protect bacterium escape host immune and antibacterials Lethal effect.Drug resistance is remarkably reinforced 10~1000 times in the presence of bacterium is in the form of BF, fights the antibiotic of planktonic bacteria Dosage not only can not effectively remove BF, also can induce drug resistance and generate.In mature BF adjustment mechanism can make part bacterium It falls off from BF, the bacterium to fall off, which such as adheres to suitable surface, to form new BF, causes the migration of infection.Result of study card Bright: the main reason for infection and infections relating protracted course of disease occur around artificial joint prosthesis and bacterium are raw in prosthetic surface bacterium The formation of object film is related.The pollution of bacterium or postoperative hematogenous bacterial are all easy to be colonized and gradually form into Periprosthetic in art Ripe BF.

3. surface modifying method

Antibiotic is that clinical application is the most extensive, antifungal mechanism is the most clear and fungistatic effect is faced for a long time in vivo The bacteriostatic agent of bed verifying.There are clear stipulaties to the minimal inhibitory concentration of all kinds of antibiotic and safe medication amount in clinical treatment. Specific aim is oral or injection of antibiotics is current prevention and the common method for treating implantation material postoperative infection.However Formulations for systemic administration Often have that affected area concentration is too low, there are the risks of genotoxic potential to other histoorgans.Therefore, local use antibiotic obtains Extensive concern is arrived.Early in 1970, antibiotic was introduced into bone cement just to reach the mesh that part inhibits TJA postoperative infection 's.Sufficiently verifying antibiotic-loaded bone cement can be effectively reduced skeleton animation rate, prosthetic loosening and depth to long term clinical results Infection.But due to the installation of bone-cement type articular prosthesis and overhaul compared with cementless prosthesis complexity, have gradually it is substituted become Gesture.Therefore the research of the antibacterial type articular prosthesis of surface load antibiotic is just got more and more attention.

3.1 coating

Coating is the common method of surface load antibiotic.Coating can be divided into passively (passive) and active (active), it has been mainly dependent on whether that antibacterial agent (antibacterial agents) is released in implant site.Passively Coating will not peripherad tissue delivery of antimicrobials, this coating mainly hinders bacterial adhesion by contacting and kills thin Bacterium.In comparison, the coating of active can release the fungicide inhibition infection for being grafted on surface, such as antibiotics, antiseptics,silver ions,growth factors/chemokines/peptides.

3.1.1 anti-stick coat (Coatings That Prevent Bacterial Adhesion)

Studies have shown that the hydrophobicity on control surface, the degree of roughness on surface, electrical property and surface compatability can be effective Reduce the contact of bacterium.Bacterium, which contacts implant surface, to be realized by adsorbed proteins layer, that is to say, that if surface Do not adsorb bacterium, will not adsorbed proteins, therefore, this surface can not only prevent the generation of bacterial biof iotalm but also can prevent Microorganism is sticked.

Polyethylene glycol (PEG) is widely used field of biomedicine.Due to the characteristic of PEG molecular structure, PEG molecule With chain flexibility and very large space steric hindrance, the reason of bacterium contact surface can be prevented here it is PEG.The researchs such as Park discovery A kind of polyurethane of PEG modification.The base that PEG molecular end has, amino and sulfonic acid group can effectively prevent large intestine Bacillus (Escherichia coli, E.coli) and staphylococcus epidermis (Staphylococcus epidermidis, Sticking S.epider-midis).They test bacterium and freeze soybean to the adhesive force of material, such as tryptose in different media Meat soup (tryptic soy broth, TSB) and human plasma, as a result, it has been found that, bacterium whether can contact material depend on medium, The process of contact and the molecular weight of PEG.In general, the effect that the PEG of high molecular weight resists bacterium contact is more preferable than low molecular weight, In addition, surface termination is more effective to the contact for resisting bacterium with sulfonate groups.

Adjusting to implant surfaces physical and chemical performance is a kind of relatively easy and economic side for preventing bacterial reproduction Formula.For example, can lead to the increase of titanium dioxide surface " spontaneous " wetability using ultraviolet (UV) ray, this mode can not only It prevents bacterium from adhering on the surface of the material, nor influences whether the bone tissue regeneration in titanium alloy surface.Can also by Crystalline texture is grafted on surface film oxide to achieve the effect that bacterium prevents adhesion.Some researches show that by titanium oxide film surface It is grafted the crystalline texture of anatase form, it is evident that bacterial adhesion can be reduced, while also without influence on the new of host cell Old metabolism behavior.

3.1.2 antimicrobial coating (Microbicidal Coatings)

Antimicrobial coating mainly includes that silver release coating (Silver-Releasing Coatings), antibiotic or antibacterial apply Layer (Antibiotic or Antiseptic-Releasing Coatings), polycation coating (Polycation-Based Coatings), nanoparticle coating (Nanomaterials), enzyme base antimicrobial coating (Enzyme-Based Antimicrobial Coatings) etc..Now most widely used is antibiotic coating.The antibiotic (antibiotics) of prevention system is usually used In the patient of implantation orthopaedic devices, in order to prevent the infection occurred at perioperative (peri-operative).However, this seed type Antibiotic have disadvantages that, including the blood concentration low in targeting moiety, and may cause system either organ poison Property.Therefore, the concern for having arrived people of local use antibiotic.

Clinical research show in bone cement load antibiotic can reduce due to consolidating total hip joint caused by depth The possibility of infection, early in 1970, antibiotic was introduced into bone cement just to achieve the purpose that part inhibits TJA postoperative infection. Sufficiently verifying antibiotic-loaded bone cement can be effectively reduced skeleton animation rate, prosthetic loosening and sense of depth to long term clinical results Dye.But it due to the installation of bone-cement type articular prosthesis and overhauls compared with cementless prosthesis complexity, there is gradually substituted trend.

Calcium phosphate bone cement (Calcium phosphate cements), is generally considered with bone guided effect, It is used to load antibiotic and other biological activities molecule.In addition to calcium phosphate, (such as PDLLA, shell are poly- for degradable polymeric material Sugar, cyclodextrin etc.) it is also widely used for the research of titanium alloy implant surface carried with antibiotics coating.However current titanium alloy surface The greatest problem of coating load antibiotic is exactly that not can guarantee long-term and effective concentration to discharge.It has been reported that all kinds of antibiotic The pharmaceutical release time of coating is to differ to 4 weeks several hours, and have a burst release stage at release initial stage, generally very short Time in release amount of medicine can all reach 70% or more, and to be extremely difficult to minimum antibacterial dense for the release amount of medicine after being released Degree, it is reported that the risk of drug resistance can be caused less than the release of minimal inhibitory concentration for a long time.Add even with LBL multilayer self assembly Carry the advanced coating technologies such as drug, it is also difficult to 4 weeks or more [1,2] will be extended to release time.Optimal antibiotic transmission applies Layer should discharge antibiotic in optimal bacterial concentration level and reach the sufficiently long time to prevent the possibility potentially infected, And the release of antibiotic should be able to quickly stop later, to eliminate the risk of antibiotic residue.

Due to consideration that Risks caused by antibiotic residue, non-antibiotic reagent is loaded in the coating into one not Wrong selection.In a variety of different dopants, since silver can inhibit bacterial adhesion, most of bacterium (gram can be resisted Negative and positive bacteria) and long-lasting antibacterial action, and be not easy remaining characteristic and silver is made to become the most well known anti- Bacterium reagent.Christian Gorzelanny etc. is compounded with diamond-like-carbon (diamond-like with Nano silver grain Carbon, DLC) and have studied the anti-microbial property of this composite material and the rate of release of Nano silver grain.Experiment shows Silver-high molecule nano composite material is carried out after plasma immerses ion implanting, DLC and implant surfaces are improved Bond energy, layering caused by reducing because of brittleness, and then DLC is improved in the adhesive force of implant surfaces.In addition, they also demonstrate Sticking and breeding for bacterium can be prevented really with Nano silver grain compound DLC coating, and this antibacterial action is to pass through silver Instantaneous relase realize, the release of the silver of early stage be it is paroxysmal, it is dense, and the growth of bacterium is prevented with this. When silver is sudden discharges into coda, the Nano silver grain of low concentration reduces life of the blood platelet on endothelial cell Long, the breeding and differentiation of cell result in vascularization, and then merge implant and bone tissue preferably.Although silver has splendid Antibacterial ability, but we should also be understood that the long-term tissue toxicity after it is chronically implanted and its potential acquisition electricity The exact mechanism of the ability of resistance and its anti-bacterial attachment and growth.

3.1.3 other coatings

Some organic antibacterial agents, such as chlorhexidine, chloroxylenol, Polyhexamethylenebiguanide (chlorhexidine, chloxylenol, polyhexamethylene list guanidine phosphate) It is verified they in the ability of antibiosis, while being likely to become the effective choosing of the one kind for avoiding bacterium from forming drug resistance risk It selects.On the surface of titanium alloy, Chlorhexidine (chlorhexidine) can be adsorbed in TiO2 coating, can be continued Discharge a couple of days.Its release mode is similar to the coating of antibiotic-loaded, initial quick release, slow later and lasting release.

Some bioactive molecules, such as hyaluronic acid, chitosan, they all have prevent bacterial adhesion and/ Or it prevents bacterial multiplication and reduces the ability of bacterial activity.Although these substances have certain attraction as implant coating Power, but still have deficiency, it is proved by vivo studies: compared with other coatings such as calcium phosphate, these bioactive molecule films It is unsatisfactory in terms of supporting Integrated implant.Really, report shows, osteoblast is viscous under the action of hyaluronan molecule chain It is attached to be subject to certain restrictions.

[1]Lv H,Chen Z,Yang X,Cen L,Zhang X,Gao P.Layer-by-layer self- assembly of minocycline-loaded chitosan/alginate multilayer on titanium substrates to inhibit biofilm formation.J Dent,2014,42(11):1464-72.

[2]Pérez-Anes A,Gargouri M,Laure W,Van Den Berghe H,Courcot E, Sobocinski J,Tabary N,Chai F,Blach JF,Addad A,Woisel P,Douroumis D,Martel B, Blanchemain N,Lyskawa J.Bioinspired Titanium Drug Eluting Platforms Based on a Poly-β-cyclodextrin-Chitosan Layer-by-Layer Self-Assembly Targeting Infections.ACS Appl Mater Interfaces,2015,7(23):12882-93

Due to relatively short releasing trend, the controlled release coating of bioactive molecule, caused pathogen resistance has Potentially possible, more and more researchs are dedicated to that antimicrobial polypeptide is loaded into implant by the effect of covalent bond Surface can achieve the purpose of long-term prevention implant infection, and at the same time, the composition of antibacterial peptide is amino acid, in human body Interior to be degraded and harmless, the popular direction of the development of the following medicine is antibacterial peptide.

Polypeptide is connected to matrix surface by amido bond using NHS/EDC by the prior art, and connection effect is not highly desirable, and Good biocompatibility.

Summary of the invention

To solve the technical problems existing in the prior art, the present invention provides a kind of antibacterial modification sides of metallic titanium surface Method.The present invention is modified by the method for covalence graft using Titanium as base material, and bacteriostatic peptide is accessed Titanium table Face, to achieve the purpose that surface modification is antibacterial.

The object of the present invention is to provide a kind of antibacterial method of modifying of metallic titanium surface.

The described method includes:

(1) Titanium particle successively uses deionized water, and ethyl alcohol, acetone, deionized water ultrasonic cleaning, drying is for use；

(2) γ-aminopropyl triethoxysilane solution is prepared, solvent is second alcohol and water；It is put into Titanium particle, water-bath 5-6h is reacted in 50-55 DEG C of heating, and triethylamine is added, and reacts 10-12h, takes out, and washs, dry, drying；

It (3) will be on the polypeptide grafted Titanium to surface amination

The Titanium particle being grafted is put into 4- (N- maleimidomehyl) hexamethylene -1- carboxylic acid sulfonic group succinyl In imines ester sodium salt solution, solvent is edetate phosphate solution；Incubate 1-2h；Ethylenediamine tetra-acetic acid microcosmic salt is used again Acid salt solution rinsing, air-dries, and polypeptide solution is added and reacts 18-24h, rinses, air-dries.

Wherein, preferably:

The particle size range of Titanium particle is 60-100 mesh.

Step (2),

γ-aminopropyl triethoxysilane solution volumetric concentration is 1-2%；

The volume ratio in solvent being ethyl alcohol and water is (90~95): (10~5).

The volume ratio that triethylamine accounts for entire solution is 0.5-1%.

The volume ratio of γ-aminopropyl triethoxysilane solution and triethylamine is 100:(0.4~0.5)；

γ-aminopropyl triethoxysilane solution and Titanium particle amount ratio are as follows: 100ml:(0.5-1) g

Step (3),

The concentration of polypeptide solution is 1-2mg/ml；

The concentration of 4- (N- maleimidomehyl) hexamethylene -1- carboxylic acid sulfonic group succinimide ester sodium salt solution is 1- 2mg/ml。

Step (3),

The concentration of edetate phosphate solution is 40-50mmol/L.

Step (3),

The mass ratio of polypeptide and the Titanium particle being grafted is 1:(250~500).

The polypeptide is antibacterial polypeptide, and preferably Cys-Melimine, particular sequence is C T L I S W I K N K R K Q R P R V S R R R R R R G G R R R R。

In the present invention ,-SiOH the functional group of KH550 can hydrolyze generation silanol group in water or in material surface water, in turn It is reacted with the thin film of titanium oxide of metallic titanium surface, this reaction is reacted with amino again relative to EDC activated carboxyl, carboxyl is first passed through Amido bond is generated, reaction efficiency is higher, comparatively reaction is easier.

Detailed description of the invention

The laser confocal microscope figure of Fig. 1 blank control group；

The laser confocal microscope figure of the unmodified material group of Fig. 2；

The laser confocal microscope figure of modified material group prepared by Fig. 3 embodiment 1；

The laser confocal microscope figure of the pure antibacterial titanium of Fig. 4.

Specific embodiment

Below with reference to embodiment, the present invention is further illustrated.

Embodiment 1

1. the chemical products used

Titanium valve, 60 mesh, 99.5%, Aladdin；Ethyl alcohol analyzes pure, Shanghai examination；Acetone analyzes pure, Shanghai examination；Dopamine, 99%, alfa aesar；TRIS, solarbio；KH550 (3- aminopropyl trifluoro oxysilane), 99%, Aladdin；TEA is more Peptide is Melimine, and sequence is Cys-Melimine (C T L I S W I K N K R K Q R P R V S R R R R R R G G R R R R)；Sulfo-smcc, source leaf science and technology；PBS, gelife；EDTA, 98%, Aladdin；

2. the preparation of product

1. selecting the little particle of Titanium, having a size of 60 mesh, each deionized water, ethyl alcohol, acetone, deionized water are super respectively Sound cleans 15min, and drying is stand-by.

2. preparing KH550,2% solution (solvent is alcohol 95 %, water 5%) takes 100ml, it is small to be put into 0.5g Titanium Particle, heating water bath react 6h to 55 DEG C, 0.5ml TEA are added, and react 12h, take out, with ethanol washing, vacuum drying 30min is placed into 130 DEG C of baking ovens and is heated 3h

3. by the polypeptide grafted Titanium to surface amination: the Titanium 0.5g for being grafted KH550 is put into 2mg/ 1h is incubated in sulfo-SMCC/PBS-EDTA (50mM) solution of ml, is rinsed with PBS-EDTA, is air-dried, polypeptide solution 2mg is added Reaction for 24 hours, rinses, and air-dries.

3. purposes or using effect

The modified XPS data of 1. metallic titanium surface of table (250 U.S. x-ray photoelectron spectroscopy (XPS) ESCALAB ThermoFisher Scientific company)

Power spectrum (EDS) data (atomic percent) of the modified Titanium of table 2.；The HITACHIS- of Hitachi, Japan 4700FESEM connected EDAX company, the U.S. produces EDAX-9100 type X-ray energy spectrometer

Element	Ti	Ti-kh550	Ti-Melimine
				C	3.10	3.39	10.29
O	--	24.90	46.24
				Si	--	0.27	0.20
Ti	96.90	64.60	53.08
				S	--	--	0.07

Bacteriostasis property:

Staphylococcus aureus is selected to be cultivated, concrete operations process is referring to GB/T21866-2008, GB4789.2- 2010.Dead bacterium fluorescent staining of living is carried out to the bacterium solution of grouping culture later, is observed under laser confocal microscope.

As can be seen from Table 1, after KH550 introduces amino, silicon content is dramatically increased in system, the reason is that It is to be completed by silicon oxygen bond, therefore silicon content will increase in system since KH550 introduces amino；Introducing, Melimine is antibacterial After peptide, sulfur content increases, the reason is that increasing one and half Guang ammonia in one end due to when synthesizing Melimine Acid is allowed to one end with sulfydryl, so as to be connected in titanium substrate, therefore be added by sulfo-SMCC coupling agent After Melimine, element sulphur can increase in system.Similarly, EDS test result explanation is same as above.

Bacteriostatic test uses confocal laser scanning microscope, with Live/Dead Baclight Bacterial Viability Kit fluorescent staining liquid.The result is shown in Figure 1-4, positive blank control group (C) and titanium substrate (Fig. 2) are absolutely mostly Number bacterium is bacterium living, and negative control group (pure antibacterial titanium Melimine) there's almost no bacterium, illustrates that Melimine is being added Initially, bacterium is killed, and then will not be bred again, therefore after diluting bacterium solution with equimultiple, it sees under the microscope It examines, is barely perceivable bacterium, the Titanium (Fig. 3) after the modification of surface, although lacking very much, explanation there is also bacterium Bacteriostasis not instead of moment completes, and as the extension of time gradually discharges, but compares with blank control, still there is one Fixed fungistatic effect.

Illustrate: positive blank control is that only culture bacterium, negative control are only to add bacteriostatic peptide, and unmodified material group is that do not have There is modified material, the material of any processing is not added, modified material group is the material of embodiment preparation.

It can also be evident that according to the bacterial number on culture medium, modified material has certain biocidal property Energy.

Embodiment 2

1. the chemical products used

Titanium valve, 100 mesh, 99.5%, Aladdin；Ethyl alcohol analyzes pure, Shanghai examination；Acetone analyzes pure, Shanghai examination；Dopamine, 99%, alfa aesar；TRIS, solarbio；KH550 (3- aminopropyl trifluoro oxysilane), 99%, Aladdin；TEA is more Peptide is Melimine, and sequence is Cys-Melimine (C T L I S W I K N K R K Q R P R V S R R R R R R G G R R R R)；Sulfo-smcc, source leaf science and technology；PBS, gelife；EDTA, 98%, Aladdin；

2. the preparation of product

1. the little particle of Titanium is selected, it is each respectively to use deionized water, ethyl alcohol, acetone, deionized water having a size of 100 mesh It is cleaned by ultrasonic 15min, drying is stand-by.

2. preparing KH550,2% solution (solvent is alcohol 95 %, water 5%) takes 100ml to be put into 1g Titanium small Grain, heating water bath react 5h to 50 DEG C, 0.4ml TEA are added, and react 10h, take out, and with ethanol washing, are dried in vacuo 30min, It places into 130 DEG C of baking ovens and heats 3h

3. by the polypeptide grafted Titanium to surface amination: the Titanium 1g for being grafted KH550 is put into 1mg/ml Sulfo-SMCC/PBS-EDTA (50mM) solution in incubate 1.5h, rinsed with PBS-EDTA, air-dry, be added polypeptide solution 2mg 18h is reacted, is rinsed, is air-dried.

The modified XPS data of 3 metallic titanium surface of table (250 U.S. x-ray photoelectron spectroscopy (XPS) ESCALAB ThermoFisher Scientific company)

Claims (8)

1. a kind of antibacterial method of modifying of metallic titanium surface, it is characterised in that the described method includes:

(1) Titanium particle successively uses deionized water, and ethyl alcohol, acetone, deionized water ultrasonic cleaning, drying is for use；

(2) γ-aminopropyl triethoxysilane solution is prepared, solvent is second alcohol and water；It is put into Titanium particle, heating water bath 50-55 DEG C, 5-6h is reacted, triethylamine is added, reacts 10-12h, is taken out, is washed, dry, drying；

It (3) will be on the polypeptide grafted Titanium to surface amination

The Titanium particle being grafted is put into 4- (N- maleimidomehyl) hexamethylene -1- carboxylic acid sulfonic group succinimide In ester sodium salt solution, solvent is edetate phosphate solution；Incubate 1-2h；Ethylenediamine tetra-acetic acid microcosmic salt hydrochlorate is used again Solution rinsing, air-dries, and polypeptide solution is added and reacts 18-24h, rinses, air-dries.

2. the antibacterial method of modifying of metallic titanium surface as described in claim 1, it is characterised in that:

The particle size range of Titanium particle is 60-100 mesh.

3. the antibacterial method of modifying of metallic titanium surface as described in claim 1, it is characterised in that:

Step (2),

γ-aminopropyl triethoxysilane solution volumetric concentration is 1-2%；

The volume ratio in solvent being ethyl alcohol and water is (90~95): (10~5)；

The volume ratio that triethylamine accounts for entire solution is 0.5-1%.

4. the antibacterial method of modifying of metallic titanium surface as claimed in claim 3, it is characterised in that:

Step (2),

The volume ratio of γ-aminopropyl triethoxysilane solution and triethylamine is 100:(0.4~0.5)；

γ-aminopropyl triethoxysilane solution and Titanium particle amount ratio are as follows: 100ml:(0.5-1) g.

5. the antibacterial method of modifying of metallic titanium surface as claimed in claim 3, it is characterised in that:

Step (3),

The concentration of polypeptide solution is 1-2mg/ml；

The concentration of 4- (N- maleimidomehyl) hexamethylene -1- carboxylic acid sulfonic group succinimide ester sodium salt solution is 1-2mg/ ml。

6. the antibacterial method of modifying of metallic titanium surface as claimed in claim 5, it is characterised in that:

Step (3),

The concentration of edetate phosphate solution is 40-50mmol/L.

7. the antibacterial method of modifying of metallic titanium surface as claimed in claim 5, it is characterised in that:

Step (3),

The mass ratio of polypeptide and the Titanium particle being grafted is 1:(250~500).

8. the antibacterial method of modifying of metallic titanium surface as described in claim 1, it is characterised in that:

The polypeptide is antibacterial polypeptide.