CN111996521B

CN111996521B - Method for constructing inorganic micro-flower embedded metal-organic composite nanocluster modified functional layer on surface of biodegradable zinc

Info

Publication number: CN111996521B
Application number: CN202010871204.8A
Authority: CN
Inventors: 万国江; 曾培杰; 钱军余; 张文泰; 莫小山; 沈岗; 黄楠
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2021-05-18
Anticipated expiration: 2040-08-26
Also published as: CN111996521A

Abstract

The invention discloses a method for constructing an inorganic micro-flower embedded metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc, which comprises the following steps: firstly preparing zinc-organic composite nano cluster dispersion liquid, and then preparing an inorganic micro-flower embedded metal-organic composite nano cluster modified functional coating on the surface of the degradable zinc metal. On one hand, the invention constructs an inorganic micro-flower embedded metal-organic composite nano-cluster modified functional layer, thereby not only delaying the degradation rate of metal, but also promoting the activity of osteoblasts. In another aspect, the invention provides a novel method for embedding zinc-organic composite nanoclusters on the surface of a coating, namely, the immobilization of particles is realized by binding an adhesive with active sites on the surface of a substrate and the particles by utilizing chemical coordination driving action.

Description

Method for constructing inorganic micro-flower embedded metal-organic composite nanocluster modified functional layer on surface of biodegradable zinc

Technical Field

The invention belongs to the technical field of surface modification of biomedical materials, and particularly relates to a method for constructing an inorganic micro-flower embedded metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc.

Background

Zinc has attracted much attention as a third-generation degradable metal due to its moderate corrosion rate and its important trace elements in human body. The degradable zinc alloy can not corrode at a too low rate like stainless steel or at a too high rate like magnesium alloy in a human body, so that the degradable zinc alloy can be used as a medical degradable metal material with a better effect, and the problems of iron-based and magnesium-based medical degradable metal materials are solved. In addition, the zinc alloy has good biocompatibility while having a controllable corrosion rate.

However, the degradable zinc-based implant degrades to release excessive zinc ions, which causes damage to surrounding tissues and cells, unstable corrosion degradation products, insufficient osseointegration performance and the like, and limits the application of the degradable zinc-based implant. Surface modification is a key technology to solve these problems. However, the research on the surface modification of zinc-based metal is in the starting stage, the method mostly uses magnesium/iron modification means for reference, and the methods are all single coatings, so that the corrosion degradation control and the biological functionality are difficult to be considered simultaneously. In addition, most of the surface modification methods use single components, the formed structure is simple, and the ideal effect cannot be achieved in the service process.

Disclosure of Invention

The invention aims to: aiming at the problem that the modification of a single coating in the prior art is difficult to simultaneously consider corrosion degradation control and biological functionality, a method for constructing an inorganic micro-flower embedded metal-organic composite nano-cluster modified functional layer on the surface of biodegradable zinc is provided.

The technical scheme adopted by the invention is as follows:

a method for constructing an inorganic micro-flower chimeric metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc comprises the following steps:

s1, mixing zinc nitrate and an organic diphosphonic acid solution, adjusting the pH value to 3.5-4.5, and heating in a water bath at 35-45 ℃ for reaction for 10-15 h;

s2, filtering the mixed solution obtained after the reaction of S1, removing filtrate, cleaning, and drying to obtain zinc-organic diphosphonic acid nano-particles;

s3, dispersing the zinc-organic diphosphonic acid nano particles obtained in the step S2 into a solvent, and adjusting the pH value to 3.5-4.5 to prepare a zinc-organic composite nano cluster suspension;

s4, after polishing the surface of the pure zinc, cleaning the pure zinc by absolute ethyl alcohol under an ultrasonic condition, and drying the pure zinc;

s5, putting the zinc polished, cleaned and dried in the S4 into an inorganic zinc phosphate solution, heating in a water bath at 35-45 ℃ for reaction for 0.5-2h, cleaning, and drying to obtain inorganic zinc phosphate composite zinc;

s6, placing the zinc compounded by the inorganic zinc phosphate obtained in the S5 into the zinc-organic compound nano-cluster suspension obtained in the S3, heating in a water bath at 55-65 ℃ for reaction for 10-15h, cleaning, and drying to obtain the zinc-zinc nano-cluster suspension.

According to the coordination chemical principle, firstly, zinc ions react with organic diphosphonic acid molecules (zoledronic acid molecules are used in the invention), and the zinc ions coordinate and chelate with N on imidazole groups in the zoledronic acid molecules and oxygen in phosphonic acid groups to obtain a metal-organic compound carrying single organic diphosphonic acid; then, the oxygen of the phosphonic acid group in the added HEDP is combined with the active zinc ion of the metal-organic complex to obtain the metal-organic complex nanocluster simultaneously containing HEDP and ZA activated molecules.

HEDP on the surface of the metal-organic composite nano-cluster realizes successful embedment of the nano-cluster through chelation coordination of zinc ion active sites on the inorganic zinc phosphate pretreatment layer and physical adsorption of the nano-cluster and the zinc phosphate layer. In the process of embedding, HEDP plays a role of a 'bridge', and nano-clusters and zinc phosphate layers are combined together.

Further, 15-25g/L of zinc nitrate hexahydrate and 1-3g/L of organic diphosphonic acid solution are mixed according to the volume ratio of 1:1 in S1.

Further, in S1, 20g/L of zinc nitrate hexahydrate and 2g/L of an organic bisphosphonic acid solution were mixed in a volume ratio of 1: 1.

Further, the organic diphosphonic acid solution is a zoledronic acid solution.

Further, the washing and drying of S2, S5 and S6 are specifically: sequentially washing with deionized water and anhydrous ethanol for 2-5 times, and drying at 60 deg.C for 20-30 hr.

Further, the washing and drying of S2, S5 and S6 are specifically: washed 3 times with deionized water and absolute ethanol in sequence, and then dried at 60 ℃ for 24 h.

Further, the solvent in S3 was a hydroxyethylidene diphosphonic acid solution with a concentration of 2 g/L.

Further, the concentration of the zinc-organic composite nano-cluster suspension prepared in S3 is 1-1.5 g/L; preferably 1.2 g/L.

Further, pure zinc is sanded to 2000# with sand paper in S4, then ultrasonically cleaned for 2-5 times, each time for 5min, and then dried at 60 ℃ for 20-30 h.

Further, pure zinc was sanded to 2000# with sandpaper in S4, followed by ultrasonic cleaning 3 times for 5min each, and then drying at 60 ℃ for 24 h.

Further, the inorganic zinc phosphate solution in S5 is prepared by mixing 10-15g/L zinc nitrate hexahydrate solution, 20-25g/L sodium dihydrogen phosphate solution and 8-12g/L calcium nitrate tetrahydrate solution in a volume ratio of 1:1: 1.

Further, the inorganic zinc phosphate solution in S5 was prepared by mixing 13g/L of a zinc nitrate hexahydrate solution, 21.5g/L of a sodium dihydrogen phosphate solution and 10g/L of a calcium nitrate tetrahydrate solution in a volume ratio of 1:1: 1.

The zinc with the surface inorganic micro-flower embedded metal-organic composite nano-cluster modified functional layer constructed by the method is adopted.

The zinc with the surface inorganic micro-flower embedded metal-organic composite nano cluster modified functional layer is applied to the preparation of medical implant materials.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

the composite coating constructed by the invention gives consideration to corrosion degradation control and bone functionalization promotion; on one hand, the corrosion degradation control of a zinc substrate is realized through the combined action of bioactive zinc phosphate (ZnP), bioactivation molecule hydroxyethylidene diphosphonic acid (HEDP) and metal organic composite nano-clusters; on the other hand, the bioactive micro-flowers formed by the inorganic zinc phosphate can induce the deposition of calcium and phosphorus salts and promote the osteogenesis; biological activating molecules HEDP and Zoledronic Acid (ZA) in the metal organic composite nano-cluster belong to diphosphonic acid molecules, have good compatibility with osteoblasts, and can promote the adhesion and proliferation of osteoblasts; the changeable surface topological structure of the micro-flower and the nano-cluster enhances the hydrophilicity and the surface energy of the surface, improves the surface bioactivity, and is more beneficial to the protein adsorption, cell attachment, spreading and growth in the physiological environment. In conclusion, under the synergistic effect of multiple components and multi-scale structures, the modified functional layer prepared by the method realizes the purposes of considering corrosion degradation control and improving biological functionality.

The synthesis method of the metal-organic composite nano cluster synthesizes the metal-organic composite nano cluster carrying two bioactive phosphonic acid molecules, wherein the two bioactive molecules are hydroxy ethylidene diphosphonic acid and zoledronic acid which have the functions of promoting bone adhesion and proliferation, so that the product has the functions of promoting bone adhesion and proliferation;

the invention constructs a multi-component modified functional layer, which comprises inorganic zinc phosphate with osteogenesis inducing function and HEDP and ZA molecules with good bone compatibility, so that the product has osteogenesis inducing function and good bone compatibility;

according to the invention, a multi-scale structure modification functional layer is constructed, and comprises inorganic micro-flowers and metal-organic composite nano-clusters, so that a surface variable topological structure is formed, the surface hydrophilicity and the surface energy are improved, and the surface bioactivity is enhanced;

the method of the invention can slowly release diphosphonic acid molecules and HEDP molecules in the service process of the metal organic nano-cluster so as to achieve the effect of promoting the activity of osteoblasts.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is SEM photographs before and after surface modification;

FIG. 2 is a graph of the infrared spectra of modified functional layers and components used in construction;

FIG. 3 is a graph showing the results of electrochemical characterization before and after modification;

FIG. 4 is a test chart of water contact angle and surface energy before and after modification;

FIG. 5 is a graph showing the results of the deposition of Ca-P salt on the front and rear surfaces before modification;

FIG. 6 is a fluorescence staining pattern of osteoblast direct culture before and after modification;

FIG. 7 is a statistical chart of the number of adherent cells in osteoblast direct culture.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The preferred embodiment of the invention provides a method for constructing an inorganic micro-flower chimeric metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc, which comprises the following specific steps:

a. preparing the metal-organic composite nano-cluster: 20g/L of Zn (NO)₃)₂˙6H₂Adjusting pH of O and 2g/L ZA solution to 4 with NaOH solution, stirring thoroughly in 40 deg.C water bath for 12 hr, filtering to obtain white solid, sequentially washing with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 hr. Preparing an HEDP solution with the pH value of 4 and 2g/L, and ultrasonically dispersing the obtained dry white solid into the solution to prepare a suspension of the metal-organic composite nano cluster with the concentration of 1.2g/L for later use.

b. Grinding pure zinc with sand paper to 2000#, cleaning with anhydrous ethanol under ultrasonic condition for 3 times, each time for 5min, and drying for use.

c. Adding 10g/L Ca (NO)₃)₂˙4H₂O,13g/L Zn(NO₃)₂˙6H₂O,21.5g/L NaH₂PO₄Mixing, adjusting pH to 3.1, placing the polished zinc sheet into the solution, reacting in a 40 deg.C water bath for 1h, sequentially cleaning with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 h.

d. And (c) adding the pretreated zinc sheet in the step (c) into the suspension in the step (a), placing the suspension in a water bath kettle at 60 ℃ for reaction for 12h, sequentially washing the suspension for 3 times by using deionized water and absolute ethyl alcohol, and drying the washed suspension for 24h at 60 ℃ to obtain the zinc sheet, wherein the zinc sheet is recorded as ZnP @ HEDP & MOC. And carrying out SEM observation on the surface appearance of the obtained sample.

The surface topography of the prepared coating is shown in figure 1. It can be seen that the polished zinc sheet has regular and parallel scratches. After the modification by the method, the coating integrally presents a micron-sized flower-like structure. Wherein the metal-organic composite nano-clusters are uniformly distributed around the petals and are in a square shape.

Example 2

a. preparation of metal-organic composite nano-clusterPreparing: 18g/L of Zn (NO)₃)₂˙6H₂Adjusting pH of O and 1.5g/L ZA solution to 4 with NaOH solution, stirring thoroughly in 40 deg.C water bath for 12 hr, filtering to obtain white solid, sequentially washing with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 hr. Preparing an HEDP solution with the pH value of 4 and 2g/L, and ultrasonically dispersing the obtained dry white solid into the solution to prepare a suspension of the metal-organic composite nano cluster with the concentration of 1.3g/L for later use.

c. Adding 9g/L Ca (NO)₃)₂˙4H₂O,11g/L Zn(NO₃)₂˙6H₂O,20.5g/L NaH₂PO₄Mixing, adjusting pH to 3.1, placing the polished zinc sheet into the solution, reacting in a 40 deg.C water bath for 1h, sequentially cleaning with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 h.

d. And (c) adding the pretreated zinc sheets in the step (c) into the suspension in the step (a), placing the suspension in a water bath kettle at 60 ℃ for reaction for 12h, sequentially washing the suspension for 3 times by using deionized water and absolute ethyl alcohol, and drying the washed suspension for 24h at 60 ℃ to obtain the zinc-rich material.

Example 3

a. preparing the metal-organic composite nano-cluster: 23g/L of Zn (NO)₃)₂˙6H₂Adjusting pH of O and 2.5g/L ZA solution to 4 with NaOH solution, stirring thoroughly in 40 deg.C water bath for 12 hr, filtering to obtain white solid, sequentially washing with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 hr. Preparing an HEDP solution with the pH value of 4 and 2g/L, and ultrasonically dispersing the obtained dry white solid into the solution to prepare a suspension of the metal-organic composite nano cluster with the concentration of 1.1g/L for later use.

c. Adding 12g/L Ca (NO)₃)₂˙4H₂O,14g/L Zn(NO₃)₂˙6H₂O,23g/L NaH₂PO₄Mixing, adjusting pH to 3.1, placing the polished zinc sheet into the solution, reacting in a 40 deg.C water bath for 1h, sequentially cleaning with deionized water and anhydrous ethanol for 3 times, and drying at 60 deg.C for 24 h.

Experimental example 1

And taking the powder on the surface of the coating, zinc-zoledronic acid Metal Organic Compound (MOC) and ZA molecular powder, and performing infrared spectrum test by a tabletting method.

The infrared spectrum test results are shown in figure 2. At 1315cm^-1And the ZA, the MOC and the coating all have characteristic peaks of C-N, and are derived from the imidazolyl in the ZA, so that the ZA exists in the zinc-zoledronic acid nanoclusters and the coating, and the nanoclusters are successfully embedded on the surface of the coating. Each sample was at 1100cm^-1And 1000cm^-1Where P0 appears₄ ^3-The characteristic peak, but the zinc-zoledronic acid nanocluster peak is obviously lower than ZA, which should be caused by coordination of Zn and hydroxyl oxygen in phosphonic acid group in ZA.

Experimental example 2

The polished zinc plate and the sample prepared in example 1 were connected with a conductive silver adhesive wire, and a sample was sealed with silicone rubber so that the coated surface was exposed. And (3) putting the sample into a three-way pipe with SBF as electrolyte, wherein a saturated calomel electrode is used as a reference electrode, metal platinum is used as a counter electrode, the sample is used as a working electrode, and an IM6 electrochemical workstation is used for carrying out potentiodynamic polarization curve test on the sample. The sample polarization curve is shown in fig. 3. It can be seen that the sample after the coating modification has a self-corrosion potential E_corrCorrection, self-etching current i_corrThe reduction indicates that the coating can slow down the corrosion of the zinc substrate.

Experimental example 3

a. Respectively dripping 5 mu LRO water on the surfaces of pure zinc and the samples prepared in the example 1, photographing, and testing the water contact angle;

b. and respectively dropping 1 mu L of diiodomethane on the surfaces of pure zinc and the samples prepared in the example 1, and testing the contact angle.

The measured water contact angle and surface energy are shown in FIG. 4. It can be seen that the water contact angle after modification is 0, because the surface components of the modified functional layer all contain hydrophilic phosphonic acid groups; the surface energy is obviously increased compared with zinc, because the surface specific surface area is increased due to the surface micro-nano multi-scale structure, and further the surface energy is enhanced, and the surface bioactivity is enhanced.

Experimental example 4

Preparing a saturated calcium phosphate solution: 2.32mM NH4H2PO4,3.87mmol CaCl2,50Mm NaCl. The solution was mixed at 25 ℃ and adjusted to pH 7.2. + -. 0.1 with 50 mM.

The sample obtained in example 1 was immersed in a saturated calcium phosphate solution for 10 seconds and then taken out, and dried in a vacuum oven at 80 ℃ for 30 min. Repeating the above steps for 10 times, washing the sample with distilled water for 3 times, adding into saturated calcium phosphate solution, standing at 37.5 deg.C for 10 hr, and washing and drying.

The results of the scanning electron microscope observation of the samples after the deposition of the calcium phosphate are shown in figure 5. It can be seen that the surface of the modified functional layer is almost completely covered by calcium phosphate, and is denser and compacter. The method is mainly characterized in that the multi-component influence on the surface of the modified functional layer is achieved, and sufficient active sites are provided for deposition of CaP by inorganic zinc phosphate and HEDP active molecules on the surface of the metal-organic nano cluster.

Experimental example 5

The resulting coating was evaluated for biocompatibility.

The cells used in this experiment were mouse preosteoblasts (MC3T3-E1) purchased from Wuhan Severe technologies, Inc. DMEM (seimer feishell instruments ltd, suzhou) supplemented with 10% FBS was used as the cell culture medium. The inoculation experiment can be carried out when the cells are cultured until about 80% of monolayer confluency, and the specific steps are as follows:

(1) preparation of the experiment: sterilizing consumables and samples required by the experiment (the consumables are sterilized at high temperature and high pressure, the samples are irradiated by ultraviolet rays, and the front and the back of each sample are 30 min).

(2) Taking out a cell culture bottle with a cell monolayer of more than 80% on a super-clean workbench, pouring out the culture medium, washing with physiological saline for three times, completely sucking with a straw, and uniformly dropwise adding 1ml of pancreatin into the culture bottle for digestion. After the cells become round and bright, 5ml of culture medium is added for blow beating to prevent the cells from agglomerating. Then taking out the cell suspension, centrifuging for 5min at 1200r/min, pouring out the supernatant, and adding a new culture medium to obtain the cell suspension with the cell density of 10000 cells/ml.

(3) Inoculation, the cell suspension was applied to the surface of the sample 1ml per well using a pipette, and then placed at 37.5 ℃ in 5% CO₂Is cultured in the incubator for 1, 3 and 5 days.

The experiment utilizes phalloidin to dye cytoskeleton so as to observe the growth form of cells; the cell nucleus staining is carried out by 4, 6-diamidino-2-phenylindole (DAPI) to observe the cell adhesion quantity on the surface of the sample, and the staining steps are as follows:

1) and (4) fixing. Absorbing the culture medium in the culture plate, washing with PBS for 3 times, and adding 2.5% glutaraldehyde for fixation for 12 h;

2) staining of cytoskeleton. The glutaraldehyde fixing solution was aspirated, washed with PBS 3 times, soaked in Triton solution for 10min, and washed with PBS 3 times. Subsequently, the sample was soaked in 5% BSA solution for 60min and washed 3 times. Finally, drying the surface of the sample, and dripping 60 mu l of phalloidin solution under the condition of keeping out of the sun and placing for 12h at the temperature of 4 ℃;

3) and (4) cell nucleus staining. And soaking the sample in the DAPI solution for about 10s under the condition of keeping out of the sun.

4) The number and state of cell adhesion were observed by fluorescence microscopy.

The results of osteoblast direct culture are shown in FIGS. 6-7. As can be seen from the fluorescence pictures, the cells on the surface of the unmodified pure zinc are subjected to shrinkage death after being cultured for 1 day, the number of adhered cells is very small, and the cells are directly cracked and die on

days

3 and 5. After the surface modification is carried out by the method, the cells on the surface of the modified functional layer after 1, 3 and 5 days of culture are obviously more than pure zinc, and the cells show good spreading state on the surface of the sample in the first day, which is because the surface multi-scale structure enhances the surface energy and further enhances the surface bioactivity. On the third and fifth days of culture, the cell density is obviously increased, which shows that the proliferation and growth of osteoblast are obviously promoted under the combined action of surface multicomponent-inorganic zinc phosphate, HEDP and ZA activating molecules.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A method for constructing an inorganic micro-flower chimeric metal-organic composite nanocluster modified functional layer on a biodegradable zinc surface is characterized by comprising the following steps:

s3, dispersing the zinc-organic diphosphonic acid nano particles obtained in the step S2 into a hydroxyl ethylidene diphosphonic acid solution serving as a solvent, and adjusting the pH to 3.5-4.5 to prepare a zinc-organic composite nano cluster suspension;

s5, putting the zinc polished, cleaned and dried in the S4 into an inorganic zinc phosphate mixed solution, heating in a water bath at 35-45 ℃ for reaction for 0.5-2h, cleaning, and drying to obtain inorganic zinc phosphate composite zinc;

2. The method for constructing an inorganic popcorn chimeric metal-organic composite nanocluster modified functional layer on a biodegradable zinc surface according to claim 1, wherein 15-25g/L of zinc nitrate hexahydrate and 1-3g/L of organic bisphosphonic acid solution are mixed in a volume ratio of 1:1 in S1.

3. The method for constructing the inorganic popcorn chimeric metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc according to claim 2, wherein the organic bisphosphonic acid solution is zoledronic acid solution.

4. The method for constructing the modified functional layer of inorganic micro-flower rice chimeric metal-organic composite nanoclusters on the surface of biodegradable zinc as claimed in claim 1, wherein the washing and drying of S2, S5 and S6 are specifically: sequentially washing with deionized water and anhydrous ethanol for 2-5 times, and drying at 60 deg.C for 20-30 hr.

5. The method for constructing an inorganic popcorn mosaic metal-organic composite nanocluster modified functional layer on the surface of biodegradable zinc according to claim 1, wherein the concentration of the hydroxyethylidene diphosphonic acid solution in S3 is 2 g/L.

6. The method for constructing an inorganic popcorn chimeric metal-organic composite nanocluster modified functional layer on a biodegradable zinc surface according to claim 1, wherein the concentration of the zinc-organic composite nanocluster suspension prepared in S3 is 1-1.5 g/L.

7. The method for constructing an inorganic micro-flower chimeric metal-organic composite nanocluster modified functional layer on a biodegradable zinc surface according to claim 1, wherein pure zinc is ground to 2000# with sandpaper in S4, and then ultrasonically cleaned for 5min 2-5 times, and then dried for 20-30h at 60 ℃.

8. The method for constructing an inorganic popcorn mosaic metal-organic composite nanocluster modified functional layer on a biodegradable zinc surface as recited in claim 1, wherein the inorganic zinc phosphate mixed solution in S5 is prepared by mixing 10-15g/L zinc nitrate hexahydrate solution, 20-25g/L sodium dihydrogen phosphate solution and 8-12g/L calcium nitrate tetrahydrate solution in a volume ratio of 1:1: 1.

9. The zinc of the surface inorganic micro-flower chimeric metal-organic composite nanocluster modified functional layer constructed using the method of any one of claims 1 to 8.

10. Use of zinc with a modified functional layer of surface inorganic micro-flowers intercalated with metal-organic composite nanoclusters according to claim 9 for the preparation of medical implant materials.