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CN-122013122-A - Composite coating with specific external biological activity and antibacterial activity and preparation method thereof

CN122013122ACN 122013122 ACN122013122 ACN 122013122ACN-122013122-A

Abstract

The invention discloses a composite coating with specific external biological activity and antibacterial activity and a preparation method thereof, and relates to the technical field of biological materials. The composite coating prepared by the invention consists of a Ta 2 O 5 lower layer and a CuO upper layer, and is a Ta 2 O 5 -CuO composite coating constructed by mutually superposing an upper layer and a lower layer, wherein the composite coating is prepared by magnetron sputtering a metal target material in an oxygen-containing atmosphere and then vacuum annealing. The composite coating can induce apatite nucleation deposition in an in-vitro simulated human body fluid environment by utilizing a Ta 2 O 5 layer, and shows in-vitro bioactivity, and the upper CuO layer shows excellent bactericidal activity after being contacted with staphylococcus aureus and escherichia coli. The Ta 2 O 5 layer and the CuO layer are constructed at the interlayer to be favorable for electron-hole separation heterojunction, active oxygen can be generated under the condition of visible light, and the antibacterial effect is synergistically enhanced. The composite coating has compact structure, stable property, good hydrophobicity, specific external antibacterial and biological activity, and is suitable for surface functionalization treatment of titanium alloy implants and surgical instruments.

Inventors

  • LIU JINKUN
  • SHU HAN
  • SHEN TAO
  • ZHU YAN
  • DONG MINGRONG

Assignees

  • 昆明理工大学

Dates

Publication Date
20260512
Application Date
20260126

Claims (8)

  1. 1. A composite coating with specific external biological activity and antibacterial activity is characterized by comprising a Ta 2 O 5 lower layer and a CuO upper layer, and is a Ta 2 O 5 -CuO composite coating constructed by mutually superposing an upper layer and a lower layer.
  2. 2. The composite coating of claim 1, wherein the lower layer of Ta 2 O 5 is comprised of aligned nano-columnar crystals and the upper layer of CuO is comprised of aligned nano-columnar crystals.
  3. 3. The method for preparing the composite coating with specific external biological activity and antibacterial activity as claimed in claim 1, which is characterized by comprising the following steps: (1) The substrate pretreatment, namely polishing the substrate, and then carrying out ultrasonic cleaning and blowing to obtain a pretreated substrate; (2) The Ta 2 O 5 lower layer is deposited, namely the pretreated substrate is fixed in a magnetron sputtering device, ta targets are symmetrically arranged on target positions, the magnetron sputtering device is vacuumized, a Ta 2 O 5 layer is deposited on the pretreated substrate in the atmosphere of mixed gas, and the substrate deposited with the Ta 2 O 5 layer is obtained after the deposition is finished; (3) Annealing the Ta 2 O 5 layer, namely annealing the substrate deposited with the Ta 2 O 5 layer in an inert atmosphere, and then cooling to obtain a Ta 2 O 5 lower layer sample; (4) The method comprises the steps of depositing a CuO upper layer, namely fixing a Ta 2 O 5 lower layer sample on a sample table of a magnetron sputtering device, symmetrically installing Cu targets on the target positions, vacuumizing the magnetron sputtering device, depositing a CuO layer on the Ta 2 O 5 lower layer sample in a mixed gas atmosphere, and obtaining a Ta 2 O 5 lower layer sample deposited with the CuO layer after the deposition is finished; (5) Annealing the CuO layer, namely annealing the Ta 2 O 5 lower layer sample deposited with the CuO layer under inert atmosphere, and then cooling to obtain the composite coating with specific external biological activity and antibacterial activity, namely the Ta 2 O 5 -CuO composite coating.
  4. 4. The preparation method of the composite coating with specific external bioactivity and antibacterial activity according to claim 3, wherein in the step (1), 1000-mesh, 1500-mesh and 2000-mesh sand paper is sequentially adopted to polish a substrate, the ultrasonic cleaning condition is that acetone, water, absolute ethyl alcohol and water are sequentially adopted to carry out ultrasonic cleaning, the ultrasonic cleaning power is 80-120W, and the substrate is pure Ti or medical titanium alloy Ti-6Al-4V.
  5. 5. The preparation method of the composite coating with specific external bioactivity and antibacterial activity according to claim 3, wherein the purity of the Ta target in the step (2) is more than or equal to 99.99%, the vacuumizing vacuum degree of the magnetron sputtering device is 3X 10 -4 ~4×10 -4 Pa, the mixed gas atmosphere is a mixed atmosphere of oxygen and argon, the flow of the oxygen is 10-12 sccm, the flow of the argon is 35-37 sccm, the deposition condition is that the rotating speed is 10-20 rpm, the distance between a fixed sputtering target material and a substrate is 80-120 mm, the deposition air pressure is 0.6-0.8 Pa, the sputtering deposition power is 40-50W, and the sputtering deposition time is 25-35 min.
  6. 6. The method for preparing the composite coating with specific external bioactivity and antibacterial activity according to claim 3, wherein the annealing treatment condition in the step (3) is that the pressure is 86.659-99.992 kPa, the annealing temperature is 800-900 ℃ and the annealing time is 20-60 min.
  7. 7. The preparation method of the composite coating with specific external bioactivity and antibacterial activity according to claim 3, wherein the purity of the Cu target in the step (4) is more than or equal to 99.99%, the vacuumizing vacuum degree of the magnetron sputtering device is 3×10 -4 ~4×10 -4 Pa, the mixed gas atmosphere is a mixed atmosphere of oxygen and argon, the flow of the oxygen is 18-22 sccm, the flow of the argon is 35-37 sccm, the deposition condition is that the rotating speed is 10-20 rpm, the distance between a fixed sputtering target material and a substrate is 80-120 mm, the deposition air pressure is 0.6-0.8 Pa, the sputtering deposition power is 15-25W, and the sputtering deposition time is 25-35 min.
  8. 8. The method for preparing the composite coating with specific external bioactivity and antibacterial activity according to claim 3, wherein the annealing treatment in the step (5) is performed under the conditions that the pressure is 86.659-99.992 kPa, the annealing temperature is 450-550 ℃ and the annealing time is 40-90 min.

Description

Composite coating with specific external biological activity and antibacterial activity and preparation method thereof Technical Field The invention relates to a composite coating with specific external biological activity and antibacterial activity and a preparation method thereof, belonging to the technical field of biological materials. Background Medical titanium alloy is widely applied to biomedical implants because of good biocompatibility, corrosion resistance and mechanical properties. However, the existing titanium alloy implant still faces some technical problems to be solved, namely firstly, the titanium alloy implant is easy to release metal ions (such as Al and V ions) in a physiological environment and generate potential biotoxicity to surrounding tissues, secondly, the surface of the implant is easy to generate bacterial adhesion and biofilm formation, which are main reasons for inducing postoperative infection, and furthermore, the surface of the implant is insufficient in bioactivity, so that apatite deposition or cellular response is difficult to effectively induce in early stage, and the rapid combination of the implant and bone tissues is influenced. The above problems, especially the low risk of infection and biological activity, are important factors that lead to early failure of the implant or to prolonged recovery period of the patient, and to cope with the above challenges, various surface modification techniques have been studied for improving the comprehensive performance of titanium implants, but it is often difficult for the related techniques to achieve good synergy between the stability of the modified layer, the long-acting antibacterial function and the high-efficiency biological activity, and the in vitro biological activity (such as the apatite deposition ability in simulated body fluid) still has a large improvement room. In order to overcome the defects, the invention adopts magnetron sputtering and subsequent heat treatment as core surface modification means. The technical path has the inherent advantages that the magnetron sputtering process parameters are controllable, the coating is uniform and compact, the bonding force with the matrix is strong, the large-scale preparation is easy to realize, the thickness of the obtained coating can be precisely controlled to hundreds of nanometers, and the excellent mechanical property of the matrix is basically not damaged. The coating obtained by sputtering has fine grains and compact stack, and the microstructure and crystallinity of the coating can be further regulated and controlled and the internal stress is released through subsequent annealing treatment, so that the stability and comprehensive performance of the coating are improved. More importantly, through target selection and process design, magnetron sputtering can effectively construct the surface with specific nanoscale morphology and chemical composition. Researches show that the surface features can inhibit initial adhesion of bacteria through physical and chemical actions, can remarkably enhance the bioactivity of the bacteria in simulated body fluid, and are shown as the capability of rapidly inducing the formation of a hydroxyapatite layer, thus laying a good foundation for subsequent osseointegration of an implant. Therefore, the magnetron sputtering is adopted to assist the annealing process, so that the method is an effective technical scheme for synchronously improving the antibacterial property and the surface biological activity of the titanium implant on the premise of ensuring the biological safety. In the selection of the coating material, the metal oxide (such as Ta 2O5 and CuO) maintains better biocompatibility while achieving effective antimicrobial properties through its own antimicrobial properties and stable M-O bonds, as compared to pure metals, which may cause cytotoxicity due to excessive release of metal ions. Although a single class of metal oxides may have limited antimicrobial efficacy, their antimicrobial mechanism can be optimized by constructing a heterojunction. In particular, the n-type semiconductor Ta 2O5 is selected to combine with the p-type semiconductor CuO to form a p-n heterojunction. The structure can effectively promote the separation of photo-generated electron-hole pairs, and remarkably improves the photocatalysis efficiency, in particular the yield of active oxygen species (ROS, such as O 2- and OH) under the irradiation of visible light. These ROS have strong oxidizing properties, and can indiscriminately attack cell membranes, proteins, nucleic acids, and metabolic key molecules of bacteria, comprehensively destroy their structures and functions, thereby efficiently killing the bacteria. The antibacterial strategy based on the photocatalytic ROS improves the antibacterial performance, simultaneously avoids the rapid dissolution of metal ions, and is beneficial to maintaining the long-acting stability and biosafety of t