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CN-121987858-A - Special antibacterial coating for medical instrument with nano silicon dioxide core-shell structure

CN121987858ACN 121987858 ACN121987858 ACN 121987858ACN-121987858-A

Abstract

The invention discloses a special antibacterial coating for medical equipment with a nano silicon dioxide core-shell structure and a preparation method thereof. The coating takes medical grade nano silicon with the grain diameter of 5+/-1 nm and the PD I of less than 0.1 as a carrier core, silver nano particles with the grain diameter of 2-5nm are loaded in situ, znO quantum dots are coated, a high-efficiency antibacterial inner core is formed, and a shell consists of a PLGA polymer matrix containing grafted heparin, an APTES adhesion force reinforcing agent and an auxiliary agent. The synergistic balance of high performance indexes is realized by optimizing the formula ratio (such as 65% of nano silicon carrier, 4% of silver, 12% of APTES and the like) and the process (microwave auxiliary load, electrostatic spraying, gradient curing and plasma grafting). The thickness of the final coating is less than 5 mu m, the adhesive force reaches 5B grade, the 24-hour bacteriostasis rate on G+/G-bacteria and fungi is more than or equal to 99.95%, the cell survival rate is more than 96%, and the silver ion release is gentle and long-acting. The invention solves the contradiction between high antibacterial property, low toxicity, strong adhesion and ultrathin design, and is suitable for surface modification of various medical instruments.

Inventors

  • He xinxing
  • WU YANXIANG
  • MENG HUA
  • HE ERLONG

Assignees

  • 广州中能特种材料科技有限公司

Dates

Publication Date
20260508
Application Date
20251225

Claims (10)

  1. 1. The special antibacterial coating for the medical instrument with the nano silicon dioxide core-shell structure is characterized by comprising the following components: The particle size of the medical grade nano silicon carrier is 5+/-1 nm, PDI is less than 0.1, the density of surface hydroxyl groups is more than or equal to 3.5groups/nm 2 , and the BET specific surface area is more than or equal to 400m 2 /g; Silver nano particles in situ loaded on the nano silicon carrier, wherein the particle size of the silver nano particles is 2-5nm; ZnO quantum dots are coated on the surface of the nano silicon carrier by a sol-gel method; a PLGA polymer matrix comprising grafted heparin, wherein the grafting density of heparin is greater than or equal to 0.6 μg/cm 2 ; An adhesion enhancer which is gamma-aminopropyl triethoxysilane; dispersing agent, cross-linking agent and defoaming agent.
  2. 2. The antibacterial coating special for the medical instrument with the nano silicon dioxide core-shell structure, which is disclosed in claim 1, is characterized by comprising 65% of medical grade nano silicon carrier, 4% of silver nano particles, 1.5% of ZnO quantum dots, 10% of PLGA polymer matrix, 0.8% of heparin, 12% of adhesion enhancer, 2.5% of dispersing agent, 0.8% of cross-linking agent and 0.2% of defoaming agent, wherein the silver nano particles are calculated according to Ag + .
  3. 3. The antibacterial coating special for medical equipment with the nano-silica core-shell structure, which is disclosed in claim 1, is characterized in that silver nano-particles are loaded on the medical grade nano-silicon carrier by adopting a microwave-assisted in-situ reduction method, and the microwave condition is 50 ℃ for 5min and the power is 300W.
  4. 4. The antimicrobial coating special for medical devices with nano-silica core-shell structures according to claim 1, wherein the heparin is directionally grafted to the surface of PLGA through plasma treatment, the plasma treatment power is 50W, and the atmosphere is Ar.
  5. 5. The antibacterial coating special for medical equipment with the nano-silica core-shell structure according to claim 1, wherein the molecular weight of the PLGA polymer matrix is 15-30kDa, and the glass transition temperature is 45-50 ℃.
  6. 6. The special antibacterial coating for medical equipment with the nano silicon dioxide core-shell structure, which is disclosed in claim 1, is characterized in that ZnO quantum dots are coated on the surface of a medical grade nano silicon carrier by a sol-gel method, and the particle size of the ZnO quantum dots is 3-5nm.
  7. 7. The antibacterial coating special for medical equipment with the nano-silica core-shell structure, which is disclosed in claim 1, is characterized in that glutaraldehyde is adopted as the cross-linking agent, and the hardness of the coating pencil after curing is more than or equal to 2H.
  8. 8. The antibacterial coating special for the medical instrument with the nano silicon dioxide core-shell structure, which is disclosed in claim 1, is characterized in that the coating is prepared through a process comprising electrostatic spraying and gradient curing, wherein the gradient curing is performed at 80 ℃ in advance, and then ultraviolet aftertreatment is performed.
  9. 9. The antimicrobial coating for medical devices with nano-silica core-shell structure according to any one of claims 1-8, wherein the thickness of the coating is less than 5 μm and the surface roughness Ra is less than 0.5 μm.
  10. 10. The antibacterial coating special for medical equipment with a nano-silica core-shell structure according to any one of claims 1 to 8, wherein the antibacterial rate of the coating on escherichia coli, staphylococcus aureus, pseudomonas aeruginosa and candida albicans for 24 hours is more than or equal to 99.95 percent, the cell survival rate measured according to the ISO10993-5 standard is more than 96 percent, and the adhesive force measured according to the ASTMD3359 standard is up to 5B grade.

Description

Special antibacterial coating for medical instrument with nano silicon dioxide core-shell structure Technical Field The invention relates to the technical field of antibacterial coatings, in particular to a special antibacterial coating for medical instruments with a nano silicon dioxide core-shell structure. Background Medical device-related infections (HAIs) are a significant challenge in clinical treatment, and the application of antimicrobial coatings to medical device surfaces is an effective means of preventing such infections. Silver nanoparticles are widely used in antimicrobial coatings due to their broad-spectrum antimicrobial properties. However, the silver-based antimicrobial coatings of the prior art have the following drawbacks in general: 1. The contradiction between the antimicrobial spectrum and toxicity is that high loading of silver is often required to achieve high antimicrobial rates (e.g., 99.995% or more), but this tends to lead to initial burst of silver ions, triggering cytotoxicity, and reduced biosafety (low cell viability). Meanwhile, the single silver antibacterial component has limited inhibition effect on fungi, and the antibacterial spectrum is not wide enough. 2. The contradiction between adhesion and coating design is that to achieve a strong adhesion (e.g., grade 5B) that meets the use requirements of medical devices, more adhesion promoters are often used or the thickness of the coating is increased, but this may affect the uniformity, flexibility or result in too thick a coating that is not suitable for precision or ultra-thin devices. 3. The contradiction between the long-acting performance and the safety is how to control the release kinetics of silver ions, so that the silver ions can not only quickly act but also slowly release for a long time, the toxicity caused by excessive release (burst release) in a short time is avoided, and meanwhile, the early exhaustion of the antibacterial capability is avoided, so that the silver ion sustained release preparation is a technical difficulty. 4. Functional singleness most coatings focus on antimicrobial, lack concern about inflammatory reactions that may be triggered by implanted or contact devices, lack anti-inflammatory or blood compatibility improving designs. Therefore, developing a composite antibacterial coating which can balance the contradiction, namely has the advantages of ultrahigh antibacterial rate, low cytotoxicity, strong adhesive force, ultrathin thickness, broad-spectrum antibacterial property (covering bacteria and fungi) and good biocompatibility, is a technical problem to be solved in the field of surface modification of medical instruments at present. Disclosure of Invention First technical problem The invention aims to provide an antibacterial coating special for medical equipment with a nano silicon dioxide core-shell structure, which has the characteristics of ultra-high broad-spectrum antibacterial property, excellent biocompatibility, strong adhesive force and ultra-thin structure, so as to overcome the contradiction between high silver load and low toxicity, strong adhesive force and ultra-thin thickness, antibacterial spectrum coverage and long-acting slow release in the prior art. (II) technical content In order to solve the technical problems, the technical scheme of the invention is that the special antibacterial coating for the medical instrument with the nano silicon dioxide core-shell structure comprises the following components: The particle size of the medical grade nano silicon carrier is 5+/-1 nm, PDI is less than 0.1, the density of surface hydroxyl groups is more than or equal to 3.5groups/nm 2, and the BET specific surface area is more than or equal to 400m 2/g; Silver nano particles in situ loaded on the nano silicon carrier, wherein the particle size of the silver nano particles is 2-5nm; ZnO quantum dots are coated on the surface of the nano silicon carrier by a sol-gel method; a PLGA polymer matrix comprising grafted heparin, wherein the grafting density of heparin is greater than or equal to 0.6 μg/cm 2; An adhesion enhancer which is gamma-aminopropyl triethoxysilane; dispersing agent, cross-linking agent and defoaming agent. Further, the antibacterial coating comprises 65% of medical grade nano silicon carrier, 4% of silver nano particles, 1.5% of ZnO quantum dots, 10% of PLGA polymer matrix, 0.8% of heparin, 12% of adhesion enhancer, 2.5% of dispersing agent, 0.8% of cross-linking agent and 0.2% of defoaming agent, wherein the silver nano particles are calculated by Ag +. Further, silver nano particles are loaded on the medical grade nano silicon carrier by adopting a microwave-assisted in-situ reduction method, and the microwave condition is 50 ℃ for 5min and the power is 300W. Further, the heparin is directionally grafted to the PLGA surface through plasma treatment, the plasma treatment power is 50W, and the atmosphere is Ar. Further, the molecular weight of the PLGA polymer