Preparation of antimicrobial surface for medical devices

Abstract

A method of preparing antimicrobial surface on medical devices: first, producing multi-functional surface with bacterial anti-adhesion and self-cleaning functions through single-stop ultrafast laser fabrication approach for development of micro/nano patterns, then producing bactericidal thin film through depositing metal nanoparticles on those micro/nano patterned surfaces. The combination of bacterial anti-adhesion and bactericidal film can inhibit initial bacterial adhesion and release heavy metal ions to kill the bacteria simultaneously. Meanwhile, the multi-functional surface with self-cleaning function can prevent the killed bacteria from accumulating at the substrate surface, thereby obtaining long-lasting antibacterial effect.

Claims

1. A method for preparing antimicrobial surface on medical devices, comprising steps of: 1) grinding and polishing a material surface at 1000 mesh, ultrasonically cleaning with alcohol for 5 minutes, and drying; wherein a material of the step 1) is commercially used in medical devices, comprising medical metallic materials of titanium alloy, bismuth-based alloy, cobalt-based alloy, chromium-based alloy, molybdenum-based alloy, stainless steel, and magnesium alloy; polymer materials of polyurethane, silica gel, polyetheretherketone and polylactic acid; and nonmetallic materials of single crystal silicon and glass; 2) producing micro/nano patterns with single-stop ultrafast laser on the material surface treated in the step 1), wherein a laser wavelength is 1064 nm, a laser power is 4-10 w, a pulse frequency is 200-1000 kHz, a pulse width is 500 fs, and a scanning speed is 500-800 mm/s, so as to obtain a micro-cone structure with a pitch of 10 μm; the micro-cone structure has a multi-functional surface with antibacterial and anti-adhesion and self-cleaning functions; and 3) depositing metal nanoparticles on the multi-functional surface by magnetron sputtering, vacuum evaporation plating, ion plating, electroplating, or electroless plating, so as to form a bactericidal film, wherein a contact angle of the bactericidal film is more than 90°.

2. The method, as recited in claim 1, wherein a material of the step 1) is commercially used in medical devices, comprising medical metallic materials of titanium alloy, bismuth-based alloy, cobalt-based alloy, chromium-based alloy, molybdenum-based alloy, stainless steel, and magnesium alloy; polymer materials of polyurethane, silica gel, polyetheretherketone and polylactic acid; and nonmetallic materials of single crystal silicon and glass.

3. The method, as recited in claim 1, wherein the single-stop ultrafast laser in the step 2) for producing the micro/nano patterns on the material surface has specific parameters of: a laser wavelength of 193-1070 nm, a laser power of 0.5-1000 W, a pulse frequency of 1 k-5 MHz, a pulse width of 50 fs-100 ns, and a scanning speed of 10-3000 mm/s.

4. The method, as recited in claim 1, wherein the metal nanoparticles in the step 3) are metals which release antibacterial ions, comprising: gold, copper, zinc, silver, and magnesium.

5. The method, as recited in claim 1, wherein in the step 3), a thickness of the bactericidal film is 10 nm-500 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the schematical illustration of a method for preparing antimicrobial surface;

(2) FIG. 2 shows the micro/nano pattern produced by an ultrafast laser in embodiment 1;

(3) FIG. 3 shows the contact angle of the micro/nano patterned surface after silver coating in embodiment 1;

(4) FIG. 4 shows the untreated sample surface and the bacteriostatic surface prepared in embodiment 1 after 24-hour-culture of Escherichia coli.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(5) Referring the embodiments, the present invention will be further illustrated.

Embodiment 1

(6) Step 1: Grinding and polishing a Ti6Al4V sample to 1000 mesh, ultrasonically cleaning with alcohol for 5 minutes, and drying;

(7) Step 2: Placing the surface treated Ti6Al4V sample under a femtosecond laser processing system (wavelength 1064 nm) to produce micro/nano pattern on Ti6Al4V sample, wherein laser processing parameters are: power of 8 W, pulse width of 500 fs, a frequency of 400 kHz, scanning speed of 800 mm/s, scanning pitch of 70 μm; scanning times of 5 to obtain micro-cone on the surface of the Ti6Al4V sample; and

(8) Step 3: Coating the micro-cone with silver nanoparticles by magnetron sputtering with coating thickness of 2 nm, thereby obtaining antimicrobial surface.

Embodiment 2

(9) Step 1: Grinding and polishing a stainless steel sample to 1000 mesh, ultrasonically cleaning with alcohol for 5 minutes, and drying;

(10) Step 2: Placing the surface treated stainless steel sample under a femtosecond laser processing system (wavelength 1064 nm) to produce micro/nano pattern on stainless steel sample, wherein laser processing parameters are: power of 10 W, pulse width of 500 fs, frequency of 200 kHz, scanning speed of 500 mm/s, scanning pitch of 40 μm; scanning times of 10 to obtain LIPSS on the surface of the stainless steel sample; and

(11) Step 3: Coating the LIPSS with copper nanoparticles by vacuum evaporation plating with coating thickness of 6 nm, thereby obtaining antimicrobial surface.

Embodiment 3

(12) Step 1: Grinding and polishing a cobalt-based alloy sample to 1000 mesh, ultrasonically cleaning with alcohol for 5 minutes, and drying;

(13) Step 2: Placing the surface treated cobalt-based alloy sample under a femtosecond laser processing system (wavelength 1064 nm) to produce micro/nano pattern on the cobalt-based alloy sample, wherein laser processing parameters are: power of 4 W, pulse width of 500 fs, frequency of 600 kHz, scanning speed of 600 mm/s, scanning pitch of 50 μm; scanning times of 10 to obtain a micro-cone on the surface of the cobalt-based alloy sample; and

(14) Step 3: Coating the micro-cone with gold nanoparticles by ion plating with coating thickness of 8 nm, thereby obtaining antimicrobial surface.

Embodiment 4

(15) Step 1: Grinding and polishing a single crystal silicon sample to 1000 mesh, ultrasonically cleaning with alcohol for 5 minutes, and drying;

(16) Step 2: Placing the surface treated single crystal silicon sample under a femtosecond laser processing system (wavelength 1064 nm) to produce micro/nano pattern on single crystal silicon sample, wherein laser processing parameters are: power of 7 W, pulse width of 500 fs, frequency of 1000 kHz, scanning speed of 500 mm/s, scanning pitch of 30 μm; scanning times of 6 to obtain micro-cone on the surface of the single crystal silicon sample; and

(17) Step 3: Coating the micro-cone with silver nanoparticles by electroplating with coating thickness of 10 nm, thereby obtaining antimicrobial antibacterial surface.