Unveiling the Anti-Biofilm Property of Hydroxyapatite on Pseudomonas aeruginosa: Synthesis and Strategy

Abstract

Biofilm-related nosocomial infections may cause a wide range of life-threatening infections. In this regard, Pseudomonas aeruginosa biofilm is becoming a serious health burden due to its capability to develop resistance to natural and synthetic drugs. The utilization of nanoparticles that inhibit biofilm formation is one of the major strategies to control infections caused by biofilm-forming pathogens. Hydroxyapatite (HA) is a synthetic ceramic material having properties similar to natural bones. Herein, a co-precipitation method followed by microwave treatment was used to synthesize HA nanoparticles (HANPs). The resulting HANPs were characterized using X-ray diffraction and transmission electron microscopy. Then, their antibiofilm properties against P. aeruginosa ATCC 10145 were examined in vitro. The needle-shaped HANPs were 30 and 90 nm long in width and length, respectively. The synthesized HANPs inhibited the biofilm formation of P. aeruginosa ATCC 10145 in a concentration-dependent manner, which was validated by light and confocal laser scanning microscopy. Hence, this study demonstrated that HANPs could be used to control the biofilm-related infections of P. aeruginosa.

Keywords: Pseudomonas aeruginosa; anti-biofilm; hydroxyapatite; nanoparticles.

Figure 1

Schematic presentation illustrating the microwave-assisted synthesis of HANPs.

Figure 2

Characterization of HANPs prepared using the microwave method: HRTEM images showing the needle-shaped nanoparticles of 30 nm width and 90 nm length (a,b) and arrow indicate the needle shapted nanoparticles; XRD analysis of HANPs showing the crystalline nature of the particle with planes at (111) and (110) (c).

Figure 3

Antibiofilm property of HANPs against P. aeruginosa biofilm ATCC 10145 treated with various concentrations of HANPs for 24 h (p ≤ 0.05).

Figure 4

Light microscopy analysis showing the biofilm inhibitory potential of HANPs against P. aeruginosa ATCC 10145 at increasing concentrations. Control, treated with HANPs at 0 µg mL⁻¹ (a); biofilm formed in the presence of HANPs at 10 µg mL⁻¹ (b), 25 µg mL⁻¹ (c), and 50 µg mL⁻¹ (d).

Figure 5

CLSM analysis showing the biofilm inhibitory potential of HANPs against P. aeruginosa ATCC 10145 at increasing concentrations. Control, treated with HANPs at 0 µg mL⁻¹ (a); biofilm formed in the presence of HANPs at 10 µg mL⁻¹ (b), 25 µg mL⁻¹ (c), and 50 µg mL⁻¹ (d).