TY - JOUR
T1 - Lethal puncturing of planktonic Gram-positive and Gram-negative bacteria by magnetically-rotated silica hexapods
AU - Quan, Kecheng
AU - Qin, Yu
AU - Chen, Kai
AU - Liu, Miaomiao
AU - Zhang, Xiaoliang
AU - Liu, Peng
AU - van der Mei, Henny C.
AU - Busscher, Henk J.
AU - Zhang, Zexin
N1 - Publisher Copyright:
© 2024 Elsevier Inc.
PY - 2024/6/15
Y1 - 2024/6/15
N2 - Planktonic bacterial presence in many industrial and environmental applications and personal health-care products is generally countered using antimicrobials. However, antimicrobial chemicals present an environmental threat, while emerging resistance reduces their efficacy. Suspended bacteria have no defense against mechanical attack. Therefore, we synthesized silica hexapods on an α-Fe2O3 core that can be magnetically-rotated to inflict lethal cell-wall-damage to planktonic Gram-negative and Gram-positive bacteria. Hexapods possessed 600 nm long nano-spikes, composed of SiO2, as shown by FTIR and XPS. Fluorescence staining revealed cell wall damage caused by rotating hexapods. This damage was accompanied by DNA/protein release and bacterial death that increased with increasing rotational frequency up to 500 rpm. Lethal puncturing was more extensive on Gram-negative bacteria than on Gram-positive bacteria, which have a thicker peptidoglycan layer with a higher Young's modulus. Simulations confirmed that cell-wall-puncturing occurs at lower nano-spike penetration levels in the cell walls of Gram-negative bacteria. This approach offers a new way to kill bacteria in suspension, not based on antimicrobial chemicals.
AB - Planktonic bacterial presence in many industrial and environmental applications and personal health-care products is generally countered using antimicrobials. However, antimicrobial chemicals present an environmental threat, while emerging resistance reduces their efficacy. Suspended bacteria have no defense against mechanical attack. Therefore, we synthesized silica hexapods on an α-Fe2O3 core that can be magnetically-rotated to inflict lethal cell-wall-damage to planktonic Gram-negative and Gram-positive bacteria. Hexapods possessed 600 nm long nano-spikes, composed of SiO2, as shown by FTIR and XPS. Fluorescence staining revealed cell wall damage caused by rotating hexapods. This damage was accompanied by DNA/protein release and bacterial death that increased with increasing rotational frequency up to 500 rpm. Lethal puncturing was more extensive on Gram-negative bacteria than on Gram-positive bacteria, which have a thicker peptidoglycan layer with a higher Young's modulus. Simulations confirmed that cell-wall-puncturing occurs at lower nano-spike penetration levels in the cell walls of Gram-negative bacteria. This approach offers a new way to kill bacteria in suspension, not based on antimicrobial chemicals.
KW - Cell wall damage
KW - Hexapods
KW - Magnetic propulsion
KW - Nano-antimicrobials
KW - Planktonic bacteria
KW - Surface free energy density
UR - http://www.scopus.com/inward/record.url?scp=85187197516&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2024.03.016
DO - 10.1016/j.jcis.2024.03.016
M3 - Article
C2 - 38471190
AN - SCOPUS:85187197516
SN - 0021-9797
VL - 664
SP - 275
EP - 283
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -