Non-Leaching Antibacterial Concept Demonstrated by In Situ Construction of 2D Nanoflakes on Magnesium

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)31A_Invited conference paper (refereed items)Yespeer-review

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Detail(s)

Original languageEnglish
Publication statusPublished - Dec 2019

Conference

Title15th International Conference on Plasma Based Ion Implantation & Deposition (PBII&D 2019)
LocationSheraton Shenzhen Nanshan
PlaceChina
CityShenzhen
Period19 - 22 December 2019

Abstract

Among the various surface functionalization strategies, antibacterial surfaces are primarily categorized as leaching surfaces with systemic effects [1] and non-leaching surfaces that kill bacteria locally.[2] The former is normally less desirable due to issues such as the potential toxicity of the leached agents and needs to replenish the antibacterial agents if long-term effects are necessary.[3] In this respect, bacteria killing on contact without the use of chemicals is simpler and produces less detrimental side effects.[4] 
In this work, the 2D nanoflakes are produced in situ on Mg by a hydrothermal process and the antibacterial activity, corrosion resistance, as well as biocompatibility are confirmed systematically both in vitro and in vivo. The mechanism is analyzed from the physicochemical, electrochemical, and biological perspectives in addition to theoretical simulation. 
Different from the common antibacterial mechanisms of bulk Mg attributed to Mg2+ release and local pH elevation, the Mg(OH)2 nanoflakes trap the bacteria on contact, stretch the cell membranes by strong surface tension, and trigger stress response including intracellular reactive oxygen species (ROS) bursts. The nanostructured surface converts a leaching-based antibacterial mechanism to a non-leaching one while promoting the anticorrosion properties and mammalian cell growth at the same time. Previous studies have shown that the synergetic effects rendered by Mg2+ release and alkalinity lead to bacterial lethality and the mechanism is thus release dependent. Actually, release-dependent antibacterial processes are the 173 mainstream ones. In spite of the good efficacy in mitigating infection, a large dose or uncontrolled drug release can spur drug resistance and produce adverse side effects. Therefore, the local antibacterial ability based on physical contact, that is, one based on a nonrelease mechanism, is more appealing as many systemic side effects can be circumvented.[4a] 
The contact-dependent and non-leaching antibacterial mechanism demonstrated here is expected to spur the development of multifunctional biomaterials with simultaneous bacterial resistance, corrosion resistance and biocompatibility.

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Citation Format(s)

Non-Leaching Antibacterial Concept Demonstrated by In Situ Construction of 2D Nanoflakes on Magnesium. / Wang, Guomin; Chu, Paul K.

2019. 15th International Conference on Plasma Based Ion Implantation & Deposition (PBII&D 2019), Shenzhen, China.

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)31A_Invited conference paper (refereed items)Yespeer-review