Vi Khanh Truong

Bio: Vi Khanh Truong is an academic researcher from RMIT University. The author has contributed to research in topics: Materials science & Titanium. The author has an hindex of 36, co-authored 122 publications receiving 5501 citations. Previous affiliations of Vi Khanh Truong include North Carolina State University & Swinburne University of Technology.

Bactericidal activity of black silicon

Abstract: Black silicon is a synthetic nanomaterial that contains high aspect ratio nanoprotrusions on its surface, produced through a simple reactive-ion etching technique for use in photovoltaic applications Surfaces with high aspect-ratio nanofeatures are also common in the natural world, for example, the wings of the dragonfly Diplacodes bipunctata Here we show that the nanoprotrusions on the surfaces of both black silicon and D bipunctata wings form hierarchical structures through the formation of clusters of adjacent nanoprotrusions These structures generate a mechanical bactericidal effect, independent of chemical composition Both surfaces are highly bactericidal against all tested Gram-negative and Gram-positive bacteria, and endospores, and exhibit estimated average killing rates of up to ∼450,000 cells min -1 cm -2 This represents the first reported physical bactericidal activity of black silicon or indeed for any hydrophilic surface This biomimetic analogue represents an excellent prospect for the development of a new generation of mechano-responsive, antibacterial nanomaterials

Natural Bactericidal Surfaces: Mechanical Rupture of Pseudomonas aeruginosa Cells by Cicada Wings

Abstract: Natural superhydrophobic surfaces are often thought to have antibiofouling potential due to their self-cleaning properties. However, when incubated on cicada wings, Pseudomonas aeruginosa cells are not repelled; instead they are penetrated by the nanopillar arrays present on the wing surface, resulting in bacterial cell death. Cicada wings are effective antibacterial, as opposed to antibiofouling, surfaces.

Bacterial Retention on Superhydrophobic Titanium Surfaces Fabricated by Femtosecond Laser Ablation

Abstract: Two-tier micro- and nanoscale quasi-periodic self-organized structures, mimicking the surface of a lotus Nelumbo nucifera leaf, were fabricated on titanium surfaces using femtosecond laser ablation. The first tier consisted of large grainlike convex features between 10 and 20 μm in size. The second tier existed on the surface of these grains, where 200 nm (or less) wide irregular undulations were present. The introduction of the biomimetic surface patterns significantly transformed the surface wettabilty of the titanium surface. The original surface possessed a water contact angle of θW 73 ± 3°, whereas the laser-treated titanium surface became superhydrophobic, with a water contact angle of θW 166 ± 4°. Investigations of the interaction of S. aureus and P. aeruginosa with these superhydrophobic surfaces at the surface−liquid interface revealed a highly selective retention pattern for two pathogenic bacteria. While S. aureus cells were able to successfully colonize the superhydrophobic titanium surfaces, ...

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal

Abstract: The antibacterial action of silver is utilized in numerous consumer products and medical devices. Metallic silver, silver salts, and also silver nanoparticles are used for this purpose. The state of research on the effect of silver on bacteria, cells, and higher organisms is summarized. It can be concluded that the therapeutic window for silver is narrower than often assumed. However, the risks for humans and the environment are probably limited.

Targeting microbial biofilms: current and prospective therapeutic strategies.

Abstract: Biofilm formation is a key virulence factor for a wide range of microorganisms that cause chronic infections. The multifactorial nature of biofilm development and drug tolerance imposes great challenges for the use of conventional antimicrobials and indicates the need for multi-targeted or combinatorial therapies. In this Review, we focus on current therapeutic strategies and those under development that target vital structural and functional traits of microbial biofilms and drug tolerance mechanisms, including the extracellular matrix and dormant cells. We emphasize strategies that are supported by in vivo or ex vivo studies, highlight emerging biofilm-targeting technologies and provide a rationale for multi-targeted therapies aimed at disrupting the complex biofilm microenvironment.