Gold-Decorated Porous Silicon Nanopillars for Targeted Hyperthermal Treatment of Bacterial Infections

Abstract

In order to address the issue of pathogenic bacterial colonization of diabetic wounds, a more direct and robust approach is required, which relies on a physical form of bacterial destruction in addition to the conventional biochemical approach (i.e., antibiotics). Targeted bacterial destruction through the use of photothermally active nanomaterials has recently come into the spotlight as a viable approach to solving the rising problem of antibiotic resistant microorganisms. Materials with high absorption coefficients in the near-infrared (NIR) region of the electromagnetic spectrum show promise as alternative antibacterial therapeutic agents, since they preclude the development of bacterial resistance and can be activated on demand. Here were report on a novel approach for the fabrication of gold nanoparticle decorated porous silicon nanopillars with tunable geometry that demonstrate excellent photothermal conversion properties when irradiated with a 808 nm laser. These photothermal antibacterial properties are demonstrated in vitro against the Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). Results show a reduction in bacterial viability of up to 99% after 10 min of laser irradiation. We also show an increase in antibacterial performance after modifying the nanopillars with S. aureus targeting antibodies causing up to a 10-fold increase in bactericidal efficiency compared to E. coli. In contrast, the nanomaterial resulted in minimal disruption of metabolic processes in human foreskin fibroblasts (HFF) after an equivalent period of irradiation.

Advances in Porous Silicon–Based Nanomaterials for Diagnostic and Therapeutic Applications

“…Alhmoud et al. studied the use of gold‐decorated pSi nanopillars for the targeted hyperthermal treatment of bacterial infections . pSi nanopillars were coated with gold nanoparticles (AuNPs) and functionalized with a targeting antibody against Staphylococcus aureus ( Figure A).…”

“…The control culture was untreated and irradiated for the same amount of time. Reproduced with permission . Copyright 2017, American Chemical Society.…”

Noble Metal Nanostructured Materials for Chemical and Biosensing Systems

“…In alkaline solution, Ag + can be reduced to Ag atoms and deposited on the surface of AuNRs to generate Au@Ag core-shell NRs, accompanied by blue shift of the LSPR of AuNRs from near-infrared region to shorter wavelengths [52]. The templating method can also synthesized NRs with better dispersibility [53][54][55]. In the synthesis of Au/Ag NRs, the use of soft template received more attention because it does not require subsequent removal of the template.…”

Photoactivated Trifunctional Platinum Nanobiotics for Precise Synergism of Multiple Antibacterial Modes

“…Some inorganic and organic nanomaterials have been synthesized to mimic natural enzymes and antibodies to eliminate bacteria and debride infections . Furthermore, several metal‐oxide‐based nanospheres treated with surface modification or hollow NPs are regarded as carriers of antimicrobial drug delivery systems . However, complicated synthetic methods as well as low drug loading and release rate remain some of the challenges in application at a large scale.…”