Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2024

Exploiting Nanostructured Silicon for Viral Inactivation: Investigating Nature-Inspired Solutions for Countering Viral Threats (#54)

Samson W.L. Mah 1 2 , Denver P. Linklater 3 , Vassil Tsanov 4 , Phuc H. Le 3 , Chaitali Dekiwadia 5 , Edwin Mayes 5 , Ranya Simons 2 , Daniel J. Eyckens 2 , Graeme Moad 2 , Soichiro Saita 6 , Saulius Joudkazis 7 , David A. Jans 8 , Vladimir A. Baulin 4 , Natalie A. Borg 1 , Elena P. Ivanova 3
  1. Health and Biomedical Science, RMIT University, Melbourne, Victoria, Australia
  2. Manufacturing Unit, CSIRO , Melbourne, Victoria, Australia
  3. Physics, RMIT University, Melbourne, Victoria, Australia
  4. Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona, Spain
  5. RMIT Microscopy and Microanalysis Facility, STEM college, RMIT University, Melbourne, Victoria, Australia
  6. The KAITEKI Institute Inc, Chiyoda-ku, Tokyo, Japan
  7. Swinburne’s Centre for Micro-Photonics, Swinburne University of Technology, Melbourne, Victoria, Australia
  8. Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia

   In light of the COVID-19 pandemic's widespread transmission via contaminated surfaces, this study delves into the innovative realm of nanostructured silicon surfaces, drawing inspiration from nature's ingenious design, to counter viral threats in our environment.

   Using inductively coupled plasma-assisted reactive ion etching, we crafted nanostructured silicon surfaces adorned with nanospikes of precise dimensions. Our experiments involved incubating human parainfluenza virus type 3 (hPIV-3) on both nanostructured and smooth silicon surfaces for varying time frames, assessing viral inactivation and morphological changes. Remarkably, our findings (Figure 1) showcased the potent virucidal activity of the nanospike silicon surface against hPIV-3. After just 6 hours, there was a striking 1.5 log reduction in infectious particles, in stark contrast to the meagre 0.5 log reduction observed on the smooth silicon control surface. Electron microscopy unravelled profound alterations in viral particle structure on the nanospike surface, indicative of irreversible damage inflicted upon the viral particles.Theoretical modelling via COMSOL simulation as shown in Figure 2 further substantiated these findings, unveiling the virucidal prowess of nanostructured substrata. This action is attributed to the sharp nanofeatures adeptly penetrating the viral envelope, ultimately culminating in the loss of viral infectivity.

Our study underscores the pivotal role of nanostructured surfaces in curtailing viral and bacterial dissemination. Moreover, it offers invaluable insights into optimizing antiviral surfaces, emphasizing the paramount importance of sharp nanofeatures in amplifying their efficacy.

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 Figure 1. (a) High magnification SEM images of intact hPIV3 fixed on non-structured Si surfaces. (b) TEM micrograph of single hPIV3 particle. (c) Histogram of the hPIV3 sizes measured from SEM images. (d)  Representative SEM micrographs of hPIV3 viral particles on non-structured and nanospike (top- and tilted view) Si surfaces. (e) The dynamic inactivation of hPIV3 over 6 h on nanostructured and non-structured surfaces was measured using plaque assay expressed as plaque forming units per mL (pfu/mL). The graph shows the log reductions (reduction of pfu/mL) of the hPIV3 virus retrieved after 1 h, 3 h, and 6 h incubation.

 

65f3eccce91dc-comsol.png
Figure 2. COMSOL modelling (using Finite Element Method) of spherical viral particle with four nanospikes. 

  1. Samson W. L. Mah, Denver P. Linklater, Vassil Tzanov, Phuc H. Le, Chaitali Dekiwadia, Edwin Mayes, Ranya Simons, Daniel J. Eyckens, Graeme Moad, Soichiro Saita, Saulius Joudkazis, David A. Jans, Vladimir A. Baulin, Natalie A. Borg, and Elena P. Ivanova ACS Nano 2024 18 (2), 1404-1419 DOI: 10.1021/acsnano.3c07099