July 2019
Volume 60, Issue 9
Open Access
ARVO Annual Meeting Abstract  |   July 2019
Feasibility of Silicon quantum dots to study dynamics of the tear film lipids
Author Affiliations & Notes
  • Sidra Sarwat
    School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
  • Peter O Mara
    School of Chemistry, University of New South Wales, Sydney, New South Wales, Australia
  • Richard Tilley
    School of Chemistry, University of New South Wales, Sydney, New South Wales, Australia
  • Justin Gooding
    School of Chemistry, University of New South Wales, Sydney, New South Wales, Australia
  • Fiona Stapleton
    School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
  • Mark Willcox
    School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
  • Maitreyee Roy
    School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
  • Footnotes
    Commercial Relationships   Sidra Sarwat, None; Peter O Mara, None; Richard Tilley, None; Justin Gooding, None; Fiona Stapleton, None; Mark Willcox, None; Maitreyee Roy, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science July 2019, Vol.60, 4176. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Sidra Sarwat, Peter O Mara, Richard Tilley, Justin Gooding, Fiona Stapleton, Mark Willcox, Maitreyee Roy; Feasibility of Silicon quantum dots to study dynamics of the tear film lipids. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4176.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Tear film lipids have major role in dry eye disease, however their basic dynamics including spread, replenishment and turnover is not fully understood. This experimental study aimed to investigate the feasibility of silicon quantum dots (Si-QDs) doped with transition metals such as scandium (Sc) and copper (Cu) as a labelling contrast agent to visualise and monitor tear film lipids at molecular level.

Methods : Sc doped Si-QDs (Sc-Si-QDs) and Cu doped Si-QDs (Cu-Si-QDs) were investigated for fluorescence detection limit by exposing them to artificial tears (a balanced electrolyte formula for dry eye therapy). An optical imaging system composed of a standard slit-lamp bio-microscope combined with a high-resolution Zyla sCOMS camera, was used with emission filters of 460 nm, 510 nm and 530 nm for in-vitro imaging. Cytotoxicity of the Sc-Si-QDs and Cu Si-QDs was assessed using cultured human corneal epithelial cells by trypan blue staining and MTT assay after exposure to the QDs for 24 hours. DMSO and cell culture media were used as positive and negative control respectively.

Results : The average size of QDs was 2.70 nm optimal for quantum yield effect which is desirable for visible photoluminescence. In-vitro imaging of Sc-Si-QDs and Cu-Si-QDs indicated bright and stable fluorescence signal with artificial tears. However, Sc-Si QDs were significantly bright with confined signal at different regions of interest than Cu-Si-QDs. Cu-Si-QDs have shown diffused fluorescence pattern compared to Sc-QDs. The fluorescence signal was detected even at low concentration of 1μg/mL with volume of 10μL. Cytotoxicity of QDs showed no cell death at 16 μg/ml however, there was significant cell membrane disruption and reduction in mitochondrial activity at higher concentrations. Results indicated 100% cell viability at cut off value (16 μg/ml) among both pairs of QDs.

Conclusions : The results showed that QDs are optically optimized and safe for biological tissues. It further demonstrated the feasibility for the development of an ocular imaging system based on slit lamp bio-microscopy and Si-QDs doped with transition metals. It may be helpful to monitor dynamics of tear film lipids in an animal model and potentially propose new drug delivery method for dry eye disease.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×