Glass - Back to the Future!

Presenting Author:
Teo Kubiena

article posted 22 August 2016

Teo Kubiena
Prior to completing his Master's degree in Mechanical Engineering at the University of Nottingham Teo first obtained a view of research through investigating the tensile and adhesive properties of artificial cephalopod suckers at the Centre for Biomimetics at the University of Reading. Following this, he undertook an internship in the oil and gas industry exploring the lifespan of drilling operations. Ultimately, Teo's research interest's have found their focus in the investigation of chalcogenide glasses. Initially examining the in vitro cytotoxic effects of chalcogen containing glass fibres, Teo now hopes to begin PhD studies looking at determining structure-property relationships in heavy metal optical glasses so as to optimise glass fibre compositions.

Investigation of cytotoxicity of mid-infrared optical fibres for use in in vivo mid-infrared optical biopsy

T. Kubiena*, H. Parnell , A. B. Seddon
Faculty of Engineering, University of Nottingham, UK

Chalcogenide glass optical fibres for use in in vivo mid-infrared optical biopsy are investigated in vitro for their cytotoxic effects towards mammalian fibroblast (3T3) cells. Direct contact cytotoxicity tests were carried out on Ge20Sb10Se70 (as batched, (at%)) fibres for the exposure durations of: 1 day, 3 days, 7 days and 14 days. For these time point’s, relative cell proliferation measured via resazurin reduction is reported alongside scanning electron microscope (SEM) images of cell-fibre interactions. Fibres chemically etched are found to support healthy cell growth as compared to a control. Non-etched fibres show a strong cytotoxic effect with stunted cell proliferation and degeneration of cell morphology alongside reduced attachment. Elution using Dulbecco's Modified Eagle's Medium with foetal bovine serum (DMEM-FBS) as an eluent was carried out on Ge20Sb10Se70 (at%), As40Se60 (at%) and Ge20Te10Sb70 (at%) fibres that were chemically etched, non-etched and chemically oxidised. Cellular viability after 24 hours of exposure to the extractables-eluent solution at volume concentrations of: 100%, 75%, 50% and 25% is reported via Neutral Red uptake measurement. All fibres are seen to be cytotoxic when chemically oxidised and non-cytotoxic when chemically etched. When non-etched only As-Se fibres show a cytotoxic effect and this is only at 100% extractables-eluent solution concentration. Contact angle measurements using de-ionised water on polished and polished/chemically oxidised Ge26.56Sb44.55Se28.89 sections were obtained. For the polished sample a 41.15 ± 0.7° contact angle is reported showing it to be hydrophilic and conducive to cell attachment. The oxide layer of the polished/chemically oxidised sample was seen to be highly soluble in aqueous solution. All results imply that cytotoxic effects from chalcogenide fibres occur as a result of the formation of an oxide layer at the surface. This oxide layer is however seen to go rapidly into solution and a strong correlation between chemical etching and positive chalcogenide biocompatibility is shown. Arsenic containing fibres are shown to induce the most significant cytotoxic response in cells. The study presents a repeatable framework for application in the future cytotoxicity testing of novel chalcogenide fibres.