Methods: PTFE was friction transferred manually or semi-automatically onto glass or titanium substrates at a range of temperatures, pressures and speeds. The PTFE fibres were characterised using SEM and light interferometry. Mammalian cell lines (human gingival fibroblasts, HGF-1 and KB cells) were used to assess the cellular response to the nano-fibres. Alignment of cells in the fibre direction and the ability of the fibres to control cell spreading were investigated. Cells were placed in direct contact with nano-fibre treated and control substrates and incubated for time periods of up to 5 days before being fixed and stained with methylene blue. Image analysis was performed using KS400 software (Carl Zeiss).
Results: SEM images of the surface-engineered substrates confirmed that under certain conditions, long parallel fibres in the nanometre range are produced. Light interferometry confirms nanometre features Cells orient in the direction of the PTFE nano-fibres. Quantification of cell orientation shows that cells are aligned in the fibre direction, whereas on control substrates there was no significant orientation. The fibres act as a barrier to cell spreading.
Conclusion: i) Friction transfer of PTFE produces fibres in the nanometre range ii) Cells align to nano-fibres iii) Fibres act as a barrier to cell spreading
The financial support of Dentsply Friadent (Industrial Sponsors), Medical Devices Faraday Partnership and EPSRC are gratefully acknowledged.