Glass - Back to the Future!

Presenting Author:
Elizabet hNorris

article posted 07 April 2016

Elizabeth Norris completed her MEng (Hons) in Mechanical Engineering at the University of Exeter in 2012. She then went on to work in industry before commencing her PhD at Imperial College with Julian Jones. Her current research focuses on the design and production of new bioactive glasses for regenerative medicine.

3-D Electrsopun Bioactive Glasses for Soft Tissue

Elizabeth Norris1#2, Ju Qun3, Akiko Obata3, Toshihiro Kasuga3, Julian R. Jones1
1Department of Materials, Imperial College London, South Kensington Campus, London, UK;
2School of Materials, University of Manchester, Research Complex at Harwell, Oxfordshire, UK;
3Department of Frontier Materials, Nagoya Institute of Technology, Nagoya, Japan

A major challenge in wound healing is to produce a material that promotes cellular activity such as angiogenesis. Bioactive glasses are very flexible compositionally, allowing metal oxides to be added, offering valuable properties for wound healing. The use of electrospinning to produce 2-D mesh bioactive glass fibremats has been widely documented [1]. Poologasundarampillai et al. electrospun the first successful sol-gel 3-D fibrous bioactive glass 70S30C (70 mol% SiO2 30 mol% CaO) scaffold for bone tissue regeneration[2]. The 3-D structure was believed to result from a re-distribution of charge at the point of electrospinning, causing the fibres to whip in the direction of the applied field, forming a structure unlike the expected 2-D structure[2]. This novel, cotton-wool like structure is ideal for packing into defects, making it easy for clinicians to insert into wound providing exciting possible industrial applications. However, there are have been problems with reproducibility. Here we present a new protocol to produce a 3-D structure. Reasons for the presence of a 3-D structure were investigated. Factors such as the sol-gel composition, relative humidity and solution viscosity were explored and their contribution to producing the 3-D structure was assessed. Results confirm that the presence of Ca2+ in the network does impact the electrospinning of the 3-D structure. Results also showed that relative humidity also impacts the production of the 3-D structure indicating that the distribution of charges in the sol-gel are not the only factors contributing to the 3-D structure. Ag ions were been successfully added to the composition, resulting in successful formation of the 3-D structure with up to 3 mol% Ag into the 70S30C bioactive glass. This suggests that additional ions such as copper or cobalt could be incorporated into the structure while still maintain the 3-D structure, extending possible applications of the materials.

Fig 1. Image of the 3-D cotton wool like bioactive glass with a composition of 70S30C.

[1] D. Liang, B.S.Hsiao, B. Chu, Adv. Drug Delivery Review, 59, 1392-1412, (2007)
[2] G. Poologasundarampillai, D. Wang, S. Li, J. Nakamura, R. Bradley, P.D. Lee, M.M. Stevens, D.S McPhail, T. Kasuga, J.R. Jones, Acta Biomater., 10, 3733-46, (2014)