1. Novel Bioglass Microspheres for Biomedical
Applications
Student: Matthew Wadge (emymw@nottingham.ac.uk)
Supervisor: Dr. Ifty Ahmed (ifty.ahmed@nottingham.ac.uk)
Advanced Materials
Research Group
1. Introduction
3. Discussion
Bulk and porous microspheres were successfully manufactured which offer
several advantages over other geometries, for example: minimally invasive
delivery due to their ability to flow easily and the potential to encapsulate
biological components i.e. stem cells[4], drugs, growth factors or other
biological factors.
One of the main issues facing current health care systems is the
increase in bone related disorders such as osteoporosis (loss of bone
tissue), and developing an effective treatment for such conditions.
For over 40 years, Bioglass™ (45S5)[1] has been the quintessential
bioactive glass composition having been used in a broad range of
applications from coatings[2] to scaffolds in tissue engineering[3].
This study focussed on manufacturing and characterising bulk and porous
microspheres (for the first time) from bioglass compositions (to also
include 13-93 & S53P4) as well as Bioglass™ (45S5) for delivery of
biological components (i.e. stem cells and other biological
factors for use in novel biomedical applications).
Acknowledgements
The author would like to acknowledge the help and support given by Dr. Ifty Ahmed & Dr. Laura
Macrì Pellizzeri during this project. In addition, special thanks to the EPSRC for funding this project.
References
[1] Hench L et al, J Mater Sci: Mater Med (2006) 17:967–978
[2] Wilson J, 1985 “Clinical Applications of Bioglass™”, Glass … Current Issues. Springer Netherlands, pp.662-669
[3] Rahaman et al. Acta Biomater. 2011 Jun; 7(6): 2355–2373
[4] Ahmed I et al. Prog Biomater. (2015) 4:1–19
[5] Ylanen H, 2011 “Bioactive Glasses: Materials, Properties and Applications”, Elsevier pp.8-14
[6] Ylanen H et al. Journal of Non-Crystalline Solids 275 (2000) 107-115
[7] http://www.slideshare.net/NationalOsteoporosisSociety/royal-college-of-physicians-conference-2016-
medicine2016 as of 17/08/16
5. Conclusions & Future Studies
• This study has concluded that both bulk and porous microspheres can be
manufactured using 13-93, 45S5 and S53P4 bioactive silicate glass
compositions (Fig. 2, 3 & 5).
• Further studies will aim to increase the yield of porous microspheres for
silicate based glasses.
• Furthermore, additional cell culture studies should be conducted to
investigate cell encapsulation within the Bioglass porous microspheres.
Fig 2. 45S5 Bulk Microspheres Fig 3. S53P4 Porous Microsphere
2. Methods
A flame spherodisation process was used to create bulk and porous
microspheres of size 63-125 µm. Characterisation of spheres included:
Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy
(EDX), XRD, SBF Testing, Thermal Analysis (DTA), and Cell culture studies.
Fig 1. Osteoporosis: The Problem[7]
4. Results
Glass Type Composition (wt%)
SiO2 Na2O CaO K2O MgO P2O5
45S5 (Predicted) 45 24.5 24.5 - - 6
45S5 (Actual - EDX) 46.98 21.77 24.84 - - 6.41
13-93 (Predicted) 53 6 20 12 5 4
13-93 (Actual - EDX) 52.98 5.34 22.28 8.87 5.94 4.59
S53P4 (Predicted) 53 23 20 - - 4
S53P4 (Actual - EDX) 53.61 20.84 20.78 - - 4.77
Further EDX analysis of SBF (Simulated Body
Fluid) samples demonstrated formation of a
silicon gel and apatite layer as early as day 3 [6].
(see Figures 6 & 7)
Fig. 3 45S5, 13-93, S53P4 compositions (wt%)
CaPSi
Fig. 7 SBF EDX 45S5 Day 3Fig. 6 SBF EDX 13-93 Day 10
X-ray Diffractometry (XRD) analysis concluded the
amorphous nature of the glasses (Fig. 4).
EDX analysis confirmed the composition of
glasses produced which were concurrent to
literature values[5] (Fig. 3).
In addition, preliminary in vitro cell culture experiments showed that bulk Bioglass
microspheres from all the compositions support cell adhesion as well as cell
proliferation at day 7 (see Figures 8 & 9).
Fig. 8 Representative images of GFP+ hMSCs (human
mesenchymal stem cells) adhered to the bulk bioglass
microspheres at d7
Fig. 9 Assessment of cell proliferation by Presto
Blue assay induced by the microspheres
0
5 0 0 0
1 0 0 0 0
1 5 0 0 0
2 0 0 0 0
2 5 0 0 0
4 5 S 5
1 3 -9 3
S 5 3 P 4
PrestoBlue
(560/590nm)
12h d7
Fig 5. Porous S53P4
Microsphere