Projects per year
Bone substitutes with enhanced biological activity are required for the replacement, repair and regeneration of skeletal tissue; presently there are over 70,000 total hip replacements and 73,000 total knee replacements carried out in the UK each year1. This project aims to design a bioreactor for stem cell expansion on novel hydroxyapatite bone substitute materials designed for accelerated osseointegration of implants. Mathematical modelling has been used alongside physical and biologucal experiments to define the bioreactor environment.
Initial experiments have been carried our using the osteogenic cell line MG63 seeded on both porous particles2,3 and disks of HA/TCP (hydroxyapatite / tricalcium phosphate). A purpose built flow chamber has been develoed to study the shear stress required to detach cells from the HA/TCP surfaces. The CFD package FLUENT has been used to model the fluid dynamics in a fluidised bed bioreactor to investigate the distributor design, aspect ratio and flowrates of the system. Experiments have been carried out to investigate the fluidisation behaviour of the HA/TCP particles.
Particles (2-4 mm diameter) in a bioreactor (0.02 m diameter, 0.12 m height) were shown to have a minimum fluidisation velocity of 0.04 ms-1 with an overall pressure drop of 3500 kPa m-1, and a 'complete' fluidisation velocity of 0.05 ms-1 with an overall pressure drop of 2800 kPa m-1. MG63s under static conditions have been shown to expand upon the HA/TCP particles. The effects of different distributor design, bioreactor aspect ratio and shear stress on cell attachment and detachment will be presented.
It has been shown that physical and biological experimental shear stress data can be combined with mathematical data to drive bioreactor design. The next stage is to use the experimentally-informed mathematical model to set up the bioreactor to expand the experimental programme to incorporate hBMSCs.
References: 1. www.njrcentre.org.uk (2008). 2. Hsu, Y. et al Key Eng. Mat. 284-286, 305-308 (2005). 3. Hsu, Y.H. et al. J Materials Sci.: Mat. in Med. 18, 1931-1937 (2007).
|Publication status||Published - 2 Nov 2011|
|Event||World Conference on Regenerative Medicine - Leipzig, Germany|
Duration: 2 Nov 2011 → 4 Nov 2011
|Conference||World Conference on Regenerative Medicine|
|Period||2/11/11 → 4/11/11|
Stem Cell Expansion in a Fluidised Bed Reactor for Accelerated Osseointegration of Bone Substitute Material
Ellis, M., Turner, I. & Benzeval, I.
1/01/11 → 31/12/13
Project: Research council