Bio-scientific research has relied heavily on models of cell monolayers cultured on plastic. For most cell types, this does not represent their in vivo tissue organisation well. As a result they behave differently in vitro from in vivo, leading to poorly predictive data. Plastic compression (PC) of collagen is used to engineer constructs with more tissue-like conditions. The aim of this study was to test the feasibility of using these constructs as a three-dimensional tissue model for assessing the fate of hyaluronan nanoparticles (HA-NP). Collagen hydrogels were seeded with cells and HA-NP and subjected to PC. Due to their small size, HA-NP retention following PC was investigated. HA-NP uptake by cells was then compared to conventional monolayer cell cultures. 19.1±1.2% of the initial HA-NP load was retained following PC, which could be increased to 31.1±3.1% by multi-layering. This entrapment was found to be largely physical as HA-NPs were released from the construct following cellular remodeling, but not without it. Cells in monolayer reached their maximum HA-NP uptake in 3 days whilst cells in collagen peaked at 7 days. This maximum uptake was 60.1 a.u., twice as large as that of 3D-cultured cells (32.8 a.u). A novel method was developed to analyse local collagen densities which revealed particular collagen distributions in micro-patterned constructs depending on the shape of template used; round grooves had a 21.4±4% increase in collagen density at their bases, whilst rectangular grooves displayed two peaks corresponding to their internal corners, which were 15.2±4% and 16.9±3% denser than the unpatterned regions. This work has enabled greater understanding of the PC and micro-moudling which will aid in creating more complex tissue constructs in a predictable and controlled way. The importance of 3D tissue organisation in in vitro models, particularly for nanoparticle testing, has also been demonstrated in this work.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:654652 |
| Date | January 2015 |
| Creators | Tan, N. S. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1465086/ |
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