AbstractCongenital heart disease (CHD) are the most common anomaly among new-borns, it affects 1% of live births worldwide and approximately 4,600 new-borns in the UK. Tissue engineering creates functional living replacements for tissues or organs with the vision to meet the demand for organs worldwide which in turn can help treat CHD.
This study explored 3D bioprinting for gelatine methacrylol (GelMA), polyethylene glycol diacrylate (PEG-DA)-Alginate and alginate- nanocellulose (AL/N) hydrogels. Also, investigated cell viability and biomechanical properties for these biomaterials.
AL/N constructs demonstrated high biocompatibility with over 80% cell viability through 21 days. The cells in AL/N detached from constructs from day 7 and by day 21 all cells were found attached to the well-plate. GelMA-based constructs presented live-cells in all concentrations by day 21, except 20% GelMA which presented abundant cell death from day 1. The addition of hyaluronic acid to the 5% concentration improved biomaterial viscosity enabling the formation of grid-pattern constructs, reduced the overall bioprinting process time and presented live-cells in constructs for 21 days. PEG-DA Alginate when directly printed with cells presented abundant cell death from day 1. When PBS-rinsed prior to cell seeding, it demonstrated live cells in constructs but from day 14 most cells were dead.
For biomechanical properties, AL/N and PEG-DA Alginate presented comparable results to native heart structures when cell-free. AL/N demonstrated significantly higher tensile strength and elastic potential compared to other biomaterials. The addition of cells to constructs reduced tensile strength and elastic potential overall.
The change in biomechanical properties with the presence of cells suggests that the constructs investigated in this study are more suitable as delivery vehicles to treat damaged tissue rather than tissue fabrication.
|Date of Award
|23 Jan 2020
|Mohamed Ghorbel (Supervisor)