Optimisation of 3D Printed Hydrogel Scaffolds for Use in Tissue Engineering

Tissues or organs that have been severely damaged may need organ or tissue transplantation to replace or reconstruct the devastated tissues or organs. Problems in current organ transplantation include shortage of donated organs and immune rejection(1). This area of research is extremely important as tissue engineering could possibly replace the need for organ and tissue transplants and may also overcome the drawbacks involved in organ transplantation. There is a shortage of organ donors moreover in 2010, a study was conducted that concluded that only 10% of the worldwide organ transplant needs were
met, which highlights the need for the advancement of tissue engineering(2).
Hydrogels
Hydrogels are a network of hydrophilic polymers where the degree of flexibility can change due to water content. Hydrogels can absorb water in the amount from 10% up to thousands of times their dry weight(3). They can retain a large amount of water or biological fluids and are characterized by a soft consistency like living tissues and this quality make them an ideal substance for a variety of applications within the body(4). The absorption of water is made possible by hydrophilic groups within the polymer matrix. Hydrogels are relevant to tissue engineering due to their biocompatibility and control of water content. This can determine its consistency to meet both material and biological requirements to treat or replace tissues and possibly in the future, more complex structures such as organs(4)(5).
Tissue Scaffolds
Certain diseases can lead to significant functional defects. Supportive materials are needed to restore healthy interactions between diseased organs and surrounding tissues(6). Supportive scaffolds are used for guided tissue growth to aid regenerative processes(3). Scaffolds provide structural support and shape to construct, a place for cell attachment and growth and are usually biodegradable and biocompatible(7).
The implanted scaffold used in the body should aim to match the mechanical stiffness of the surrounding extracellular matrix that it is supporting. A challenge faced by tissue engineers is the application of a fully biodegradable biomaterial. This is because biodegradable materials that have the perfect balance of mechanical strength, desired duration of biodegradability, with manageable costs is still limited(8).
PVA
PVA has received great popularity with many articles involving its use due to its biocompatibility, biodegradability, non-toxicity, solubility in water, chemical resistance and relatively inexpensive price(9)(10). However, PVA has still not been used as a scaffold within the body. The risks associated with it have not been fully documented despite it being nontoxic, the break down products after degradation may be toxic and thus not entirely safe(11). There are limitations with the use of pure PVA such as stiffness, however these may be overcome by forming a composite. Many studies have used PVA composites for many different purposes.
Research and Objective Plan
There are two main objectives for this project which are to:
1) assess the impact of design (formulation) on the processing of PVA and PVA
composites hydrogel scaffolds to provide adequate mechanical support and support
cell growth.
2) evaluate the effect of manufacturing (conventional versus 3D printing) on transports
properties and thus the ability this must mimic the ECM and support cell growth.
References
1. https://doi.org/10.1098/rsif.2006.0124
2. https://doi.org/10.1016/j.msec.2021.111927
3. https://doi.org/10.1016/S0168-583X(99)00118-4
4. https://doi.org/10.1016/j.msec.2015.07.053
5. https://doi.org/10.1007/s10965-013-0273-7
6. https://doi.org/10.1016/j.jconrel.2020.11.044
7. https://doi.org/10.1007/978-1-349-09574-2_24
8. https://doi.org/10.3389/fbioe.2019.00127
9. https://doi.org/10.1179/1753555713Y.0000000115
10. https://doi.org/10.1021/bm200083n
11. https://doi.org/10.1016/j.ijbiomac.2018.07.159