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Lookup NU author(s): Đurđa Vukajlović, Dr Oana Bretcanu, Professor Katarina Novakovic
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A broad range of bioglass and glass-ceramic scaffolds exhibit advantageous characteristics including biocompatibility, biodegradability and antibacterial properties. Furthermore, they have the ability to bond to human bone, which makes them suitable for orthopaedic implants. Following the discovery of Bioglass 45S5 (BG) in 1969, many other bioglass and glass-ceramic scaffolds with improved mechanical properties and slow degradation rate were developed. However, until now, inadequate mechanical properties of these scaffolds, and in particular their brittleness, are their biggest drawbacks. In this work, seeking to overcome these limitations, BG and apatite-wollastonite (AW) scaffolds were coated with chitosan-based hydrogels. Chitosan was introduced as an organic part of the composite in order to improve the mechanical properties and mimic the composition of human bone. As chitosan is derived from chitin, which is the second most abundant natural polymer and a waste material in the seafood industry, its utilisation is also environmentally beneficial. Herein, highly porous BG and AW scaffolds were made by using the sponge replication method. Different heat treatments for producing scaffolds were evaluated and the most appropriate in terms of sinterability were chosen for further testing. The BG and AW scaffolds were then immersed in hydrogel solutions for different times and polymerized at 37°C. Scanning electron microscopy images of coated scaffolds showed that the coating reduces the porosity, as pores were partially covered by the hydrogel. However, the scaffolds still maintained an open porosity which is suitable for blood flow and cell ingrowth. Compressive strength values of AW scaffolds before and after coating were higher than those of BG scaffolds. However, the compressive strength reached only the lower limit for cancellous bone. BG scaffolds showed a decrease in strength after coating with the hydrogel. Conversely, the strength of AW scaffolds improved after coating. This behaviour can be explained if we consider the biomaterial’s reactivity. As BG is very reactive, it gradually dissolves in the hydrogel making the coated scaffolds weaker than the uncoated ones. On the other hand, AW is less reactive than BG and the AW scaffolds increased their strength after hydrogel coating. The hydrogel acts as a glue, binding the glass-ceramic structure and improving its strength. Therefore, AW scaffolds will be further investigated for applications in tissue engineering.
Author(s): Vukajlovic Dj, Parker J, Bretcanu O, Novakovic K
Publication type: Conference Proceedings (inc. Abstract)
Publication status: Published
Conference Name: You-CGMed-Workshop for Young Researchers in Ceramics and Glasses for Medical Applications
Year of Conference: 2019
Print publication date: 10/10/2019
Online publication date: 10/10/2019
Acceptance date: 24/07/2019
