Static vs. dynamic dissolution and cellular compatibility tests of bioactive borosilicate glass scaffolds
Liu, Hongfei (2020)
2020
Biotekniikan DI-tutkinto-ohjelma - Degree Programme in Bioengineering, MSc (Tech)
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2020-03-05
Julkaisun pysyvä osoite on
http://urn.fi/URN:NBN:fi:tuni-202003022447
http://urn.fi/URN:NBN:fi:tuni-202003022447
Tiivistelmä
The tissue engineering strategy is an optimal solution for the shortage of grafts and other limitations in bone implantation. In this approach, an ideal scaffold made by biomaterial is used to provide mechanical support and improve bone regeneration. Bioactive glass has been found to be suitable to produce scaffolds for bone application. The incorporation of ions, such as B, Mg, and Sr can bring extra benefits, such as higher conversion rate into hydroxyapatite, mechanical strength, chemical du¬rability and the promotion of cell proliferation and differentiation. The scaffold should own the controlled and optimal internal structure as well as enough mechanical properties which are comparable with nature bones. The 3D printing technologies can achieve the mechanical and structural requirements, customized design and high reproducibility of ideal scaffolds.
In this project, borosilicate glass (B12.5) and borosilicate glass containing Mg and Sr (B12.5-Mg5-Sr10) were prepared using the robocasting method and the porogen burn-off technique for comparison. The basic structural properties were measured and compared between different types of scaffolds. The dissolution behaviour of obtained scaffolds was tested in static and dy¬namic conditions. Finally, the ability of the scaffolds to support cell attachment and proliferation was assessed using MC3T3 pre-osteoblastic cells.
As a result, the 3D printing methods efficiently produced scaffolds with excellent porosities, pore size, and reproducibility, but the resolution of printing and the stability and homogeneity of ink cannot be controlled very well. Comparing with the static dissolution, the pH and ionic concentrations in the dynamic dissolution test were closer to the condition in vivo which can alleviate the risk for toxicity. In the cell viability test, 3D printed scaffolds which contained Mg and Sr exhibited the best performance. And the pre-incubation time was supposed to be 72 hours at least in order to prevent the burst of ions that could lead to cell death. Furthermore, the size of the scaffolds should be adjusted to limit the release of ions.
In this project, borosilicate glass (B12.5) and borosilicate glass containing Mg and Sr (B12.5-Mg5-Sr10) were prepared using the robocasting method and the porogen burn-off technique for comparison. The basic structural properties were measured and compared between different types of scaffolds. The dissolution behaviour of obtained scaffolds was tested in static and dy¬namic conditions. Finally, the ability of the scaffolds to support cell attachment and proliferation was assessed using MC3T3 pre-osteoblastic cells.
As a result, the 3D printing methods efficiently produced scaffolds with excellent porosities, pore size, and reproducibility, but the resolution of printing and the stability and homogeneity of ink cannot be controlled very well. Comparing with the static dissolution, the pH and ionic concentrations in the dynamic dissolution test were closer to the condition in vivo which can alleviate the risk for toxicity. In the cell viability test, 3D printed scaffolds which contained Mg and Sr exhibited the best performance. And the pre-incubation time was supposed to be 72 hours at least in order to prevent the burst of ions that could lead to cell death. Furthermore, the size of the scaffolds should be adjusted to limit the release of ions.