Static vs. dynamic dissolution and cellular compatibility tests of bioactive borosilicate glass scaffolds

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

Examining the trade-off between compensation and promptness in eWOM-triggered service recovery:A restorative justice perspective

Our research examines the effectiveness of monetary compensation and the promptness of response during electronic word-of-mouth (eWOM)-triggered service recovery. Drawing upon restorative justice theories, we explore three main questions: whether the hotel’s response to negative online reviews are always beneficial; whether offering compensation or responding promptly is more efficient under different levels of service failure severity; and how the hotel’s response influences consumers’ future engagement through eWOM media. Experimental results reveal that making minimum online service recovery effort is only effective in fixing consumer attitudes for less severe service failures. Compensation is the optimal solution for less severe failures, while prompt response is optimal for more severe service failures. The hotel’s responsiveness to negative reviews and the service recovery outcome positively influence consumers’ future eWOM behaviours through the same online medium. Implications for hotels seeking cost-effective management of negative reviews and for online media owners are offered