In this work the preparation of calcium-silicate based composites consisting of natural waste from calcium source as eggshell and silica gel from desiccator as a silicon source both presenting alternative materials for cheap preparation of eco-friendly calciumsilicate bioceramics has been investigated. The effect of CaO/SiO 2 ratio on microstructural properties has also been studied. The pseudo-wollastonite formation has been observed in the case of 40 wt.% CaO and 60 wt.% SiO 2 with lowest porosity and highest density 2.6 g/cm 3 . In the case of 50 wt.% CaO and 50 wt.% SiO 2 the phase transformation from pseudo-wollastonite to wollastonite was observed. Increasing the calcium content caused higher apparent porosity with 19%. It was shown that the development of novel ceramics from reused waste, eggshell or silica can be an optimal solution for low-cost preparation of calcium silicates with potential applications in medicine or cement, food industry.

Bioactive glasses (BGs) are especially useful materials in soft and bone tissue engineering and even in dentistry. They can be the solution to many medical problems, and they have a huge role in the healing processes of bone fractures. Interestingly, they can also promote skin regeneration and wound healing. Bioactive glasses are able to attach to the bone tissues and form an apatite layer which further initiates the biomineralization process. The formed intermediate apatite layer makes a connection between the hard tissue and the bioactive glass material which results in faster healing without any complications or side effects. This review paper summarizes the most recent advancement in the preparation of diverse types of BGs, such as silicate-, borate- and phosphate-based bioactive glasses. We discuss their physical, chemical, and mechanical properties detailing how they affect their biological performances. In order to get a deeper insight into the state-of-the-art in this area, we also consider their medical applications, such as bone regeneration, wound care, and dental/bone implant coatings.