The earliest bioactive materials which were used within the body were identified as called Prostheses (Hench and Thompson,
2010). These Prostheses had to be standardized according to the physical properties of living tissues. Professor Bill Bonfield et al. (1981) was the pioneer of researching mechanical properties of living tissues, its skills were especially centered on bone to make Prosthesis. The basic objective of making the Difference Between Prosthesis was to achieve a combination of physical properties of living tissue with minimal toxic response to the surrounding structures (Hench and Thompson, 2010). These prosthesis had the limitation of stress shielding and bone resorption. Professor Bill Bonfeild explore the concept of Bioactive materials and design bio composite that matches more to the mechanical properties of living tissues and removed the limitation i.e., resorption of the underlying bone structure (Hench and Thompson, 2010). The Bio active mechanism is the procedure through which living tissues are attached and integrated to an artificial implant with a chemical bond (Tilocca, 2009).
There are many applications of bioactive materials in tissue engineering (Tilocca, 2009). Tissue engineering is the art and science of biological substitution through which tissue function is restored. This is achieved with the formation of biological scaffold provide structural support to the tissue which later filled with number of cells and implantations (Chen et al., 2012). The requirements of scaffold materials to fulfill the demand of tissue engineering, are biocompatibility, the material doses not respond on unresolved inflammatory reaction, mechanical properties must be sufficient to prevent surface failure, controllable interconnected porosity which can help to grow cells and support vascularization (Chen et al., 2012). About 90% porosity with 100micrometer is essential for cell growth and proper vascularization (Chen et al., 2012). Bone has natural combination of inorganic calcium phosphatase appetite and a biological polymer called Collagen in which associates are deposited (Chen et al., 2012; Buzea et al., 2015).
In tissue engineering 3-dimensional scaffold is formed which is fabricated with natural or artificial materials exhibit high porosity and pore interconnectivity (Hoppe et al., 2011; Maeno et al., 2005; Sachot et al., 2013). The function of scaffold is not only to provide structural support to the bony structure but also to enhance cell proliferation and differentiation of Osteoblastic cell (Hoppe et al., 2011; Aversa et al., 2016). Several Inorganic Bioactive materials could form a desired porous scaffold with suitable mechanical properties. According to the researched literature the ionic dissolution is the key procedure through which inorganic material behavior in forming scaffold and interact with living tissue can be understood in vitro and Vivo. Some inorganic elements such as Sr, Cu, Co, Zn was already present in the human body and play anabolic effect on bone metabolism (Hoppe et al., 2011). The introduction of therapeutic ions in the scaffold material to increase its bioactivity (Sachot et al., 2013). The release of ions after exposure of physiological environments is effected on the bioactivity of scaffold related to osteogenisis and angiogenesis (Hench and Wilson, 1993; Hoppe et al., 2011; Hutmacher, 2000; Okuda et al., 2007).
Role of Inorganic Ions in Bone Metabolism
Human bone has natural process of healing through the process of remodeling. Remodeling is the process of deposition and resorption of bone tissue by Osteoblastic and Osteoclastic cell activities. As remodeling occurs, Osteoblastic cells produced new bone cells and Osteoclastic bone cells destroyed or resorbed existing bone. This formation and resorption process called Remodeling. Failure in maintaining the balance of remodeling results in multiple problems like Osteoporosis and Arthritis (Habib et al., 2007).
The remodeling procedure is regulated by few growth factors, hormones and inorganic ions such as Calcium (Ca) (Heinemann et al., 2013; Julien et al., 2007; Liu, 2003; Saltman and Strause, 1993), Phosphorous(p) (Heinemann et al., 2013; Julien et al., 2007), Silicon (Si) (Liu, 2003), Strontium(Sr) (Liu, 2003), Zinc(Zn) (Liu, 2003; Saltman and Strause, 1993), Boron(B), Vanadium(V), Cobalt (Co), Magnesium(Mg) (Cepelak et al., 2013), Magneese (Mn, Copper(Cu) (Liu, 2003; Saltman and Strause, 1993). Inorganic ions dissolution plays a very important role in the process of bone healing (Mouriño et al., 2012; Mirsayar et al., 2016, 2017; Petrescu et al., 2015, 2016 a-e; Petrescu and Calautit, 2016 a-b; Aversa et al., 2016 a-o, 2017 a-e).