The usability of ark clam shell (Anadara granosa) as calcium precursor to produce hydroxyapatite nanoparticle via wet chemical precipitate method in various sintering temperature
Recently, hydroxyapatite (HA) was widely used in the field of orthopedic and biomedical application (Rujitanapanich et al. 2014; Singh and Purohit 2011; D?dourková et al. 2012; Hoque et al. 2014). The structure of HA which is similar to the structure of bone become the main criteria in the creation and innovation of future synthetic bone. HA has been synthesis using various methods, and the most practical technique is known as wet chemical precipitation. HA with the molecular formula of Ca10(PO4)6(OH)2 is one of the essential mineral consist from the calcium phosphate salt group (Rajkumar et al. 2011). It is the most stable calcium phosphate salt among the other salt such as tricalcium phosphate (TCP) and tetracalcium phosphate (TTCP) at the range pH value in between 4 and 12 and at normal temperatures (Koutsopoulos 2002; Sadat-Shojai et al. 2013; Abidi and Murtaza 2014). The composition of HA will be formed when the stoichiometric of Ca/P ratio approximately in the range of 1.67 (Rujitanapanich et al. 2014; Abidi and Murtaza 2014). HA is usually found in the vertebrate group, especially in the hard tissue of bone and teeth enamel. The similarity properties of the chemical composition and the crystal structure of HA with the natural human bone give an alternative biomedical application uses in the human body such as bone implant for bone tissue substitution and drug delivery system (Santhosh and Prabu 2013). Besides, HA can be directly ingrowths in the host bone as artificial bones in human body and it was widespread used in orthopedic application due to its special abilities in bioactivity and biocompatibility (Zhang 2007).
HA is not only biocompatible, nontoxic, esteoconductive, non-inflammatory, but also bioactive (Fathi et al. 2008). The biocompatibility refer to the properties of material which is show biologically compatible with living system without gives any respond in local or systemic environment while bioactivity can be describe in any interaction or effect of material on living system. These properties are very important for synthetic bone which acts as bone grafting in successfully of osteoconductivity. This compound was commonly used as coating on metal implant to enhance their osteointegration (ability of biomaterial that can guide the reparative growth of natural bone) which promote the bone ingrowths between the host bone and artificial bone (Moore et al. 2001).
Sadat-Shojai et al. (2013) has been review the HA as a material used for the medical applications. From the evaluation, they state that HA can be synthesize using several methods such as wet method, dry method, high temperature process method, biogenic sources method and combination procedure method. Each method may produced different structure and morphology of HA due to its different starting “Methods”. According to their study, focusing on the wet method, it consist of several sub-group methods, which is known as conventional wet chemical precipitation, hydrolysis method, sol–gel method, hydrothermal method, emulsion method and sonochemical method. The wet chemical precipitate method was selected in this research due to promise the HA product in nano size with regular morphology. According to the statistic, the conventional wet chemical precipitation method is usually used in synthesize HA due to the economical advantages and versatile route (Angelescu et al. 2011). Moreover, it is also one of the easy ways to prepared HA powder under atmospheric condition (Wang et al. 2010). However, it needs extra attention to control the Ca:P ratio as well as the crystallinity (Mustafa 2005). The physical and chemical properties of HA produce in this method is depend on the techniques used and calcium precursor sources. Thus, the different technique and calcium source can affect the thermal stability of the as synthesized HA produce (Kamalanathan et al. 2014).
Recently, the uses of wastes material in order to synthesize HA was received encourage response from many researcher across the world. This idea gives an innovation to produce a new valuable product from the wastes material. Besides that, these wastes material also can be recycled, then change it into more valuable things and keep environment safely In previous report, HA was synthesize by using wastes material such as sea shell (Santhosh and Prabu 2013), eggshell (Dávila et al. 2007), animal bones (Sobczak et al. 2009), shell of garden snail (Singh 2012), and fruit waste extract (Wu et al. 2013). These materials consist of high source of calcium that can be act as calcium precursor which is suitable to produce HA. Therefore, this study has focused on the synthesis of HA by using the ark clam shell (ACS) as wastes material to be used in synthesis HA via wet chemical precipitate method. Some researcher found that the content of calcium carbonate (CaCO3) in ACS is approximately between 98 and 99 % (Kamba et al. 2013; Mohamed et al. 2012). ACS which is rich in calcium content was seen pursuant act as an initial material in synthesize HA. Mustafa et al. (2015), synthesize HA from ACS by sol–gel precipitate method give a positive result in getting high purity of HA. Furthermore, Rujitanapanich et al. was successfully to synthesize HA from abalone shell which is same group of clam shell via the same method at various pH value from 8 to 10 (Rujitanapanich et al. 2014). They found that, the crystallinity of the HA from abalone shell is good compare to the HA from commercial CaO. From that, they observed the crystallize size of HA was in nano size about 89.5 nm. The previous researcher prove that the HA nanocrystalline can be prepared from waste material at room temperature by simple wet precipitate. In Table 1, the summarizes of recent studies in synthesis HA from waste material with various method and properties.
Recent studies of synthesis HA powder from waste and various method in period of 2010–2015
In this research, HA powder was synthesized via wet chemical precipitate method using ACS with control pH value at 8. The purpose of this research is to investigate the effect of HA on physical, chemical properties, morphology and behaviour of biphasic HA/?-TCP at various sintering temperature.