Synthesis and Characterization of Nano-Hydroxyapatite Obtained from Eggshell via the Hydrothermal Process and the Precipitation Method

Abstract

Hydroxyapatite (HA) is a major component of the inorganic minerals in the hard tissues of humans and has been widely used as a biomedical ceramic material in orthopedic and dentistry applications. Because human bone contains several impurities, including carbonates, chlorides, fluorides, magnesium, and strontium, human bone minerals differ from stoichiometric HA. Additionally, natural bone is composed of nano-sized HA, and the nanoscale particles exhibit a high level of biological activity. In this paper, HA is prepared via the hydrothermal process because its reaction conditions are easy to control and it has been shown to be quite feasible for large-scale production. Therefore, the hydrothermal process is an effective and convenient method for the preparation of HA. Furthermore, eggshell is adopted as a source of calcium, and mulberry leaf extract is selectively added to synthesize HA. The eggshell accounts for 11% of the total weight of a whole egg, and it consists of calcium carbonate, calcium phosphate, magnesium carbonate, and organic matter. Eggshell contains a variety of trace elements, such as magnesium and strontium, making the composition of the synthesized HA similar to that of the human skeleton. These trace elements exert considerable benefits for bone growth. Moreover, the use of eggshell as a raw material can permit the recycling of biowaste and a reduction in process costs. The purpose of this study is to prepare HA powder via the hydrothermal method and to explore the effects of hydrothermal conditions on the structure and properties of the synthesized HA. The room-temperature precipitation method is used for the control group. Furthermore, the results of an immersion test in simulated body fluid confirm that the as-prepared HA exhibits good apatite-forming bioactivity, which is an essential requirement for artificial materials to bond to living bones in the living body and promote bone regeneration. In particular, it is confirmed that the HA synthesized with the addition of the mulberry leaf extract exhibits good in vitro biocompatibility. The morphology, crystallite size, and composition of the carbonated nano-HA obtained herein are similar to those of natural bones. The carbonated nano-HA appears to be an excellent material for bioresorbable bone substitutes or drug delivery. Therefore, the nano-HA powder prepared in this study has great potential in biomedical applications.

Hydroxyapatite as a Material for Transplantology: Clinical Experience and Prospects of Application

“…Table 2 summarizes the results of recent studies. These data, in addition to the high feasibility of using this raw material, give an idea of the high degree of biomimetic potential of the obtained hydroxyapatite in comparison with the mineral phase of human bone [165]. This is supported by the data that testify in favor of similarity of leading morphological and microarchitectural parameters of treated hydroxyapatite, including agglomeration of hydroxyapatite particles as a result of high-temperature treatment [183].…”

“…Special attention should be paid to the methods of hydroxyapatite production from biogenic sources, the main examples of which are presented in Table 2. The most popular raw material for this method of hydroxyapatite production is the use of various biological wastes: bovine bone mass [163,164], eggshells [165,166], marine organisms [167][168][169][170] and plant materials. The latter can be used to extract hydroxyapatite per se [171] as a solvent [172,173] or as a source of calcium [174] and as a source of phosphate [175,176].…”

“…The cells had distinct filopodia. [165] The main requirement for this type of feedstock is the removal of organic matter, which can be achieved by temperature treatment per se [165] and by using subcritical water [179,180]. The use of alkaline thermal hydrolysis [180] and enzymatic treatment methods [181] and so on are also commonly practiced.…”

Synthesis and Characterization of Hydroxyapatite/Titania Composite and its Application on Photocatalytic Degradation of Remazol Red B Textile Dye under UV Irradiation

“…Considering the wide application of hydroxyapatite, production and searching for raw materials from natural sources should be done continuously. The natural materials that can be used for HA synthesis are those that are rich in calcium, either from biological sources such as mammal bones, fish bones, egg shells, coral, and shellfish or from inorganic materials, such as limestone (Wu et al, 2023;Kumar et al, 2020;Arif et. al., 2020).…”

Characterization of nano-hydroxyapatite synthesized from eggshells for absorption of heavy metals

“…Eggshells that are thrown away may be converted into hydroxyapatite, as demonstrated by several research works that employ the synthesis methods mentioned above. The impact of hydrothermal conditions on both the structure and properties of the produced hydroxyapatite (HA) was explored by Wu et al [32]. The findings indicate that the crystallinity of hydroxyapatite (HA) was improved by the hydrothermal reaction.…”