Synthesis and Cellular Biocompatibility of Two Nanophase Hydroxyapatite with Different Ca/P Ratio

Abstract

The cellular biocompatibility of two types of nanophase hydroxyapatites including nanophase standard hydroxyapatite (n-HA) and nanophase calcium deficient hydroxyapatite (n-CDHA) synthesized by a wet chemical method were assessed using primary cultured osteoblasts. Cytotoxicity of both materials was investigated with L929 cell line. The MTT method was used to evaluate the proliferation of osteoblasts on the third day and ALP activity assay was carried out on the fifth day. SEM was used to observe the morphology of the osteoblasts on the third day. Two types of nanophase hydroxyapatite both showed no cytotoxicity. Higher cell proliferation was observed on n-CDHA than n-HA. At the same time, cells spread more actively on the n-CDHA group. The ALP level of n-CDHA was also significantly higher on the former. Our results show that the n-CDHA is more suitable for osteoblasts growth and is also helpful for ALP synthesis.

Enhancing mechanical and biological properties of biphasic calcium phosphate ceramics by adding calcium oxide

“…Generally, the enhancement of mechanical property suppresses the bioactivity of BCP ceramics, so it is urgent to seek a balance between the enhancement of mechanical characteristics and the improvement of biological properties in BCP ceramics. Previous studies have proved that CDHA shows excellent bioactivity due to its bone‐like mineral 16‐18 . Our previous works further demonstrated that the addition of calcium alginate could stabilize CDHA in BCP ceramics and enhance their biological properties, 20,21 but the mechanical property of the obtained BCP ceramics was unsatisfied.…”

“…Previous studies have proved that CDHA shows excellent bioactivity due to its bone-like mineral. [16][17][18] Our previous works further demonstrated that the addition of calcium alginate could stabilize CDHA in BCP ceramics and enhance their biological properties, 20,21 but the mechanical property of the obtained BCP ceramics was unsatisfied. In this study, in order to simultaneously improve the mechanical property and bioactivity of BCP ceramics, we introduced an effective approach by adding CaO, and the effects of CaO on the sintering behaviors and biological performances of BCP ceramics were systemically investigated.…”

“…It is well known that bone mineral contains calcium‐deficient hydroxyapatite (CDHA) in the form of nanocrystalline, 14,15 and CDHA have be certified to own superior bioactivity in previous studies 16‐18 . For instance, Zhao et al compared two nanophase hydroxyapatite (HA) with different Ca/P ratio, finding that n‐CDHA was more suitable for osteoblast growth and ALP synthesis than n‐HA 18 . In fact, the initial BCP precursor is composed of CDHA phase, but CDHA will decompose into HA phase and β‐TCP phase in the sintering process of BCP ceramics, so it is generally difficult to find CDHA phase in BCP ceramics after sintering 19,20 .…”

“…[16][17][18] For instance, Zhao et al compared two nanophase hydroxyapatite (HA) with different Ca/P ratio, finding that n-CDHA was more suitable for osteoblast growth and ALP synthesis than n-HA. 18 In fact, the initial BCP precursor is composed of CDHA phase, but CDHA will decompose into HA phase and β-TCP phase in the sintering process of BCP ceramics, so it is generally difficult to find CDHA phase in BCP ceramics after sintering. 19,20 In 2018, our group suggested that the decomposition products (ie CaO) of calcium alginate might react with ceramic precursor to stabilize the CDHA phase during the sintering process.…”

Application of inorganic nanomaterials in bone tissue engineering and regenerative medicine

“…Ca/P比, 并且可以加速成骨细胞MC3T3-E1的初始黏 附, 增殖和分化 [14] . 通过研究成骨细胞对普通nHA 和钙缺陷nHA两种材料的生物效应, 发现其对成骨 细胞的活性和ALP的产生均有促进作用, 钙缺陷nHA 的成骨分化能力要显著高于普通nHA [15] . 单一nHA 支架的粒径对骨细胞的生物学功能也起到重要的调 控作用.…”