Cell responses to two kinds of nanohydroxyapatite with different sizes and crystallinities

Abstract

Introduction:Hydroxyapatite (HA) is the principal inorganic constituent of human bone. Due to its good biocompatibility and osteoconductivity, all kinds of HA particles were prepared by different methods. Numerous reports demonstrated that the properties of HA affected its biological effects. Methods: Two kinds of nanohydroxyapatite with different sizes and crystallinities were obtained via a hydrothermal treatment method under different temperatures. It was found that at a temperature of 140°C, a rod-like crystal (n-HA1) with a diameter of 23 ± 5 nm, a length of 47 ± 14 nm, and crystallinity of 85% ± 5% was produced, while at a temperature of 80°C, a rod-like crystal (n-HA2) with a diameter of 16 ± 3 nm, a length of 40 ± 10 nm, and crystallinity of 65% ± 3% was produced. The influence of nanohydroxyapatite size and crystallinity on osteoblast viability was studied by MTT, scanning electron microscopy, and flow cytometry. Results: n-HA1 gave a better biological response than n-HA2 in promoting cell growth and inhibiting cell apoptosis, and also exhibited much more active cell morphology. Alkaline phosphatase activity for both n-HA2 and n-HA1 was obviously higher than for the control, and no significant difference was found between n-HA1 and n-HA2. The same trend was observed on Western blotting for expression of type I collagen and osteopontin. In addition, it was found by transmission electron microscopy that large quantities of n-HA2 entered into the cell and damaged the cellular morphology. Release of tumor necrosis factor alpha from n-HA2 was markedly higher than from n-HA1, indicating that n-HA2 might trigger a severe inflammatory response. Conclusion: This work indicates that not all nanohydroxyapatite should be considered a good biomaterial in future clinical applications.

Nanohydroxyapatite shape and its potential role in bone formation: an analytical study

“…The idea that different NP shapes may differentially influence cell behaviour has been measured using apoptosis and proliferation assays [15], as well as protein expression analysis [16] and stains for NP uptake in a macrophage cell line [16 -19]. An experiment testing two differently sized rod-shaped HA NPs on an osteoblast-like (osteosarcoma) cell line found that although the smaller particles caused a significant amount of cells to apoptose, there was no difference in alkaline phosphatase activity [20]. Another study found that rod-shaped particles caused primary osteoblasts to decrease their proliferation after 3 days of culture compared with spherical-shaped.…”

Calcium orthophosphate bioceramics

“…Again, similar cell morphologies and good cell viability were observed; however, it was concluded that high surface area could increase cell-particle interaction [739]. Nevertheless, another study with cellular response to rod-shaped HA bioceramics, revealed that some types of crystals might trigger a severe inflammatory response [742]. In addition, CaPO 4 -based sealers appeared to…”

Modified porous scaffolds of silk fibroin with mimicked microenvironment based on decellularized pulp/fibronectin for designed performance biomaterials in maxillofacial bone defect

“…MG‐63 osteoblasts were seeded in each scaffold with 1 × 10 6 cells and maintained in an alpha‐MEM medium (α‐MEM: Gibco ® , Invitrogen™, Carlsbad, CA) with the addition of 1% penicillin/streptomycin, 0.1% Fungizone, and 10% fetal bovine serum at 37°C in a humidified 5% CO 2 /95% air incubator. The medium was changed every 3–4 days . An osteogenic medium (OS: 20 m M b ‐glycerophosphate, 50 µ M ascorbic acid, and 100 n M dexamethasone; Sigma‐Aldrich) was used for osteoblast differentiation of the MG‐63 osteoblast cells …”