title: In vitro assessment of cellular responses to rod-shaped hydroxyapatite nanoparticles of varying lengths and surface areas.
abstract: Rod-shaped hydroxyapatite nanoparticles of varying dimensions (≈ 60 ± 10, 120 ± 15, 240 ± 30 nm in length, labeled respectively as nHA60, nHA120 and nHA240) with specific surface areas (47.02, 23.33, 46.12 nm(2), respectively), were synthesized and their effects on cell viability, reactive oxygen species generation and cellular interaction with BEAS-2B, RAW264.7 and HepG2 were investigated. In vitro exposure of these cell lines to rod shape nHA particles within a range of 10-300 μg/ml for 24 h did not significantly alter cell viability studied by the WST-8 assay. A significant increase in reactive oxygen species (ROS) generation was however observed with the dihydrofluorescein diacetate (DFDA) assay after 4 h incubation with these nanoparticles. The lowest level of ROS generation was observed with nHA120 (with the smallest specific surface area); whereas nHA60 and nHA240 exhibited comparable ROS generation. Subsequently, the Alizarin Red-S (ARS) assay indicated a weaker association of calcium with cells compared to nHA60 and nHA240. The results thus suggest that high surface area may increase cell-particle interaction, which in turn influenced ROS generation. The combined results from all the cell lines thus indicated high biocompatibility of rod-shaped nHA.
authors: School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors: Xinxin
authors: X
authors: Zhao
authors: Boon Chin
authors: BC
authors: Heng
authors: Sijing
authors: S
authors: Xiong
authors: Jun
authors: J
authors: Guo
authors: Timothy Thatt-Yang
authors: TT
authors: Tan
authors: Freddy Yin Chiang
authors: FY
authors: Boey
authors: Kee Woei
authors: KW
authors: Ng
authors: Joachim Say Chye
authors: JS
authors: Loo