RESEARCH PAPER Investigating the effects of particle size and chemical structure on cytotoxicity and bacteriostatic potential of nano hydroxyapatite/chitosan/silica and nano hydroxyapatite/ chitosan/silver; as antibacterial bone substitutes Shima Tavakol • Mohammad Reza Nikpour • Elham Hoveizi • Behnaz Tavakol • Seyed Mahdi Rezayat • Mahdi Adabi • Sahebeh Shajari Abokheili • Mohsen Jahanshahi Received: 13 May 2014 / Accepted: 21 August 2014 / Published online: 2 September 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract The restoration of defective bone tissue and complications related to surgery and fracture site infection are major concerns in orthopedic surgeries. However, it is crucial to develop osteoconductive and bacteriostatic composites. Chitosan/nano hydroxyap- atite (CT/n-HAp) powder containing of Ag and Si were prepared by an in situ hybridization method. The aim of this work was to elucidate the effect of size, surface roughness, and chemical structure of men- tioned nanocomposites on cytotoxicity and bacterio- static activity via human osteoblast cells and Escherichia Coli, respectively. Particle size, surface roughness, reactive oxygen specious production, and bioactivity of nanocomposites were investigated by X ray diffraction, atomic force microscopy, DPPH assay, and SEM/UV–Visible spectrophotometer, respec- tively. Bacterial colony counting test, MTT assay and lactate dehydrogenase (LDH) release were per- formed as bacteriostatic and biocompatibility tests. The results showed that CT/n-HAp/Ag with smaller particle size in the range of 1–22.6 nm (10.00 ± 0.09 nm) than CT/n-HAp/Si in the range S. Tavakol (&) Á S. M. Rezayat Á M. Adabi Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran e-mail: sh_tavakol@razi.tums.ac.ir S. Tavakol Student’s Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran S. Tavakol School of Medicine, Razi Institute for Drug Research, Iran University of Medical Sciences, Tehran, Iran M. R. Nikpour (&) Á M. Jahanshahi (&) Nanobiotechnology Research Group, Nanobiotechnology Research Department, Nanotechnology Research Institute, Babol University of Technology, P.O.BOX: 484- 47144, Babol, Iran e-mail: rezanikpour16@yahoo.com M. Jahanshahi e-mail: mjahan@nit.ac.ir E. Hoveizi Department of Biology, Faculty of Sciences, Shahid Chamran University, Ahvaz, Iran B. Tavakol Department of Medicine, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran S. Shajari Abokheili Faculty of Chemical Engineering–Polymer Branch, Azad University of Shiraz, Shiraz, Iran 123 J Nanopart Res (2014) 16:2622 DOI 10.1007/s11051-014-2622-9 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by eprints Iran University of Medical Sciences