title: Friction stir processing of magnesium-nanohydroxyapatite composites with controlled in vitro degradation behavior.
abstract: Nano-hydroxyapatite (nHA) reinforced magnesium composite (Mg-nHA) was fabricated by friction stir processing (FSP). The effect of smaller grain size and the presence of nHA particles on controlling the degradation of magnesium were investigated. Grain refinement from 1500μm to ≈3.5μm was observed after FSP. In vitro bioactivity studies by immersing the samples in supersaturated simulated body fluid (SBF 5×) indicate that the increased hydrophilicity and pronounced biomineralization are due to grain refinement and the presence of nHA in the composite respectively. Electrochemical test to assess the corrosion behavior also clearly showed the improved corrosion resistance due to grain refinement and enhanced biomineralization. Using MTT colorimetric assay, cytotoxicity study of the samples with rat skeletal muscle (L6) cells indicate marginal increase in cell viability of the FSP-Mg-nHA sample. The composite also showed good cell adhesion.
authors.affiliation: Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: B
authors.initials: B
authors.lastname: Ratna Sunil
authors.affiliation: Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India. Electronic address: tssk@iitm.ac.in.
authors.forename: T S
authors.initials: TS
authors.lastname: Sampath Kumar
authors.affiliation: Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Uday
authors.initials: U
authors.lastname: Chakkingal
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: V
authors.initials: V
authors.lastname: Nandakumar
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Doble
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001826:Body Fluids / Q000737:chemistry / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D003343:Corrosion; D017886:Durapatite / Q000737:chemistry*; D004563:Electrochemistry; D017276:Friction; D057927:Hydrophobic and Hydrophilic Interactions; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects; D051381:Rats; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite; D008274:Magnesium
keywords: Biodegradation; Friction stir processing; Magnesium; Metal matrix composites; Nano-hydroxyapatite