title: Bioinspired synthesis of hydroxyapatite nanocrystals in the presence of collagen and l-arginine: Candidates for bone regeneration.
abstract: This work aims at the bioinspired synthesis of hydroxyapatite (HAp) crystals in the presence of both collagen and l-arginine, in an effort to obtain a homogeneous hybrid material, having a bone-like nanostructure. Collagen (Col) is the most commonly utilized protein in most species of life, while L-arginine (Arg) encourages cell attachment, proliferation, and differentiation on HAp surfaces. Transmission electron microscopy, X-ray diffraction and Fourier transform-infrared spectroscopy were used to analyze surface morphology and structure of nanocrystals obtained under different synthesis conditions. It was shown that collagen and arginine content affect HAp crystallization. Collagen has an inhibition effect since HAp crystal size is reduced with the increase of collagen content. The presence of arginine is crucial as a critical content exists (Ca(2+):Arg = 1:1) under which HAp nanocrystals coexist with brushite. Under the optimum synthesis conditions (HAp/Col weight ratio 70/30 and Ca(2+):Arg molar ratio 1:1) HAp nanoplates of a uniform size (around 10 × 10 nm) were obtained. The biocompatibility of this hybrid powder was assessed using human bone marrow derived mesenchymal stem cells (MSCs). Cell response in terms of MSC attachment (scanning electron microscopy) and viability/proliferation (Alamar Blue) demonstrated a noncytotoxic effect of the new material.
authors.affiliation: Section of Metallurgy and Materials Technology, School of Mining Engineering and Metallurgy, National Technical University of Athens, 15780, Athens, Greece.
authors.forename: Despoina
authors.initials: D
authors.lastname: Brasinika
authors.affiliation: Department of Mechanical and Aeronautical Engineering, Laboratory of Biomechanics and Biomedical Engineering, University of Patras, 26504, Rio, Greece.
authors.forename: Olga
authors.initials: O
authors.lastname: Tsigkou
authors.affiliation: Section of Metallurgy and Materials Technology, School of Mining Engineering and Metallurgy, National Technical University of Athens, 15780, Athens, Greece.
authors.forename: Athena
authors.initials: A
authors.lastname: Tsetsekou
authors.affiliation: Department of Mechanical and Aeronautical Engineering, Laboratory of Biomechanics and Biomedical Engineering, University of Patras, 26504, Rio, Greece.
authors.forename: Yiannis F
authors.initials: YF
authors.lastname: Missirlis
mesh_terms: D001120:Arginine / Q000737:chemistry / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D003094:Collagen / Q000737:chemistry / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D003094:Collagen; D017886:Durapatite; D001120:Arginine
keywords: arginine; bioinspired approach; collagen; cytotoxicity evaluation; hydroxyapatite nanocrystals