title: Bioactive composite gradient coatings of nano-hydroxyapatite/polyamide66 fabricated on polyamide66 substrates.
abstract: Tightly bonding of bioactive coating is the first crucial need for orthopaedic implants. This study describes a novel and convenient technique to prepare bioactive coating with high adhesion on orthopaedic substitutes made of polymeric matrix. Here, a chemical corrosion method has been adopted to fabricate a coating on the surface of injection-moulded polyamide66 (PA66) substrates by corrosive nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite slurry. Scanning electron microscopy observation shows that a porous chemical corrosion region presents between the coating and dense PA66 substrate. Energy-dispersive X-ray spectroscopy analysis indicates that the chemical corrosion region is mainly composed of PA66 matrix, and the coating layer is an n-HA-rich layer. Both the pore size and n-HA composition increase gradually from the polymeric substrate towards the coating surface. Mechanical testing shows the bonding strength can reach 13.7 ± 0.2 MPa, which is much higher than that fabricated on polymeric matrix by other coating methods. The gradual transition in coating structure and composition benefits for the interface bonding and for the surface bone-bonding bioactivity. Subsequent cell experiments corroborate n-HA-rich coating and a porous structure is benefitting for cell attachment and proliferation. The convenient coating method could be popularized and applied on similar polymer implants to produce a tightly and porous bioactive coating for bone tissue regeneration.
authors.affiliation: Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064, People's Republic of China.
authors.forename: Di
authors.initials: D
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zuo
authors.forename: Jidong
authors.initials: J
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Zou
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Mei
authors.initials: M
authors.lastname: Gong
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Limei
authors.initials: L
authors.lastname: Li
authors.forename: Yubao
authors.initials: Y
authors.lastname: Li
mesh_terms: D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry*; D016062:Porosity; D019736:Prostheses and Implants
chemical_list: D020099:Coated Materials, Biocompatible; D009757:Nylons; D017886:Durapatite