Bone

Autor: Rossi, Andre L., Barreto, Isabela Cerqueira, Maciel, William Q., Rosa, Fabiana Paim, Leão, Maria H. Rocha, Werckmann, Jacques, Rossi, Alexandre Malta, Borojevic, Radovan, Farina, Marcos
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Repositório Institucional da UFBA
Universidade Federal da Bahia (UFBA)
instacron:UFBA
DOI: 10.1016/j.bone.2011.10.022
Popis: Texto completo: acesso restrito. p. 301–310 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-08-27T15:11:22Z No. of bitstreams: 1 Andre L. Rossi.pdf: 2285072 bytes, checksum: f0610b4fbca7b37b207d359d1dab3c95 (MD5) Approved for entry into archive by Patricia Barroso (pbarroso@ufba.br) on 2014-08-28T21:31:27Z (GMT) No. of bitstreams: 1 Andre L. Rossi.pdf: 2285072 bytes, checksum: f0610b4fbca7b37b207d359d1dab3c95 (MD5) Made available in DSpace on 2014-08-28T21:31:27Z (GMT). No. of bitstreams: 1 Andre L. Rossi.pdf: 2285072 bytes, checksum: f0610b4fbca7b37b207d359d1dab3c95 (MD5) Previous issue date: 2012 We report the ultrastructure of regenerated bone surrounding two types of biomaterials: hydroxyapatite–alginate composite and sintered hydroxyapatite. Critical defects in the calvaria of Wistar rats were filled with micrometer-sized spherical biomaterials and analyzed after 90 and 120 days of implantation by high-resolution transmission electron microscopy and Fourier transform infrared attenuated total reflectance microscopy, respectively. Infrared spectroscopy showed that hydroxyapatite of both biomaterials became more disordered after implantation in the rat calvaria, indicating that the biological environment induced modifications in biomaterials structure. We observed that the regenerated bone surrounding both biomaterials had a lamellar structure with type I collagen fibers alternating in adjacent lamella with angles of approximately 90°. In each lamella, plate-like apatite crystals were aligned in the c-axis direction, although a rotation around the c-axis could be present. Bone plate-like crystal dimensions were similar in regenerated bone around biomaterials and pre-existing bone in the rat calvaria. No epitaxial growth was observed around any of the biomaterials. A distinct mineralized layer was observed between new bone and hydroxyapatite–alginate biomaterial. This region presented a particular ultrastructure with crystallites smaller than those of the bulk of the biomaterial, and was possibly formed during the synthesis of alginate-containing composite or in the biological environment after implantation. Round nanoparticles were observed in regions of newly formed bone. The findings of this work contribute to a better understanding of the role of hydroxyapatite based biomaterials in bone regeneration processes at the nanoscale.
Databáze: OpenAIRE