title: PHYSICOCHEMICAL CHARACTERIZATION OF LYOPHILIZED BOVINE BONE GRAFTS.
abstract: To evaluate the physicochemical characteristics of lyophilized bovine grafts manufactured on a semi-industrial scale (Orthogen; Baumer S/A*) in accordance with a protocol previously developed by the authors.
  
  
  METHODS
  The lyophilized bovine bone grafts were characterized by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD), thermogravimetric (TG) analysis, differential exploratory scanning calorimetry (DSC) and Fourier-transform infrared (FT-IR) spectroscopy.
  
  
  RESULTS
  Ca was the main component (60%) found in the samples, followed by P (28%) and O (5%). The mean (sd) pore size was 316 μm (146.7), ranging from 91.2 to 497.8 μm, and 333.5 μm (304.8), ranging from 87.2 to 963.9 μm, at 50x and 150x magnification, respectively. The hydroxyapatite peaks were at 26°C and 32°C, and mass losses were observed between 250°C and 640°C, corresponding to organic material and water. Two temperature transitions (45.67°C and 91.89°C) showed denaturation of type 1 collagen and dehydration of hydroxyapatite.
  
  
  CONCLUSIONS
  The physicochemical assessment of lyophilized bovine bone grafts in accordance with the protocol developed at semi-industrial scale confirmed that this product presents excellent biocompatibility, with characteristics similar to natural bone.
authors.affiliation: Contracted Physician in the Hip Group and Technical Coordinator of the Tissue Bank, HCPA, Porto Alegre, RS; MSc in Surgery from UFRGS, Porto Alegre, RS, Brazil.
authors.forename: Carlos Roberto
authors.initials: CR
authors.lastname: Galia
authors.affiliation: Orthopedist and Traumatologist. Resident of Hand Surgery, Hospital das Clínicas de Curitiba, UFPR, Curitiba, PR, Brazil.
authors.forename: André Luis
authors.initials: AL
authors.lastname: Lourenço
authors.affiliation: Physician in the Hip Group and Tissue Bank, HCPA, Porto Alegre, RS, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Rosito
authors.affiliation: Adjunct Professor in the Department of Surgery, School of Medicine, UFRGS, and Orthopedics and Traumatology Service, HCPA; Head of the Orthopedics and Traumatology Service, HCPA, and Head of the Hip Group, HCPA, Porto Alegre, RS, Brazil.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Souza Macedo
authors.affiliation: Invited Researcher, Tissue Bank, HCPA, Porto Alegre, RS, Brazil.
authors.forename: Lourdes Maria Araujo Quaresma
authors.initials: LM
authors.lastname: Camargo
keywords: Biocompatible Materials; Bone Transplantation; General Surgery