Physicochemical properties of 3D bovine natural scaffolds as a function of the anterior-posterior, lateral and superior-inferior directions

Abstract

Bovine trabecular bone (BTB) is a hydroxyapatite (HAp) source for bone regeneration due to its high metabolic activity inside the human body. In this work, the physicochemical properties of BTB raw, defatted-deproteinized, and incinerate (580 °C) cubic pieces (1 × 1 × 1 cm) were analyzed as a function of the anatomical directions. In these natural scaffolds, Inductively Coupled Plasma (ICP) showed the presence of Na, Mg, Zn, and K as minority ions. Scanning Electron Microscopy (SEM) shows that BTB is anisotropic, and X-ray patterns showed hydroxyapatite nanocrystals with preferred orientation in the superior-inferior axis. Micro–Computed Tomography allowed 3D reconstruction of a BTB cube and calculate the areal bone mineral density (aBMD) in Pixel/cm2, which is around 70%. aBMD exhibits an inversely proportional behavior to the porosity of the samples. BTB cubes present higher Young's modulus for the Z-direction than the X- and Y-direction, regardless of their pretreatment. This finding confirms that the mechanical properties of the scaffolds are governed by the crystalline structure, morphology, and spatial distribution of the hydroxyapatite nanocrystals. Infrared analysis showed the presence of carbonate.