Preparo e caracterização de scaffolds de hidroxiapatita/vidro bioativo/colágeno para utilização em engenharia de tecidos

Abstract

Bioactive glasses (BGs) and hydroxyapatite (HAp) are biomaterials widely used in tissue engineering due to their good biocompatibility. However, these materials can undergo shape loss and migration under load, which is why they are commonly immobilized in polymeric matrices. In this work, bioactive glass and hydroxyapatite particles were initially mixed after dispersing them in ethanol. The mixtures in 3 different HA/VB mass ratios (75/25, 85/15 and 95/05) prepared were then heat treated in air at temperatures ranging between 600 °C and 800 °C. The structural changes induced by these treatments have been investigated because it is well established that the reaction between HAp and BG can occur at these temperatures, leading to compounds with different properties. We observed that BG has an average particle size and surface area of about 122 m and 44 m2.g-1, while 12 m and 6 m2.g-1 were evaluated for HAp. DSC tests revealed that BG has Tg, Tx, and Tc of about 720 °C, 790 °C, and 860 °C, respectively. A HAp/BG mass ratio of 75/25 and a heat treatment temperature of 800 °C were maintained due to the high biocompatibility and specific surface area of the bioactive glass. After preparing the composite scaffolds, they were sterilized with EO. No residues derived from the sterilization process were observed in the prepared samples, which deserves to be highlighted. MEV and micro-CT images revealed the uniform distribution of HAp, BG, and Col in the composite scaffolds, revealing that the mixing, freezing, and freeze-drying steps were successfully performed. It was revealed in immersion in SBF, a remarkable formation of HAp, which points to their good biocompatibility and potential application in tissue engineering.