Síntese e caracterização de nanopartículas densas e esféricas de vidro bioativo contendo íons cobalto para potencial aplicação em engenharia de tecidos cardíacos

Abstract

Cardiovascular diseases are one of the leading causes of death and hospitalization in the world today, and due to the low natural regenerative capacity of the heart muscle, treatment options for severe cases of heart disease are quite limited. Therefore, tissue engineering has been investigated as an alternative treatment for such diseases. The current approach involves the incorporation of stem cells or cardiomyocytes into biocompatible three-dimensional scaffolds capable of stimulating cell development. However, the vascularization of artificial patches is a challenge. Bioactive glasses (BGs), which have been extensively used for bone regeneration, are now being investigated for applications in soft tissues. One of the reasons being their ability to stimulate vascularization, especially when ions with known angiogenic properties are incorporated into their structure, such as cobalt (Co) ions. In this work, VB nanoparticles were synthesized in the SiO2/CoO system in different nominal compositions by a modified Stöber method, and chemical analysis confirmed that cobalt was successfully incorporated into the system, with a maximum concentration of 11.1% mol. Spherical and dense nanoparticle morphology was confirmed, with particle size ranging from 63 ± 9 to 66 ± 7 nm by transmission electron microscopy. Co3O4 formation deposited as a second phase on the particles’ surface was observed and confirmed by X-Ray Diffraction, and X-Ray Photoelectron Spectroscopy (XPS) indicated that cobalt was also incorporated into the glass network as Co2+. Despite a rapid release profile of Co in phosphate-buffered saline (PBS), the obtained particles were not cytotoxic to human umbilical cord vein endothelial cells (HUVEC) at concentrations up to 500 µg.mL-1. Thus, the sol-gel methodology employed proved effective for the obtention of dense spherical BG nanoparticles containing cobalt as a network modifier, with potential applications in cardiac engineering.