Desenvolvimento e caracterização de scaffolds magnéticos à base de quitosana-hidroxiapatita com inclusão de manganita de lantânio dopada com estrôncio para uso na engenharia tecidual óssea

Abstract

Bone tissue engineering aims to regenerate damaged tissues, and the use of threedimensional structures such as scaffolds is an important advent in this field. These, in turn, must have a porous structure, to allow the adhesion and proliferation of bone cells. In general, the scaffold matrix consists of a biodegradable polymer combined with a ceramic material for producing composites. More recently, there has been much interest in producing smarter and more effective scaffolds. Hence, the addition of magnetic particles into scaffolds has gained significant interest in biomedical applications, since it increases osteogenic differentiation, angiogenesis and bone regeneration. In this work strontium-doped or not lanthanum manganite chitosan-hydroxyapatite scaffolds were produced and characterized (Qui/HA/Manganite). The powders of lanthanum manganite (LaMnO3, La0,8Sr0,2MnO3, La0,4Sr0,6MnO3), and strontium SrMnO3, hydroxyapatite and scaffolds Qui/HA/Manganite with different compositions, were characterized using Fourier Transform Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). In addition, the scaffolds were also characterized in terms of porosity, compressive strength, magnetic properties and thermal stability, the last using Thermogravimetric Analysis (TGA) technique. The XRD analysis showed that the sample contained a single-phase HA with a hexagonal structure, the lanthanum manganite sample exhibited a rhombohedral perovskite structure and the strontium manganite presented a single-phase hexagonal structure. Micrograph analysis showed the presence of open pores and their size ranged from 50 to 310 µm, which favors bone cells penetration. The manganites (La0,4Sr0,6MnO3 and La0,8Sr0,2MnO3) presented magnetization in both forms (powder and scaffold). The highest compressive strength was observed for Qui/HA/La0,8Sr0,2MnO3 scaffold (4.34 MPa). There was a higher mass loss for Qui/HA/La0,4Sr0,6MnO3 scaffold (49%), mainly associated with chitosan (TGA analysis). Finally, magnetic strontium-doped lanthanum manganite chitosanhydroxyapatite scaffolds may be promising for bone loss therapy.