RESUMO
In this study, the interplay between the structural complexity, microstructure, and mechanical properties of calcium phosphates (CaPs) derived from fish bones, prepared at various calcination temperatures, and their corresponding sintered ceramics was explored. Fourier-transform infrared analysis revealed that the calcined powders primarily consisted of hydroxyapatite (HAp) and carbonated calcium hydroxyapatite, with an increasing concentration of Mg-substituted ß-tricalcium phosphate (ß-TCP) as the calcination temperature was increased. X-ray diffraction patterns showed enhanced sharpness of the peaks at higher temperatures, indicating a larger crystallite size and improved crystallinity. The ceramics exhibited a significantly larger crystallite size and an increased concentration of the ß-TCP phase. Rietveld analysis revealed a larger volume of the ß-TCP phase in the ceramics than in their calcined powders; this could be attributed to a newly formed ß-TCP phase due to the decomposition of HAp. Extended X-ray absorption fine structure analysis revealed the incorporation of Mg in the Ca2 site of HAp, Ca2 site of ß-TCP, and Ca5 site of ß-TCP, with a higher substitution of Mg in the Ca5 site of ß-TCP at elevated temperatures. The mechanical properties of HAp ceramics can be improved by increasing the calcination temperature because of their improved relative density and dense porous structure at elevated temperatures. This comprehensive investigation sheds light on the phase evolution, microstructural changes, and consequential impact on the mechanical properties of CaPs derived from fish bones, thereby facilitating the development of tailored CaP ceramics for biomedical applications.
RESUMO
The aim of this study is to synthesize Titania nanotubes (TNTs) on the 3D-printed Ti-6Al-4V surface and investigate the loading of antibacterial vancomycin drug dose of 200 ppm for local drug treatment application for 24 h. The antibacterial drug release from synthesized nanotubes evaluated via the chemical surface measurement and the linear fitting of Korsmeyer-Peppas model was also assessed. The TNTs were synthesized on the Ti-6Al-4V surface through the anodization process at different anodization time. The TNTs morphology was characterized using field emission scanning electron microscope (FESEM). The wettability and the chemical composition of the Ti-6Al-4V surface and the TNTs were assessed using the contact angle meter, Fourier transform infrared spectrophotometer (FTIR) and the X-ray photoelectron spectroscopy (XPS). The vancomycin of 200 ppm release behavior under controlled atmosphere was measured by the high-performance liquid chromatography (HPLC) and hence, the position for retention time at 2.5 min was ascertained. The FESEM analysis confirmed the formation of nanostructured TNTs with vertically oriented, closely packed, smooth and unperforated walls. The maximum cumulative vancomycin release of 34.7% (69.5 ppm) was recorded at 24 h. The wetting angle of both Ti-6Al-4V implant and the TNTs were found below 90 degrees. This confirmed their excellent wettability.
