Dy2O3-unpurified hydroxyapatite: a promising thermoluminescent sensor and biomimetic nanotherapeutic

• Published in: Applied physics. A, Materials science & processing Vol. 127; no. 12
• Main Authors: Ortiz, S. López, Lugo, V. Rodríguez, Salado-Leza, D., Reyes-Valderrama, M. I., Alcántara-Quintana, L. E., González-Martínez, P., Anaya, D. Mendoza
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2021; Springer Nature B.V
• Subjects: Ammonium phosphates; Applied physics; Aspect ratio; Biomimetics; Characterization and Evaluation of Materials; Condensed Matter Physics; Dysprosium; Epithelium; Fluorescence; Fourier transforms; Gamma rays; Hydroxyapatite; In vitro methods and tests; Ionizing radiation; Machines; Manufacturing; Materials science; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Radiation; Radiation dosage; Slaked lime; Surfaces and Interfaces; Thermoluminescence; Thin Films; Toxicity; Transmission electron microscopy; X-ray diffraction; Monoclinic phase; Cytotoxicity; Hydrothermal synthesis; Nanohydroxyapatite; Prostate cells; Thermoluminescence
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-021-05010-w

In the present work, nanostructured hydroxyapatite (nano-Hap) was synthesized by following a hydrothermal process using calcium hydroxide and ammonium phosphate. The nano-Hap was unpurified with different amounts of dysprosium oxide (Dy
2
O
3
), from 0.5 to 2.0 wt%. Its physicochemical properties were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). TEM confirmed the formation of rod structures (L/D aspect ratio > 1) with average sizes ranging from ~ 15 to 19 nm in diameter, and ~ 26 to 32 nm in length. The presence of the monoclinic and hexagonal crystalline phases of Hap was confirmed by XRD. The thermoluminescence (TL) studies showed a linear relationship between the Dy
2
O
3
concentration and TL intensity induced by gamma radiation in a dose range from 10 to 200 Gy. The nano-Hap unpurified with 2.0 wt% of Dy
2
O
3
showed the highest TL response. Additionally, in the perspective of exploring the therapeutic potential of Dy
2
O
3
-unpurified Hap, the viability of human prostatic epithelial cells was evaluated. The safety of pure Hap was confirmed by performing resazurin/resorufin fluorescence-based assays. A significant toxicity was observed as a function of the impurity content and nanopowders concentration. In summary, the nano-Hap TL results make it a good candidate for ionizing radiation sensoring and, the in vitro test encourages the development of a biomimetic Dy-Hap drug-free nanotherapeutic platform.