Novel three-dimensional (3D) nanohydroxyapatite-PLGA scaffolds with high porosity
was developed to better mimic mineral component and microstructure of natural bone. To perform
a final assessment of this nanomaterial as a potential bone substitute, its toxicological profile was
particularly investigated. Therefore, we performed a comet assay on human monocytes for in vitro
genotoxicity investigation, and the systemic subchronic toxicity investigation on rats being per oral
feed with exactly administrated extract quantities of the nano calcium hydroxyapatite covered with
tiny layers of PLGA (ALBO-OS) for 120 days. Histological and stereological parameters of the liver,
kidney, and spleen tissue were analyzed. Comet assay revealed low genotoxic potential, while
histological analysis and stereological investigation revealed no significant changes in exposed
animals when compared to controls, although the volume density of blood sinusoids and connective
tissue, as well as numerical density and number of mitosis were slightly increased. Additionally,
despite the significantly increased average number of the Ki67 and slightly increased number of
CD68 positive cells in the presence of ALBO-OS, immunoreactive cells proliferation was almost
neglected. Blood analyses showed that all of the blood parameters in rats fed with extract
nanomaterial are comparable with corresponding parameters of no feed rats, taken as blind probe.
This study contributes to the toxicological profiling of ALBO-OS scaffold for potential future
application in bone tissue engineering.
