Introduction: With the fast development of nanotechnology and its wide application
within the biomedical field, the toxic effect of nanomaterials has attracted numerous
attention. Consequently, a crucial subfield termed nan-toxicology has emerged,
which is mostly defined because the study of the interactions between nanomaterials
and biological systems with a stress on identifying the link between the physicochemical
parameters and therefore the occurrence of toxic effects. Aim: The aim was to
study the possible toxic effect of intraperitoneal administration of gold nanoparticles
on the periodontal ligament of albino rats and moreover the possibility of onemonth
recovery period through hematoxylin and eosin stained sections for histological
evaluation and transmission electron microscope for ultrastructural evaluation.
Material and Methods: Forty-six male albino rats were employed in this investigation.
They were divided into the subsequent groups: Group (1) (16 rats) served as controls,
they received daily intraperitoneal injection of the solvent (deionized water 0.5 ml) for
21 days. Group (2) (15 rats) received 10mg/kg weight of AuNP solution intraperitoneally
daily for 21 days. Group (3) (15 rats) were treated the identical way as Group 2
for 21 days and so left for one-month as a recovery period. The experiment lasted for
21 days for group 2 then the rats were euthanized by cervical dislocation. While the rats
of group 3 were euthanized by cervical dislocation after 1 month of treatment stoppage
with gold nanoparticles for recovery period; their lower jaws of each rat were dissected
out, separated into two halves, the right halves were used for structural examination
while the left halves were used for ultrastructural examination. Results: Examination
of the PDL obtained from the group II animals showed marked dissociation and degeneration
of collagen fiber bundles. The examined fibers of the rats which were allowed a
recovery period showed improvement within the condition of structure and ultrasturctural
features of the fibers and cells of PDL. Conclusion: Our data suggest that AuNPs
exert detrimental effects on cell structure and ultrastructure consequently cell function
that would reverse following AuNPs removal.