Morpho-Histopathological Assessment of Platelet-Rich Fibrin, Stem Cell-Derived Micro vesicles, and ZnO Nanoparticles on Achilles Tendon Healing in Rabbits

Abstract

Abstract The objective of this study was to evaluate the effect of zinc oxide nanoparticles (ZnONP), mesenchymal stem cell-derived micro vesicles (MVs), and Advanced platelet-rich fibrin (A-PRF) on the healing of Achilles tendon defects in rabbits during the inflammatory, proliferative, and remodeling phases through histological examination and quantitative assessments. Twenty-four adult male New Zealand albino rabbits with Achilles tendon defects were divided into four equal groups of six animals each. In the control group, the Achilles tendon defect was left untreated. In the ZnONP group, the defect was injected with 0.5 ml of 0.2% ZnONP. In the MVs group, MSC-derived MVs were injected into the defect twice within one week apart. In the A-PRF group, the defect was filled with a PRF membrane. Tendon tissue was harvested at 2, 4, and 6 weeks after treatment and sections were stained with hematoxylin-eosin and Masson trichrome. Histological examination revealed that proliferation and remodeling of collagen fibers and approximation of normal tendinous tissue occurred earlier in the ZnONP group after 6 weeks than in other treated groups. This study demonstrated that ZnONP have a significant ability to enhance and accelerate the healing and regeneration processes of the Achilles tendon.