Green Synthesis of Silver Nanoparticles by Thymus Vulgaris; Synthesis, Characterization and Application in Healing of Metacarpal and Metatarsal Bone Fractures in Sheep and Goats

Long bones injuries and fractures are common orthopedic problems occur in sheep and goats.This study aimed to evaluate fractures of the metacarpal and metatarsal bones in sheep and goats (clinical study) and to describe the accelerating action of silver nanoparticles Thymus vulgaris (Ag-NPs-THV) on healing process of fracture in goats (experimental study).AgNPs were reduced using THV to form AgNPs-THV.The formulated AgNPs-THV was characterized for size, charge, morphology, and the drug content of THV was determined for further experiments.Twenty-four adult male Barbary goats were randomly assigned into two equal groups.A cortical bone defect 3.5mm diameter was made at the middle third of the right metacarpal bone in each goat.Group 1 (THV Extract) and Group 2 (AgNPs-THV) were injected with THV extract liquid, and AgNPs-THV at the bone defect, respectively.The healing process was evaluated for eight weeks after surgery depending on the radiological, turnover biomarkers of bone, and histopathological assessment.Additionally, 49 sheep and goats with metacarpal and metatarsal bone fractures were included in this study on the basis of clinical, and radiographical examinations.The formulated AgNPs-THV was oval and formed as cluster.The size was in nano range, while the charge was -18.11.74mV.Furthermore, the recorded wavelength was 388.52.2nm, and THV was recorded in AgNPs-THV as 5765.336g/mL.The radiographic union scale was significantly affected by treatment and time, P<0.001.AgNPs-THV significantly provided better radiographic union scale than that provided by THV Extract at 2,5 and 8 weeks post treatment.Histopathologically, at 5 weeks postoperative, Ag-NPs-THV treated group showed a significant decrease of fracture gap that filled with woven bone beside lamellar bone in comparison with THV Extract group (P<0.01) that still had wider gap filled with granulation tissue and limited woven bone.At 8 weeks post-treatment, 100% of cases treated with Ag-NPs-THV showed complete healing with lamellar bone compared with 50% of THV extract treated group.Ag-NPs-THV colloidal nano-formulation could be used as a promising formulation to speed up healing process of tibial bone fracture in rabbit.