This study evaluated the application of chitosan/polyvinyl alcohol/graphene oxide/nano titanium oxide
(CS/PVA/GO/nano TiO2) hydrogels for bone defect reconstruction in dogs. Dogs were subjected to middiaphyseal
circular bone defects (0.8 cm2) in the radius bones. Bone defects were implanted with the
hydrogel in the treated group (n = 9), while the control group were subjected to spontaneous healing
(n = 9). Dogs were subjected to clinical, radiographic, and scanning electron microscopy (SEM)
evaluations at 15-, 30-, and 45-days post-surgery. Dogs in the treated group recorded no lameness by
the end of the third week post-surgery, while dogs in the untreated group still exhibited lameness of
grade 1. There was a significant decrease (p o 0.05) in the cortical defect (mm) of the treated group
(5.46 � 0.17 and 1.45 � 0.13) compared with the control group (7.57 � 0.05 and 7.59 � 0.06) at 30- and
45-days post-surgery, respectively. The depth of the bone defects (mm) decreased significantly (p o 0.05)
in the treated group (2.26 � 0.12 and 0.008 � 0.002) compared with the untreated group (4.05 � 0.05
and 2.16 � 0.07) at 30- and 45-days post-surgery, respectively. Throughout the period of study, there was
a significant increase (p o 0.05) in the radiographic density of the bone defects (px) in the treated group
(474 � 17.88) compared with that in the control group (619.6 � 6.85). SEM results revealed complete
closure of the bone defects in the treated group. Thus, implantation of bone defects with the CS/PVA/
GO/nano TiO2 hydrogel represents a promising bone graft substitute for accelerating bone healing.