Repair of alveolar cleft bone defects by bone collagen particles combined with hUC-MSCs in rabbit

Background: Alveolar cleft is a kind of cleft lip and palate, which seriously affects the physical and mental health of patients. In this study, a similar model of human alveolar cleft phenotype was established in rabbits to evaluate the effect of bone collagen particles combined with human umbilical cord mesenchymal stem cells (hUC-MSCs) on the repair of alveolar cleft bone defects. Methods: In this study, 24 adult Japanese white rabbits (JWRs) were selected and randomly divided into 4 groups. Including normal group, control group, materials group and MSCs group. The model of alveolar clefts was established by removing the incisors on the left side of the upper jaw. The normal group did nothing. In the control group, the incisors were removed and sutured directly. In the material group, the incisor were removed, then filled with bone collagen particles, and finally sutured. In the MSCs group, the incisors were first removed, then filled with bone collagen particles incubated by hUC-MSCs, and then stitched. Blood biochemical analysis was performed 3 months after the operation. Skull tissues were collected for gross observation, and micro-focus computerized tomography (micro-CT) analysis. Paraffin sections were prepared for histological and immunohistochemical staining. Results: The bone collagen particles and hUC-MSCs are not biotoxic and can promote alvenlus regeneration. Bone collagen particles combined with hUC-MSCs were much better than those used alone in inducing bone repair and regeneration. Conclusions: HUC-MSCs can be used as a bone generation inducer combined with bone collagen materials for bone regeneration and repair.