Establishment of rabbit radius fracture model and the role of stromal vascular fraction-acellular bone extracellular matrix-chitosan scaffold in promoting the healing of rabbits

Abstract

Objective To prepare stable structure and good bone induction and biological compatibility of stromal vascular fraction (SVF)-acellular bone extracellular matrix(ABECM)-chitosan composite scaffold study SVF-ABECM-chitosan scaffolds to promote the healing of rabbit radius fracture. Methods Using Triton X-100 and sodium dodecyl sulfate (SDS) acellular method of porcine femur were decellularized, using a solution blending, freeze drying method preparing ABECM-chitosan composite scaffolds. The qualitative analysis of SVF-ABECM-chitosan scaffolds, observe SVF-ABECM-chitosan composite porous scaffold morphology, porosity, mechanical properties and cell scaffold composite culture compatibility.12 adult healthy New Zealand white rabbits were selected, and the fracture model was caused by the fracture gap of about 0.3 cm, which was exposed to the radial shaft of the radial side of the forearm of the rabbit. The SVF-ABECM-chitosan composite scaffold was prepared in the right radius fracture space of each animal, and the left side was the blank control group. The fracture healing was compared between the two sides of the radius fracture model of rabbits by X-ray, biomechanical test and tissue morphology. Results ABECM materials were stained with he and hoechest 33258 fluorescence staining showed no residual cells, immunohistochemical staining of alizarin red staining and type I collagen and bone morphogenetic occurred protein-2 antibody staining positive. Scanning election microscopy (SEM) showed that the scaffolds have a porous structure, the aperture 50-200 μm, porosity of (53.50±4.23)%, dry mechanical test support longitudinal compression modulus is (33.23±14.45) mPa, support wet state of compression modulus of (2.27±1.13) mPa. Cell scaffold composite culture has good compatibility. After 4 weeks and 12 weeks in the experimental group by X-ray films reflect the bone healing was stronger than that of the control group. After 12 weeks, the biomechanical test group in the maximum load, anti bending strength of HA load/displacement parameters and control group comparison differences were statistically significant, and elastic modulus difference were statistically significant (t=7.418, 5.131 and 2.838, P=0.004, 0.009 and 0.027), and elastic modulus difference between the two groups no statistical significance (t=1.455, P=0.064), at 12 weeks after operation, the histomorphometric results showed. In experimental group, the bone and shaping was significantly better than the control group. Conclusion Preparation of ABECM-CS composite porous scaffolds to cells completely, retained the removal of cells from the bone matrix main component, have the appropriate aperture and porosity, cell compatibility is good. SVF-ABECM-chitosan composite scaffold can effectively promote the healing of rabbit radius fracture. Key words: Stromal vascular fraction; Acellular bone matrix; Chitosan; Radius fracture; Rabbit