Cell-seeded Bone Tissue Engineering In Experimental Animal Models: A Systematic Review And Meta-analysis

Objective:The objective of this systematic review was to answer the focused question: in animal models,whether cell-based bone tissue engineering strategies enhance regeneration in alveolar bone,compared with grafting with only biomaterial scaffolds or autogenous bone.Methods:The electronic search of the Medline(PubMed),Embase and Cochrane Library were been performed.And the manual retrieval also covered a variety of oral medical journals and related meeting literatures in English.electronic databases were searched for controlled animal studies reporting maxillary or mandibular CSD/SD and implantation of mesenchymal stem cells(MSCs)or osteoblasts(OBs)seeded on biomaterial scaffolds.In strict accordance with the inclusion criteria and exclusion criteria,the data extraction and offset-risk assessment will be carried out.A meta-analysis was performed for the outcome histomorphometric new bone formation(%NBF)and in the effect size expressed as standardized mean difference(SMD).Results:A total of 25 articles were found to meet the eligibility criteria,involving 61 Large-animals,187 defect sites were included,(90 CSD models and 97 SD models).On average,studies presented with an “unclear-to-high” risk of bias and “moderate-to-high” reporting quality.The meta-analysis indicated statistically significant benefits in favour of: cell-seeded vs.cell-free scaffolds :[SMD=3.27,95%CI(2.14-4.39)] for % NBF in CSD models with 12 researches and [SMD=6.67,95%CI(2.94-10.4)] for % NBF in SD models with 5 researches.While,there is no significant effect about the cell-seeded scaffolds vs.autogenous bone graft: [SMD=-0.66,95%CI(-1.39,0.07)] for % NBF in CSD models with 2 researches and [SMD=-0.82,95%CI(-2.11,0.48)] for % NBF in SD models with 4 researches.For the percentage of residual scaffold,the meta analysis indicated that there is a significant effect about cell-seeded vs.cell-free: [SMD=3.01,95%CI(1.42,4.59)] with 2 researches.ConclusionIn summary,alveolar bone regeneration is enhanced by addition of MSCs or OBs to biomaterial scaffolds;and the cell-based tissue-engineered may result in comparable alveolar bone regeneration with what is achieved with the autogenous bone.Cells seeding into scaffolds could induce more mineralization by facilitating the degradation of scaffold.