The Experimental Research Of Tricalcium Phosphate/chitosan Scaffolds Which Applied To Periodontal Tissue Regeneration Engineering

BackgroundPeriodontitis is an inflammatory disease impacting on the gingiva, periodontal ligament, cementum and alveolar. Periodontitis can lead to bone resorption and eventually the tooth loss, which seriously affect nearly10%of the adult population. The ultimate goal of periodontal treatment is to repair the damaged supporting organization which caused by periodontal inflammatory disease. Hereinto the regeneration of the periodontal ligament is one of the main purposes. In the current studies of periodontal therapy, much emphasis has been placed on the regeneration process of how to improve tissue regeneration induction or the induction of other clinical enamel matrix. Researchers have already started to pay attention to the application of tissue engineering methods to regenerate the periodontal ligament. For tissue engineering, the cell-based tissue engineering technology is one of the most reliable alternative. This method is mainly depended on the interaction among the reaction cells, supporting matrix and biological molecules.Three-dimensional micro-environment for tissue engineering is very necessary. Chitosan is the N-terminal chitin deacetylation of the product. It was repairable, biodegradable, biocompatible, non-antigenic, non-toxic. The value of Chitosan as the materials for tissue engineering has been studied, Although chitosan is non-antigenic, researchers still found an immune response in host tissue towards the transplant with chitosan as an engineering material. Generally, these materials can lead to very little host immune rejection to foreign body.Tricalcium phosphate has good biocompatibility, bioactivity and biodegradability. Animal or human cells in a calcium phosphate material can have a normal growth, differentiation, and reproduction. Available information indicates that tricalcium phosphate has been widely used in orthopedic, oral and maxillofacial surgery, periodontal repair and so on. The mixed material with tricalcium phosphate and chitosan may be better used in the field of biological engineering. In this experiment, tricalcium phosphate/chitosan mixture would be prepared through a freeze-drying method. The mixture would proceed the study in vivo and in vitro of its growth and proliferation of human periodontal ligament stem cells in nude mice as well as biocompatibility and periodontal ligament stem cells differentiation.MethodsDifferent ratios of tricalcium phosphate/chitosan(TCP/chitosan) scaffolds were prepared through a freeze-drying process. Human periodontal ligament stem cells(hPDLSCs) were incubated on the scaffolds in vitro. Cells were cultured on the scaffolds, detected by scanning electron microscopy (SEM).PDLSCs were analyzed by MTT assay and alkaline phosphatase(ALP) activity detection. Experiments method in vivo: PDLSCs were seeded onto the scaffolds. Then these scaffolds were implanted subcutaneously into athymic mice. The state of periodontal tissue regeneration was detected after4weeks.ResultsAs the ratio of TCP increase, TCP/chitosan scaffolds accelerate PDLSCs proliferation significantly higher than the pure chitosan scaffold. PDLSCs produced the cementoid tissue in vivo.ConclusionsThe periodontal tissue regeneration engineering could be applied with TCP/chitosan scaffolds.