| Objective:A variety of oral diseases, such as periodontitis, apicitis and trauma, can cause alveolar bone defects,which seriously affect oral function and the patient’s quality of life.The repair and regeneration of alveolar bone defect has been always the problem which dentists want to solve. Tissue engineering technology is an effective way to repair bone defects.Bletilla striata polysaccharide, which is also known as Bletilla striata glucomannan, is a natural macromolecule polysaccharide extracted from traditional Chinese medicine in Bletilla striata. Bletilla striata glucomannan has the capabilities of anticoagulant, anti-infective, anti-tumor and promoting wound healing, and has good biocompatibility and biodegradability. It can be used in various forms of drug dressings and biomaterials. Hydroxypropyl Chitosan is a derivative of chitosan, which get widely attention by scholars as one of the water-soluble chitosan in recent years. Nacre powder is a natural biological material which is composed of calcium carbonate crystallized in the form of aragonite. Lopez first found nacre has the ability of osteoinductive in1992.The artificial bone made by nano-nacre powder is a kind of ideal natural materials which has good biodegradability and biocompatibility. Bletilla striata glucomannan was oxidized by sodium periodate to get dialdehyde Bletilla striata glucomannan. The dialdehyde Bletilla striata glucomannan was mixed with hydroxypropyl chitosan and nano-nacre powder, and then the Bletilla striata glucomanna/hydroxypropyl chitosan/nano-nacre powder composited scaffolds were created by freeze-dry method. Test the properties of the composited scaffolds for further research in alveolar bone regeneration and tissue engineering.Methods:1. The Bletilla striata was dissolved in water, adding a certain amount of papain in the solution to remove protein, then get the purified Bletilla striata. Polysaccharide concentration was measured by phenol-sulfuric acid method. The purified Bletilla striata was dissolved in water, adding a certain amount of sodium periodate to get DBsGM by oxidation modification.2. Different concentrations of DBsGM and HPCS solution was prepared and blended with nano-nacre powder in different quality. DBsGM and HPCS were crosslinked with each other to form hydrogel by shiff base, observe the formation of the hydrogel. The Bletilla striata glucomanna/hydroxypropyl chitosan/nano-nacre powder composited scaffolds was created by freeze-dry method3. Observe the apparent structure of the scaffolds by scanning electron microscope and tested its porosity, pore diameter size and compressive strength. The optimal ratio was get by orthogonal analysis, tested the degradation and biocompatibility of the optimal composite scaffold.Results:1. Phenol-sulfuric acid method measured the content of purified Bletilla striata is92.66%, and the DBsGM was prepared successfully.2. All experimental material can form hydrogel,9groups composite porous scaffold materialwas get by freeze drying.3. Scanning electron microscopy observed the surface of the material as the three-dimensional porous structure. The porosity of the scaffold was about84.25%to94.67%, the pore diameter size of125.19～164.57μm and the compressive strength of41.58to100.52kPa. Orthogonal analysis indicates that the fifth composite scaffolds have the best comprehensive performance. The scaffolds has good degradation and biocompatibility. Conclusions:This study synthesized DBsGM/PCS/NNP composite porous scaffold material successfully. Scaffolds for three-dimensional porous structure, has the good physical properties and biological compatibility. Scaffolds is expected to become new tissue engineering regeneration material and provides theory basis for its performance in the further study. |
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