The Preparation Of Hydroxyapatite/Chitosan Bionic Scaffold Material And Its Performance Study

Calcium phosphate/chitosan composite materials have been reported in many literatures.The research results show that the porous property and mechanical strength render mutual constraint relationship. Different methods were used to build the hydroxyapatite/chitosan material, at the same time, the technical specifications of the material were tested, including mechanical properties, in-vitro release behavior, in-vitro degradation behavior, water absorption rate and biological compatibility and so on.Naringin can promote the effect of bone cell proliferation differentiation, which often used in healing bone injury experiment, therefore the drug was introduced to delivery material to discuss their performance. Firstly, based on the traditional co-precipitation technique, the chitosan/hydroxyapatite-naringin (CS/HA-N) composite with 10%,20% and 30% chitosan contain were prepared. The samples were characterized by SEM, IR and XRD. Their mechanical properties, in-vitro release behavior and in-vitro degradation behavior were studied as well. The results showed that the crystals of this CS/HA-N composite containing carbonate has low crystallinity, which was similar to natural bone. SEM results showed that the hydroxyapatite (hydroxyapatite-N,HA)presented plate shaped crystals. Mechanical performance test results showed that the material had good mechanical properties. With chitosan content increasing in composite, water absorption rate of CS/HA-N was getting higher. The results of in-vitro release and in-vitro degradation test showed that CS/HA-N had good sustained release effect. The drug release rate and the degradation rate increased with the increase of chitosan content in CS/HA-N. CS/HA-N had good application prospect as drug delivery systems for bone tissue engineering.In addition, the chitosan/hydroxyapatite (CS/HA) composite was also prepared by urease-catalyzed method, then the negative wax mold made by 3D printing technology were used to build 10% honeycomb structure chitosan/hydroxyapatite composite, which has good porosity and mechanical strength. The morphology of honeycomb structure HA/CS was observed by SEM, other technical specifications such as mechanical strength, porosity, in-vitro degradation were also tested. After the evaluation of cytotoxicity test, the result exhibited that the toxicity degree of honeycomb structure HA/CS is I level, which conforms to the requirements of the cell toxicity and it is non-toxic material. According to the SEM photos of MC3T3-E1 osteoblast cultured with honeycomb structure scaffold, the osteoblast grew well and became fibrous. Moreover, after the scaffold and cell co-cultured for 5 days, the tests about alkaline phosphatase and total protein determination were carried on, although the scaffold did not obviously interact with the ALP of MC3T3-E1 osteoblast, but the total protein content was increased, which suggested that the activity of protein secretion was high. All in all, the honeycomb structure HA/CS scaffold has the potential to substitute material in bone tissue engineering.