Preparation and characterization of sustained-release levofloxacin bone tissue-engineered three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold / 中国组织工程研究

ABSTRACT

BACKGROUND: Preliminary study has prepared the three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold successfully.OBJECTIVE: To explore the mechanical properties, physical characteristics, chemical composition and antibiotic sustained-release ability of three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold loaded with levofloxacin. METHODS: Levofloxacin/chitosan (31) microspheres were constructed by emulsion settlement filter method. 5, 7.5 and 10 g of microspheres were added into 2％ of silk fibroin/chitosan/nano-hydroxyapatite mixed solution through freeze drying and chemical cross-linking to obtain the scaffolds loaded with antibiotics. The scaffolds loaded with antibiotics underwent scanning electron microscope observation, and chemical composition analysis. The sustained release, mechanical properties, porosity, water absorption expansion rate and hot water soluble loss rate were detected. RESULTS AND CONCLUSION: (1) Scanning electron microscope observed that there were drug microspheres at the inner wall of the scaffold, and the voidage was decreased with mass of microspheres increasing. (2) Energy spectrum analysis showed that the three kinds of scaffolds were rich in calcium and phosphonium ions. (3) The three kinds of scaffolds showed the same releasing trend, which presented with sudden-release effect at the former 3 days (release> 50％) , and then tended to be stable. The release rate was the slowest in the scaffold loaded with 10 g of microscopes, and the rapidest in the scaffold loaded with 5 g of microscopes. (4) With the mass of microspheres increasing, there was an increase in the compressive and tension abilities and hot water soluble loss rate, and a decrease in the porosity, mean pore size and water absorption expansion rate. (5) These results indicate that the three-dimensional tissue-engineered scaffold loaded with levofloxacin is constructed successfully by freeze drying and chemical cross-linking method, which holds good sustained-release effect and compressive ability, water absorption expansion rate and hot water soluble loss rate.