Preparation, characterization and in vitro analysis of etimicin-encapsuled chitosan/hydroxyapatite nano-scaffolds for bone tissue engineering

Objective To prepare a novel etimicin-encapsuled chitosan/hydroxyapatite nano-scaffolds and offer assistances for bone defect or osteomylitis.Methods Drug-carried chitosan nanoparticles which was prepared by ionotropic gelation were combined with nano-hydroxyapatite.The mixture were shaped in molds and then prepared into porous scaffolds by freeze-dry.The surface of one scaffold was scanned.The grinded,particles of the scaffold were detected by field emission scanning electron microscope; X-ray diffraction was used to analyze components of the scaffold and total porosity.Staphylococcus aureus was choosed as the experimental bacteria,we studied lasting antibacterial property of drug-carried bone scaffold by antibacterial experiments,long-term drug releasing experiments and accumulation drug releasing experiments.Bone mesenchymal stem cells were used to detect the histocompatibility and inductivity of etimicin-carried scaffold.Results Freeze-dried porous scaffold has a surface with proper pore distribution (total porosity 70.68％) and the grinded scaffold has a globular and coliformed microstructure known after scanned by electron microscope.The drug-carried scaffold has a typical wave of hydroxyapatite under X-ray diffraction.The lasting antibacterial property study indicated that the drug-carried bone scaffold had maintained an inhibition zone for more than 7 days.The long-term drug releasing experiments and accumulation drug releasing experiments show that the fictional drug-carried bone scaffold released above the bacteriostasis concentration after one week and the accumulative amount within the safety scale.The scaffold had not an inhibitory effect on bone mesenchymal stem cells.Conclusion The etimicin-encapsuled chitosar/ hydroxyapatite nano-scaffolds has similar microstructure and components of bone tissue.It is promising in bone tissue engineering applications because of its slow-release,antibacterial properties and satisfactory histocompatibility. Key words: Chitosan;  Hydroxyapatites;  Aminoglycosides;  Tissue engineering