Bacterial infection after implantation of bone tissue engineering scaffolds is still a serious clinical problem. Ag-nano-hydroxyapatite/polyamide66 (Ag-nHA/PA66) antibacterial composite scaffold were prepared with phase-inversion method in this study. The scaffolds were mineralized in saturated calcium phosphate solution at 37 degrees C for 1 day. The microstructure and the newly formed nano-apatite deposition on the scaffolds before and after mineralization were observed using scanning electron microscopy (SEM). In order to investigate the release behaviors of Ag+, the Ag-nHA/PA66 scaffolds were immersed into 5 ml PBS at 37 degrees C for a different period between 3 h and 168 h before and after mineralization. Then the samples were cultured with E. coli (8099) to test the antibacterial effect of the scaffolds. The results showed that, after mineralization, Ag-nHA/PA66 porous scaffolds still possessed a good inter-connection and a new apatite layer was formed on the surface of the scaffolds. The average macropore size was 626.61 +/- 141.94 microm, the porosity was 76.89 +/- 8.21% and the compressive strength was 2.94 +/- 1.12 MPa. All these physical parameters had no significant difference from those of the un-mineralized scaffolds. The Ag+ release of the scaffolds with and without mineralization was fast within 1 day and then kept slow and stable after 1 day. The antibacterial test confirmed that after mineralization the scaffolds had good antibacterial effects on E. coli.
Biocompatible Materials ; Bone Substitutes ; chemistry ; Durapatite ; chemistry ; Nanocomposites ; chemistry ; Nylons ; chemistry ; Porosity ; Silver ; chemistry ; Surface Properties ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

Objective To study the irrational intravenous (IV) medication orders and promote rational medication applications.Methods A retrospective analysis was conducted to analyze the irrational prescriptions from January to December 2016.Results Among 39 948 IV medication orders reviewed, there were 134 irrational prescriptions of cytotoxic drugs (0.33％) and 222 irrational prescriptions of total parenteral nutrition(TPN)(0.56％).Within 356 irrational prescriptions, 19 had improper amount of diluent(5.34％), 95 inappropriate dosage(26.69％), 12 drug incompatibility(3.37％), 8 wrong diluent (2.24％) and 222 inappropriate TPN orders (62.36％).Conclusion The interventions of the clinical pharmacists are needed to reduce medication errors and improve the drug safety and effectiveness.