Development Of An Anti-infective Subcutaneous Buried Epidural Analgesia Pump

Objective:To develop an anti-infective subcutaneous-buried epidural analgesia pump and appraise the anti-infective function of the pump in vitro.Method:The drawings of the anti-infective subcutaneous-buried epidural analgesia pump were designed. Its main component was an implantable subcutaneous injection pot. Cordierite micro porous ceramic was used as the inner tank of the injection pot and the micro porous aperture of the tank was controlled by adjusting the quality ratio of the clay powder and medical paraffin.The chitosan/nano silver composite solution was synthesized in silver nitrate solution through chemical reduction method. Sodium borohydride and chitosan were used as the reducing agent and stabilizer respectively in this process. The surface of the Cordierite micro porous ceramics were then coated with certain concentrations of the chitosan/nano silver composite solution in situ.The antibacterial function of the inner tank of cordierite micro porous ceramics coated with chitosan/nano silver in situ was detected in vitro with Escherichia coli and Staphylococcus aureus according to GB/T20944.1-2007. The cordierite micro porous ceramics added with chitosan/nano silver (not in situ) were set as control group. The antimicrobial duration experiments were also performed. Chitosan/nano silver-coated filter paper and cordierite samples were dipped in phosphate buffered saline, distilled water and10%morphine for30days firstly and then tested the antibacterial properties (antibacterial).Results:The drawings of the anti-infective subcutaneous buried epidural analgesia pump were successfully designed. The pore rate of the ceramic inner tank was about26.4%. When the quality ratio between clay powder and medical paraffin reached100:13, the most probable pore size is φ6.6μm.The antibacterial experiment in vitro indicated that the nano silver generated in situ performed better in anti-bacterial function, which made the chitosan/nano silver layer with stronger antibacterial ability, and the Chitosan/nano silver antimicrobial coating cordierite with good resistance to Escherichia coli and staphylococcus aureus; In addition, the cordierite with the chitosan/nano silver layer showed decent washable qualities with its anti-bacterial function lasting at least for30days.Conclusion:This research has successfully developed a good anti-infective subcutaneous-buried epidural analgesia pump and the anti-infective function of the Chitosan/nano silver antimicrobial coating cordierite lasted at least for30days, which may effectively prevent long-term catheterization related infection of the epidural analgesia pump.