ABSTRACT
Eighty percent of bacterial infections are related to the formation of bacterial biofilm. Compared with planktonic bacteria, bacterial biofilm is 10-1 000 times more resistant to antibiotics, which is the main cause of current bacterial drug resistance. A comprehensive understanding of the characteristics and resistance mechanisms of bacteria biofilm will help us treat the stubborn infections caused by the bacterial biofilm better and solve the problem of bacterial drug resistance. In this review, the composition and quorum sensing of bacterial biofilm, two major patterns of biofilm formation and drug resistance mechanisms were presented. Furthermore, representative compounds with anti-biofilm activity and compounds synergistic with antibiotics in anti-biofilm actions were introduced. Nano drug delivery strategies used for anti-biofilm in recent years as well as a novel drug delivery system-molecularly imprinted polymer was also introduced.
ABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to determine the feasibility of transcatheter pulmonary valve replacement in sheep up to 6 months post procedure.</p><p><b>METHODS</b>Fresh sheep pericardium treated with a 0.6% glutaraldehyde solution for 36 hours was sutured to a valvular ring and then fixed onto a newly designed nitinol self-expandable stent. Thoracotomy was performed in sheep (23.5 +/- 3.1) kg under general anesthesia and the device was delivered into the native pulmonary valve of the sheep via the anterior wall of right ventricle by catheter and fooled for 6 months.</p><p><b>RESULTS</b>One sheep died 4 months after the procedure due to in-stent thrombosis. Another 4 animals survived the 6-month observing period. Angiographic and hemodynamic measurements confirmed good positioning and function of the stents with a competent valve immediately post procedure and 6 months post the procedure in surviving animals.</p><p><b>CONCLUSION</b>Implantation of the nitinol self-expandable stent in the pulmonary valve position by a transcatheter approach is feasible and good function of transcatheter implanted memory nitinol valved stents was shown after 6 months of implantation in sheep.</p>