A Study On PVC Endotracheal Tubes Coated With Titanium Dioxide Against Bacterial Colonization

Objective To design a rabbit model of ventilator-associated pneumonia (VAP),and study the function of the new endotracheal tube(TiO2/PVC ETT) against bacterial biofilm(BF). To investigate the practical efficiency of the new ETT on antibiosis and sterilization in vivo by using New Zealand white rabbits ,and to provide the basic experimental parameters and evidences .Methods Paralysed rabbits were intubated with used ETTs With the same concentration of Microbial Adhesion, and were mechanically ventilated for 48 hours. A rabbit model of VAP was designed. Thirty-two major rabbits were divided into 4 groups according to the type of ETTs and different illumination ,with eight animals of every group. Eight rabbits were intubated with a standard ETT without illumination (Group C); Eight rabbits were intubated with a TiO2/PVC ETT without illumination (Group T); Eight rabbits were intubated with a standard ETT With ultraviolet radiation (Group C+uv); Eight rabbits were intubated with a TiO2/PVC ETT with ultraviolet radiation (Group T+uv) .After 48 hours' mechanical ventilation we measured bacteria load on the surface of ETTs the animals air duct and lungs,and analyzed the bacterial biofilm on the ETT with scanning electron microscopy and laser scanning confocal microscopy, and sent the lungs of the rabbits to the pathologist for microscopic study for quantization, then compared the difference of the indexes.Results The amount of alive bacterium including PA and other aerobes on the surface of ETTs in Group T+uv was significantly higher than others , there is significant difference between Group T+uv and other groups(P<0. 01). there is significant difference between Group T+uv and other groups(P<0. 01). As for bacteria load on the surface of ETTs the animals air duct and lungs,Group T+uv was significantly lower than others(P<0. 01) . thickness of BF on the surface of ETTs in Group T+uv is significantly less than other groups by scanning electron microscopy (P<0. 01). thickness of BF on the surface of ETTs in Group T+uv is significantly less than other groups by laser scanning confocal microscopy (P<0. 01). Comparing microscopic study for quantization among with Group C, thc score in Group T+uv is significantly lower than other groups(P<0.01).Conclusion In rabbit model of ventilation, TiO2/PVC ETT by photoactivtion can prevent bacterial biofilm ,so it can decrease significantly bacterial colonization .