In Vivo Animal Study and Cisplatin Level in Blood and Tissue

No animal died of airway complications during the period of study. Intermittent stridor was noted at times of agitation in two rabbits; bronchoscopy of these animals showed a moderate amount of airway secretion. The activity and appetite of all animals were normal. Obvious weight gain was noted during the period of study. Bronchoscopic pictures revealed excellent lumen patency, with only minimal airway secretions in most of the animals. We did not observe stent fragmentation in any of the animals. Furthermore, no evidence of fac-ture at the surfaces or at the welded spots was noted for the biodegradable stents.

The in vivo release characteristics of the biodegradable drug-eluting stents Viagra Online. The cisplatin levels in the stented trachea were measurable from the first week and stably maintained at high levels until the end of the observation period (5 weeks). Similar trends were observed in the trachea segment near the stent and over the right upper lung parenchyma. In contrast, the serum levels of cisplatin were low throughout the experiment.

The trachea with stent in place. Grossly, the stented area showed mild edematous change with mucosa congestion. Microscopically, there were marked mononuclear cell infiltrates of various proportions of lymphocytes, plasma cells, and eosinophils in the submucosa of the stented area 1 week after implantation. The cilia of the epithelium were preserved. Similar findings were noted at weeks 3 and 5.

SEMSs have been of great value in palliation of malignant airway obstruction but are also notorious for various troublesome complications. This is partly due to the embedded nature of the stent but is also related to the lack of effective locoregional therapy for endobronchial lesions. Given the promising results from several EITC studies, we believe that a biodegradable stent that exerts strong stenting force and sustainable drug-eluting characteristics would be an ideal combination. In the current study, we successfully demonstrated that the biodegradable PCL stents have mechanical strength comparable to the strength of SEMSs, with minimal tissue reaction. Furthermore, for the first time, to our knowledge, through the combined use of PLGA materials and the spray coating technique, a controlled amount of cisplatin could be released locally over a few weeks with minimal systemic concentration.

Author: admin on October 17, 2014
Category: Critical Care

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