ISSN:
0021-9304
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
A rat model was used to investigate the effect of net surface charge on polymer biocompatibility and its potential to modify and stimulate the inflammatory response. Poly(ether)urethane was taken as the base material and the net charge altered by introducing sulphonate ionic groups to the polymer backbone. Three differently charged poly(ether)urethanes were made with 10, 20, and 30% sulphonate substitution, giving a range of negative charge, with unmodified poly(ether)urethane used as a control. The polymers were implanted intramuscularly into rats for 2 days, and for 1, 2, and 12 weeks. After explantation, the cellular infiltration in the tissue surrounding the implants was evaluated using immunohistochemistry to stain for specific cell types: macrophages, neutrophils, lymphocytes, and the cytokine TNFα. In situ hybridization was used to detect expression of mRNA encoding TNFα. Stained sections were analyzed and the cellular response quantified using image analysis. Initially macrophages and neutrophils were observed around all the materials, but neutrophils were absent in all samples at 12 weeks. The 2-day time point had significantly more macrophages than the later time points. By 2 weeks the 20%-charged polymer elicited significantly less neutrophil infiltration than the other three polymers. In all samples where macrophages were observed, cells staining positive for TNFα protein and message also were observed. No T or B lymphocytes were observed in the infiltrates around the materials at any time point. The results indicate that surface charge can influence the early phase acute inflammatory response to an implanted material. © 1996 John Wiley and Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
Permalink
