Tissue reaction and biodegradation of implanted cross-linked high amylose starch in rats

The biocompatibility and degradation characteristics of cross-linked high amylose starch (Contramid((R))) were investigated in rats over 4 months. Contramid((R)) pellets (3-mm diameter and thickness) obtained by direct compression, were implanted subcutaneously and intramuscularly. On sequential time points, macroscopic observations of implantation sites were performed and tissue samples were removed, fixed, and histologically evaluated. No macroscopic inflammatory reaction was observed with Contramid((R)). Upon histologic examination, inflammatory reaction produced by Contramid((R)) was moderate and restricted to implantation sites. The sequence of inflammatory events with Contramid((R)) was similar regardless of implantation site. Degradation of Contramid((R)) pellets was characterized by fragmentation with formation of fibrovascular septa and phagocytosis by macrophages. Finally Contramid((R)) was mostly absorbed by the end of the 4-month period and substituted by adipocytes. It has been demonstrated that Contramid((R)) is a biocompatible and absorbable material. (C) 2002 Wiley Periodicals, Inc.