<i>In Vitro</i> Cytotoxicity and <i>In Vivo</i> Tissue Response Study of Foreign Bodies Iron Based Materials

Abstract

A foreign body is any object originating outside the body. It may migrate from its entry site and cause pain, inflammation and infection. This study aims to examine in vitro cytotoxicity and in vivo tissue response at different implantation sites of two iron-based foreign body (FeFB) specimens: pure Fe wire, Cr-coated Fe wire, and SS316L wire as control. In vitro cytotoxicity was assessed towards rat smooth muscle cells with direct method of methyl thiazolyl tetrazolium (MTT) assay. In vivo tissue response was examined using mice animal model until day 14 after surgical implantation in subcutaneous nape area and intramuscular right femoral muscle. Cell viability, surface morphology and Fe ion release were examined. Implant density and tissue response were examined by using radiographic imaging and histology, respectively. Results showed that both FeFB specimens exhibited similar cell viability with SS316L. Iron ion concentration was higher in both FeFB medium compared to that of SS316L and with oxide layer formation on their surface. Radiographic analysis showed that the density of both FeFB implants end-side was increased. Meanwhile, histological tissue response at intramuscular sites for FeFB specimens showed a prominent inflammatory response compared to SS316L. Detailed analysis on cell and tissue-material interactions of the iron-based foreign body specimens is discussed further in this article.