Biocompatibility evaluation of surface‐treated AISI 316L austenitic stainless steel in human cell cultures

Abstract

Abstract:The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding ϩ post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided ϩ post-oxidized samples, while only slight differences in cytokine (TNF-␣, IL-6, and TGF-␤1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided ϩ post-oxidized ones. All the sample types induced a remarkable increase in TNF-␣ and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer.

Potential proinflammatory effects of hydroxyapatite nanoparticles on endothelial cells in a monocyte–endothelial cell coculture model

“…[30][31][32][33][34] Recently, some researchers have attempted to use an in vitro coculture model of immune cells and ECs to evaluate the inflammatory potential of Figure 4C). Separating the two cell types and treating HUVECs with conditioned media from HANP-exposed THP-1 cells also significantly increased the release of IL-6, indicating that the induction of IL-6 in HUVECs may be largely dependent on the HANP-activated monocytes ( Figure 4C).…”

Human Bone Marrow-Derived Mesenchymal Cell Reactions to 316L Stainless Steel: An in Vitro Study on Cell Viability and Interleukin-6 Expression

“…In another study by Martinesi et al 7 it was reported there was biocompatibility between surface-treated 316L-SS and human cell cultures containing human umbilical vein endothelial cells (HUVEC) and human peripheral blood mononuclear cells (PBMC). HUVEC proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided post-oxidized 316L-SS after 72 hours of contact.…”

In vitro response of human peripheral blood mononuclear cells to AISI 316L austenitic stainless steel subjected to nitriding and collagen coating treatments

“…Low temperature nitriding is particularly useful for increasing the corrosion resistance of austenitic stainless steels in chloride-ion containing solutions [6][7][8][9]13]. This treatment produces a modified surface layer, which consists mainly of S phase.…”

“…Therefore, it would be necessary to modify the surface of the metallic implants, in order to obtain a better resistance to corrosion and a better biocompatibility. Among the surface treatment techniques, surface alloying with nitrogen by means of low temperature nitriding improves corrosion resistance of austenitic stainless steels in chloride-ion containing solutions, as body fluids are [6][7][8]. When treatment temperatures lower than 450°C are used, nitrogen is retained in a supersaturated solid solution, known as expanded austenite or S phase [9], and the precipitation of chromium nitrides, which usually decreases corrosion resistance, is avoided.…”

“…When treatment temperatures lower than 450°C are used, nitrogen is retained in a supersaturated solid solution, known as expanded austenite or S phase [9], and the precipitation of chromium nitrides, which usually decreases corrosion resistance, is avoided. Moreover, this treatment maintains, or even increases, the biocompatibility of austenitic stainless steels [7,10,11]. Another adopted strategy is the coating of medical devices with more biocompatible materials.…”