Effects Of Gelatine-Coated Vascular Grafts On Human Neutrophils

Abstract

6the aim of the study was to investigate the immune-modulatory potential of commercially available PTFE and polyester vascular grafts with and without gelatine-coating. The biomaterial-cell-interaction was characterized by changes of established parameters such as PMN-related receptors/mediators, phagocytosis potential and capacity as well as the effect of an additional plasma-dependent modulation. material and methods. By means of a standardized experimental in vitro model, various vascular graft material (PTFE/polyester/uncoated/gelatine-coated) was used for incubation with or without plasma and co-culturing with human neutrophile granulocytes (PMN) followed by analysis of representative receptors and mediators (CD62L, CD11b, CXCR2, fMLP-R, IL-8, Elastase, LTB 4 ). Oxidative burst assessed phagocytosis capacity. Results. Comparing the vascular grafts, un-coated PTFE induced the lowest magnitude of cell stimulation whereas in case of gelatine-coating, cell response exceeded those of the other vascular grafts. This was also found comparing the polyester-based prosthetic material. Gelatine-coated polyester led to a more pronounced release of elastase than gelatine-coated PTFE and the uncoated materials. The results of oxidative burst indicated a reduced phagocytosis capacity in case of gelatine-coated polyester. Plasma incubation did also provide an impact on the cellular response. While in case of gelatinecoating, PMN-related receptor stimulation became lower, it increased by native polyester. The latter one did also induce more mediators such as IL-8 and LTB 4 than gelatine-coated material. conclusions. There have been no extensive data on cell-cell interactions, cytokines and general histo-/hemocompatibility of human cells by the new generation of vascular grafts. It remains still open whether healing process and infectious resistance can be compromised by material-dependent overstimulation or reduced phagocytosis potential of the immune cells of the primary unspecific immune response induced by gelatine-coated materials.

Failure Analysis of TEVG’s I: Overcoming the Initial Stages of Blood Material Interaction and Stabilization of the Immune Response

“…Monocyte activation promotes the release of the macrophage colony-stimulating factor (M-CSF) and monocytes chemoattractant protein 1 (MCP1), promoting the leukocyte colonization on the lumen of the VG [28]. On the other hand, during the first 24 h post implantation, neutrophils from the perivascular tissue have been reported to infiltrate into the graft wall and amplify the signal, thereby leading to the release of MCP1 for the monocyte chemiotaxis [88]. Such an effect has been consistently observed in VG, where the number of monocytes is correlated with the number of present neutrophils [15].…”

“…Figure 7 shows a proposed scheme of the role of ac inflammation in TEVG's endothelialization. Other types of inflammatory cells have also been shown to be attracted by the perivascular tissue in VGs, including dendritic cells and lymphocytes T and B [88]. However, they have not been correlated with vascular graft failure, which suggests that an innate immunity response plays a more significant role than humoral immunity in the performance of vascular grafts [101].…”