Inflammatory cell recruitment, distribution, and chemiluminescence response at IgG precoated- and thiol functionalized gold surfaces

Abstract

The role of complement activation by artificial surfaces relative to inflammatory response is not well understood. This study was performed to evaluate the inflammatory cell recruitment, distribution, and ex vivo metabolic activation of surfaces with different plasma protein adsorption and complement activation properties in vitro. The implants were (1) pure gold (reference), (2) albumin-precoated (3) IgG-precoated gold, and (4) 3-mercapto-1, 2-propanediol [mercaptoglycerol (MG)] and (5) glutathione (GSH) immobilized to gold. The implant disks were inserted subcutaneously in rats for 24 h, and the number of inflammatory cells that were recruited to the implant adjacent to the surrounding fluid phase (exudate) and the surfaces were quantified by DNA measurements. The oxidative burst was analyzed ex vivo using spontaneous and phorbol myristate acetate (PMA)-stimulated, luminol-enhanced chemiluminescence (CL). The in vitro surface-induced anti-rat C3 binding was evaluated by ellipsometry and antibody techniques after plasma incubations for 1 and 30 min. The ellipsometric results showed that immobilized mercaptoglycerol and IgG-coated, but not the immobilized glutathione or the reference Au, bound anti-C3. The in vivo results revealed that the largest amount of cells was associated with the IgG-coated surfaces, followed by immobilized GSH and MG, albumin-coated, and gold surfaces, respectively. No spontaneous ex vivo luminol-enhanced CL was recorded from the cells irrespective of surface functionality or localization. A down-regulation of surface-associated and exudate leukocyte CL was observed ex vivo, irrespective of surface functionality. The results do not indicate a clear relationship between the degree of complement activation in vitro and leukocyte recruitment and adhesion in vivo for differently functionalized surfaces.

Complement activation on immunoglobulin G-coated hydrophobic surfaces enhances the release of oxygen radicals from neutrophils through an actin-dependent mechanism

“…This is in correlation with previous in vivo 6 and in vitro 4,5 studies. Ellipsometric data from hydrophobic silicon surfaces showed that the IgG surface concentration was retained at a consistent level for days, but declined within hours on hydrophilic silicon.…”

“…3 Albumin is suggested to blunt the inflammatory response 4 and adsorbed IgG is known to activate and recruit blood cells in vitro 4,5 and in vivo. 6 The activation of complement during blood-bio material interactions is a clinically observed phenomenon, [7][8][9][10][11] although the mechanisms are not fully understood. Probably both the classical and the alternative complement pathways are involved.…”

Platelets stimulated by IgG-coated surfaces bind and activate neutrophils through a selectin-dependent pathway

“…Tang and Eaton showed that IgG-deficient mice apparently respond with a normal inflammatory reaction after implantation [29], but in another study a very potent in vivo inflammatory reaction was triggered by surface-bound IgG [30]. We have previously demonstrated that platelets amplify the IgG-triggered neutrophil respiratory burst in response to phagocytosable [17] and non-phagocytosable preys [31] in non-stirred systems.…”

An in vitro study of blood compatibility of vascular grafts made of bacterial cellulose in comparison with conventionally‐used graft materials

“…Examples of such products are C3a, C5a, and sC5b‐9; they cause local or systemic inflammatory reactions governed by the site for activation 6. The activated complement cascade can pose a major problem concerning medical implants and extracorporeal blood treatment devices 7, 8. It also seems to have long‐term implications, for example, in‐wear debris from total joint arthroplasty9 and xenotransplantation 10…”