Immunogenicity of polymeric implants: Long‐term antibody response against polyester (Dacron) following the implantation of vascular prostheses into LEW.1A rats

Abstract

Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.

Antibody response to collagen after functional implantation of different polyester vascular prostheses in pigs

“…Subsequent to previous studies where we were able to document IgG-antibodies against polymers (polyester, polyurethane, PTFE) in rats and in domestic pigs, 15,16,20 the question of humoral immune response to the coating or impregnation of vascular prostheses logically arose. This study focused upon the use of collagen due to the fact that bovine type I collagen, along with albumin and heat-denatured collagen, is widely used as a sealant for widelypored vascular prostheses.…”

“…15,16 Quantitative IgG determination of pig sera was also undertaken using a modified sandwich ELISA. 16 For this, microtiter plates (Greiner, Nü rtingen, Germany) were coated with rabbit-anti-pig-IgG (Fc-␥-specific). After blocking, the diluted pig sera (1/200,000 -1/6,400,000; dilution factor 2) were incubated for 2 h at 37°C.…”

“…Enzyme-substrate reaction (o-phenylenediamine/H 2 O 2 ) was stopped by sulfuric acid and measurement was performed at dual wavelength (490/630 nm) as described previously. 16 The assays' sensitivity and specificity were optimized by a monoclonal antibody (ab6308, Abcam Limited, Cambridge, UK) recognizing the native (helical) form of bovine collagen type I 18 and an irrelevant monoclonal antibody against the 65-kD isoform of glutamic acid decarboxylase (GAD65) of the same isotype (IgG1). 19 Ab 6308 does not react with other collagens as well as the thermally denatured collagen type I and recognizes in our ELISA native collagen type I at a high titer of 1:10,000,000 [ Fig.…”

“…Subsequent to our previous investigations where the existence of specific IgG antibodies against the polymeric prosthesis matrix could be proven, 15,16 this study aimed to investigate a specific humoral immune response against the collagen impregnation of three polyester vascular prostheses, which differ in their porosity, following functional implantation in the animal model pig.…”

Maßgeschneiderte autologe bioartifizielle Gefäßprothesen

“…Diese reichen von unspezifischen Fremdkörperreak-tionen bis hin zu spezifischen humoralen Reaktionen durch Antikörper, die gegen das Prothesenmaterial gerichtet sind [21,24]. Darüber hinaus kommt es über die Ablagerung von Zellen und Proteinen aus dem Blut zur Neointimabildung bis hin zu intraluminaler Thrombenbildung [10,22].…”