Absence of NF-kappaB activation by a new polystyrene-type adsorbent designed for hemoperfusion.
OBJECTIVE
The aim of the study was to evaluate biocompatibility of anew polystyrene-type adsorbent (BetaSorb) designed for hemoperfusion, using second-level biomolecular analyses. The device has recently been developed to enhance beta2-microglobulin removal during hemodialysis. Molecular structure and chemical modifications of the surface beads of this cartridge should prevent exposure of dense hydrophobic surface sites to proteins, and avoid the major drawbacks of previous polystyrene-type adsorbent materials.


METHODS
Whole blood of healthy donors was incubated in sterile minicolumns packed with BetaSorb Cuprophan, Hemophan, polysulfone and cellulose acetate. In parallel experiments, whole blood was recirculated for 180 min in a sham dialysis circuit equipped with the study sorbent or Hemophan or polysulfone. Biocompatibility was assessed by means of new biomolecular approaches focused on nuclear factor kappaB (NF-kappaB) activation (assessed by electrophoretic mobility shift assay), TNF-alpha and IL-1beta gene expression (evaluated by real-time PCR), TNF-alpha and IL-1beta production (measured by Western blot assay and ELISA), nitric oxide (NO) generation (detected by electron paramagnetic resonance), free oxygen radical production (by chemiluminescence in a biological assay) and the generation of the complement breakdown product C3d.


RESULTS
In coincubation experiments, 5-min contact with any dialysis device, but BetaSorb, was enough to induce activation of NF-kappaB. The amount of TNF-alpha precursor form was found to increase after 5 min of exposure to each tested polymer, but no traces of mature forms of TNF-alpha or IL-1beta were detected in in vitro experimental conditions using healthy blood. NO and free oxygen radical generation were significantly lower in blood samples exposed to BetaSorb than in control dialysis devices. C3d levels were found to be increased with Hemophan, unaffected by polysulfone, and remarkably decreased with the BetaSorb device. In the sham hemodialysis experiments, NF-kappaB activation and C3d and NO profiles were similar to direct incubation experiments. Compared to basal levels, quantitation of TNF-alpha and IL-1beta mRNA revealed a 15- and 9-fold increase, respectively, in samples exposed to Hemophan for 180 min.


CONCLUSIONS
The new BetaSorb device not only appears to be highly biocompatible, but shares properties that make it probably able to interfere with the activation of the inflammatory state.
Menegatti
Elisa
E
Scuola di Specializzazione di Patologia Clinica, Università di Torino, Torino, Italia.
Ronco
Claudio
C
Winchester
James F
JF
Dragonetti
Antonella
A
Di Simone
Debora
D
Davit
Annalisa
A
Mengozzi
Giulio
G
Marietti
Giorgio
G
Loduca
Giuseppina
G
Mansouri
Morteza
M
Sancipriano
Gian Piero
GP
Sena
Luigi M
LM
Roccatello
Dario
D
D000327:Adsorption; D016207:Cytokines / Q000378:metabolism; D015870:Gene Expression; D006454:Hemoglobins / Q000032:analysis; D006464:Hemoperfusion / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D008163:Luminescent Measurements / Q000379:methods; D008422:Materials Testing / Q000379:methods; D016328:NF-kappa B / Q000097:blood / Q000378:metabolism*; D009569:Nitric Oxide / Q000032:analysis; D011137:Polystyrenes / Q000737:chemistry*; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000235:genetics / Q000378:metabolism
D016207:Cytokines; D006454:Hemoglobins; D007375:Interleukin-1; D016328:NF-kappa B; D011137:Polystyrenes; D014409:Tumor Necrosis Factor-alpha; C008657:nitrosyl hemoglobin; D009569:Nitric Oxide