Incorporation of Erythrocytes into Polypyrrole to Form the Basis of a Biosensor to Screen for Rhesus (D) Blood Groups and Rhesus (D) Antibodies

Abstract

Antibodies to Rhesus (Rh) antigens are important indicators in screening for haemolytic disease of the new‐born (HDN) and autoimmune haemolytic anaemia (AIHA). Identification of the Rh antibodies formed by immune stimulation is also essential in order to maximize the in vivo survival time of transfused erythrocytes. Currently this is performed by agglutination based assays that are time consuming. A prototype of an immuno‐biosensor for detecting antibodies recognizing the Rhesus blood group antigen, Rh (D), was constructed. Human erythrocytes were incorporated into a conducting polypyrrole, polyelectrolyte matrix. The process was followed by using oximetry and light microscopy to demonstrate the integrity of the erythrocytes in the polymerization solution and in the polymer matrix; cyclic voltammetry and resistometry for electrochemical characterization of the polymer and then agglutination, ELISA techniques and cyclic resistometry for analysis of the immuno response from antigen/antibody binding. Antigen/antibody binding could be detected qualitatively by using resistometry while cycling the polymer between +0.35 V and –0.7 V (vs. Ag/AgCl). A characteristic cyclic change in resistance (a resistogram) was recorded. After addition of Anti‐Rh (D) antibody (250 µg/mL), the change in resistance during the resistogram decreased by 1.1 Ω (p<0.0008) in polymers containing Rh (D) positive erythrocytes, whereas polymers without erythrocytes showed no significant change.

Promoting neurite outgrowth from spiral ganglion neuron explants using polypyrrole/BDNF‐coated electrodes

“…SGN survival was observed in the vicinity of the implanted electrodes 47. Viable cells have also been incorporated into Ppy and another conducting polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT),48, 49 and with further development it may be possible for neurotrophin‐releasing cells to be incorporated into conducting polymers for extended release of neurotrophins. With this combination, the impedance of the electrodes is not compromised while providing a continuous supply of neurotrophins.…”

Organic electrode coatings for next-generation neural interfaces

“…The latter limitation in efficiency restricted further development of this concept. In 1999, non-nucleated cells were successfully embedded in the PPy electrodeposited onto metal electrodes (Campbell et al, 1999). Cell surface antigen integrity was maintained and because the biosensor application required only presentation of cell surface antigens, there was no requirement for long-term viability and cell function.…”

Preparation and characterization of polypyrrole nanocomposites by using various surfactants and Fe2O3 nanoparticles in aqueous media

“…Conjugated polymer is a class of polymer that can distinguish significant levels of electrical conductivity and are different from polymers filled with metals . In recent years, intrinsic conducting polymers with conjugated double bonds have attracted much attention as advanced materials . These polymers include polyaniline, polyphenylene, polythiophene, polyacetylene, and polypyrrole (PPy).…”