Involvement of complement activation in the pulmonary vasoactivity of polystyrene nanoparticles in pigs: Unique surface properties underlying alternative pathway activation and instant opsonization

Tamás Mészáros, Gergely Tibor Kozma, Taro Shimizu, Koga Miyahara, Keren Turjeman, Tatsuhiro Ishida, Yechezkel Barenholz, Rudolf Urbanics, János Szebeni

Research output: Article

5 Citations (Scopus)


Background: It has been proposed that many hypersensitivity reactions to nanopharmaceuticals represent complement (C)-activation-related pseudoallergy (CARPA), and that pigs provide a sensitive animal model to study the phenomenon. However, a recent study suggested that pulmonary hypertension, the pivotal symptom of porcine CARPA, is not mediated by C in cases of polystyrene nanoparticle (PS-NP)-induced reactions. Goals: To characterize PS-NPs and reexamine the contribution of CARPA to their pulmonary reactivity in pigs. Study design: C activation by 200, 500, and 750 nm (diameter) PS-NPs and their opsonization were measured in human and pig sera, respectively, and correlated with hemodynamic effects of the same NPs in pigs in vivo. Methods: Physicochemical characterization of PS-NPs included size, ζ-potential, cryo-transmission electron microscopy, and hydrophobicity analyses. C activation in human serum was measured by ELISA and opsonization of PS-NPs in pig serum by Western blot and flow cytometry. Pulmonary vasoactivity of PS-NPs was quantified in the porcine CARPA model. Results: PS-NPs are monodisperse, highly hydrophobic spheres with strong negative surface charge. In human serum, they caused size-dependent, significant rises in C3a, Bb, and sC5b-9, but not C4d. Exposure to pig serum led within minutes to deposition of C5b-9 and opsonic iC3b on the NPs, and opsonic iC3b fragments (C3dg, C3d) also appeared in serum. PS-NPs caused major hemodynamic changes in pigs, primarily pulmonary hypertension, on the same time scale (minutes) as iC3b fragmentation and opsonization proceeded. There was significant correlation between C activation by different PS-NPs in human serum and pulmonary hypertension in pigs. Conclusion: PS-NPs have extreme surface properties with no relevance to clinically used nanomedicines. They can activate C via the alternative pathway, entailing instantaneous opsonization of NPs in pig serum. Therefore, rather than being solely C-independent reactivity, the mechanism of PS-NP-induced hypersensitivity in pigs may involve C activation. These data are consistent with the “double-hit” concept of nanoparticle-induced hypersensitivity reactions involving both CARPA and C-independent pseudoallergy.

Original languageEnglish
Pages (from-to)6345-6357
Number of pages13
JournalInternational journal of nanomedicine
Publication statusPublished - jan. 1 2018


ASJC Scopus subject areas

  • Biophysics
  • Bioengineering
  • Biomaterials
  • Pharmaceutical Science
  • Drug Discovery
  • Organic Chemistry

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