Scientists from University of Brussels have developed a new targeting therapy against cancer and degenerative disease based on nano particles, which is without any side-effects to patients. This finding was published in Nanomedicine: Nanotechnology, Biology and Medicine.

The unique physical and chemical properties of carbon nanotubes(CNTs) make them very desirable materials in a range of biomedical applications. Although influenced by the dispersants used, CNTs are recognized by the innate immune system, predominantly by the classical pathway of the complement system.

In this study, the researchers show several types of pristine and non-covalently functionalized CNTs activate the complement system predominantly via the classical pathway, which continues up to the activation of C3 and C5, confirming the finding of that the entire complement system is activated, leading to the formation of MAC. The interaction of C1q with these CNTs appears to occur via the gC1q domain since the recombinant forms of the gC1q regions of A, B and C chains bind CNTs stably.

The binding of globular heads takes place in an orientation that inhibits the binding of serum C1q, thus suppressing C1-mediated classical pathway activation. They also report that complement activation and deposition on the surface of these CNTs enhance their uptake by macrophages(U937 cell line) in a time-dependent manner.

The scientists propose that CNT-mediated complement activation may cause recruitment of cellular infiltration, followed by phagocytosis without inducing a pro-inflammatory immune response.

Reference:

Pondman K M, Sobik M, Nayak A, et al. Complement activation by carbon nanotubes and its influence on the phagocytosis and cytokine response by macrophages[J]. Nanomedicine: Nanotechnology, Biology and Medicine, 2014.