The accumulation of circulating histones on heparan sulphate in the capillary glycocalyx of the lungs.

Recent findings on the role of circulating histone proteins in mediating acute lung injury prompted us to investigate whether there is a specific mechanism for accumulation of histones in the lungs. Binding sites for polycations are already known in the vasculature of the lungs, and we postulated that these could also be involved in histone accumulation, since histones have a high content of positively charged amino acids. Using a histone-coated colloid of a radiolabelled nanocomposite to track histone biodistribution with imaging techniques, it was found that histones bind avidly in the lungs of rabbits after intravenous injection.

Cationised radiolabelled nanoparticles for perfusion imaging of the lungs.

Diagnostic imaging of the blood perfusion of the lungs is currently performed using particles of macro-aggregated albumin, which are mechanically arrested at limiting diameters of the capillary bed. While the proportion of blood flow obstructed is typically very low and temporary, it would seem more desirable to image lung perfusion in patients using a non-obstructive method, and using materials that avoid biological hazards. We have characterised the in vitro and in vivo properties of a colloid of a cationised radiolabelled nanocomposite.