Liposome encapsulation of haemoglobin (LEH) holds promise as a way to deliver high concentration of haemoglobin and perhaps provide sufficient oxygen carrying-capacity in conditions of significant blood loss. Many experimental studies have confirmed that LEH reduces the toxicity causes by free haemoglobin in plasma. Refinement of the vesicle surface with polyethylene glycol has been shown to increase their half-life and biocompatibility, rendering them “stealth”.

In this experimental study, the investigators evaluated the immunogenicity of a new PEG-surface-modified LEH as compared to saline during a chronic extended dosing protocol. Repeated dosing over 4 weeks did not alter histological observations and immunochemical staining results suggest that it is immune neutral. These results are promising but the true review of the utility of these vesicles will have to wait for an evaluation of their in vivo oxygen transport.

– Amy G. Tsai