Ultrasound-assisted fabrication of acoustically active, erythrocyte membrane “bubbles”

Graphical abstract

Highlights

• •

  The work presents a method for fabricating a novel contrast agent from RBC membranes.

• •

  This work proves the originality and potential of these materials in medical imaging.

• •

  RBC membranes are inherently biocompatible and can take up multiple payloads.

• •

  This technology offers new possibilities for multiple imaging modalities.

Abstract

In this communication, we report an ultrasound-assisted method, utilising human red blood cell (RBC) or erythrocyte membranes, to produce acoustically active “bubbles”, intended for vasculature imaging. The resulting RBC membrane bubbles have an average size of 1.5 μm with a generally spherical morphology, altered internal aqueous compartment contents, and small gas-containing protrusions or “pockets” in between the membrane bilayer. We also found that this method produced some nanobubbles (200–400 nm diameter), due to the shedding of lipid components from the RBC membranes to compensate for the membrane structural changes. In vitro ultrasound imaging showed that RBC membrane bubbles had comparable ultrasound contrast enhancement as the standard DEFINTY ^TM microbubble preparation (~13% v/v) and lower concentrations of this standard contrast agent. This current technology demonstrate a new and important application of ultrasound and of RBC membranes, having inherent biocompatibility, as potential material for the development of new types of ultrasound imaging agents, without the use of additional lipid components and pre-made microbubbles.