Nano Lett. 13, 3248–3255 (2013)

The two main strategies of nanoparticle delivery of anticancer therapeutics, passive and active targeting, are limited by variations in the architecture of tumours and the complexity of incorporating targeting groups into the delivery vehicle, respectively. Marcelle Machluf and colleagues at the Technion Israel Institute of Technology have now demonstrated tumour-specific delivery of a therapeutic using nanoghosts — nanoparticles produced from the membranes of mesenchymal stem cells (MSCs).

Intact MSC cell membranes (ghost cells) were reduced to nanoscale particles, while entrapping the biological anticancer agent sTRAIL, the clinical use of which is limited by hepatoxicity and a short half-life. A single administration of drug-loaded nanoghosts derived from human- or rat-MSCs was found to inhibit the growth of tumours in mice with human prostate cancer by over 70% and for up to two weeks. Nanoghosts derived from human smooth muscle cells (SMCs) and loaded with sTRAIL did not have any therapeutic effect, illustrating that the effective nanoghosts were specific to the tumour and not the species.

Although the uptake mechanism has not yet been fully elucidated, Machluf and colleagues highlight that the SMC-nanoghosts shared the same size and physical properties as MSC-nanoghosts, providing insight into the differences between active and passive strategies of targeting tumours.