Camouflaged Nanoparticles That Avoid Immune Rejection Developed

A key challenge in the field of Nanomedicine is now getting tackled by scientists cloaking nanoparticles, which could become very useful in advanced drug delivery, in the membranes of white blood cells in order to protect them from being rapidly destroyed by the bodies immune system.

"Our goal was to make a particle that is camouflaged within our bodies and escapes the surveillance of the immune system to reach its target undiscovered," said the study's principal investigator Ennio Tasciotti, Ph.D.

The cloak consists of the same material, lipids and proteins, that is present on the membrane of immune system leukocytes (white blood cells), and which is used to coat a nanoparticle, fooling the body's immune system to recognize these nanoparticles as its own. To accomplish that, Tasciotti and his group at The Methodist Hospital Research Institute took metabolically active leukocytes (white blood cells) and developed a procedure to separate membranes from cell innards.

"Using the membranes of the white blood cells to coat a nanoparticle has never been done before," Tasciotti said. "The leukolike vectors (LLVs) are half man-made - the synthetic silicon core - and half made of man - the cell membrane."

The nanoparticles can be made to deliver different types of drugs to specific cell types, for example, chemotherapy to cancer cells. But until now the ability of the body's defenses to destroy nanoparticles within minutes is a major barrier to the use of nanotechnology in medicine.

As the technology is further developed, a patient's own white cells could be harvested and used to create personalized LLVs.

"LLVs are dotted with specific proteins that help the particles reach specific targets, such as inflamed or damaged tissues and cancer cells recruiting blood vessels," Tasciotti said.

Once the nanoparticles reach their target tissue, the membrane lipids and proteins will break away in a controllable release, leaving the nanoparticles to degrade naturally after releasing their payload.

Paper:
Alessandro Parodi et al., Synthetic nanoparticles functionalized with biomimetic leukocyte membranes possess cell-like functions, Nature Nanotechnology, 2013, DOI: 10.1038/nnano.2012.212