Making nanomedicines more precise

Nanomedicine uses ultra-small particles to deliver drugs directly to the tissues and cells that need them, improving treatment effectiveness while reducing side effects. This approach underpins some clinically approved RNA-based technologies and chemotherapy drugs.

But designing effective nanomedicines is no easy task. The body's immune system can mistake nanoparticles for harmful invaders and try to clear them, limiting their effectiveness and sometimes causing adverse effects. A key player in this process is the protein corona, a layer of proteins that forms around nanoparticles when they enter the bloodstream and can influence how the immune system reacts to them.

Findings from researchers at the University of Delaware College of Engineering, published Sept. 29 in Proceedings of the National Academy of Sciences, offer fresh insights into how the protein corona affects immune system recognition of nanoparticles and the particles' ability to reach their destination.

"Understanding the influence of the protein corona on a nanoparticle's fate will help us design nanomedicines that more reliably evade immune clearance and deliver therapies precisely," said senior author Emily Day, professor in the Department of Biomedical Engineering.

Targeting blood stem cells

For this study, a team from Day's laboratory focused on nanoparticles targeting hematopoietic stem cells, which give rise to all types of blood cells. Nanomedicines that deliver drugs or gene therapies directly to these cells could serve a range of purposes, from helping prepare the body for a bone marrow transplant to correcting the genetic variation that causes sickle cell disease.

"The rarity of hematopoietic stem cells - they comprise just 0.01% of bone marrow cells - makes them a challenging target," said first author Eric Sterin, who received his doctorate in biomedical engineering from UD earlier this year. "One approach we've been using to improve targeted delivery is wrapping the nanoparticles with a membrane derived from bone marrow cells known as megakaryocytes, which coats them with proteins that help guide them to the marrow."