Nanoshell shields foreign enzymes used to starve cancer cells from immune system

July 7, 2014




For example, doctors have long relied on an enzyme called asparaginase to starve cancer cells as a patient undergoes chemotherapy. But because asparaginase is derived from a nonhuman organism, E. Coli, it is quickly neutralized by the patient’s immune system and sometimes produces an allergic reaction.

In animal studies with asparaginase, and other therapeutic enzymes, the research team found that their porous hollow nanoshell effectively shielded enzymes from the immune system, giving them time to work.

Asparaginase works by reacting with amino acids that are an essential nutrient for cancer cells. The reaction depletes the amino acid, depriving the abnormal cells from the nutrients they need to proliferate.

“Ours is a pure engineering solution to a medical problem,” said Inanc Ortac (Ph.D. ’13), who developed the technology as part of his doctoral research in the laboratory of nanoengineering professor Sadik Esener at UC San Diego Jacobs School of Engineering.

A filter in the bloodstream

The nanoshell acts like a filter in the bloodstream. The enzymes are loaded into the nanoparticle very efficiently through pores on its surface and later encapsulated with a shell of nanoporous silica. The shell’s pores are too small for the enzyme to escape but big enough for diffusion of amino acids that feed cancer cells in and out of the particle. The enzymes remain trapped inside where they deplete any amino acids that enter.

“This is a platform technology that may find applications in many different fields. Our starting point was solving a problem for cancer therapeutics,” said Ortac.

Ortac is currently serving as the chief technology officer of DevaCell, a local start-up which licensed the technology and is working to commercialize it under the name Synthetic Hollow Enzyme Loaded nanoShells or SHELS.

The work is featured on the June 2014 cover of the journal Nano Letters. The research was supported by the National Cancer Institute.



Leave a Reply


You are commenting using your account. Log Out /  Change )

Google photo


Twitter picture


Facebook photo


Connecting to %s