ACS develops therapeutic protein that is released when red blood cell carriers are stimulated by light

While protein therapies can be more potent and selective of biochemical targets, they are also more likely to be degraded by enzymes at a faster rate. 

But researchers at ACS Central Science have been working on a therapeutic protein that is released by red blood cell carriers when stimulated by light, according to an ACS press release. 

"Because protein drugs are unstable in the body, they must be given at high levels, which can cause side effects. Scientists have tried to protect protein therapies from degradation by encapsulating them in carriers, such as liposomes, nanoparticles and RBCs. But it has been challenging to make the carriers release their cargo at the appropriate place and time. Brianna Vickerman, David Lawrence and colleagues wanted to engineer RBCs to release therapeutic proteins at specific regions of the body when triggered by certain wavelengths of light," ACS Central Science said in the press release.

The red blood cells were embedded with the peptide melittin so that the red blood cell ruptured when exposed to light. Then a blood-clotting enzyme, thrombin, was embedded in the red blood cells. The red blood cells were then injected into mice. 

"They then shone a light on a small region of each mouse’s ear and examined sections of the tissue. The analysis showed thrombin-related blood clotting only at the illuminated sites. The strategy could prove useful for the light-triggered release of protein, peptide and nucleic acid therapeutics from a variety of lipid-based carriers, the researchers say," ACS said in the press release.