For decades, scientists have used fluorescent probes to detect molecules, monitor cellular activity and deliver drugs inside cells. Probes based on a compound called naphthalimide are especially popular because they can easily be made in large quantities and their fluorescence can be tweaked by changing their constituent atoms. But they are usually absorbed by cells only in small quantities, which hampers their effectiveness. In addition, little is known about how they cross the cell membrane to reach inside.

Programming the body’s immune system to attack cancer cells has had promising results for treating blood cancers such as lymphoma and leukemia. This tactic has proven more challenging for solid tumors such as breast or lung cancers, but MIT researchers have now devised a novel way to boost the immune response against solid tumors.

By developing nanoparticle “backpacks” that hold immune-stimulating drugs, and attaching them directly to T cells, the MIT engineers showed in a study of mice that they could enhance those T cells’ activity without harmful side effects. In more than half of the treated animals, tumors disappeared completely.

Despite high hopes and high investment in CRISPR-Cas9 gene editing, scientists still have a lot to learn about how it works in humans.In the latest example, University of California, Berkeley, scientists found that people’s assumptions about how cells repair the genome after the Cas9 enzyme snips DNA are wrong.

The discovery gives insight into why CRISPR-Cas9 gene editing works remarkably well in nearly every cell attempted, though not with equal success in all cells. And it could help researchers boost the efficiency with which cells insert new DNA into the genome – to replace a harmful mutation with the correct DNA sequence, for example – and generally tweak CRISPR-Cas9 editing to get the desired outcome.

In an advance that could lead to new treatments for a variety of diseases, MIT researchers have devised a new way to deliver messenger RNA (mRNA) into cells.

Messenger RNA, a large nucleic acid that encodes genetic information, can direct cells to produce specific proteins. Unlike DNA, mRNA is not permanently inserted into a cell’s genome, so it could be used to produce a therapeutic protein that is only needed temporarily. It can also be used to produce gene-editing proteins that alter a cell’s genome and then disappear, minimizing the risk of off-target effects.

Using sound waves, researchers have developed a gentle, contact-free method for separating circulating tumor cells from blood samples that is fast and efficient enough for clinical use.

Circulating tumor cells (CTCs) are small pieces of a tumor that break away and flow through the bloodstream. They contain a wealth of information about the tumor, such as its type, physical characteristics and genetic mutations that are associated with prognosis and whether certain treatments may be effective. The ability to quickly and efficiently harvest and grow these cells from a blood sample would enable “liquid biopsies” capable of providing robust diagnosis, prognosis and suggestions for treatment strategies based on individual CTC profiling.