Exploding nanoparticles (literally) open up the path to repairing damaged cells

We could theoretically repair cells by artificially inserting the missing proteins or DNA. Unfortunately, we couldn't come up with a safe, effective (and awesome) way to do it - until we used tiny lasers to blow up the cellular membrane.

These so-called nanoblasts hold the key to innovative gene-based therapies in which helpful molecules, proteins, and DNA strands are inserted into damaged cells. As Georgia Tech professor Mark Prausnitz explains:

"This technique could allow us to deliver a wide variety of therapeutics that now cannot easily get into cells. One of the most significant uses for this technology could be for gene-based therapies, which offer great promise in medicine, but whose progress has been limited by the difficulty of getting DNA and RNA into cells."

The process works by placing carbon nanoparticles in a fluid mix around the cells you want to fix, then hitting the area with bursts of near-infrared light. The carbon will absorb this light, heating up the nanoparticles, and turning the surrounding fluid into steam. The carbon and steam then react together to form hydrogen and carbon monoxide, which in turn form a bubble as the laser provides more and more energy. Then, the laser is suddenly switched off, which causes the bubbles to instantly collapse. This sudden change creates shockwaves that puncture the cell membrane. At this point, any therapeutic agents in the fluid have a chance to scurry inside the cell before the membrane closes back up.

Lead author Prerona Chakravarty explained the effectiveness of the method in experimental tests:

"We could get almost all of the cells to take up these molecules that normally wouldn't enter the cells, and almost all of the cells remained alive. Our laser-activated carbon nanoparticle system enables controlled bubble implosions that can disrupt the cell membranes just enough to get the molecules in without causing lasting damage."

The researchers found that DNA inserted into the cells using this method remained active and able to direct the expression of proteins. Prausnitz is hopeful that this could be a long-term solution for gene therapy treatments:

"This is the first study showing proof of principle for laser-activation of reactive carbon nanoparticles for drug and gene delivery. There is a considerable path ahead before this can be brought into medicine, but we are optimistic that this approach can ultimately provide a new alternative for delivering therapeutic agents into cells safely and efficiently."

[Nature Nanotechnology]