In a trial involving mice, an international team of researchers used microscopic "nanoneedles" to coax the body into generating new blood vessels. Applied to humans, the technology could eventually be used to get organs and nerves to repair themselves.
Researchers from Imperial College London and the Houston Methodist Research Institute used the nanoneedles to deliver nucleic acids — the building blocks of all living organisms and transmitters of genetic information —to a specified area. Once delivered to a cell or tissue, the nucleic acids do their work by regenerating lost function. The researchers, a team led by Ciro Chiappini and Molly Stevens from the Imperial College London, describe their findings in the latest issue of Nature Materials.
In the case of the current study, DNA and siRNA nucleic acids were successfully delivered to human cells in the lab. Also, the researchers were able to facilitate a six-fold increase in the formation of new blood vessels in the back muscles of mice. The technique, conducted over a two-week period, didn't cause any inflammation or other harmful side effects.
Acting like sponges, the porous nanoneedles — which are 1,000 times smaller than a human hair — can pack considerably more nucleic acids than solid structures. They work by bypassing the outer membrane of a cell, piercing it to deliver the nucleic acids. Notably, it does so without harming or killing the cell. By accessing a cell's cytoplasm directly, the researchers were able to efficiently reprogram it.
And because the nanoneedles are made from biodegradable silicon, they can be left in the body and not leave a toxic residue; they dissolve in about two days, leaving a negligible trace of harmless orthosilicic acid.
The nanoneedles have not been tested on humans, but the work on mice looks promising. Eventually, they could be used to restore lost function in tissues and organs, or used during organ transplants for an added boost as the organs settle into their new environment.
Conceivably, they could also be incorporated into a flexible bandage. For example, when applied to severely burnt skin they could reprogram the cells to heal the injury with functional tissue instead of forming a scar.
Read the entire study at Nature Materials: "Biodegradable silicon nanoneedles delivering nucleic acids intracellularly induce localized in vivo neovascularization".