A nanotech replacement for virus vectors offers a safer way to introduce DNA into cells for gene therapy. The combination of specially designed peptides and a polymer scaffolding makes it possible to mimic the variety of sizes and shapes that viruses have evolved to efficiently insert their genes into cells. From the University of Georgia via KurzweilAI.net “UGA research may lead to safer, more effective gene therapy“:
The potential of gene therapy has long been hampered by the risks associated with using viruses as vectors to deliver healthy genes, but a new University of Georgia study helps bring scientists closer to a safe and efficient gene delivery method that doesn’t involve viruses.
Assistant professor of chemistry Yan Geng and her colleagues in the UGA Franklin College of Arts and Sciences have created a novel synthetic gene vector that packages DNA into well-defined nanostructures that allow it to efficiently deliver genes without triggering immune responses. The study, primarily carried out by doctoral student Jennifer Haley, appears in the June issue of the journal Molecular BioSystems [citation] and also may have implications for cancer treatment and vaccine development.
…Synthetically packaging long strands of DNA into compact, small structures has long been a challenge, but Geng’s team has developed a unique combinative self-assembly method that allows scientists to control precisely the size and shape of the vector. The Geng team synthesized small peptides — which are short chains of amino acids — that bind to genes and emulate natural proteins to minimize potential immune reactions. The researchers then attach the small peptides onto a biocompatible polymer scaffold to create a clustered effect. The clustered peptides of the combined molecule will automatically assemble with DNA, while the polymer wraps around the assembly, creating a protective shell. The researchers have discovered that the assembly process is extremely sensitive to the clustered arrangement of the gene-binding peptides. To change the shape and size of the vectors, the researchers simply change the attachment density of the peptides on the polymer scaffold, resulting in shapes that vary from spherical to donut shaped to long filaments.
“These gene vectors also can be further conjugated with targeting molecules, which will allow us to deliver the right genes to the right spot in our body,” Geng added.
With the synthesis of the vector complete, the scientists now plan to assess how effective it is in integrating genes into cancer cells. Geng said her ultimate goal is to use tumor-suppressor genes to treat cancer. Another possibility is to use the synthetic vectors to introduce genes that boost the immune system.
“Our research is still at an early stage,” Geng said, “but we’ve developed a very promising system.”
—Jim
