'New drug delivery technique can inject genes into kidneys'

Researchers have developed a novel drug carrying system, and used it to deliver genes directly into the kidneys of mice, an advance that may pave the way for effective gene therapy techniques.

The scientists from Mayo Clinic, an American non-profit organisation academic medical centre, studied the effectiveness of delivering three different sized vectors, or carriers, to mouse kidneys via an intravenous route.

These included the protein package enveloping three viruses, including the small adeno-associated virus (AAV) vectors, larger adenovirus vectors, and lentiviral vectors, repurposed and engineered for drug delivery.

According to the study, published in the journal Mary Ann Liebert, Inc., some of the vectors could leak out of the kidney, creating the possibility for off-target tissue effects.

When gene delivery was observed in the kidney, the researchers found that its activity was not present evenly throughout the organ, and focussed in a cluster of small blood vessels at the end of kidney tubules.

Since the kidneys filter out large molecules in the blood stream, the scientists also tested two different direct injection routes to the organ, and found these to be superior to intravenous injections.

Concluding the research, the scientists said the potential for direct injections may open new possibilities for treating kidney diseases with gene therapy.

However, they said additional improvements to the delivery technique are needed.

"These data demonstrate the utility of direct kidney injections to circumvent the kidney size exclusion barrier. They also identify the effects of vector size on on-target and off-target transduction," the researchers wrote in the study.