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SPEAKER 1: And the new cannulas you developed are cannulas that prevent the reflux of the infusate and allow the infusate to remain in the region that you targeted. Is that correct?
KRYSTOF BANKIEWICZ: That's right. Because if you use a not-specialized cannula for the infusion of gene therapy, what happens is the majority, if not all, the fluid that is carrying the viral particles that is being injected into the brain is going to travel straight back into the cortical surface. That's called reflux. So that's one issue.
The second one is we, utilizing what's called the convection-enhanced delivery-- it's a system that would permit us to open extracellular spaces based on the pressurized infusions, creating little spaces, little pores within the tissue that will allow viral vectors, which are 20 nanometers, to travel to very distant areas from just the insertion tip. So this was very critical to develop.
The other thing that we've learned, and we've successfully implemented, is that all the gene therapy strategies are being performed in an MR scanner. So the targeting is also performed in the scanner to allow for incredibly precise placement of the cannula. But at the same time, we can observe the viral particles being distributed within the tissue to assure proper coverage then.
This is not really particles that we are imaging. We're adding an MR tracer that travels at the same speed as the particles, giving us a very, very close correlation, this being as a surrogate mark.
SPEAKER 1: So you infuse also gadolinium together with the infusate so that you can make sure that you are covering the area. And you can follow with MRI also the coverage, and there is no migration of the infusate.
KRYSTOF BANKIEWICZ: Yeah, so these are trace amounts of gadolinium given locally, so multiple reasons for that. One, as I just explained, it's assuring us that we achieved a proper delivery strategy.
But also it allows us during the infusion to manipulate the cannula tip in the sense that we can prevent this from leaking through the perivascular spaces into the CSF. That really is a critical component of the whole procedure that allows neurosurgeons to be very proactive in assuring that we really get a proper coverage.
