Striatal rAAV Delivery Using CED for Cortex-Wide Expression
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Solution Overview
Problem
Existing methods for delivering adeno-associated virus (AAV) vectors to the cerebral cortex and striatum are inefficient, limiting widespread expression and treatment efficacy for neurologic disorders.
Innovation Solution
A method involving the administration of recombinant AAV particles, specifically AAV1 or AAV2 capsids, to the striatum using convection-enhanced delivery (CED) to achieve widespread expression in the cerebral cortex and striatum, with targeted administration to the putamen and caudate nucleus, and optionally including retrograde or anterograde transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If simple injection method is used to deliver AAV vectors, then the procedure is simple and safe, but the distribution is limited to only 1- to 3-mm radius
Solution Approach 1:
The patent employs convection-enhanced delivery (CED) using a pump to deliver AAV vectors through a cannula into the brain parenchyma. The pump creates hydrostatic pressure to overcome interstitial fluid pressure, forcing the viral particles into close contact with the dense perivasculature. This hydraulic mechanism enables distribution over large distances throughout the parenchyma, resolving the contradiction between simple administration and limited distribution radius.
2Productivity
If convection-enhanced delivery (CED) is used to increase distribution, then the delivery efficacy is improved, but the complexity of the delivery system increases
Solution Approach 1:
The patent introduces a reflux-resistant cannula as an intermediary device to facilitate CED. The cannula includes a reflux barrier that prevents backflow of cerebrospinal fluid while allowing forward flow of AAV vectors. This intermediary component simplifies the overall system by providing a self-regulating mechanism that reduces the need for complex external monitoring and control systems, while still achieving widespread distribution.
Solution Approach 2:
The patent incorporates monitored delivery with real-time MRI imaging as a feedback mechanism. This allows quantification and control of aberrant events such as cannula reflux and leakage of infusate into ventricles. The feedback from MRI imaging enables real-time adjustment of delivery parameters, improving safety and efficacy while providing control over the complex CED process.
3Area of stationary object
If AAV vectors are delivered to achieve widespread expression in cortex and striatum, then treatment coverage is improved, but the delivery precision and control become more difficult
Solution Approach 1:
The patent employs stereotactic delivery to achieve precise local placement of the cannula tip in the striatum. By controlling the delivery location and utilizing the natural anatomy of the brain (striatum as entry point with known projections to cortex), the system achieves both precision and widespread expression. The local quality of the striatal injection site enables targeted delivery that naturally spreads to multiple brain regions through anatomical pathways.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the safety and efficacy of AAV vector delivery, allowing for widespread expression of therapeutic nucleic acids in the brain regions, effectively treating neurologic disorders such as Huntington's and Parkinson's diseases.
Implementation Method 1
pumping infusate into brain parenchyma under sufficient pressure to overcome the hydrostatic pressure of interstitial fluid
Implementation Method 2
convection-enhanced delivery (CED) involves pumping infusate into brain parenchyma under sufficient pressure to overcome the hydrostatic pressure of interstitial fluid, thereby forcing the infused particles into close contact with the dense perivasculature of the brain
Implementation Method 3
Pulsation of these vessels acts as a pump, distributing the particles over large distances throughout the parenchyma
Implementation Method 4
the rAAV particle undergoes retrograde or anterograde transport in the cerebral cortex
Implementation Method 5
the rAAV particle undergoes retrograde or anterograde transport in the cerebral cortex
Data Source
AI summary
Provided herein are novel methods for delivering recombinant adeno-associated viral (rAAV) particles to the central nervous system of a mammal (e.g., a human). In aspects, the methods involve administering rAAV particles containing a heterologous nucleic acid to the striatum and causing expression of the heterologous nucleic acid in at least the cerebral cortex and the striatum of the mammal.