Figure 1. Brain section of polymer coated microwire probe. Red–  microglia (Iba-1), white – astrocyte (GFAP), green – neuronal body (Nissl). Chronic Inflammatory response is evident surrounding the implantation site, but no adverse effect of the degradation of the polymer is evident. Scale bar 120 um

     This research seeks to provide a biodegradable polymer that can be used to fabricate neural prosthetic devices to improve brain machine interface (BMI) performance.  Cortical neural probes use microchip technology to create electrodes that are inserted into the brain and used to stimulate and/or record signals directly from neurons. 

     The Kohn Lab's work facilitates the design of polymeric biomaterials to prolong their performance via stealth approach. A fast degrading shuttle is used to insert the probe into the brain, the shuttle provides stiffness  to  enable the insertion of the electrodes, and ameliorates the acute response to the injury. More importantly, the polymer coating is expected to minimize the chronic long-term response to the foreign body present in the brain (Figure 1). This response inhibits, and even prevents, the probe’s function due to isolation from the neurons in its immediate surroundings.  The Kohn Lab research identified a unique, quickly degrading polymer that appears to have all the properties required for this application, and a method to test this device in animals.

Reconstructed confocal image of brain tissue immune response to implanted polymer fiber. Green- neurons, blue- microglia, yellow- astrocytes

Project Leader: Dan Lewitus, PhD candidate
Funding Source: RESBIO - The National Resource for Polymeric Biomaterials via the National Institutes of Health (EB001046).