TY - JOUR
T1 - Foreign body response to intracortical microelectrodes is not altered with dip-coating of polyethylene glycol (PEG)
AU - Lee, Heui C.
AU - Gaire, Janak
AU - Currlin, Seth W.
AU - McDermott, Matthew D.
AU - Park, Kinam
AU - Otto, Kevin J.
N1 - Publisher Copyright:
© 2017 Lee, Gaire, Currlin, McDermott, Park and Otto.
PY - 2017/9/14
Y1 - 2017/9/14
N2 - Poly(ethylene glycol) (PEG) is a frequently used polymer for neural implants due to its biocompatible property. As a follow-up to our recent study that used PEG for stiffening flexible neural probes, we have evaluated the biological implications of using devices dip-coated with PEG for chronic neural implants. Mice (wild-type and CX3CR1-GFP) received bilateral implants within the sensorimotor cortex, one hemisphere with a PEG-coated probe and the other with a non-coated probe for 4 weeks. Quantitative analyses were performed using biomarkers for activated microglia/macrophages, astrocytes, blood-brain barrier leakage, and neuronal nuclei to determine the degree of foreign body response (FBR) resulting from the implanted microelectrodes. Despite its well-known acute anti-biofouling property, we observed that PEG-coated devices caused no significantly different FBR compared to non-coated controls at 4 weeks. A repetition using CX3CR1-GFP mice cohort showed similar results. Our histological findings suggest that there is no significant impact of acute delivery of PEG on the FBR in the long-term, and that temporary increase in the device footprint due to the coating of PEG also does not have a significant impact. Large variability seen within the same treatment group also implies that avoiding large superficial vasculature during implantation is not sufficient to minimize inter-animal variability.
AB - Poly(ethylene glycol) (PEG) is a frequently used polymer for neural implants due to its biocompatible property. As a follow-up to our recent study that used PEG for stiffening flexible neural probes, we have evaluated the biological implications of using devices dip-coated with PEG for chronic neural implants. Mice (wild-type and CX3CR1-GFP) received bilateral implants within the sensorimotor cortex, one hemisphere with a PEG-coated probe and the other with a non-coated probe for 4 weeks. Quantitative analyses were performed using biomarkers for activated microglia/macrophages, astrocytes, blood-brain barrier leakage, and neuronal nuclei to determine the degree of foreign body response (FBR) resulting from the implanted microelectrodes. Despite its well-known acute anti-biofouling property, we observed that PEG-coated devices caused no significantly different FBR compared to non-coated controls at 4 weeks. A repetition using CX3CR1-GFP mice cohort showed similar results. Our histological findings suggest that there is no significant impact of acute delivery of PEG on the FBR in the long-term, and that temporary increase in the device footprint due to the coating of PEG also does not have a significant impact. Large variability seen within the same treatment group also implies that avoiding large superficial vasculature during implantation is not sufficient to minimize inter-animal variability.
KW - CX3CR1-GFP
KW - Chronic neural implant
KW - Foreign body response (FBR)
KW - Neuroprosthetics
KW - Polyethylene glycol (PEG)
UR - http://www.scopus.com/inward/record.url?scp=85029838817&partnerID=8YFLogxK
U2 - 10.3389/fnins.2017.00513
DO - 10.3389/fnins.2017.00513
M3 - Article
AN - SCOPUS:85029838817
SN - 1662-4548
VL - 11
JO - Frontiers in Neuroscience
JF - Frontiers in Neuroscience
IS - SEP
M1 - 513
ER -