Gold Nanoparticle Patterning on Planar Type MEA for Selective Inhibition of Cultured Neuronal Network Using NIR Photothermal Effect

Abstract

Event Abstract Back to Event Gold Nanoparticle Patterning on Planar Type MEA for Selective Inhibition of Cultured Neuronal Network Using NIR Photothermal Effect Gu-Haeng Lee1* and Yoonkey Nam2 1 Korea Advanced Institute of Science and Technology, Dept. of Bio and Brain Engineering, Korea 2 Korea Advanced Institute of Science and Technology, Dept. of Bio and Brain Engineering, Korea 1. Motivation MEA (multi-electrodes array) is a powerful tool to research about dissociated neuronal culture activities. There are several methods to control neuronal networks like electrical stimulation, drug stimulation and cell patterning. Especially, limited methods are used to inhibit neurons using drug or optogenetic method. Inhibition method using the photothermal effect of gold nanoparticles is recently shown [1]. In this work, we tried to combine photothermal inhibition and patterning method for selective inhibition that is hard to achieve using conventional electrical stimulation. 2. Material and Methods GNR (gold nanorod) was PEGylated by SH-PEG-NH2(+) to stabilize and modify the surface property. Substrates were planar type MEAs.with the surface of silicon nitride or ONO(Oxide/Nitride/Oxide). After one minute of air plasma treatment on substrates, GNR solution was loaded on the substrate for 12~24 hours. Then, substrates were rinsed with distilled water and dried by an airgun. A PDMS stamp was treated with air plasma for one minute and it was brought in contact with the GNR coated substrates for one minute. After peeling off stamp carefully, we can see the lift-up result. 3. Results Figure1(left). SEM image of the lift-up result on the cover glass. GNRs remain on the bright part. Size of single dot is 3 ¥ìm Figure 2(right). Modified phase contrast image of MEA with GNR(dark) pattern. Distance between center of electrodes is 200 ¥ìm For the lift-up result, the removal ratio of GNR on the substrate was changed to the different condition, like property of GNR, GNR loading time, time after GNR coating, plasma treatment time on PDMS. We saw consistent results from a cover glass substrate that was not necessary to align pattern. There were no limits of pattern shape similar to micro contact printing and achieve circle shape 3-¥ìm size pattern to smallest pattern. We performed lift-up from two kinds of surface condition and GNR charge property. 4. Discussion Lift-up soft lithography can be used in a large area, so it is good for controlling large size network. Cell patterning using micro contact printing or micro-molding in the capillary can be added, because GNR patterning does not affect to network morphology. 5. Conclusion We show GNR micro patterning using lift-up soft lithography was operating well on MEA surface. We may selectively inhibit cultured neuronal network by GNR patterning which is relatively easy compared to light patterning or optogenetic methods. We expect this work helps research about neuronal network by controlling network activities.