Research Website

https://engineering.purdue.edu/NPRlab/tiki-index.php

Keywords

LPS, Lipopolysaccharide, LAL, Limulus amebocyte lysate, Microelectrode, Chronic, Neuroinflammation

Presentation Type

Event

Research Abstract

Penetrating microelectrode arrays have a great potential to be used as control and communication interfaces for neuroprosthetics. A persistent obstacle in the clinical implementation of microelectrode arrays is the chronic degradation of these devices, putatively due to the foreign body response. Though researchers have studied the progression of the foreign body response and the effect of anti-inflammatory drugs on the efficacy of the implant, the exact biological mechanisms of implant degradation are not fully understood. To more closely investigate the effect of the foreign body response on device degradation, neuroinflammation can be exacerbated by coating dummy electrodes implanted into mice brains with lipopolysaccharide (LPS) – a cell wall component of bacteria which induces inflammation. Quantifying the amount of LPS released from a coated electrode is crucial in performing such an experiment. Using a Limulus amebocyte lysate (LAL) test – a test based on the extract of the blood from horseshoe crab which reacts with LPS – the concentration of LPS can be accurately quantified, allowing for a more careful characterization of the inflammatory response. In particular, the devices coated in 1 mg/ml concentration of LPS eluted a mean mass of 4.55 EU with a standard deviation of .51, where 1 endotoxin unit (EU) ≈ 1 ng. A linear regression of the standard concentrations resulted in an r2 of .9806, indicating a reliable model for calculating the concentration of LPS present in a sample. These results suggest that LPS elution can be accurately and precisely measured using the LAL assay.

Session Track

Biotechnology

FinalPoster.pdf (1283 kB)
Poster

Share

COinS
 
Aug 7th, 12:00 AM

Quantification of LPS Eluate from Coated Microelectrode Devices

Penetrating microelectrode arrays have a great potential to be used as control and communication interfaces for neuroprosthetics. A persistent obstacle in the clinical implementation of microelectrode arrays is the chronic degradation of these devices, putatively due to the foreign body response. Though researchers have studied the progression of the foreign body response and the effect of anti-inflammatory drugs on the efficacy of the implant, the exact biological mechanisms of implant degradation are not fully understood. To more closely investigate the effect of the foreign body response on device degradation, neuroinflammation can be exacerbated by coating dummy electrodes implanted into mice brains with lipopolysaccharide (LPS) – a cell wall component of bacteria which induces inflammation. Quantifying the amount of LPS released from a coated electrode is crucial in performing such an experiment. Using a Limulus amebocyte lysate (LAL) test – a test based on the extract of the blood from horseshoe crab which reacts with LPS – the concentration of LPS can be accurately quantified, allowing for a more careful characterization of the inflammatory response. In particular, the devices coated in 1 mg/ml concentration of LPS eluted a mean mass of 4.55 EU with a standard deviation of .51, where 1 endotoxin unit (EU) ≈ 1 ng. A linear regression of the standard concentrations resulted in an r2 of .9806, indicating a reliable model for calculating the concentration of LPS present in a sample. These results suggest that LPS elution can be accurately and precisely measured using the LAL assay.

http://docs.lib.purdue.edu/surf/2014/presentations/8