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pHEMA Encapsulated PEDOT-PSS-CNT Microsphere Microelectrodes for Recording Single Unit Activity in the Brain.

Castagnola E, Maggiolini E, Ceseracciu L, Ciarpella F, Zucchini E, De Faveri S, Fadiga L, Ricci D - Front Neurosci (2016)

Bottom Line: This enhancement significantly reduces the size of the implantable device though preserving excellent electrical performances.Moreover, the spherical shape of the electrode together with the surface area increase provided by the nanocomposite deposited on it, maximize the electrical contact and may improve recording stability over time.These results have a good potential to contribute to fulfill the grand challenge of obtaining stable neural interfaces for long-term applications.

View Article: PubMed Central - PubMed

Affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia Ferrara, Italy.

ABSTRACT
The long-term reliability of neural interfaces and stability of high-quality recordings are still unsolved issues in neuroscience research. High surface area PEDOT-PSS-CNT composites are able to greatly improve the performance of recording and stimulation for traditional intracortical metal microelectrodes by decreasing their impedance and increasing their charge transfer capability. This enhancement significantly reduces the size of the implantable device though preserving excellent electrical performances. On the other hand, the presence of nanomaterials often rises concerns regarding possible health hazards, especially when considering a clinical application of the devices. For this reason, we decided to explore the problem from a new perspective by designing and testing an innovative device based on nanostructured microspheres grown on a thin tether, integrating PEDOT-PSS-CNT nanocomposites with a soft synthetic permanent biocompatible hydrogel. The pHEMA hydrogel preserves the electrochemical performance and high quality recording ability of PEDOT-PSS-CNT coated devices, reduces the mechanical mismatch between soft brain tissue and stiff devices and also avoids direct contact between the neural tissue and the nanocomposite, by acting as a biocompatible protective barrier against potential nanomaterial detachment. Moreover, the spherical shape of the electrode together with the surface area increase provided by the nanocomposite deposited on it, maximize the electrical contact and may improve recording stability over time. These results have a good potential to contribute to fulfill the grand challenge of obtaining stable neural interfaces for long-term applications.

No MeSH data available.


Related in: MedlinePlus

Representative SEM micrographs of the same pHEMA-encapsulated PEDOT-PSS-CNT microsphere (A) before and (B) after one week immersion in a PBS solution containing 30 mM of H2O2 to mimick the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction.
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Figure 4: Representative SEM micrographs of the same pHEMA-encapsulated PEDOT-PSS-CNT microsphere (A) before and (B) after one week immersion in a PBS solution containing 30 mM of H2O2 to mimick the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction.

Mentions: To perform in-vitro tests for evaluating the stability of pHEMA encapsulation, we have immersed pHEMA coated microspheres in a phosphate buffered saline (PBS) solution containing 30 mM of H2O2 for 1 week, mimicking the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction (Fonseca and Barbosa, 2001; Patrick et al., 2011). The pHEMA encapsulation showed to withstand the test without visible erosion or cracks. An image of the same pHEMA-encapsulated PEDOT-PSS-CNT probe before and after the immersion test is shown in Figures 4A,B.


pHEMA Encapsulated PEDOT-PSS-CNT Microsphere Microelectrodes for Recording Single Unit Activity in the Brain.

Castagnola E, Maggiolini E, Ceseracciu L, Ciarpella F, Zucchini E, De Faveri S, Fadiga L, Ricci D - Front Neurosci (2016)

Representative SEM micrographs of the same pHEMA-encapsulated PEDOT-PSS-CNT microsphere (A) before and (B) after one week immersion in a PBS solution containing 30 mM of H2O2 to mimick the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834343&req=5

Figure 4: Representative SEM micrographs of the same pHEMA-encapsulated PEDOT-PSS-CNT microsphere (A) before and (B) after one week immersion in a PBS solution containing 30 mM of H2O2 to mimick the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction.
Mentions: To perform in-vitro tests for evaluating the stability of pHEMA encapsulation, we have immersed pHEMA coated microspheres in a phosphate buffered saline (PBS) solution containing 30 mM of H2O2 for 1 week, mimicking the situation where the device is implanted in the human body and hydrogen peroxide is generated by an inflammatory reaction (Fonseca and Barbosa, 2001; Patrick et al., 2011). The pHEMA encapsulation showed to withstand the test without visible erosion or cracks. An image of the same pHEMA-encapsulated PEDOT-PSS-CNT probe before and after the immersion test is shown in Figures 4A,B.

Bottom Line: This enhancement significantly reduces the size of the implantable device though preserving excellent electrical performances.Moreover, the spherical shape of the electrode together with the surface area increase provided by the nanocomposite deposited on it, maximize the electrical contact and may improve recording stability over time.These results have a good potential to contribute to fulfill the grand challenge of obtaining stable neural interfaces for long-term applications.

View Article: PubMed Central - PubMed

Affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia Ferrara, Italy.

ABSTRACT
The long-term reliability of neural interfaces and stability of high-quality recordings are still unsolved issues in neuroscience research. High surface area PEDOT-PSS-CNT composites are able to greatly improve the performance of recording and stimulation for traditional intracortical metal microelectrodes by decreasing their impedance and increasing their charge transfer capability. This enhancement significantly reduces the size of the implantable device though preserving excellent electrical performances. On the other hand, the presence of nanomaterials often rises concerns regarding possible health hazards, especially when considering a clinical application of the devices. For this reason, we decided to explore the problem from a new perspective by designing and testing an innovative device based on nanostructured microspheres grown on a thin tether, integrating PEDOT-PSS-CNT nanocomposites with a soft synthetic permanent biocompatible hydrogel. The pHEMA hydrogel preserves the electrochemical performance and high quality recording ability of PEDOT-PSS-CNT coated devices, reduces the mechanical mismatch between soft brain tissue and stiff devices and also avoids direct contact between the neural tissue and the nanocomposite, by acting as a biocompatible protective barrier against potential nanomaterial detachment. Moreover, the spherical shape of the electrode together with the surface area increase provided by the nanocomposite deposited on it, maximize the electrical contact and may improve recording stability over time. These results have a good potential to contribute to fulfill the grand challenge of obtaining stable neural interfaces for long-term applications.

No MeSH data available.


Related in: MedlinePlus