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{748}
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ref: Leung-2008.08 tags: biocompatibility alginate tissue response immunochemistry microglia insulation spin coating Tresco recording histology MEA date: 01-28-2013 21:19 gmt revision:4 [3] [2] [1] [0] [head]

PMID-18485471[0] Characterization of microglial attachment and cytokine release on biomaterials of differing surface chemistry

  • The important result is that materials with low protein-binding (e.g. alginate) have fewer bound microglia, hence better biocompatibility. It also seems to help if the material is highly hydrophilic.
    • Yes alginate is made from algae.
  • Used Michigan probes for implantation.
  • ED1 = pan-macrophage marker.
    • (quote:) Quantification of cells on the surface indicated that the number of adherent microglia appeared higher on the smooth side of the electrode compared to the grooved, recording site side (Fig. 2B), and declined with time. However, at no point were electrodes completely free of attached and activated microglial cells nor did these cells disappear from the interfacial zone along the electrode tract.
    • but these were not coated with anything new .. ???

____References____

[0] Leung BK, Biran R, Underwood CJ, Tresco PA, Characterization of microglial attachment and cytokine release on biomaterials of differing surface chemistry.Biomaterials 29:23, 3289-97 (2008 Aug)

{1036}
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ref: -0 tags: decoding recording todo read biocompatibility histology electrodes future date: 01-28-2013 20:52 gmt revision:9 [8] [7] [6] [5] [4] [3] [head]

Things to read!

decoding:

  • PMID-20359500 Population decoding of motor cortical activity using a generalized linear model with hidden states
  • Robust satisficing linear regression: Performance/robustness trade-off and consistency criterion
  • PMID-15813408 Closed-loop cortical control of direction using support vector machines
  • Efficient Decoding With Steady-State Kalman Filter in Neural Interface Systems
    • Fixed gain: We analyze a low-complexity Kalman filter implementation in which the filter gain is approximated by its steady-state form, computed offline before real-time decoding commences.
    • We also find that the steady-state Kalman filter reduces the computational load (algorithm execution time) for decoding the firing rates of 25±3 single units by a factor of 7.0±0.9.

electrodes:

other random scribblings: Vascularization {1027} histology {736},{737} and size {1028},{747},{1026}, insulation {1033}. How very very important -- as important or moreso than the recording technology. What has happened to {149} ?

{746}
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ref: Sanders-2000.1 tags: polymer fiber immune reaction biocompatibility rats polycaprolactone recording electrodes histology MEA date: 01-28-2013 00:01 gmt revision:11 [10] [9] [8] [7] [6] [5] [head]

PMID-10906696[0] Tissue response to single-polymer fibers of varying diameters: evaluation of fibrous encapsulation and macrophage density.

  • Fibers smaller than 6μm6 \mu m show reduced immune response.
    • Fibers implanted in the subcutaneous dorsum (below the skin in the back of rats).
    • Polypropylene. (like rope).
    • Wish the result extended to small beads & small electrodes. 7μm7 \mu m is tiny, but possible with insulated Au wires.
      • Beads: try PMID-1913150 -- shows that the 600um - 50um beads ('microspheres') are well tolerated.
      • Also {750}.
  • Macrophage density in tissue with fiber diameters 2.1-5.9um comparable to that of unoperated contralateral control.

"

fiber diametercapsule thickness
2.1-5.90.6
6.5-10.611.7
11.1-15.820.3
16.7-26.725.5

____References____

[0] Sanders JE, Stiles CE, Hayes CL, Tissue response to single-polymer fibers of varying diameters: evaluation of fibrous encapsulation and macrophage density.J Biomed Mater Res 52:1, 231-7 (2000 Oct)

{1033}
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ref: Seymour-2009.1 tags: Parylene MEA biocompatibility pin hole water saturation PPX date: 01-25-2013 01:19 gmt revision:2 [1] [0] [head]

PMID-19703712[0] The insulation performance of reactive parylene films in implantable electronic devices.

  • Describe the development and testing of a superior form of parylene: poly(p-xylylene) functionalized with reactive group X (PPX-X)
  • Heat-treated PPX-X device impedance was 800% greater at 10kHz and 70% greater at 1Hz relative to heated parylene-C controls after 60 days (in saline).
  • Better wet attachment to the metal.

____References____

[0] Seymour JP, Elkasabi YM, Chen HY, Lahann J, Kipke DR, The insulation performance of reactive parylene films in implantable electronic devices.Biomaterials 30:31, 6158-67 (2009 Oct)

{749}
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ref: Biran-2007.07 tags: tresco biocompatibility tether skull electrodes Michigan probe recording Tresco date: 01-24-2013 20:11 gmt revision:6 [5] [4] [3] [2] [1] [0] [head]

PMID-17266019[0] The brain tissue response to implanted silicon microelectrode arrays is increased when the device is tethered to the skull.

  • Good, convincing, figures.

____References____

[0] Biran R, Martin DC, Tresco PA, The brain tissue response to implanted silicon microelectrode arrays is increased when the device is tethered to the skull.J Biomed Mater Res A 82:1, 169-78 (2007 Jul)

{1053}
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ref: Leach-2010.02 tags: BMI challenges histology biocompatibility review date: 01-16-2012 18:22 gmt revision:4 [3] [2] [1] [0] [head]

PMID-20161810[0] Bridging the Divide between Neuroprosthetic Design, Tissue Engineering and Neurobiology

  • Neuroprosthetic device technology has seen major advances in recent years but the full potential of these devices remains unrealized due to outstanding challenges, such as the ability to record consistently over long periods of time.
  • Discuss promising new treatments based on developmental and cancer biology (?)
  • Suggest controlled drug release as the tissue is healing. Makes sense.

____References____

[0] Leach JB, Achyuta AK, Murthy SK, Bridging the Divide between Neuroprosthetic Design, Tissue Engineering and Neurobiology.Front Neuroeng 2no Issue 18 (2010 Feb 8)