Conformal, Mechanically Matched Hydrogel Coating for Long Term Biocompatibility of Neural Implants

Technology #17418

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Various side views of a hydrogel coated capillary tube in an initial swollen state, a dried state, and in a rehydrated and swollen state.Hydrogel coating thickness as a function of the number of spray coats, and the elastic modulus as a function of polymer concentration (w/w) in phosphate buffered saline before crosslinking.
Professor Michael Cima
Department of Materials Science and Engineering, MIT
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Jay Sy
Koch Institute, MIT
Kevin Spencer
Department of Materials Science and Engineering, MIT
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Ben Rockney
MIT Technology Licensing Officer
Patent Protection

Systems and Methods for Reducing Scar Formation About a Neural Implant

US Patent Pending US 2016-0354034

Systems and Methods for Reducing Scar Formation About a Neural Implant

PCT Patent Application WO 2016-196903


This technology increases long term effectiveness of medical devices that come in contact with brain or other neurological tissues.

Problem Addressed

Deep brain stimulation using neural implants is an effective treatment for several neurological circuit disorders. Electrodes are surgically implanted into the brain and may perform a variety of functions besides stimulation, such as releasing pharmaceutical compounds or monitoring neural activity. However, long term biocompatibility remains a problem due to normal micro-motions of the brain which encourage an inflammatory response in the brain, leading to the development of glial scar tissue. This scar tissue envelopes the implant, creating a barrier between the device and neural cells causing diminished effectiveness or failure of these implants. This technology increases biocompatibility by utilizing a hydrogel coating that more closely mimics the mechanical properties of brain tissue thereby reducing scarring and allowing for long term use of neural implants.


This invention presents a novel method of reducing brain tissue strain and therefore glial scarring through lowering the elastic modulus of neural implants to more closely mimic that of brain tissue. Although the brain’s elastic modulus varies between 5-100kPa, most implants have elastic moduli on the order of GPa, a significant contributing factor to low long term biocompatibility. To increase biocompatibility, a dry hydrogel coating is covalently bonded to a device to allow for confirmation of coating integrity. The thickness and elastic modulus of the coating may be adjusted for its specific application through polymer composition, making it applicable to most implant materials and designs. Upon implantation, the hydrogel swells to match the mechanical properties of brain tissue and thereby reduce scarring. This technology will reduce the incidence of neural implant failure, while increasing its effectiveness for long term use. 


  •  Improves effectiveness of existing neural implants
  •  Applicable to almost any device design or material
  •  Flexible thickness and elastic modulus for variety of applications