Zwitterionic Polydopamine Engineered Interface for In Vivo Sensing with High Biocompatibility.

Area of Science:

• Biomaterials Engineering
• Electrochemical Sensing
• Neuroscience

Background:

• Electrochemical sensor performance degrades due to biofouling from non-specific protein binding in biological fluids.
• Developing robust biointerfaces to prevent biofouling is a significant challenge for reliable biosensing.

Purpose of the Study:

• To engineer a robust biointerfacing material to resist non-specific protein binding.
• To enhance the electron transfer, electrochemical stability, and in vivo performance of tissue-implantable electrodes.

Main Methods:

• Utilized polydopamine (PDA) as a base material for biointerfacing.
• Grafted zwitterionic sulfobetaine methacrylate (SBMA) molecules onto PDA via Michael Addition.
• Integrated the SBMA-PDA biointerface with tissue-implantable electrodes for in vivo brain implantation in rats.

Main Results:

• The SBMA-PDA biointerface effectively resisted non-specific protein binding in complex biological fluids.
• Demonstrated enhanced interfacial electron transfer and electrochemical stability of the electrodes.
• Achieved sustained in vivo sensing performance, retaining 92.0% of initial sensitivity after 2 hours of implantation in rat brain tissue.
• Observed low acute neuroinflammatory responses and good stability in both normal and Parkinson's disease (PD) rat brain tissue.

Conclusions:

• The SBMA-PDA biointerface offers a promising solution for robust and stable electrochemical sensing in complex biological environments.
• This engineered biointerface significantly improves the performance and longevity of tissue-implantable electrodes for in vivo neurological monitoring.
• The findings suggest potential applications in chronic neurological disease monitoring and diagnostics.