Photopolymerizable Zwitterionic Polymer Patterns Control Cell Adhesion and Guide Neural Growth

Area of Science:

• Biomaterials Science
• Neuroscience
• Tissue Engineering

Background:

• Fibrosis encapsulation of neural prosthetic implants hinders device performance by degrading the tissue/electrode interface.
• Developing advanced materials to mitigate this foreign body response is crucial for long-term neural device efficacy.

Purpose of the Study:

• To investigate the potential of zwitterionic polymers, specifically sulfobetaine methacrylate (SBMA) and carboxybetaine methacrylate (CBMA), in controlling cellular interactions relevant to neural prosthetics.
• To assess the ability of these zwitterionic materials to prevent fibroblast adhesion and guide the growth of neural cells.

Main Methods:

• Photografting and micropatterning of SBMA and CBMA polymers onto glass surfaces.
• Characterization using X-ray photoelectron spectroscopy, water contact angle measurements, and protein adsorption assays.
• In vitro cell culture studies using fibroblasts, astrocytes, and Schwann cells to evaluate cell adhesion, morphology, and neurite outgrowth.

Main Results:

• Zwitterionic surfaces, particularly CBMA, significantly inhibited fibroblast adhesion, a key cell type in fibrotic encapsulation.
• Astrocytes and Schwann cells exhibited reduced adhesion and altered morphology on zwitterionic surfaces.
• Micropatterned zwitterionic surfaces demonstrated controlled alignment of Schwann cells and spiral ganglion neuron neurites.

Conclusions:

• SBMA and CBMA photografted surfaces show promise in reducing foreign body response and fibrosis around neural implants.
• These zwitterionic materials can modulate cell behavior, offering a strategy to improve the neural tissue/implant interface.
• Patterned zwitterionic coatings provide directional cues for neural cell growth, potentially enhancing neural regeneration and prosthetic integration.