Biopolymer based artificial tissues and implant coatings:
A collaboration with C. Barrett (Polymer Chemistry) , O. Mermut (Biomedical Physics, York U.)
There is a great interest in developing artificial polymer ‘tissues’, scaffolds, and coatings, to mimic real biological materials, and serve as bio-compatible coatings for artificial implants. There are many possible biomedical applications for these polymer assembles now demonstrated, yet many of the basic questions important to their development are the same: what do these materials look like at the molecular level, how are they assembled together, and how can a detailed understanding of this structure help guide new materials to function better for a range of biomedical applications.
These polymer layers and structures are generally self-assembled from aqueous solution from water- soluble components, making the materials also ‘green’, low-toxicity’, and bio- and environmentally friendly.
A ‘Layer-by-Layer’ self-assembly approach is employed, to alternately coat surfaces (and implants) with positively-, then negatively-charged water-soluble polymers (polyelectrolytes), repeating many cycles (by hand, or robotically) and under varying pH or salt conditions to build up multi-layers of the desired thickness and physical properties to successfully mimic a wide variety of natural tissues.
Most recent successes (and patents) now include incorporating real biopolymers such as silk, cellulose, and chitosan.
Landry et al. Macromolecular Bioscience, 2019, 19, 1900036.
The design, characterization and evaluation of the film properties requires a wide range of tools:
In-situ ellipsometry: Film swelling
Atomic force microscopy (AFM): Film mechanical properties and adhesion:
Solid-state NMR Spectroscopy: Molecular -level film structure:
Fortier-McGill et al. "13C MAS NMR study of poly (methacrylic acid)–polyether complexes and multilayers."
Macromolecules 47.(2014): 4298.
Current Projects
Light triggered Biodegradable films
Biocompatible Implant coatings
HEdwards KE, Kim M, Borchers TH, Barrett CJ. Controlled disassembly of azobenzene cellulose-based thin films using visible light. Materials Advances. 2022;3(15):6222-30
Landry, Michael J., et al. "Tunable engineered extracellular matrix materials: polyelectrolyte multilayers promote improved neural cell growth and survival." Macromolecular Bioscience 19.5 (2019): 1900036.
For more information:
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Prof. Chris Barrett
http://barrett-group.mcgill.ca/
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Prof. Ozzy Mermut
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