Functional Polysaccharide Materials

Nathan S. Mosier

Ag. and Bio. Engineering

Purdue University

Glycoscience in

Mammalian Systems

• Attached to cells and enzymes

• Important for protein function and cell-to-cell communication/interactions

• Research focus on health, drug development, and diagnostics

Glycoscience in

Non-Mammalian Systems

• More complex arrangements of saccharides

• More diverse functions

• Focus on plant cell wall assembly/dissasembly

• Applications focused on non-food source of reduced carbon for biomolecule/bioproduct production

Polysaccharides Properties

• Biocompatible

• Hydrophilic

• Controllable, biocatalytic assembly of complex polymers

• Potential for self-assembly of complex matrices of polymers

Functional Polymers

• Natural and bio-compatible

• Mature technologies in food, cosmetics, and pharmaceuticals

– Pectin (plant), xanthan gum (bacterial), carrageenan (algal) as thickening/gelling agents

– MCC as excipient

• Developing technology for as scaffolds for tissue engineering, nanoelectronic, etc.

Xanthan Gum

Green synthesis of chitosan-based nanofibers and their applications Lei Qian and Haifei Zhang Green Chem., 2010, 12, 1207-1214

Chitosan-based Nanofibers

Chitosan-based Biocompatible Proton Field-Effect Transistor

Zhong, C. et al. A polysaccharide bioprotonic field-effect transistor. Nat. Commun. 2:476 doi: 10.1038/ncomms1489 (2011).

Photo-crosslinked Maleic Chitosan-Polyethylene Glycol Diacrylate Hybrid Hydrogels

“Bionanoprotonics”

Functional Materials

Moon et al., Chem Soc Rev 2011.

Plant Cell Wall Assembly, Structure, and Deconstruction

Cytoskeletal and Secretion

Machinery for Trafficking

Polysaccharides (hemicellulose

and pectin) to the cell wall

Cellulose Biosynthesis

Assembly of the Cellulose

Microfibril

Lignin Biosynthesis and

Deposition

Nano and Molecular

Scale Architecture

Gaining Molecular Control Over Cell Wall Assembly

1. What constitutes a functional actin track for wall material delivery

and how is the network organization created?

3. What controls the packaging

and delivery of CESA and

non-cellulosic polysaccharides?

2. What microtubule structures efficiently recruit compartmentalized CESA?

Control of Cellulose Microfibril Deposition

Hemicellulose Structure Variability: Impact on Structure

Complex Mixture of Enzymes Needed to Degrade Hemicellulose

…..Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4X…..

…...Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4Xß1-4X…..

I 3 I I Af I 5 I Fer I Fer-O-Fer- I 5 I Af I I 3 I

I 3 I Af

Lignin

4Xß1-4X

2X

Xylanase

Ac I 3 I

Acetylxylan

esterase

mGu I 1 I 2 I

-Glucuronidase

ß-xylosidase

Arabinofuranosidase

Feruloyl esterase

Selinger et al., 1996

Up to 21

Enzymes

Required!

Temperature sensitive hydrogels prepared from Eucalyptus hemicellulose cross-linked with maleic anhydride

Yang, Zhou, Fang “Synthesis and characterization of temperature sensitive hemicellulose-based Hydrogels,” Carb. Poly. 86, 1113-1117, (2011)

Figure 6. Adhesion between a cellulose sphere and a neat xyloglucan graft on gold.

Top-Down Grafting of Xyloglucan to Gold Monitored by QCM-D and AFM: Enzymatic Activity and Interactions with Cellulose

Niklas Nordgren, Jens Eklöf, Qi Zhou, Harry Brumer, IIIand Mark W. Rutland

Biomacromolecules, 2008, 9 (3), pp 942–948

Interactions between Xylans and Cellulose

Opportunities

• Wide array of natural and synthetic polymers and materials for a multitude of applications

• Potential for engineered structures and chemistries produced in vivo or in vitro

– Self assembled

– Self healing

• Molecular and nano scale control of chemistry and structure

Challenges

• Understanding relationships between structure and function

• Understanding glycoside-glycoside interactions at Angstrom and nano scale

• Predict properties (physical, chemical, mechanical, etc) based upon sequence/structure