Cellulose-pectin composite hydrogels: Intermolecular interactions and material properties depend on order of assembly

Patricia Lopez-Sanchez; Marta Martinez-Sanz; Mauricio R Bonilla; Dongjie Wang; Elliot P Gilbert; Jason R Stokes; Michael J Gidley

doi:10.1016/j.carbpol.2017.01.049

Cellulose-pectin composite hydrogels: Intermolecular interactions and material properties depend on order of assembly

Carbohydr Polym. 2017 Apr 15:162:71-81. doi: 10.1016/j.carbpol.2017.01.049. Epub 2017 Jan 15.

Authors

Patricia Lopez-Sanchez¹, Marta Martinez-Sanz², Mauricio R Bonilla³, Dongjie Wang⁴, Elliot P Gilbert⁵, Jason R Stokes³, Michael J Gidley⁴

Affiliations

¹ ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, 4072, Australia. Electronic address: patricia2011.ls@gmail.com.
² ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, 4072, Australia; Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales, 2232, Australia.
³ School of Chemical Engineering, The University of Queensland, Brisbane, 4072, Australia.
⁴ ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, 4072, Australia.
⁵ Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales, 2232, Australia.

PMID: 28224897
DOI: 10.1016/j.carbpol.2017.01.049

Abstract

Plant cell walls have a unique combination of strength and flexibility however, further investigations are required to understand how those properties arise from the assembly of the relevant biopolymers. Recent studies indicate that Ca²⁺-pectates can act as load-bearing components in cell walls. To investigate this proposed role of pectins, bioinspired wall models were synthesised based on bacterial cellulose containing pectin-calcium gels by varying the order of assembly of cellulose/pectin networks, pectin degree of methylesterification and calcium concentration. Hydrogels in which pectin-calcium assembly occurred prior to cellulose synthesis showed evidence for direct cellulose/pectin interactions from small-angle scattering (SAXS and SANS), had the densest networks and the lowest normal stress. The strength of the pectin-calcium gel affected cellulose structure, crystallinity and material properties. The results highlight the importance of the order of assembly on the properties of cellulose composite networks and support the role of pectin in the mechanics of cell walls.

Keywords: Cellulose; Mechanics; Pectin; SANS; SAXS; XRD.

MeSH terms

Cell Wall
Cellulose / chemistry*
Hydrogels / chemical synthesis
Hydrogels / chemistry*
Pectins / chemistry*
Scattering, Small Angle
X-Ray Diffraction

Substances

Hydrogels
Pectins
Cellulose