Structuring of multiple parallel pectin gel filaments by applied shear

• Published in: International journal of biological macromolecules Vol. 128; pp. 304 - 313
• Main Authors: Kato, Norihiro, Nagayoshi, Keisyu, Takayama, Yuriko, Nasuno, Eri
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2019
• Subjects: Aqueous two-phase system; Pectin; Shear-induced structuring; Shear-induced structuring; Pectin; Aqueous two-phase system
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2019.01.109

The bundled structure of micron-sized pectin gel filaments was formed by quick shear-induced gelation of the filamentous domains of pectin-polyethylene glycol (PEG) assemblies. Highly concentrated pectin with PEG in a separated pectin-rich phase under aqueous two-phase separation in the pectin/PEG/NaCl system enabled the formation of the pectin-PEG assembly, which was elongated in the flow direction, resulting in the generation of filamentous domains using a microfluidic device. The pectin gel filaments were formed by crosslinking with Ca2+ in the presence of shear-responsive PEG assemblies formed in the PEG-rich phase, because the filamentous PEG assemblies prevented fusion of the pectin filaments to form the seamless cylindrical gel. The shear-dependent elongation applied to the pectin-PEG assembly under the aqueous two-phase separation condition enabled the formation of the biomimetic bundled filamentous structure using bio-safe PEG as a sacrificial polymer, without the requirement of a multi-hole nozzle. Potential applications for gel filaments possessing a bundled structure are matrices in the biomedical field, such as a biodegradable scaffold for cell engineering.