Tuning the aqueous self-assembly process of insulin by a hydrophobic additive

• Published in: RSC advances Vol. 5; no. 112; pp. 92254 - 92262
• Main Authors: Bäcklund, Fredrik G., Solin, Niclas
• Format: Journal Article
• Language: English
• Published: 01.01.2015
• Subjects: Additives; Insulin; Media; Plugs; Self assembly; Solubility; Spherulites; Tuning
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C5RA16144D

Biomolecular self-assembly is an efficient way of preparing soft-matter based materials. Herein we report a novel method, based on the use of insoluble additives in aqueous media, for influencing the self-assembly process. Due to their low solubility, the use of hydrophobic additives in aqueous media is problematic; however, by mixing the additive with the biomolecule in the solid state, prior to solvation, this problem can be circumvented. In the investigated self-assembly system, where bovine insulin self-assembles into spherical structures, the inclusion of the hydrophobic material α-sexithiophene (6T) results in significant changes in the self-assembly process. Under our reaction conditions, in the case of materials prepared from insulin-only the growth of spherulites typically stops at a diameter of 150 μm. However, by adding 2 weight% of hydrophobic material, spherulite growth continues up to diameters in the mm-range. The spherulites incorporate 6T and are thus fluorescent. The method reported herein should be of interest to all scientists working in the field of self-assembly as flexible material preparation, based simply on co-grinding of commercially available materials, adds another option to influence the structure and properties of products formed by self-assembly reactions.