Application of bile acids for biomedical devices and sensors

Abstract

Bile acids (BAs) are physiologically important biosurfactants (Singh, Metrani, Shivanagoudra, Jayaprakasha, & Patil, 2019), which solubilize cholesterol, lipids, proteins, fatty acids, monoglycerides and vitamins in a human body. The strong solubilization power of BAs is related to their amphiphilic chemical structure, which is fundamentally different from the structures of other surfactants. As a general feature, natural BAs molecules have a steroid nucleus with concave hydrophilic and convex hydrophobic sides, containing OH and methyl groups, respectively (Figure 1a and Table 1). The chemical structures of BAs contain a short hydrocarbon chain with COOH or SO 3 H end groups. As a result, dissociated BAs molecules exhibit anionic properties in solutions. Properties of BAs are influenced by the number of OH groups bonded to a steroid core and nature of anionic groups. Modifying the hydroxyl or carboxyl groups of BAs creates a diverse set of BA-based compounds, maintaining some original properties and introducing novel properties as well. The unique distribution of hydrophilic and hydrophobic domains allows these molecules to self-organize into supramolecular assemblies in water. BAs salts form mixed micelles (Figure 1b) with various water-insoluble molecules and facilitate their dissolution. Moreover, BAs allow dispersion of hydrophobic materials, such as carbon nanotubes (Ata, Poon, Syed, Milne, & Zhitomirsky, 2018). The bifacial amphipathic BAs molecules act as compatibilizing agents between the water-insoluble

Surfactant assisted dip-coating method for deposition of polyethylmethacrylate-diamond coatings

“…Steroid molecules, such as bile salts solubilise different biomolecules in a human body [41]. Bile acids and bile salts have generated significant interest in materials processing [41,42]. However, we were not able to dissolve PEMA in the presence of bile acids or bile salts.…”

A Versatile Strategy for the Fabrication of Poly(ethyl methacrylate) Composites

“…Moreover, we achieved solutions of relatively high concentrations using high molecular mass PEMA, which was a key factor of film deposition by a dip-coating method. The use of LA was motivated by the analysis of literature [34,35] on solubilization of different biomolecules in a human body by bile salts. The remarkable solubilization power of bile salts in water are related to their electric charge and amphiphilic structure.…”

Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

“…[ 38 ] However, there are reports where the catechol‐type ligand is not acting as linker, but rather it is a material complexed onto the metal oxide surface alongside it. In these systems, the third coadsorbate material is present for enhancing colloidal stability, typically a bile acid salt such as deoxycholic acid, [ 57,102 ] or a molecule with long hydrocarbon tails such as oleic acid. [ 78,103 ] The function of these coabsorbates is to act as dispersants to provide additional colloidal stability enhancement, whereas the catechol‐type ligands continue to provide photoabsorption enhancement.…”