Market and product

Compiled by Bao Hien

Beyond cleaning, detergents are being redesigned to support protein research, drug discovery and drug delivery. A series of new studies points to deliberate molecular design, although most of the work is still at the laboratory stage.

Detergents are used in cleaning, disinfection and drug discovery. Dr Leonhard H. Urner of the Department of Chemistry and Chemical Biology at TU Dortmund University (Germany) likens these molecules to “molecular diplomats”: they help substances that do not normally mix, such as oil and water, blend together.

The core mechanism is emulsification. Detergent molecules adsorb at the interface between two immiscible liquids, allowing them to disperse into each other. In water, these molecules also assemble into micelles, nanometre-sized carriers that can dissolve water-repelling substances such as drugs and proteins.

Optimising household products

For household use, price still dominates the choice of detergents for mass-market products. The potential health benefits of detergents for the public remain largely unexplored.

Bockmühl and colleagues reviewed how dishwashing performance can be optimised by combining detergent chemistry with the structure of dishwasher programmes. Birnbach and colleagues developed an experimental framework to tune how quickly mixtures adsorb at interfaces, by combining technical ethoxylates with rhamnolipids, a type of biosurfactant. This bottom-up approach helps optimise multicomponent formulations whose behaviour is otherwise hard to predict.

Veronico and colleagues showed that simply adding salt to mixed micellar systems changes the shape of molecular aggregates from spherical to bicelle-like (two-layer discs). This change creates transient particle networks, making the system more stable, viscoelastic and better at taking up oil.

Precise measurement for better design

For micelles to form, a detergent must reach a minimum concentration known as the critical micelle concentration (CMC). This value is usually measured in water, whereas real applications take place in more complex buffer solutions. Nielinger and colleagues established a method to measure CMC by dynamic light scattering in both water and buffer.

Müh and colleagues found that polyethylene glycol stabilises the monomers of two common nonionic detergents to the same extent. The finding may improve understanding of crystal-form transitions in membrane protein crystallography.

New tools for drug discovery

About 60% of current drugs bind to membrane proteins. These proteins are difficult to extract from the membrane while keeping their structure intact, which makes suitable detergents an essential tool.

Behnke and colleagues developed ways to synthesise hybrid detergents, combining ionic and nonionic headgroups in a single molecule. The open question was whether their properties are genuinely new or simply an average of the two parent types. Using gas-phase infrared spectroscopy, Kirschbaum and colleagues showed that hybrid detergents have distinct structures and properties.

Song and colleagues introduced nonionic anthracene-bridged detergents to solubilise G protein-coupled receptors (GPCRs), an important class of drug targets, and to image them by electron microscopy. Cornut and colleagues tested fluorinated lactobionamide detergents and found that each type was suited either to solubilising or to stabilising proteins, underlining the importance of detergent screening.

Bio-based origins and drug delivery

Bio-based detergents are expected to open the way to more environmentally friendly processes and products. Sani and colleagues showed that emulsifiers can be designed from proteins, specifically a truncated form of outer membrane protein A from bacteria.

In drug delivery, poor solubility is a major hurdle because it reduces absorption. Kumari and colleagues developed nanocarriers based on dendritic oligoglycerol amphiphiles. Zou and colleagues designed multifluorinated dendrimers aimed at photonic applications.

Together, these studies show detergent chemistry shifting from experience-based formulation towards molecular design grounded in structure–property relationships. Most results remain at laboratory scale, with no data yet on production costs or commercial viability.