Thermodynamics and Kinetics of Small Molecule Interactions with Biological Materials

Lead Research Organisation: Imperial College London
Department Name: Dept of Chemistry

Abstract

"Materials such as cotton, hair, skin, wood and foods are biological materials with complex hierarchical structures, including significant levels of amorphous molecular disorder. As is common with materials of a biological origin, these materials are all hydrophilic & hygroscopic. Cellular biological materials are ubiquitous in our world, yet surprisingly, how they interact with small molecules is poorly understood. Such molecules can be delivered by liquid or gas phases and include perfume and malodour molecules, moisture, pesticides, drugs, VOC's and pollutants, as well as solvents to name but a few relevant species. The molecular interactions of these molecules with complex biological materials forms the basis of a range of important research questions in the domains of consumer products, environmental science, food research, drug delivery and cellular science.


This project will investigate using a range of vapour solids characterization techniques, both the kinetics and thermodynamics of the interactions of small molecules with selected biological materials substrates including cotton, hair, skin and food materials. Current research techniques are unable easily to differentiate between surface adsorption and bulk sorption of molecules by the substrates, and on the whole only provide a quantitative understanding of the small molecule binding processes. Recent developments in IGC (inverse gas chromatography) and DVS (dynamic vapor sorption) have indicated that these new vapour sorption characterization tools are very promising ways to obtain the highest quality thermodynamic and kinetics descriptors for small molecule vapour interactions with all types of solids. Such physicochemical descriptors are not only practically useful and relevant, but can be used to developing predictive models for these molecular interactions. The flexibility on the types of samples studied, accurate control of both environmental temperature and humidity makes these types of techniques highly advantageous for conducting measurements in real world test conditions, eg those experienced by patients, manufacturers, consumers. This work will be complemented by NMR and SAXS studies on these biological materials (Ces and Law) which have been exposed to selected vapours including water. Solid state NMR and SAXS will provide detailed structural and relaxation information, allowing structural changes to be correlated with vapour sorption data."

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R512540/1 01/10/2017 30/09/2021
1935850 Studentship EP/R512540/1 30/09/2017 29/09/2021 Susannah Molisso
 
Title Research as Art Submission 
Description 3 clear A5 resin blocks containing hair and copper wire NMR spectra and graphs. 
Type Of Art Artwork 
Year Produced 2019 
Impact Awarded third prize for the Research as Art competition at Imperial College London in 2019 
URL https://www.imperial.ac.uk/news/192048/phd-students-creativity-show-annual-summer/
 
Description Solid State NMR has been used to demonstrate that 1H T1 relaxation times for compounds change when in hair, and these changes are related to the size and lipophilicity of the compound. This information can be used to infer how much a compound is interacting with the hair fibre as greater changes in T1 times result from less molecular rotation and more dipolar interactions between the compound and hair.

Also, a high performance liquid chromatography method has been devised to track dye and alkalizer loss from dyed hair in real time. This uses deionized water in an attempt to mimic real life loss of colour from dyed hair in consumers. This has been used to determine the kinetics of loss of these small molecules.
Exploitation Route This could be used by the hair care industry as new tools to develop products by analysing how small molecules in formulations are interacting in hair and their kinetics of loss from the hair fibre.
Sectors Healthcare