Scheme: University Research Fellowship
Organisation: University of Bath
Dates: Oct 2015-Mar 2017
Summary: Zeolites are remarkable minerals with valuable chemical and catalytic properties, which depend on the precise shape of the tiny pores and channels and acid sites within their frameworks. I first became fascinated by zeolites because of their beautiful structures with complex framework geometries. Ideally, for every molecule and reaction, we would like to have a zeolite as a catalyst, but at the moment we are limited to only around 201 known structures, only a few of which are widely used.
Zeolites exhibit unique catalytic properties because the confined space within their pores allows them to select among different molecules by their size and shape, and the pores contain acid sites which promote chemical reactions. They make industrial processes greener by reducing reaction temperatures and waste production. Their biggest impact has been in petrochemistry, where they are used extensively for cracking and refining crude oil to make petrol. In the future, of course, we must move away from fossil fuels, and so much of the modern petrochemistry may soon be obsolete. The future of renewable and sustainable energy will require new chemical processes and the development of new zeolite catalysts is doubly urgent.
Recently, we discovered a new geometric property of frameworks, the “flexibility window”, which is calculated using specialised “geometric” computer simulations. If a framework has this unique property, it can exist without any strain in its tetrahedral structural units. It seems this property may be required for a framework to exist as a zeolite. We have also found that flexibility windows are connected to the pressure behaviour of zeolites. Many zeolites have been extensively studied at high temperatures, but there is a surprising lack of high-quality structural and spectroscopic high-pressure data on zeolites, and more data are needed in order to understand how the flexibility window and pressure behaviour interact. This project aims to remedy this.
Dates: Jan 2011-Sep 2015
Summary: Currently vaccines and many other drugs require to be refrigerated from the time they are produced to the time of administration to patients. For most countries worldwide, this time period from purchasing vaccines to getting viable vaccines to the patients can extend for as long as 6-9 months, and vaccines have to be refrigerated during the whole period.This is called "cold chain distribution", and most vaccines have to be stored between 2-8C at all times. Cold chain along costs at least $300 million every year, and more than 20 million children worldwide are not vaccinated by the age of 12 months, due to vaccine waste and problems with cold chain. Many vaccines denature at room temperatures within hours, which leads to insufficient efficacy of vaccines. Some studies have shown that patents have been vaccinated with denatured vaccines leaving them vulnerable to the diseases and reducing the heard immunity against vaccine-preventable diseases in the local communities.
I am using an inorganic material, amorphous silica, SiO2 to prevent protein denaturation in vaccines. We do this by growing covalent inorganic network around the proteins, which then helps to prevent proteins from unfolding, which is a leading cause for protein denaturation. We now have results for two proteins, where we can show that silica helps us to preserve both structure and function of those proteins both from heat and during long term storage at room temperature. After we remove the silica coating, both proteins function as before ensilication. We are now working on extending the ensilciation protocol for use of insulin and will start work on MMR and tetanus vaccines in the near future.
Application of this ensilication method to vaccines, insulin and other drugs will potentially save millions of pounds, will reduce the waste of vaccines dramatically, but most importantly will save millions of lives worldwide.