Global Challenges Research Fund

The Global Challenges Research Fund (GCRF) is a £1.5 billion fund that supports cutting-edge research to address challenges faced by developing countries. It is part of the UK’s official development assistance (ODA).The fund addresses the United Nations sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.

The VilelaLAB has been awarded funding from the GCRF to produce an affordable, long-lasting and non-toxic surface disinfectant technology which is activated by ambient light.

Motivation:

It is well documented that the population of Brazil suffers greatly from the devastating effects of arboviruses (e.g. Dengue, Zika and Chikungunya).[1] Furthermore, Brazil is one of the countries that is worst affected by the worldwide SARS-CoV-2 virus pandemic.[2] The research herein proposed aims at developing a technological solution that can indiscriminately irradicate viruses and bacteria from surfaces and drastically reduce surface-to-human contagion. [3]

Currently employed surface disinfectant agents, whilst very effective, have several serious drawbacks. Notably, they rely on mixtures that contain toxic and harmful substances such as alcohols (approx. 70%), surfactants and hydrogen peroxide, and they need to be constantly applied to a surface in order to maintain it disinfected. [4] Furthermore, once the alcohol has evaporated or absorbed, the surface is prone to further contamination. Whilst this is an effective way to clean a surface it does not constitute a long-lasting decontamination barrier. To achieve this, large amounts of these disinfecting agents need to be constantly applied, and given their toxicity, this method is not ideal when disinfecting public spaces with high human mobility and interaction. [5] Ultimately, new technologies need to be developed and carefully implemented to address this public health challenge, especially in public spaces with high human mobility such as university campuses. Therefore, another challenge is to ensure that the public (visitors, students and university staff) understand, accept and are reassured with new and unconventional disinfecting technologies.

Our Technology:

Continuous disinfection of large-scale surfaces using oxygen and ambient light

We will tackle these challenges via the implementation of polymeric materials that can be easily spread across surfaces to create a long-lasting self-disinfecting barrier able to destroy multiple human pathogens. Specifically, the self-disinfecting formulation will mainly be comprised of biodegradable polymeric microparticles with negligible cytotoxicity, functionalized with organic dyes that can absorb visible light and thereafter react with oxygen in air to continuously produce reactive oxygen species (ROSs). ROSs will then inactivate viruses and bacteria by destroying their membranes and/or genetic material.[6]

Figure 1: The production of ROSs singlet oxygen through the use of photosensitisers and ambient visible light

Because ROSs produced on surfaces are short-lived (nano seconds), they are not harmful to humans or animals. The duration of the self-disinfecting surface is dependent on: (i) the stability of the deposited surface layer, (ii) the photo-stability of the dye, and (iii) the rate of degradation of the biodegradable microparticles. From our experience in developing materials that produce ROSs, and in relation to points (ii) and (iii) we envisage that such materials can potentially have a long-lasting effect (in the order of weeks or months), therefore reducing the number of applications on a given surface. To address general acceptance of this unconventional disinfecting technology, we will produce a Technology Transfer Report that can be implemented in the 3 campuses ensuring that cleaning staff are able to safely use and understand the new technology, and effectively inform the general public of its benefits. This will ultimately valorize the work of often-neglected professionals.

Microparticle formation will be achieved via the use of droplet microfluidic strategies in continuous flow. This low energy and scalable method is made possible with the application of low-pulse pump technology from Vapourtec R-Series pump modules. Using this technology will allow for the continuous preparation of monodisperse Microparticles ensuring dependable production and analysis.

Figure 2: The Vapourtec RS-200 Automated Control Flow reactor

Gender equality:

In UNESP campuses of Sorocaba, Jaboticabaland Botucatu, women play a central role in cleaning and disinfecting activities and work directly with hundreds of people. Part of the implementation strategy of this project will be developed in conjunction with three distinct teams of cleaning professionals (predominantly women) to ensure that they have a leading role in the better utilisation of the proposed technology whilst concomitantly being able to inform the general public on how it works. As a result, our project will contribute towards the reduction of gender inequalities and social stigma as all beneficiaries, (including visitors, students and staff),will further valorise the work of these professionals. We also estimate that this technology has the potential to generate opportunities for job creation and business development within this often-neglected societal group. At the end of this project, we propose the delivery of a Gender Equality Report detailing the impact that this technology can potentially have in reducing gender inequalities and best improve business opportunities and career development for women within the three university campuses.

Our research partners:

Heriot-Watt university

• Dr Valeria Arrighi (co-I) Institute of Chemical Sciences

• Professor Vicki Stone (co-I) Institute of Biological Chemistry, Biophysics and Bioengineering

• Dr David Brown (RA) Institute of Biological Chemistry, Biophysics and Bioengineering

São Paulo State University

• Dr Leonardo F. Fraceto

• Dr Jayme A. S. Neto

• Dr David F. L. Santos

University of Sorocaba

• Dr Renata de Lima

References