Exploration of Linking Chemistry in the Design of Aptamer-Molecularly Imprinted Polymer Hybrids (aptaMIPs)

Molecular imprinting involves making a binding pocket in a polymer which is chemically and shape specific for the target compound. These "smart plastics" offer robustness compared to biological molecular recognition elements such as antibodies and enzymes. They also have the ability to work in extreme environmental conditions. However, they can sometimes lack the necessary specificity/affinity.

Aptamers are small pieces of DNA/RNA that have the ability to target proteins and small molecules and bind to them with high specificity and affinity. They are not toxic and are attractive alternatives to antibodies. They have been used primarily in research due to their susceptibility to enzymatic and chemical degradation, though this is slowly changing and they are becoming commercially relevant. The global aptamers market is projected to reach $2.4 billion by 2020, up from $1.1 billion in 2015.

A 12-month proof-of-concept study, supported by the EPSRC and led by the PI (a molecular imprinting specialist), created novel hybrid materials made by incorporating aptamers into molecularly imprinted polymers (MIPs). In simple terms, the aptamer structure is modified to allow it to be directly incorporated into a polymer, so it will hold its shape while being protected from environmental conditions. Novel, high affinity and stable materials were created.

These "aptaMIPs" demonstrated exceptional molecular recognition and offer significant improvements on both MIPs and aptamers in terms of stability, and specific target recognition, effectively maintaining the best properties of both classes of materials.

This proposal seeks to explore the potential of aptaMIPs through a two year study into the core chemistry used to create these novel materials. We will build on the results of the pilot study and create useful, effective materials with high commercial potential.

The research in this proposal will focus on:
(i) Identifying the right linker chemistry;
(ii) Developing polymerisable modifications for all four bases;
(iii) Identifying how many linkers are needed;
(iv) Identifying the best position for these linkers.

An in-depth study on these four points will enable a full understanding of the key chemistry of how the aptamer incorporates itself into the polymer and, through this, allow us to understand what makes a good aptaMIP and why. Alongside these the synthetic strategies used will be analysed to ensure the creation of these hybrids is simple and effective.

Two targets have been selected to study these chemistries. These differ in size and application: a protein and a bioactive drug, but both targets have significant commercial potential. Through these model systems we aim to demonstrate the validity and potential of aptaMIP materials.

Alongside the PI, two project partners form the research team:

The Watts group were collaborators on the pilot study and are based at the University of Massachusetts RNA Therapeutics Institute (a world leading school in novel aptamer synthesis). They will support the proposal through access to state-of-the-art synthesis equipment, combined with know-how in oligomer synthesis and application.

Aptamer Group are a commercial aptamer development company based in York. Their expertise will benefit the project by providing the known oligomer sequences which will act as the basis for our studies and access to specialised instrumentation. The impact of the project will be supported by their detailed knowledge of the aptamer field and commercial outlook.

The experience of the whole team will allow this interdisciplinary proposal, covering the fields of polymer, nucleic acid, protein and analytical chemistries to succeed. We will take aptaMIPs from the existing proof-of-concept stage and develop them, and their synthetic process, into viable competitors in artificial molecular recognition, ready for application in systems where their functionality can be exploited.

This proposal seeks to fully develop the aptaMIP concept through a rational design process. It expands on the prior proof-of-concept study (EP/K015095/1), furthering the technology to a point where it may be used effectively within commercial projects. The potential of aptaMIPs establishing a superior area of imprinting over international competitors is supported by the preliminary data (improved affinity/stability).

In the short term there will be significant impact in the form of:
- The development and analysis of methods to incorporate aptamers (and nucleic acids) into synthetic polymer structures and, from this, into other materials;
- An understanding of how this process affects the affinity and specificity of "fixing" aptamers towards their targets;
- Demonstration of the robustness that the aptaMIP process imparts to the aptamer structures;
- A step-forward in the development of macromonomer-bearing molecularly imprinted polymers.

The PI and Aptamer Group (AG), a York based biotech company, are ready to exploit the IP from the findings through a license agreement arrangement. This will be fully supported by the university's business office. Through this joint venture we envisage a boost to the UK economy, as AG will gain a commercial advantage from the project outputs. This will lead to further inward investment and interest. Both parties will explore options to collaborate with other interested commercial partners, through further licensing, ensuring the best use of the technology for UK business. This will boost not just AG, but also other UK industries, and ensure the findings of this work are fully applied.

The impact on academics working in the fields of both aptamers and MIPs will be significant, as the marrying of the two offer benefits to both fields. Scientific progression will be observed from the success of this work, as new avenues of research are opened by the potential of this technology through the improved robustness, superior affinity/specificity, ease of design and cost-effectiveness.

There will be impact on the people associated with the project. The PI and partners will benefit from interest in this work, which will bolster their reputations and careers. As a result, they are likely to attract further investment, from both national and international sources.

The attached PDRA will gain significant experience in a cross-disciplinary, multi-organisation project. They will have the opportunity to expand their academic portfolio through further study, interactions with industry and the opportunity to work in a USA university environment. Such exchanges of personnel allows for knowledge/skills to be brought back to UK.

The UK MIP community currently has no specific forum where academics meet on a regular basis, discounting a biannual student forum. The last specific meeting occurred in 2009 and was organised by the PI. This type of meeting will have impact on input to current funded projects, support joint proposal development, offer means to disseminate research, help boost a collegiate community and give the opportunity to interact with industry; all these are vital for a lively research environment.

The OU, through its media links, FutureLearn and other activities, will promote this work giving a visible presence for EPSRC-funded research, and will aim to use the development in this field within new pedagogic materials, affirming the drive for research-informed teaching.

In the longer term, the potential of the methods will enable these artificial hybrid recognition elements to overcome the limitations of and outperform currently used materials. This will lead to a new phase of study in the field of artificial molecular recognition and improvements in diagnostics, sensors, medicine and therapeutics. Given the size of the industries that would be affected, this would see a major benefit to the potential of UK companies and researchers working in these sectors.