Formulation of molecularly-imprinted microparticles for delivery of thuricin CD to treat recurrent Clostridium difficile gut infections

Treatment of recurrent Clostridium difficile infections with broad-spectrum antibiotics is common but frequently leads to poor treatment outcomes. In particular, the NHS Pathway of Care (PoC) requires antibiotics to be administered in a sequence, starting with the least potent; this, in principle at least, is intended to reduce the chance of resistance developing to last-line antibiotics but in practice the effect is to weaken significantly the majority of the native (commensal) gut flora while concomitantly generating a multi-drug resistant C. difficile strain. Patients in this situation are usually admitted to intensive care and faecal transplant is the only remaining treatment option. We aim to address this challenge by delivering thuricin CD (an antimicrobial peptide with specific C. difficile activity) to the gut.1 Unlike the antibiotics currently used to treat C. difficile (e.g. vancomycin, metronidazole), thuricin CD does not affect the composition of commensal gut bacteria which helps to prevent recurrent infections.2 However, it is highly susceptible to proteolysis and acid hydrolysis in the stomach, and is poorly soluble in water,3 and therefore cannot be delivered in conventional oral dosage forms. Here, we propose the highly promising approach of using molecularly-imprinted microparticles to provide protection from acid and proteases, aid solubility, and enable the peptide to reach the gut intact. The microparticles will be formulated in a printable matrix, so the final dosage forms can be 3D printed. This will enable the release kinetics of the peptide to be fine-tuned, maximising its therapeutic potential against C. difficile infections. Key aims of the work will be i) isolation of thuricin CD; ii) development of 3D-printed microparticle formulations; and iii) testing formulations on C. difficile growth in vitro using an isothermal microcalorimetric assay and microbiological techniques.

Pharmaceutical technologies underpin healthcare product development. Medicinal products are becoming increasingly complex, and while the next generation of research scientists in the life- and pharmaceutical sciences will require high competency in at least one scientific discipline, they will also need to be trained differently than the current generation. Future research leaders need to be equipped with the skills required to lead innovation and change, and to work in, and connect concepts across diverse scientific disciplines and environments. This CDT will train PhD scientists in cross-disciplinary areas central to the pharmaceutical, healthcare and life sciences sectors, whilst generating impactful research in these fields. The CDT outputs will benefit the pharmaceutical and healthcare sectors and will underpin EPSRC call priorities in the development of low molecular weight molecules and biologics into high value products.

Benefits of cohort research training: The CDT's most direct beneficiaries will be the graduates themselves. They will develop cross-disciplinary scientific knowledge and expertise, and receive comprehensive soft skills training. This will render them highly employable in R&D in the pharmaceutical, healthcare and wider life-sciences sectors, as is evidenced by the employment record in R&D intensive jobs of graduates from our predecessor CDTs. Our students will graduate into a supportive network of alumni, academic, and industrial scientists, aiding them to advance their professional careers.

Benefits to industry: The pharmaceutical sector is a key part of the UK economy, and for its future success and international competitiveness a skilled workforce is needed. In particular, it urgently needs scientists trained to develop medicines from emerging classes of advanced active molecules, which have formulation requirements that are very different from current drugs. The CDT will make a considerable impact by delivering a highly educated and skilled cohort of PhD graduates. Our industrial partners include big pharma, SMEs, CROs, CMOs, CMDOs and start-up incubators, ensuring that CDT training is informed by, and our students exposed to research drivers in, a wide cross-section of industry. Research projects in the CDT will be designed through a collaborative industry-academia innovation process, bringing direct benefits to the companies involved, and will help to accelerate adoption of new science and approaches in the medicines development. Benefit to industry will also be though potential generation of IP-protected inventions in e.g. formulation materials and/or excipients with specific functionalities, new classes of drug carriers/formulations or new in vitro disease models. Both universities have proven track records in IP generation and exploitation. Given the value added by the pharma industry to the UK economy ('development and manufacture of pharmaceuticals', contributes £15.7bn in GVA to the UK economy, and supports ~312,000 jobs), the economic impacts of high-level PhD training in this area are manifest.

Benefits to society: The CDT's research into the development of new medical products will, in the longer term, deliver potent new therapies for patients globally. In particular, the ability to translate new active molecules into medicines will realise their potential to transform patient treatments for a wide spectrum of diseases including those that are increasing in prevalence in our ageing population, such as cardiovascular (e.g. hypertension), oncology (e.g. blood cancers), and central nervous system (e.g. Alzheimer's) disorders. These new medicines will also have major economic benefits to the UK. The CDT will furthermore proactively undertake public engagement activities, and will also work with patient groups both to expose the public to our work and to foster excitement in those studying science at school and inspire the next generation of research scientists.