Development of an Auxetic, antiMicrobial, suPramolecular coordination poLymer as a meta-materIal For bIomedical applications

Project Information

AMPLIFI

Grant agreement ID: 101026382

DOI

10.3030/101026382

Project closed

EC signature date 22 March 2021

Start date 1 October 2021

End date 30 September 2024

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 222 073,92

EU contribution

€ 222 073,92

Coordinated by

UNIVERSITA TA MALTA
Malta

Periodic Reporting for period 1 - AMPLIFI (Development of an Auxetic, antiMicrobial, suPramolecular coordination poLymer as a meta-materIal For bIomedical applications)

Reporting period: 2021-10-01 to 2024-09-30

Summary of the context and overall objectives of the project

By 2050, the global population aged 60 and older is projected to reach 2 billion, a significant increase from the 900 million recorded in 2015. This rise in average life expectancy is largely driven by continuous advancements in healthcare, influenced by innovations across sectors such as patient comfort and care, and medical and biomedical devices—including catheters, implants, and orthopaedic devices. While these biomedical devices are essential to healthcare, their use is often associated with challenges, such as patient comfort, biocompatibility, and the need for specific mechanical and physical properties. For instance, devices require a smooth surface, flexibility, and strength to withstand mechanical forces, while avoiding kinking, collapse, and susceptibility to bacterial infections. Consequently, the extensive use of these devices places substantial demands on healthcare, economic, and social resources. There is therefore a pressing need for the development of advanced materials that can address these challenges.

One potential solution to the mechanical challenges in biomedical device design lies in the application of auxetic materials. These materials, known for their unique properties resulting from a negative Poisson’s ratio, expand transversely when uniaxially stretched. This property grants auxetic materials distinct advantages, such as synclastic curvature (forming a dome shape when bent), increased resistance to indentation and enhanced fracture and vibrational damping properties. Such qualities suggest that auxetic materials could significantly improve medical devices by enhancing durability, vibration resistance, and adaptability to complex body structures.

In response to the critical need for advanced materials in biomedical device design, the AMPLIFI project aimed to create a new base material tailored for specialised biomedical applications, featuring enhanced properties such as auxeticity. The project’s first objective was to identify suitable building blocks for creating a polymer with auxetic characteristics using molecular modelling techniques. The second objective focused on synthesizing and characterizing the units identified in the first objective, as well as optimizing conditions for polymer assembly. The third objective sought to assess the resulting material’s mechanical, antimicrobial, and adsorption properties.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

This project made meaningful contributions to scientific knowledge as a material with innovative properties was developed. Molecular simulations played a key role in the design of potential molecular systems which may exhibit a negative Poisson’s ratio. More specifically, the study was based on calixarene polymers which could be potentially synthesised. Through these simulations, several promising candidates were identified, ultimately narrowing down to two molecules that were selected for synthesis. A synthetic route was devised, drawing on established literature to ensure feasibility. The chosen polymers were then synthesized and characterized using a range of advanced techniques for both solution and solid-state chemistry. These included methods such as 1H NMR, 13C NMR, IR, UV-vis, MS, pXRD, SEM-EDX and XPS. The resulting polymer, obtained in powder form, demonstrated a notable capacity for absorbing environmental pollutants, marking a significant step forward in its potential applications. Further studies incorporated the polymer into a solid rubber matrix, where its mechanical properties were rigorously evaluated, highlighting its suitability for future environmental and industrial applications.

The work carried out in this project was disseminated to the scientific community through both oral and poster presentations at five international conferences, two local conferences and one online conference. A number of seminars were organised at the University of Malta, University of Parma, Italy and at the Malviya National Institute of Technology, Jaipur, Rajasthan, India, Two scientific articles have been published in peer-reviewed, academic journals while a number of others are in the process of being reviewed or prepared for publications. Interest from industry was garnered through an industrial visit. Various public dissemination events were carried out, including an article on the MSCA-NET website and on a local newspaper. An interview was given on the radio and an online lecture gave an importance of having more women in STEAM. Exhibitions were targeted at the general public at the European Researcher’s Night event, Science in the City, as well as students of all levels (primary school visits, visits by secondary school students and higher education institutions as well as University students).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

• Molecular simulations of auxetic structures have traditionally focused on theoretical models considered too complex to synthesize. The successful synthesis of a polymer simulated to exhibit auxetic behaviour marks a significant advancement in the field.
• The synthesis of a 3D network based on calixarenes presents a considerable challenge. This work successfully describes one such polymer, which also demonstrates crystalline properties.
• Furthermore, the use of covalent bonds, as opposed to reversible bonds, results in a material that is more robust than those typically found in the literature.
• Previous studies on calixarene systems for pollutant absorption have only explored 2D structures. This study advances the field by examining pollutant adsorption within a 3D system.
These advancements represent significant progress beyond the state of the art, with expected outcomes including the development of more durable, high-performance materials. Molecular auxetics remains a largely untapped area of research with substantial potential to drive societal advancements, particularly through their ability to introduce auxetic properties to applications requiring precision and miniaturization. Their potential applications are extensive and transformative. In biomedicine, molecular auxetics could be engineered for implants that better mimic the behaviour of natural tissue, leading to improved patient outcomes in reconstructive surgeries and organ repair. In drug delivery, they could enable materials that respond dynamically to physiological changes, thereby enhancing the targeted delivery of therapeutics. The material developed in this project offers a promising foundation for further development of synthesizable molecular auxetics, paving the way for future technological innovations that address critical needs in various fields, from healthcare to environmental sustainability.

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