The Mission of our project

4NanoEARDRUM is designed to accomplish inclusive and sustainable research and innovation. Means are available for maximising ethically sustainable tests to obtain all the obtainable data in vitro, in silico and ex vivo, thus paving the way to future responsible preclinical studies. 

 Owing to its peculiar anatomy and function, the optimal restoration of damaged tympanic membrane (TM) must take into account several features on the nanoscale level, which in this body setting more than in others, can be decisive for an optimal performance within an infectious and chronically inflamed microenvironment (e.g. due to otitis media chronica). To date, none nanotech manufacture is applied to eardrum reconstruction, but rather auto/allografts from other tissues (unspecific) are used, which renders this project highly innovative and original. Through an incremental approach, 4NanoEARDRUM is aimed at synergising different nanotechnologies for an optimal eardrum restoration, including acoustic, regenerative, and pathologic cues, to achieve a durable and effective performance in implanted patients. A biomimetic TM scaffold will be designed and fabricated, with features on the nano/microscale all the way to accomplish its full function (regenerative, anti-infective, immunomodulatory, oto-compatible and acousto-mechanical) thanks to the cooperation of academic and health experts in otology, biomaterials engineering, microbiology, nanotechnology, biofabrication, mechano-acoustics and bioacoustics, as well as industrial partners of the nano-biotech.

An anisotropic TM scaffold with radial and circular nanofibres based on a biodegradable polymer/chitin nanofibril (CN) composite will be fabricated via electrospinning and additive manufacturing. CNs are chosen for their immunomodulatory and antibacterial properties. Antibiotic loaded and molecularly imprinted polymer nanoparticles (NPs) will be prepared with tailored release profiles. Modelling will be used through the project.

The new device will be “4 times” “nano”, as it will comprise nanofibres, nanofibrils, NPs, and accomplish nanoscale vibration, as well as it will be “for” “nano”, thus meaning for enabling exploitable nanotechnologies in otologic surgery, with improved reliability and reduced costs for the National Health System.

4NanoEARDRUM is aimed at synergising different nanotechnologies for an optimal restoration of tympanic membrane (TM), including acoustic, regenerative, and pharmaceutical cues, to achieve a durable and effective performance in implanted patients, which still represents an unmet medical need. Specifically, the new device will be “4 times” “nano”, as it will comprise nanofibres supportive for human mesenchymal stem cell (hMSC) differentiation, immunomodulatory nanofibrils, antibiotic-delivery nanoparticles (NPs), and accomplish nanoscale vibration. At the same time, it will be “four” “nano”, thus meaning for enabling exploitable nanotechnologies and nanomedicine products in otologic surgery. To reach this goal, 4NanoEARDRUM involves actors from medical, biology, materials engineering academia and hospitals, as well as nanotech and pharmaceutics SMEs. Academic and hospital researchers will develop and validate the proof of concept from technical and medical standpoints. The presence of nanotech and pharma SMEs will enable production of reliable nanofibre scaffolds, bioreactors and tailored/smart NPs under a translational approach. The immunomodulatory properties will be given by chitin nanofibrils (CN), a green nanocomponent that is approved in dermatology and cosmetics, thus facilitating clinical translation. The project thus addresses the fields of targeted drug transport and regenerative medicine. 4NanoEARDRUM is formally located in EuroNanoMed III - Category 1: “Innovation applied research projects”, but it approaches Category 2: “Project with high potential of applicability at medium term”. Indeed, in first instance, the “4Nano” TM scaffold will act as a medical device (i.e., able to promote in vivo regeneration by local cells via physical cues) and not as an advanced therapy medicinal product (i.e., to be implanted with living cells). This approach will facilitate time to market (expected time 6 years).

In TM, the mechanical support entitled for frequency tuning is accomplished by a few-μm layer of collagen nanofibres (mainly collagen type II) with anisotropic orientation, radial and circular, assembled into a concave tissue. By vibrating through displacements on the nanoscale according to frequencies, TM thus succeeds as an overall high-fidelity sound transmitter, which is essential for the hearing sense as it relies on the recognition of transients. As such, suboptimal performance is achieved using isotropic patches or different tissues. Ear infections and related inflammatory processes greatly challenge the success rate of TM substitutes. In fact, middle ear biocompatibility is a specific and restricted area for biomaterial application. Due to their superb properties, nanomaterials can make a difference. Unlike macro/micro-size chitin, nanosized chitin (CN) is high biocompatible and exert immunomodulatory, anti-inflammatory and antibacterial properties. CN/polymer composite nanofibres will also result into mechanical strengthening of nanofibre scaffolds. Different nanofibre size ranges will be tested to ensure the best mechano-acountic behaviour of scaffold. In addition, biodegradable polymer NPs will be loaded with specific antibiotics to ensure local and controlled delivery after surgery enhancing drug efficacy. Two approaches will be used: (i) Molecularly imprinted polymers (MIPs), and (ii) co-precipitation method. MIPs are synthetic materials with specific recognition properties for target molecules which are considered as alternatives to biomolecules and characterized by superior chemical and physical stability, increased availability and reduced cost. To determine the best release kinetic profile different strategies will be tested. However, since nano-objects and drugs can diffuse from middle into inner ear and induce cochlear damage, ototoxic effects will be disclosed (nanosafety). The topographic control of the scaffolds, from electrospun nanofibres (tens-to-hundreds of nm) to microscale (tens of μm) patterning, will guide hMSC orientation and differentiation, regenerating the native tissue structure. The targeted nanostructured implant is unique worldwide and fills a therapeutic gap in chronic otitis media (COM) treatment. The modular nanotechnology approach of 4NanoEARDRUM is designed to further enable personalised products (e.g. antibiotic/target choice). Reaching nanoscale resolution for TM scaffolds is thus necessary to succeed.

COM is present when the middle ear is permanently or repeatedly inflamed, being usually characterised by TM perforations, which can result in long-term hearing damage. None form of a COM, including cholesteatoma, can heal without proper medical and/or surgical therapy, leading to complications (hearing loss, tinnitus or dizziness) and recurrence. Depending on the extent of eardrum damage, autologous tissue (e.g. cartilage, fascia or perichondrium) is currently used for TM reconstruction. However, the acoustical and mechanical properties for sound pick-up and propagation are suboptimal and vary among the materials, which makes it difficult to reconstruct the hearing function properly. A complete acousto-mechanical restoration of TM cannot take place since all the autologous materials do not fulfil the characteristics of the normal TM. The larger the defect, the more difficult it is to close this with autologous material. As a consequence, successful TM closure is not always achieved. In addition, hearing outcomes cannot be predicted preoperatively and also depend on the surgeon’s experience. Only several days after the procedure, the success can be subjectively determined via audiometric measurements. Graft tissues are often resorbed, especially in case of chronically inflamed ears, without allowing any structural TM restoration. 4NanoEARDRUM is aimed to fill an exposed gap in COM treatment by providing biomimetic, reliable and highly performant TM devices provided with targeted drug delivery and anti-inflammatory activity, ultimately enabling in situ TM regeneration with optimally reconstructed acoustics. With such a flexible and also robust scaffold patient safety could be achieved at all areas of normal lifestyle (e.g. even during flights or diving).

To date, none nanotech manufacture is clinically applied to eardrum reconstruction, but rather auto/allografts from other tissues (unspecific) are used, which renders this project highly innovative and original. As research on this implant family is at an early stage, comparisons can only be drawn to a limited extent.