Public Release: 

Researchers sound out scaffolds for eardrum replacement

IOP Publishing

An international team of researchers has created tiny, complex scaffolds that mimic the intricate network of collagen fibres that form the human eardrum.

It is hoped the scaffolds can be used to replace eardrums when they become severely damaged, reducing the need for patients to have their own tissue used in reconstruction surgery.

The scaffolds have been presented today, 7 May, in IOP Publishing's journal Biofabrication.

The eardrum, otherwise known as the tympanic membrane (TM), is a thin, flexible and tough membrane that separates the external ear from the middle ear.

The eardrum is composed of collagen fibres that are precisely aligned in a complex network to enable sound waves to be transmitted to the ear ossicles-- three tiny bones in the ear.

It is quite common for the eardrum to become perforated, especially in children, through infection or physical damage, which can often lead to temporary hearing loss. Most minor damage to the eardrum can heal on its own; however, more severe damage can require a type of surgery known as myringoplasty.

One of the first recorded attempts at repairing the eardrum was made in the 17th century using an ivory tube covered by pig's bladder.

Since then, researchers have investigated several different techniques to repair or replace the eardrum, using a patient's own tissue (an autograft) or tissue taken from a donor (a homograft), but the optimal replacement has yet to be found.

In this study, the researchers explored a tissue engineering approach by creating polymer scaffolds onto which cells could be grown on. The scaffolds were composed of two FDA-approved copolymers of wide biomedical use and were built using two different approaches.

In the first approach, the scaffolds were created by electrospinning (ES) in which fine fibres of poly(lactic-co-glycolic acid) (PLGA) were drawn out from a liquid using an electrical charge to create a one dimensional structure.

In the second approach, ES was combined with 3D printing to manufacture two dimensional and three dimensional structures from poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) with radial and circular patterns.

The sizes of the scaffolds were comparable to that of a human eardrum, with a diameter of 15 mm and a thickness of around 100 μm.

Once created, a preliminary biological study was conducted by culturing human mesenchymal stromal cells (MSCs) onto the scaffolds to test how cells could grow and then survive on the structures.

The cells were viable when grown on all of the scaffolds, with particularly good results seen on the three dimensional scaffold.

Co-author of the study Dr Serena Danti, from the University of Pisa, said: 'Since the eardrum is a unique tissue in the human body, traditional replacements are usually autografts that have come from other tissues which do not have specific structural similarity with the eardrum. Consequently, their acoustic performances are not optimal.

'The eardrum has a complex structure with collagen fibres arranged precisely to interact with sound waves. We have replicated this structure in our scaffolds by combining electrospinning with 3D fibre deposition, and we believe this will eventually allow for replacements that are anatomically and acoustically similar to the eardrum.'

###

From Thursday 7 May, this paper can be downloaded from http://iopscience.iop.org/1758-5090/7/2/025005

Notes to Editors

Contact

1. For further information, a full draft of the journal paper or contact with one of the researchers, contact IOP Press Officer, Michael Bishop: Tel: 0117 930 1032 E-mail: michael.bishop@iop.org For more information on how to use the embargoed material above, please refer to our embargo policy.

IOP Publishing Journalist Area

2. The IOP Publishing Journalist Area gives journalists access to embargoed press releases, advanced copies of papers, supplementary images and videos. In addition to this, a weekly news digest is uploaded into the Journalist Area every Friday, highlighting a selection of newsworthy papers set to be published in the following week. Login details also give free access to IOPscience, IOP Publishing's journal platform. To apply for a free subscription to this service, please email Michael Bishop, IOP Press Officer, michael.bishop@iop.org, with your name, organisation, address and a preferred username.

Multiscale fabrication of biomimetic scaffolds for tympanic membrane tissue engineering

3. The published version of the paper 'Multiscale fabrication of biomimetic scaffolds for tympanic membrane tissues engineering' (Carlos Mota et al 2015 Biofabrication 7 025005) will be freely available online from Thursday 7 May. It will be available at http://iopscience.iop.org/1758-5090/7/2/025005.

Biofabrication

4. A journal focusing on using cells, proteins, biomaterials and/or other bioactive elements as building blocks to fabricate advanced biological models, medical therapeutic products and non-medical biological systems.

IOP Publishing

5. IOP Publishing provides publications through which leading-edge scientific research is distributed worldwide.

Beyond our traditional journals programme, we make high-value scientific information easily accessible through an ever-evolving portfolio of books, community websites, magazines, conference proceedings and a multitude of electronic services.

IOP Publishing is central to the Institute of Physics, a not-for-profit society. Any financial surplus earned by IOP Publishing goes to support science through the activities of the Institute.

Go to ioppublishing.org or follow us @IOPPublishing.

Access to Research

6. Access to Research is an initiative through which the UK public can gain free, walk-in access to a wide range of academic articles and research at their local library. This article is freely available through this initiative. For more information, go to http://www.accesstoresearch.org.uk

The Institute of Physics

7. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.

In September 2013, we launched our first fundraising campaign. Our campaign, Opportunity Physics, offers you the chance to support the work that we do.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.