Researchers at the Institute of Materials Science of Barcelona (ICMAB) of the CSIC are developing new biologically active nanocellulose dressings to treat wounds in the cornea. The project team consists of three researchers from the ICMAB-CSIC's Group of Nanoparticles and Nanocomposites (@NNgroupICMAB): Anna Roig, who leads the project, Irene Anton-Sales and Anna Laromaine. In addition, the project counts with the collaboration of the Barraquer Ophthalmology Center, which will aid from the clinical perspective with materials and technical expertise.

The surface ocular bandages, which are adjustable in size according to clinical needs and are approximately one millimetre thick, are made of bacterial nanocellulose, a material of biological origin syntesized by bacterial cultures. The bacterium Komagataeibacter xylinus (K. xylinus) is one of the most efficient species in the production of this type of cellulose. When these bacteria are in an aqueous medium with glucose, they produce interwoven cellulose nanofibres forming a continuous and stable membrane.

This nanocellulose has excellent characteristics that make it a promising alternative to the materials currently used for ocular bandages: it is semi-transparent, has a high water retention capacity (like a hydrogel), it is biocompatible, toxin-free, flexible but very resistant, and can be used as a substrate for cell growth.

The study, published in Biomaterials Science, shows that nanocellulose can be fixed by suture, has a very good adaptation to the eye contour and a great stability in contact with tissues. The next step of the project consists of adding bioactive molecules to the nanocellulose, such as growth factors and anti-inflammatory substances to accelerate corneal regeneration.

"So far, severe corneal injuries are treated with amniotic membrane bandages, but these treatments are not accessible to everyone. However, nanocellulose dressings would be much easier to produce and store and, above all, much more affordable", explains Anna Roig.

Figure: Electronic microscopy images of the material tested for corneal bandage (bacterial cellulose) and the benchmark material (amniotic membrane) highlighting its similarities. 

"In the future, if this technology is transferred to the industry, these ocular bandages could be obtained from much more accessible and economical raw materials, such as organic waste," adds Irene Anton-Sales, predoctoral fellow at the ICMAB-CSIC.

Corneal injuries are extremely delicate, uncomfortable and painful. Their care is important to ensure that they do not lead to more serious problems. In this sense, nanocellulose bandages will protect the cornea and accelerate its proper regeneration by preventing infection and providing adequate hydration until it heals.

Previously, Anna Laromaine directed the PLANT NANOHEALING project in which it was demonstrated that this nanocellulose strengthens healing in plants.

The CORNEAL-BC project will receive funding from the LLAVOR programme, the AGAUR (Agència de Gestió d'Ajuts Universitaris i de Recerca, Generalitat de Catalunya), FEDER (Fons Europeu de Desenvolupament Regional) and the Secretaria d'Universitats i Recerca del Departament d'Empresa i Coneixement de la Generalitat de Catalunya. This program selects innovative research projects with the possibility of incorporating products into the productive and industrial sector.

Reference Article:

Anton-Sales, I. et al. Bacterial nanocellulose as a corneal bandage material: A comparison with amniotic membrane. Biomater. Sci. Advance Article, (2020). DOI: 10.1039/D0BM00083C

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Read the article at R+D CSIC (22 April 2020): Dressings made of biologically active nanocellulose for treating corneal wounds