In recent years, electrospinning has aroused much interest in the biomedical field of ophthalmology due to the possibilities it offers for the treatment of various pathologies affecting the eye. Especially with the proliferation of available electrospinning biomaterials.
Electrospinning is a fiber production technique based on the use of powerful electric fields, which are applied to a solution formed by one or more polymers (and alternatively other types of materials as well, including even biological materials) and one or more solvents. This solution, usually contained in a syringe-type container when working at laboratory scale, is pumped through a needle or capillary. In electrospinning, a high voltage is applied to the tip of the needle, so that the accumulation of electrical charges on the surface of the droplet produces an electrical repulsion effect between the particles of the solution, until finally the electrical force overcomes the surface tension of the droplet, stretching it to generate a jet. As the jet moves toward the collector, which is at zero or negative voltage, the solvent evaporates, generating polymer fibers that are eventually deposited onto the collector.
The fibers generated by electrospinning can vary from the nanometer and micrometer range according to the interest of each particular application, which is very interesting for biomedical applications, since the proper selection of the polymer allows the creation of fibrillar structures that resemble the extracellular matrix (ECM) in size and arrangement. It is possible to use different electrospinning biomaterials: biopolymers, bioabsorbable polymers, non-bioabsorbable polymers, etc, as long as they are of biomedical grade.
Electrospinning applications in ophthalmology
Vision is one of the five primary senses of the human being, so any pathology affecting the ocular system has a great impact on people’s quality of life. According to a report by the World Health Organization, at least 2.2 billion people in the world suffer from vision-related pathologies . Of these, it is estimated that almost 1 billion could be preventable or treatable .
In this context, fibers generated from electrospinning biomaterials offer a number of advantages in the development of new ocular therapies. Nanofibers offer a very high surface area, which is advantageous for tissue regeneration and controlled drug release applications. In addition, the adjustable porosity of nanofiber matrices favours cell growth and proliferation and does not interfere with tissue respiration and gas exchange.
Main applications of electrospinning in ophthalmology
- Controlled drug delivery
Electrospinning is being used to create nanofiber arrays in which drugs and active ingredients are incorporated. The spatial configuration of the nanofibers allows a sustained and controlled release of drugs into the eye in a very efficient manner. The nanofiber matrix is based on appropriately selected electrospinning biomaterials as required by the specific application.
For example, in the treatment of glaucoma, the controlled release of drugs can reduce intraocular pressure for a longer period of time. On the other hand, if the nanofiber matrix is loaded with anti-inflammatory agents, pathologies such as uveitis or post-operative inflammation can be treated more effectively. If antibiotics are used, corneal infections can be treated.
- Ocular tissue engineering
Nanofiber arrays generated with electrospinning biomaterials are the ideal support for ocular tissue engineering due to their similarity to the extracellular matrix, thus promoting cell adhesion and proliferation, as well as regeneration of damaged tissues in the eye. These nanofiber matrices can replace damaged corneal tissue, as well as contribute to the regeneration of retinal and optic nerves.
- Ocular medical devices
Ocular medical devices, such as intraocular lenses, artificial corneal implants, or even contact lenses, can benefit from the possibility of depositing a thin layer of nanofibers on or around them. In this way, this nanofiber layer will act as an interface between the medical device and the eye, stimulating the growth of cells around the device, thus increasing its biocompatibility and reducing the possibility of rejection. In intraocular devices, this nanofiber interface and subsequent cell proliferation also helps to better fix the implant inside the eye.
Electrospinning is a very versatile technique that has numerous applications in the field of ophthalmology due to its ability to control the characteristics of the nanofibers obtained. These applications are constantly evolving and improving thanks to the new electrospinning biomaterials that are becoming increasingly available. Advances in electrospinning and its applications in ophthalmology will provide researchers and physicians with a powerful tool to improve the quality of life of people with ocular pathologies.
References D. Sakpal et al., “Recent advancements in polymeric nanofibers for ophthalmic drug delivery
and ophthalmic tissue engineering,” in Biomaterials Advances 141 (2022) 213124. D. Mishra et al., “Ocular application of electrospun materials for drug delivery and cellular
therapies,” in Drug Discovery Today vol. 28, num. 9, 2023.