More than 12.7 million people worldwide suffer from corneal blindness, making it one of the leading causes of preventable blindness, with a high percentage of these cases affecting low- and middle-income countries (Flaxman et al., 2017).

Natural corneal healing is usually possible in mild corneal disorders. However, in some cases or when corneal disorders are severe, the natural healing mechanism of the cornea is insufficient, leading to the development of nonhealing defects such as corneal melting, corneal neovascularization, loss of transparency or scar formation, among others (Saghizadeh et al., 2017, Voiculescu et al., 2015). In this cases, different treatments are applied to restore the homeostasis of corneal tissue, such as anti-inflammatory and anti-scarring agents, growth factors and proteins, or even biological products like amniotic membrane and blood-derived products (Dang et al., 2022). In some cases, corneal lesions may become complicated and lead to corneal ulcers and perforations, which may compromise the integrity of the ocular surface tissues and, as a consequence, cause visual impairment or even blindness (Schuerch et al., 2020). In these cases, the main therapeutic option is to use a human donor cornea to replace the injured tissue, either by total or partial replacement of the corneal thickness (Lagali, 2020). However, the use of human donor corneas has some limitations, such as corneal graft failure due to allograft rejection, but the main limitation to its use is the worldwide shortage of donated corneas. In this regard, numerous efforts have been made to develop an artificial substitute for the human cornea that is capable of providing a 3D-fiber scaffold on which cells from the surrounding tissues can repopulate to restore injured tissue. In addition, it should be necessary for these artificial substitutes to provide a structure that resembles the extracellular matrix of native tissues (Formisano et al., 2021). However, one of the main challenges of bioengineering is to develop a 3D scaffold that mimics the structure of the human cornea. In pursuit of this milestone, several biomaterials have been used as biological substitutes for the cornea, including amniotic membrane, collagen, and fibrin gel alone or combined with collagen (bovine pericardium) (Alio et al., 2018, Walkden, 2020).

Human amniotic membranes are limited by the lack of standardization (obtention, processing and preservation), heterogeneity and low mechanical strength (Gicquel et al., 2009, Ramuta and Kreft, 2018). Furthermore, its allogenic origin carries the risk of disease transmission (HIV, Hepatitis B, C and HTLV) and limits their accessibility (Rahman et al., 2009). Their relative opacity is an aspect to improve when it is placed in the visual axis of the eye. For that, there is a niche of research to develop bioactive membranes that incorporate growth factors and biomolecules to potentiate corneal healing and at the same time has an improved optical property for their use at the ocular surface.

Over the past three decades, different blood-derived products, such as autologous serum, platelet-rich plasma (PRP) and plasma rich in growth factors (PRGF), have been used for the treatment of several ocular surface disorders (Anitua et al., 2015, Cui et al., 2021, Rodríguez and Alió, 2019). One of the main advantages of these products is that they not only lubricate the ocular surface by acting as a substitute for natural tears, but also provide a wide range of growth factors and proteins that improve and accelerate the healing of ocular surface tissues (Anitua et al., 2021b). On the other hand, PRGF is a type of PRP with specific characteristics, one of which clearly differentiates it from other PRP, and that is its wide versatility. PRGF technology has been extensively used in the ophthalmology field as an eye drop for the treatment of different ocular surface disorders (Lopez-Plandolit et al., 2010, Merayo-Lloves et al., 2016, Sanchez-Avila et al., 2020), but also as an injectable formulation for the treatment of cicatrizing conjunctivitis (de la Sen-Corcuera et al., 2020). In addition, it has been also used as a fibrin scaffold for the treatment of ocular surface disorders and as an adjuvant in pterygium and glaucoma surgery (Idoipe et al., 2021, Rodríguez-Agirretxe et al., 2018). This latter use suggests that the PRGF fibrin scaffold could be used as a biological substitute for the cornea due to the promising results obtained in corneal regeneration. However, the fibrin scaffold obtained from PRGF technology has some limitation due to its low transparency that could restrain the adequate regeneration of the corneal parenchyma. The low transparency of the PRGF fibrin clot may be associated with its high platelet content and the random arrangement of fibrin fibers that could scatter the light (Anitua et al., 2016, Cardona Jde et al., 2011). A PRP fibrin clot with greater transparency but maintaining its mechanical properties could improve and accelerate corneal tissue regeneration, enhance patient follow-up by the clinician, and would allow the patient to see during the rehabilitation process in those cases where the visual axis is compromised by both ocular damage and treatment application.

In the present work, we propose the development of bioactive membranes with improved optic properties from plasma rich in growth factors technology. The morphological characteristics and degradation ability of the new PRGF fibrin membrane were also evaluated. Finally, the stability of the new PRGF membrane stored at different temperature conditions was also analyzed.