Photocurable GelMA Adhesives for Corneal Perforations.

Inês A Barroso,Kenny Man,Thomas E Robinson,Sophie C Cox,Anita K Ghag

doi:10.3390/bioengineering9020053

Abstract

The current treatments for the management of corneal and scleral perforations include sutures and adhesives. While sutures are invasive, induce astigmatism and carry a risk of infection, cyanoacrylate glues are toxic, proinflammatory and form an opaque and rough surface that precludes vision. Consequently, the clinical need for a fast curing and strong tissue adhesive with minimised cytotoxicity and host inflammation remains unmet. In this paper, we engineer a gelatine methacryloyl (GelMA) adhesive that can be crosslinked in situ within 2 min using UV or visible light and a riboflavin (RF)/sodium persulfate (SPS) system. Optical coherence tomography (OCT) images demonstrated that the flowable GelMA adhesive could completely fill corneal wounds and restore the ocular curvature by forming a smooth contour on the ocular surface. Further, ex vivo studies in porcine eyes showed that GelMA bioadhesives exhibited burst pressures that were comparable to cyanoacrylates (49 ± 9 kPa), with the hydrogels exhibiting a transmittance (90%), water content (85%) and storage modulus (5 kPa) similar to the human cornea. Finally, using human dermal fibroblasts, we showed that our GelMA adhesive was non-toxic and could effectively support cell adhesion and proliferation. Taken together, the adhesive’s performance, injectability and ease of administration, together with gelatin’s availability and cost-effectiveness, make it a potential stromal filler or sealant for corneal and conjunctival applications.

Highlights

Academic Editor: DimitriosGlobally, corneal blindness is estimated to affect approximately 23 million people, with an estimated 1.5 million new cases per year [1,2]
~1.8 ppm, corresponding to the acrylic protons of methacryloyl of lysine and hydroxyl lysine groups and the methyl proton of methacryloyl grafts, respectively [55,56,57]. These groups are absent in the spectra of unmodified gelatine, indicating the covalent functionalisation of gelatine with the methacryloyl groups
3.1–3.2 ppm indicated that the DF% was 60% after 2 h reaction with 6% (v/v) MA

Summary

Introduction

Academic Editor: DimitriosGlobally, corneal blindness is estimated to affect approximately 23 million people, with an estimated 1.5 million new cases per year [1,2]. Corneal wounds and perforations can arise from infections, traumatic injuries, surgical procedures (e.g., cataract surgery), autoimmune diseases (e.g., ulcerative keratitis) or degenerative disorders [3,4]. Full-thickness corneal injuries can leak and allow the ingress of pathogens into the eye. Given the risk of ocular morbidity and vision loss, corneal perforations are considered surgical emergencies [5]. The sealing of corneal wounds remains challenging for surgeons and sutures are still the gold standard treatment for the closure of ocular wounds due to their high tensile strength [5,6]. Sutures are time consuming to position, inflict additional trauma to the tissues, can act as a nidus for infection, induce astigmatism and often require secondary removal procedures [2,7,8]

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