Photocurable GelMA Adhesives for Corneal Perforations

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.

Printable hyaluronic acid hydrogel functionalized with yeast-derived peptide for skin wound healing

“…The 1 H NMR spectra for 10 mg/mL of the polymers in D2O were recorded, and the NMR data processing (Fourier transform, phase correction, baseline correction, and chemical shift referencing of the spectrum) was performed using MestReNova x64 software [33,34]. The infrared spectra of the HA, HA-Ty, HA-Ty-NH2, HA-Ty-NH2-B, HA-Ty-NH2-C, and the peptide were determined using the FT/IR-6600 spectrometer (JASCO, Japan) with a resolution of 4 cm -1 and 64 scans per spectrum.…”

“…Introducing phenol groups to the HA backbone allows for inducing gel formation by employing photocrosslinking mechanisms [27]. Using photosensitizers and exposition to the light with a wavenumber at 405nm enables photocrosslinking leading to covalent and temperature-irreversible gelation [33,34].…”

A “T.E.S.T.” hydrogel bioadhesive assisted by corneal cross-linking for in situ sutureless corneal repair

“…Accordingly, ROS generated during RF photosensitization mediates the production of new covalent bonds between collagen molecules, leading to an increase in biomechanical strength and stiffness of the corneal stroma [ 24 , 25 ]. The Young's modulus of collagen-based hydrogel has been reported to significantly increase after UV irradiation mediated by RF [ [26] , [27] , [28] ]. The application of RF in the cornea is clinically verified to be safe and effective.…”

“…Of note, RF has a high absorption effect on UV (∼370 nm) rays, preventing most UV light from passing through the cornea. The Young's modulus of collagen-based hydrogel has been shown to significantly increase after UV irradiation mediated by RF [ [26] , [27] , [28] ]. However, as the collagen derivative, GelMA-based hydrogel cross-linking used in cornea repair is mostly based on type I photoinitiators such as Irgacure-2959, UV curing of GelMA based on CXL technology has not been well-developed but worth studying.…”

GelMA Hydrogel Reinforced with 3D Printed PEGT/PBT Scaffolds for Supporting Epigenetically-Activated Human Bone Marrow Stromal Cells for Bone Repair

“…Hence, there is growing precedence for controlling the delivery of MSCs in situ to maximise their therapeutic efficacy. GelMA hydrogels have demonstrated their potential for different tissue engineering applications due to their plethora of desirable properties [ 34 , 38 , 39 ]. Hence, this study aimed to evaluate the capability of GelMA hydrogels reinforced with a 3D printed structural scaffold to support the MI192-induced mineralisation of hBMSCs.…”