Prevention of Ocular Tenon Adhesion to Sclera by a PDMAA Polymer to Improve Results after Glaucoma Surgery

Abstract

The authors describe a process that may eventually reduce the risk of scar formation after glaucoma surgery. For this, a thin hydrogel coating is photochemically generated and linked to the sclera surface at the surgical site. This coating is generated from a photoreactive prepolymer containing anthraquinone groups, which is administered as a thin pad to the sclera surface. Short UV irradiation leads to a reaction of the photogroups with neighboring chains via C–H insertion crosslinking, thus transforming the precursor polymer into a hydrogel. Simultaneously, a reaction between the photogroups and the underlying sclera tissue occurs, so that the hydrogel patch becomes covalently linked to the tissue. The authors show that the resulting thin coating is strongly cell repellent and hinders tenon fibroblasts to form tenon tissue at the site of the coating and is suitable for inclusion into a surgical procedure.

Effects Of SMILE-Derived Decellularized Lenticule As An Adhesion Barrier In A Rabbit Model of Glaucoma Filtration Surgery

“…The present study reveals that decellularized lenticule promotes IOP reduction and prolongs bleb survival in trabeculectomy in rabbits with no complications. A strategy to reduce scar formation following glaucoma ltration surgery is to reduce the adhesion of the tenon broblasts to the underlying sclera at the surgical site [21]. Our in vivo studies suggest that decellularized lenticule has a space-keeping effect that prevents adhesion between the tenon broblasts and sclera (Fig.…”

Kinetics of Photocrosslinking and Surface Attachment of Thick Polymer Films

“…In a negative photoresist, a thin polymer film becomes insoluble in light-exposed areas, mostly through crosslinking. The most popular negative photoresists are epoxy-based polymers (e.g., SU-8) ,, and off-stoichiometry thiol-enes. , Typical negative photoresists can also contain photoreactive groups such as benzophenone, − thioxanthone, − anthraquinone, − benzoin ether, , and acylphosphine moieties. , Upon irradiation through a mask, a negative photoresist transits from compounds, such as oligomers or (low molecular weight) polymers, to crosslinked polymers which have an infinite molecular weight (i.e., spanning the whole irradiated area). Accordingly, the polymer becomes completely insoluble in all irradiated locations, whereas in the shaded areas under the mask, it remains uncrosslinked and is washed away in a following development step.…”

“…Recently, a promising way to photochemically generate covalently surface-attached polymer networks (SAPNs) has been presented, which is based on C,H insertion crosslinking (CHic). ,, In this process, photoreactive groups are first incorporated into polymer chains via copolymerization. Then, any coating technique, for example, dip or spin coating, doctor blading, or casting, is then used to generate a thin film.…”

“…During network formation, the polymer chains simultaneously attach to any organic substrate. In this context, benzophenones, , thioxanthones, sulfonylazides, − diazo compounds, and anthraquinones were used as photoreactive groups to induce the network formation and surface attachment. If the substrates have no C–H bonds, the formation of a self-assembled layer, for example, through silanization, can be performed prior to the CHic reaction.…”

“…As C,H groups are usually abundantly present in the polymer layers, even small amounts of crosslinking groups are already sufficient enough to covalently crosslink polymer chains. The main advantage of CHic is that it can react with different kinds of materials containing C,H groups. ,,,,,, …”