An Ex Vivo Model for Suture-Less Amniotic Membrane Transplantation with a Chemically Defined Bioadhesive

Abstract

Purpose: Chemically defined bioadhesives (CDB) are “two-component reactive adhesives” made from antibiotic food additives. They contain no animal-derived ingredients and are characterized by a high level of self-degradability, low toxicity, and strong bonding properties. Amniotic membrane (AM) transplantation is used to repair severe ocular surface disease in humans and horses. AM requires meticulous suturing to the injured cornea. The purpose of this study is to determine whether CDB can facilitate the suture-less placement and adherence of equine AM to porcine cadaver cornea.

Design: Prospective study.

Materials and Methods: To determine whether there are differences in ex vivo adhesion force between equine AM bonded with CDB to porcine cadaver cornea and equine AM sutured to porcine cadaver cornea. The following groups were tested (n = 5 per group): (1) CDB group: trephined (8 mm in diameter) cornea was bonded with CDB to 8-mm-sized discs of AM. (2) Suture group: the 8-mm trephined cornea was sutured with 8–0 absorbable suture to the AM. (3) Control group 1: two sheets of nitrocellulose paper were bonded with CDB. (4) Control group 2: two sheets of nitrocellulose paper were attached with suture and tested. Each sample was anchored to a tensiometer materials testing machine, and the strength of adhesion measured and expressed in units of kilogram-force (kgf).

Results: Mean ± SD strength of adhesion force found no statistically significant difference between CDB group (0.091 ± 0.054 kgf; 15 min of CDB adhesion time) and suture groups (0.095 ± 0.037 kgf), whereas there was significant difference (P < 0.05) between control group 1 (0.679 ± 0.048 kgf) and control group 2 (0.585 ± 0.092 kgf). These results revealed that the 15 min of CDB adhesive time had adhesive properties as strong as suture group.

Conclusions and Clinical Relevance: CDB provides a satisfactory level of adherence to ex vivo suture-less attachment of equine amniotic membrane transplantation to the porcine cornea.

KEYWORDS::

• Equine amniotic membrane
• Bioadhesives
• Amniotic membrane
• Transplantation
• Ex vivo
• Porcine

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.

Notes

*The Instron tension tester is a laboratory testing machine, which enables the measurement of the force displacement in tension mode. The tension tester has two grips that are available to meet the testing requirements of virtually any materials. The testing machine determines the modulus of elasticity and energy absorbing capacity of a material from the proportional and elastic limits of stress strain curves obtained when unit stress is plotted against unit strain (elongation). In this study, 8-mm wide and 25–mm long nitrocellulose papers were anchored by the grips to the material′s testing machine. The maximum adhesive force was recorded at the point of the maximum peak load.

**This software evaluates the peel, tear, sheer, tensile, compression, and flexes tests of the tissue determined by the tension tester and is included in the standard TestWorks 4 package.