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 &#xb1; SD strength of adhesion force found no statistically significant difference between CDB group (0.091 &#xb1; 0.054 kgf; 15 min of CDB adhesion time) and suture groups (0.095 &#xb1; 0.037 kgf), whereas there was significant difference (P < 0.05) between control group 1 (0.679 &#xb1; 0.048 kgf) and control group 2 (0.585 &#xb1; 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.