A biodegradable and biocompatible gecko-inspired tissue adhesive

TLDR

There is a significant medical need for tough biodegradable polymer adhesives that can adapt to mechanical deformations while remaining strongly attached to tissue, yet translating gecko‑inspired adhesives to medical use is complex due to multiple parameters such as biocompatibility, biodegradation, strong bonding, compliance, and conformability. The study aims to develop a biodegradable polymer adhesive that mimics gecko foot nanotopography for strong tissue attachment and potentially delivers drugs or growth factors to promote healing. The adhesive is fabricated from poly(glycerol‑co‑sebacate acrylate) with a nanostructured surface, and adhesion was optimized by tuning pillar dimensions such as tip‑to‑pitch and tip‑to‑base ratios. The resulting adhesive, a biocompatible, biodegradable elastomer with a nanostructured surface and oxidized dextran coating, showed markedly increased adhesion to porcine intestine in vitro and rat abdominal subfascial tissue in vivo, suggesting potential for wound sealing and suture or staple replacement.

Abstract

There is a significant medical need for tough biodegradable polymer adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached to the underlying tissue. We approached this problem by using a polymer poly(glycerol-co-sebacate acrylate) and modifying the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces. Translation of existing gecko-inspired adhesives for medical applications is complex, as multiple parameters must be optimized, including: biocompatibility, biodegradation, strong adhesive tissue bonding, as well as compliance and conformability to tissue surfaces. Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing. As a first demonstration, we have created a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment. This gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples.