Gecko-inspired chitosan adhesive for tissue repair

Abstract

The advent of nanotechnology has opened the possibility of fabricating nanoscopic pillars on the surface of polymeric films mimicking the Gecko's foot, in an attempt to increase their adhesive capabilities enhanced by van der Waals forces. However, these forces are considerably weakened in a wet physiological environment. To circumvent this loss in force, current biocompatible adhesives with nanopillars require complex multiple-step fabrication, including an extra layer of adhesive coating to stabilize tissue bonding under physiological conditions. In this report, we describe a simple one-step fabrication process of a single-layer chitosan film that has pillars with base diameter in the range of 100-600 nm and a height of~70 nm. The nanostructured adhesive is laser-bonded to tissue and does not require pillar coating to enhance bonding in water. In comparison with a 'flat' adhesive (without pillars), the nanostructured adhesive bonded significantly stronger to tissue under either stress or pressure. Atomic force spectroscopy also confirmed the superior bonding capability of the nanostructured adhesive. This study demonstrates a one-step fabrication technique to produce a monolayer gecko-inspired adhesive that is biocompatible and bonds effectively to tissue.

A conducting polymer with enhanced electronic stability applied in cardiac models

“…S9C), which indicated that photoadhesion is an effective technology (movie S2) to apply patches to the heart in a potentially less invasive manner. It is reported in the literature that the adhesion is due to a photocrosslinking mechanism between biomolecules initiated by the activation of RB into an excited state ( 56 , 57 ). Further investigations involving spectroscopy techniques are needed to elucidate the exact molecular mechanism underlying the bonding between chitosan films and tissue via green lasers.…”

Multilayered spraying and gradient dotting of nanodiamond–polycaprolactone guidance channels for restoration of immune homeostasis

“…Advanced biomaterials are playing an increasingly important role in nerve tissue regeneration 23 . For severe long-range peripheral nerve defects, autografts cannot meet the present demands and may have some negative Fig.…”

Biomimetic approaches toward smart bio-hybrid systems

“…Modifying the device and substrate surfaces with biomimetic micro/nano-structures thus becomes more promising. Typical biomimetic micro/nano-structures showing good bio-integration mainly include (1) micro-/nano-pillar arrays coated with synthetic polymer that mimics the wet adhesive proteins [71–73], (2) mechanical interlock structures [74–77], (3) octopus sucker cups [78–80]. Here we focus on the second and the last structures without any chemical coating.…”