Antifibrinogen, Antireflective, Antifogging Surfaces with Biocompatible Nano-Ordered Hierarchical Texture Fabricated by Layer-by-Layer Self-Assembly

Abstract

Endoscopic surgery is a minimally invasive approach that is widely used in various clinical departments, including digestive surgery, thoracic surgery, and urology, because it can minimize the burden on patients. To perform more elaborate procedures, highly functional coatings that enhance the operation efficiency of the related equipment are required; for example, coatings to improve the visibility through endoscope lenses are needed. In this study, we designed multifunctional surfaces that displayed antithrombogenicity, antireflection, and antifogging by controlling nano-ordered hierarchical structures fabricated via layer-by-layer self-assembly. The coatings were composed of polyelectrolyte multilayers prepared from blends of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) that were deposited in alternating layers with blends of poly(allylamine hydrochloride) (PAH), PVA, and PAA. Although mixing cationic PAH and anionic PAA solutions generally causes polyelectrolyte−polyelectrolyte complexes (PECs) to form through electrostatic interactions, we found that PAH and PAA hardly formed PECs when PVA was present in the solution containing PAA. Consequently, PAA behaved differently in cationic and anionic solutions, resulting in the formation of coatings with hierarchical texture. The structures possessed antireflective properties with a graded refractive index and >95% transmittance. The coatings also displayed resistance to protein adsorption derived from free hydroxyl groups and antifogging performance caused by hydrophilicity combined with the strong hydrogen bonding ability of PVA. The results of this study would be valuable for the development of innovative biomedical devices through a simple and environmentally friendly approach.

Micro‐/Nanostructured Interface for Liquid Manipulation and Its Applications

“…The PEMs showed ion‐specific oil repellency in water . Shiratori et al prepared antifibrinogen, antireflective, and antifogging surfaces by alternative deposition of PAH−PVA−PAA mixture (as the cationic solution) with PVA−PAA mixture (as the anionic solution) . Li et al fabricated oil‐repellent antifogging films by alternative deposition of hyaluronic acid (HA) and branched poly(ethylenimine) (bPEI) with further perfluorooctanesulfonic acid (PFOS) modification .…”

Bioinspired Superwettability Micro/Nanoarchitectures: Fabrications and Applications

“…Although techniques are still far from replicating the intricate and precise architectures found in biological systems, the combination of existing fabrication techniques offers a route toward the creation of hierarchical architectures from composite materials with enhanced complexity . The created architectures with advanced wettability and functions have given rise to emerging applications such as lab‐on‐chip devices, versatile coatings, functional textiles, and smart soft robotics . Furthermore, the practical applications of the fabricated bioinspired architectures with superwettability have also advanced.…”

Mussel‐inspired catechol‐based chemistry for direct construction of super‐hydrophilic and waterproof coatings on intrinsic hydrophobic surfaces

“…For example, at n = 2, the PE/(bPEI‐C/PAA‐D)*2 (where PAA‐D is the outmost layer) has a CA of 24.01 ± 16.41°. This meets the requirements of antifogging behavior because CA <40° according to previous studies . The PAA‐D with many carboxyl groups provides more hydrophilic moieties to reduce the surface tension.…”