Formylated polystyrene for the fabrication of pore selective aldehyde group functionalized honeycomb patterned porous polystyrene films

Hyaluronic acid hydrogels with excellent self-healing capacity and photo-enhanced mechanical properties for wound healing

A continuously stable moist healing environment is immensely beneficial for wound healing, which can be availably achieved by providing an in situ hydrogel with enough strength resembling skin tissue and self-healing ability. Herein, through a dual-crosslinking strategy, hyaluronic acid-based hydrogels with excellent self-healing capacity and enhanced mechanical properties are fabricated via the acylhydrazone linkages and subsequent photocrosslinking based on hydrazide-modified sodium hyaluronate and aldehyde-modified maleic sodium hyaluronate. The hydrogels demonstrate the fast gelation process (< 1 min), the controlled swelling behaviors, and the good biocompatibility. Notably, they possess enhanced mechanical strength similar to the human dermis (∼ 2.2 kPa). Also, they can self-heal rapidly with a self-healing efficiency of ∼90 % at 6 h. Based on this, the hyaluronic acid-based hydrogels, without any biological factors involved, can facilitate the full-thickness skin wound reconstruction process by accelerating the three phases of the wound repair, including reducing wound inflammation in the inflammatory phase, promoting angiogenesis in the proliferative phase, and promoting the deposition and reconstruction of collagen in the remodeling phase. The produced hyaluronic acid hydrogel can serve as an ideal candidate for wound healing.

Modified Breath Figure Methods for the Pore-Selective Functionalization of Honeycomb-Patterned Porous Polymer Films

Recent developments in the field of the breath figure (BF) method have led to renewed interest from researchers in the pore-selective functionalization of honeycomb-patterned (HCP) films. The pore-selective functionalization of the HCP film gives unique properties to the film which can be used for specific applications such as protein recognition, catalysis, selective cell culturing, and drug delivery. There are several comprehensive reviews available for the pore-selective functionalization by the self-assembly process. However, considerable progress in preparation technologies and incorporation of new materials inside the pore surface for exact applications have emerged, thus warranting a review. In this review, we have focused on the pore-selective functionalization of the HCP films by the modified BF method, in which the self-assembly process is accompanied by an interfacial reaction. We review the importance of pore-selective functionalization, its applications, present limitations, and future perspectives.

In Search of a Green Process: Polymeric Films with Ordered Arrays via a Water Droplet Technique

As an efficient technique for the preparation of polymeric hexagonal orderly arrays, the breath figure (BF) process has opened a modern avenue for a bottom-up fabrication method for more than two decades. Through the use of the water vapor condensation on the solution surface, the water droplets will hexagonally pack into ordered arrays, acting as a template for controlling the regular micro patterns of polymeric films. Comparing to the top-down techniques, such as lithography or chemical etching, the use of water vapor as the template provides a simple fabrication process with sustainability. However, using highly hazardous solvents such as chloroform, carbon disulfide (CS2), benzene, dichloromethane, etc., to dissolve polymers might hinder the development toward green processes based on this technique. In this review, we will touch upon the contemporary techniques of the BF process, including its up-to-date applications first. More importantly, the search of greener processes along with less hazardous solvents for the possibility of a more sustainable BF process is the focal point of this review.