Self-regenerating giant hyaluronan polymer brushes

Abstract

Tailoring interfaces with polymer brushes is a commonly used strategy to create functional materials for numerous applications. Existing methods are limited in brush thickness, the ability to generate high-density brushes of biopolymers, and the potential for regeneration. Here we introduce a scheme to synthesize ultra-thick regenerating hyaluronan polymer brushes using hyaluronan synthase. The platform provides a dynamic interface with tunable brush heights that extend up to 20 microns – two orders of magnitude thicker than standard brushes. The brushes are easily sculpted into micropatterned landscapes by photo-deactivation of the enzyme. Further, they provide a continuous source of megadalton hyaluronan or they can be covalently-stabilized to the surface. Stabilized brushes exhibit superb resistance to biofilms, yet are locally digested by fibroblasts. This brush technology provides opportunities in a range of arenas including regenerating tailorable biointerfaces for implants, wound healing or lubrication as well as fundamental studies of the glycocalyx and polymer physics.

Effects of Glycyrrhiza polysaccharide in diet on growth performance, serum antioxidant capacity, and biochemistry of broilers

“…In the second part of our study, we analyzed the effect of GCP on LPS-induced acute stress. Exposure of an organism to LPS—a gram-negative bacteria–derived endotoxin—initiates an immune and oxidative stress response ( Ngkelo et al., 2012 ; Yücel et al., 2017 ; Wei et al., 2019 ). Thus, inhibition of an LPS-induced stress response is considered a key strategy to prevent disease and improve production performance.…”

The need to freeze—Dehydration during specimen preparation for electron microscopy collapses the endothelial glycocalyx regardless of fixation method

“…The level of collapse depends on the number of monomers in a given polymer. Each disaccharide repeat is considered as a monomer unit and is approximately the length of 1 nm for GAGs 46 . The length (r) scales with the number of disaccharide repeats (N) as a function of the Flory exponent x (r ~ N x ), which is approximately 0.6 for a good solvent and 0.33 for a poor solvent 47 .…”

“…The length (r) scales with the number of disaccharide repeats (N) as a function of the Flory exponent x (r ~ N x ), which is approximately 0.6 for a good solvent and 0.33 for a poor solvent 47 . One example is HA that can have up to 25 000 repeats, 46 which means that a polymer can be stretched up to approximately 435 nm in a good solvent and collapse and have an end‐to‐end distance of around 28 nm in a poor solvent. Yet, it cannot be ruled out that the binding of LaDy to negatively charged glycosaminoglycans (GAGs) prior to initiation of fixation and dehydration to some extent can stabilize the labile GAG structures.…”

Recent Advances for Improving Functionality, Biocompatibility, and Longevity of Implantable Medical Devices and Deliverable Drug Delivery Systems

“…Bacterial infection might also appear with medical implants, as bacteria can colonize and thrive on top of the implant surface, and even generating a biofilm. [79,80] Many attempts were made to create an LBL coating for medical devices, to provide an antimicrobial treatment for the implantation site. Yet, all of them posed a repeating problem, which is provoking bacterial resistance.…”