Enzymatic Crosslinked Hydrogels for Biomedical Application

Abstract

Self-assembled structures mostly arises through enzyme-regulated phenomena in nature under persistent conditions. Enzymatic reactions are one of main biological processes in fabrication and construction of supramolecular hydrogel networks required for biomedical applications. The enzymatic processes provide a unique opportunity to integrate hydrogel formation. In most of cases, structure and substrates of hydrogels are adjusted by enzyme catalysis due to the chemo-, regio- and stereo-selectivity of enzymes. Hydrogels processed by using various enzyme schemes showed remarkable characteristics as dynamic frames for cells, bioactive molecules and drugs in biomedical applications. A novel class of enzyme-mediated crosslinking hydrogels mimics the extracellular matrices by displaying unique physicochemical properties and functionalities like water-retention capacity, drug loading ability, biodegradability, biocompatibility, biostability, bioactivity, optoelectronic properties, self-healing ability, shape memory ability. In recent years, many enzymatic systems investigated hydrogel cross-linking. Results of biocompatible hydrogel products show that these mechanisms of crosslinking can fulfill requirements for variety of biomedical applications including tissue engineering, wound healing and drug delivery.

A Comprehensive Review of Cross-Linked Gels as Vehicles for Drug Delivery to Treat Central Nervous System Disorders

“…Physically cross-linked gels are created by changes in environmental conditions whereby gelation often occurs under the influence of pH, temperature and other stimuli that could influence interactions between polymers [ 174 ]. Ionic interactions, hydrogen bonding, crystallization, and hydrophobic association are physical techniques utilized to crosslink polymers into reversible gels [ 175 ]. Ionic cross-linking usually occurs between two molecules or polymers of opposite charges [ 176 ].…”

“…Chemically cross-linked gels comprise covalent bonds among polymer chains are formed via radical polymerization, Click reactions, Schiff base cross-linking reactions and enzymatic cross-linking of complementary groups [ 175 ]. Free radical polymerization is the most commonly used mechanism of hydrogelation [ 179 ].…”

“…Enzymes form covalent bonds between polymers, they are significantly sensitive and specific in chemical reactions [ 80 ]. The majority of enzymes involved in polymer cross-linking are common enzymes that catalyze reactions in the body [ 175 ]. Plasma Amine Oxidase and Lysyl Oxidase are examples of human enzymes that have been used as crosslinkers to develop biocompatible, in-situ gelling hydrogels [ 175 ].…”

A Transparent, Tough and Self-Healable Biopolymeric Composites Hydrogel for Open Wound Management

“…Both hydrophilic and hydrophobic polymers have been utilized to establish hydrogels through physical or chemical cross-linking. 3,8 The chemical cross-linking synthesis process includes co/graftpolymerization, photo reaction, 9 enzymatic reaction, 10 and radiation. 11 The development of hydrogels with chemical cross-linking generally demands a reaction environment and cross-linking agents.…”

Effectiveness of insolubilized polyvinyl alcohol-based electrospun fibers loaded methylprednisolone by enzyme-catalyzed cross-linking in spinal cord regeneration

“…Such hydrogels were obtained by adding an H2O2 aqueous solution to that of polymer-Phs and HRP [24,29,30]. However, to the best of our knowledge fabrication of brous mats through HRP-mediated reaction is not developed well for most of biopolymers [31][32][33].…”