Enzymatic synthesis of dextran-containing hydrogels

Area of Science:

• Biocatalysis
• Polymer Chemistry
• Materials Science

Background:

• Dextran, a natural glucose-based polysaccharide, offers a versatile scaffold for chemical modification.
• Acylation of polysaccharides can yield materials with novel properties and applications.
• Enzymatic synthesis presents a greener alternative to traditional chemical catalysis.

Purpose of the Study:

• To biocatalytically synthesize dextran acrylates using specific enzymes.
• To characterize the structure and properties of the synthesized dextran derivatives.
• To prepare and analyze gels formed from dextran acrylates.

Main Methods:

• Enzymatic acylation of dextran with vinyl acrylate (VA) using Proleather FG-F and lipase AY in anhydrous dimethylsulfoxide.
• Characterization of dextran acrylate (dexT70-VA) using gel permeation chromatography and Nuclear Magnetic Resonance (NMR) spectroscopy.
• Preparation of gels via free radical polymerization of dexT70-VA solutions and analysis of gel pore sizes through swelling experiments.

Main Results:

• High reaction efficiency (ca. 71%) and isolated yields (ca. 45%) were achieved using Proleather FG-F.
• NMR analysis confirmed mono-substitution of dextran glucopyranose residues, forming two positional isomers at the 2 and 3 positions in equal amounts.
• Gels exhibited varying pore sizes (ca. 18–182 Å) depending on dextran acrylate degree of substitution and monomer concentration.

Conclusions:

• Biocatalytic synthesis of dextran acrylates is an efficient and viable method.
• The synthesized dextran acrylates can form gels with tunable pore sizes.
• These dextran-based gels hold potential for various applications requiring controlled porosity.