Enzymatic Degradation Behavior and Molecular Weight Regulation of Dextran: Empirical Modeling and Multi-Scale...

Area of Science:

• Biotechnology
• Enzymology
• Polymer Chemistry

Background:

• High-molecular-weight dextran has limited pharmaceutical applications.
• Controlled production of low-molecular-weight dextran (< 10 kDa) is crucial for pharmaceutical development.
• Enzymatic degradation offers a precise method for dextran modification.

Purpose of the Study:

• To develop an efficient enzymatic process for producing low-molecular-weight dextran (< 10 kDa).
• To optimize process conditions for dextran enzymatic hydrolysis.
• To characterize the properties of the enzymatically produced low-molecular-weight dextran.

Main Methods:

• Enzymatic hydrolysis of high-molecular-weight dextran using PC-Edex dextranase.
• Systematic investigation of enzyme concentration, substrate concentration, temperature, and pH.
• Application of a staged empirical control strategy based on the Malhotra model.
• Multi-scale characterization of the resulting dextran fragments.

Main Results:

• Optimized conditions yielded dextran < 10 kDa within 60 min.
• Achieved 94.56% mass fraction of fragments < 10 kDa with > 98.96% degradation rate.
• Produced dextran with narrow molecular weight distribution (Mw/Mn = 1.528).
• Enzymatic degradation preserved dextran's backbone structure, amorphous nature, and thermal stability.

Conclusions:

• A robust and reproducible laboratory-scale enzymatic process for low-molecular-weight dextran production was established.
• The process is suitable for industrial scale-up for pharmaceutical applications.
• Enzymatically modified dextran retains desirable structural and thermal properties.