Diffusion in and around alginate and chitosan films with embedded sub-millimeter voids

Area of Science:

• Biomaterials Science
• Materials Engineering
• Drug Delivery

Background:

• Hydrogel scaffolds from biopolymers are promising for controlled drug release and tissue engineering.
• Alginate and chitosan are widely studied biopolymers for scaffold fabrication.

Purpose of the Study:

• To investigate the solute release behavior of alginate and chitosan films containing sub-millimeter voids.
• To quantify the effect of these voids on diffusion and mass transfer coefficients.

Main Methods:

• Fabrication of hydrogel films with embedded voids using nitrogen gas bubbles prior to crosslinking.
• Characterization of void dimensions using digital microscopy and scanning electron microscopy.
• Measurement of porosity and gravimetric analysis.
• Solute (Vitamin B-12) release studies in PBS buffer at ambient and 37°C with lysozyme.
• Estimation of diffusion and mass transfer coefficients using a mathematical model.

Main Results:

• Embedded voids significantly enhanced the diffusion coefficient within the hydrogel films.
• The presence of voids altered the mass transfer characteristics at the gel-interface.
• Comparison with void-free films highlighted the void-induced enhancement in solute release.

Conclusions:

• Porous hydrogel scaffolds with embedded voids offer improved controlled release properties.
• This approach can be utilized to optimize drug delivery systems and tissue engineering scaffolds.
• The study provides insights into the relationship between scaffold architecture and solute transport kinetics.