Biocompatible oligochitosans as cationic modifiers of alginate/Ca microcapsules

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Cell Encapsulation Technology

Background:

• Oligochitosan's molecular mass influences capsule properties.
• Biocompatible capsules are essential for various biomedical applications.
• Alginate capsules are widely used but require surface modification for enhanced functionality.

Purpose of the Study:

• Investigate oligochitosan samples (3-5 kDa) as biocompatible coatings for alginate/Ca capsules.
• Assess the impact of oligochitosan molecular mass on capsule properties.
• Evaluate the non-cytotoxicity and metabolic effects of oligochitosan on C2C12 myoblasts.

Main Methods:

• Depolymerization and purification of oligochitosan samples.
• Preparation of alginate/Ca capsules coated with oligochitosan.
• Assessment of oligochitosan non-cytotoxicity using C2C12 myoblasts.
• Analysis of capsule membrane properties (e.g., cut-off) and mechanical stability.

Main Results:

• Oligochitosan samples were non-cytotoxic and did not affect mammalian cell metabolism.
• Oligochitosans reduced the membrane cut-off of alginate capsules.
• Capsule mechanical stability and membrane cut-off reduction depend on oligochitosan molecular mass and alginate composition.
• Low molecular weight chitosan (< 5000 g/mol) enabled formation of mechanically stable capsules at physiological pH.

Conclusions:

• Low molecular weight oligochitosan is a viable and advantageous coating for alginate capsules.
• Optimized oligochitosan coatings enhance capsule stability and control membrane permeability.
• This approach offers a significant advantage for developing stable, biocompatible microcapsules at physiological conditions.