Fabrication and Characterization of Chitosan-Based Scaffolds with Iron Supplements for Tissue Engineering Applications

Background: Tissue engineering aims to repair/regenerate damaged tissues through the combined use of living cells and biomaterials. One of the main challenges in this field is the design of biodegradable scaffolds that achieve an optimal balance of mechanical and biological properties. This study investigated chitosan-based scaffolds, fabricated with and without iron supplementation, to evaluate their physical properties and potential suitability for tissue regeneration.   

Methods: Scaffolds were fabricated via a freeze-drying technique. Chitosan (0.5g) was dissolved in 20ml 2% (v/v) acetic acid solution at room temperature using a magnetic stirrer with applied heat. For iron-incorporated scaffolds, analytical grade (Sigma-Aldrich), ferrous sulfate tablets (0.5g) were incorporated into the polymer solution (5% g/ml) prior to dissolution. The resulting solutions were transferred into glass vials, covered with aluminum foil, frozen at −20°C in a freezer, and freeze-dried using a Freeze-dryer (Labconco, USA) for 48h under vacuum (7.0Pa and collector temperature -50°C. Scaffolds were then washed with phosphate buffer saline (PBS). Cylindrical shaped scaffolds were cut (1 mm thickness) with a sharp razor blade and subsequently characterized by measuring mass, dimensions, density, water absorption capacity, and microstructural morphology via scanning electron microscopy (SEM). At least three specimens were tested, and the average and standard deviations were calculated.  

Results: Chitosan scaffolds maintain structural integrity when immersed in culture medium. Iron incorporation increased scaffold density from 0.0302 g/cm³ to 0.0534 g/cm³. Both scaffold types exhibited substantial water uptake, though this capacity was reduced with iron incorporation, 2240% for unmodified chitosan versus 1809% for Fe/chitosan scaffolds. SEM imaging revealed a porous, interconnected microstructure, with pore diameters ranging from several micrometers up to 300 micrometers.  

Conclusion: These findings demonstrate a preliminary investigation that material composition significantly influences scaffold density, and water absorption. Iron incorporation increases scaffold density while moderating water uptake, suggesting a tunable approach to scaffold design.