Comparative study on complexes formed by chitosan and different polyanions: Potential of chitosan-pectin biomaterials as scaffolds in tissue engineering

Polyelectrolyte complexes of chitosan (Ch) and pectin (Pc) or alginate (Alg) were produced in the presence or absence of the silicone gel Silpuran® 2130 A/B (Sil) and the surfactant Kolliphor® P188 (Kol). Ch-Pc-Kol-based formulations presented higher porosity (up to 83.3%) and thickness (maximum of 2273.5 μm in PBS). Lower water contact angle was observed for Ch-Alg formulations (minimum of 36.8°) and these formulations presented higher swelling and mass loss in PBS (reaching up to 21.7 g/g and 80.4%, respectively). The addition of Sil to the matrices improved their elastic moduli, reaching a maximum of 4-fold change at 40% strain. The use of pectin instead of alginate augmented the elastic moduli, reaching 66 and 4-fold changes for dense and porous formulations, respectively. Pectin-containing scaffolds presented poroviscoelasticity, a typical mechanical feature of many soft tissues. The suitability of the materials for tissue engineering applications was demonstrated in terms of stability upon degradation in culture medium or lysozyme solution, as well as lack of cytotoxicity. This study evidences the potential of Ch-Pc-based materials to be further explored for this purpose, especially to improve the mechanical properties of chitosan-based scaffolds aiming medical applications.