Evaluation of Hybrid Chitosan-Cellulose Biodegradable Scaffolds for Tissue Engineering Applications

Natural polymers continue to provide effective biocompatible scaffolds for use in tissue engineering applications. In some respects, their chemical structure closely mimics that of the extracelluar matrix of biological tissues. Eventhough a wide variety of biopolymers can be used for these applications, no single polymer has been yet found to fulfill all requirements needed in a scaffold material. In an attempt to combine the advantages of two natural polymers, hybrid scaffolds of chitosan/cellulose constructs had been evaluated as candidates for tissue engineering applications. Four groups of hybrid chitosan/cellulose scaffolds were prepared with different cellulose concentrations. The surface and bulk porosities scaffolds have been examined using scanning electron microscope (SEM). The SEM photographs revealed that all hybrid scaffold groups exhibited an interconnected highly porous structure. Percent porosity and pore volume distribution were evaluated using mercury intrusion porosimetry (MIP). The scaffolds were mechanically tested to evaluate their compressive strength. The biodegradation rate in lysozyme-containing saline had been also determined over a six week period. The MIP results showed that all scaffolds had percent porosity in excess of 75% and that the percent porosity decreased by increasing the cellulose concentration. The incremental intrusion versus diameter curves revealed that most of the scaffolds porosity occurred in the macro-scale. The compressive strength of the scaffold showed an increase with an increase in the cellulose concentration. However, the biodegradation rate was found to vary inversely with the cellulose content in the hybrid. In order to evaluate the cytocompatibility of the chitosan-based scaffolds, mesenchymal stem cells were statically seeded and their attachment had been evaluated. The results revealed that after three and eight day of seeding, the scaffolds became highly populated with cells. This serves as a clear indicatation that the scaffolds thus investigated promote cell attachment and support cell proliferation and proliferation. Thus, the investigated scaffolds are promising candidates for tissue engineering applications.