Tunable hybrid cryogels functionalized with microparticles as supermacroporous multifunctional biomaterial scaffolds

This study aims at incorporating microparticles (MPs) into polymeric network of cryogels to fabricate a multifunctional biomaterial scaffold (cryogel-microparticle [C-MP] composite) which has microstructured biocompatible pore surface, supermacroporous interconnected pore distribution and capability to simultaneously deliver bioactive molecules. Three types of MPs (i.e. poly(D,L-lactide-co-glycolide), chitosan, and silica MPs) were separately incorporated in three different cryogels (i.e. chitosan-agarose, chitosan-agarose-gelatin, and chitosan-gelatin), demonstrating the generality of the approach. Factors affecting distribution of MPs within the cryogel were investigated to achieve uniform distribution of MPs within the pore wall of cryogel as well as the whole cryogel monolith to create microstructured pore surface of C-MP composites, which was characterized by scanning electron microscopy, fluorescence microscopy, infrared spectral analysis (FTIR), and water uptake properties. Further, mouse embryonic fibroblasts (NIH 3T3), mouse myoblasts (C2C12), and human lung cancer cells (NCI-H460) were grown on microstructured C-MP composites and nonstructured cryogels to check adherence and growth of cells, and investigate their biocompatibility. To test the potential of C-MP composites for delivery of bioactive/drug molecules to cells growing in three-dimensional (3D) conditions, doxorubicin-loaded silica MP-chitosan-gelatin C-MP composites were fabricated and anti-proliferative effect of doxorubicin was observed on growing human cervical cancer cells (HeLa).