(584az) Microsphere-Collagen Hydrogel With Adipose Derived Stem Cells for Soft Tissue Engineering

A composite hydrogel system containing microspheres was developed for tissue engineering applications. Collagen hydrogels (Col) are one of the widely used cell culture matrices as they can closely mimic the in vivo environment. Similarly gelatin microspheres (GMs) are well known for their ability to simultaneously deliver both cells and growth factors for various biomedical applications. Here, we present a system of GMs-incorporated-Col to vary the mechanical strength of the hydrogels for their effects on soft tissue engineering.

GMs were fabricated and further cross-linked before being incorporated into gelatin microsphere-collagen hydrogel composites (Col-GMs). Visco-elastic properties of the scaffolds showed that mechanical strength can be tuned by the composition of GMs. The GMs were then loaded with basic fibroblast growth factor (bFGF) and seeded with human adipose derived stem cells (hADSCs).

hADSCs seeded on the GMs migrated into the relatively softer collagen matrix and seems to populate the whole scaffold within one week of culture period. Osteogenic and adipogenic differentiation of ADSCs were studied. Different amounts of osteogenic genes were expressed, showing higher mechanical strength seeming to enhance the osteogenic differentiation abilities of the ADSCs. Encapsulated bFGF showed that gene expression of osteogenic marker genes was enhanced by the GMs in Col-GMs compared to merely encapsulating bFGF in collagen hydrogels.

Our study showed that co-encapsulation of bFGF loaded Gelatin microspheres along with ADSCs with in a collagen hydrogel matrix enhances the osteogenic differentiation of ADSCs and can be a potential stem cell based therapeutic strategy for different types of tissue regeneration.