Characterization of controlled highly porous hyaluronan/gelatin cross-linking sponges for tissue engineering

This study examines the suitability of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride for use as a cross-linker in the preparation of highly porous hyaluronan (HA)/gelatin sponges through the solvent casting and particulate leaching (SCPL) process. The modulus, water absorption rate, bonding, morphology, cell viability, and chondrocyte mRNA expression of the HA/gelatin sponges were measured and compared. Water uptake by the sponges resulted in pores with spherical diameters ranging from 100μm to 200μm. With higher porosity, the strength and modulus declined. Larger salt leaching amounts resulted in higher water uptake. The cross-linking bonds in the HA/gelatin sponges were mostly ester bonds. According to our study, the amount of salt in the SCPL process was the main factor that influenced strength, pore interconnectivity, and water uptake ability. The results also showed that the scaffold had a non-viability effect on human chondrocytes, but the mRNA expression level of aggrecan and type II collagen in the cartilage was significantly higher than that of the control group after 5d of culture. The sponges developed in the present study are potential candidates for chondrocyte proliferation and differentiation in cartilage regeneration.