The use of antifreeze proteins to modify pore structure in directionally frozen alginate sponges for cartilage tissue engineering

It is thought that osteoarthritis is one of the world's leading causes of disability, with over 8.75 million people in theUKalone seeking medical treatment in 2013. Although a number of treatments are currently in use, a new wave of tissue engineered structures are being investigated as potential solutions for early intervention. One of the key challenges seen in cartilage tissue engineering is producing constructs that can support the formation of articular cartilage, rather than mechanically inferior fibrocartilage. Some research has suggested that mimicking structural properties of the natural cartilage can be used to enhance this response. Herein directional freezing was used to fabricate scaffolds with directionally aligned pores mimicking the mid-region of cartilage, anti-freeze proteins were used to modify the porous structure, which in turn effected the mechanical properties. Pore areas at the tops of the scaffolds were 180.46±44.17 μm2 and 65.66±36.20 μm2 for the AFP free and the AFP scaffolds respectively, and for the bases of the scaffolds were 91.22±19.05 μm2 and 69.41±21.94 μm2 respectively. Scaffolds were seeded with primary bovine chondrocytes, with viability maintained over the course of the study, and regulation of key genes was observed.