2022, Vol. 26 ›› Issue (28): 4519-4524

Preparation and mechanical properties of collagen type II-silk fibroin-hyaluronic acid composite scaffold

Liu Gang1, 2, Gao Lilan1, 2, 3, Shi Feifei4, Wang Shixin3, Luo Lailong3, Li Ruixin5, Zhang Chunqiu1, 2   

Abstract: BACKGROUND: Collagen type II, silk fibroin and hyaluronic acid, which can provide an ideal microenvironment for cells, have become ideal scaffold materials for cartilage repair.
OBJECTIVE: To evaluate physicochemical properties and biomechanical properties of cartilage tissue engineering scaffolds prepared from collagen type II, silk fibroin and hyaluronic acid.
METHODS: Collagen type II-silk fibroin-hyaluronic acid composite scaffolds were prepared by low-temperature 3D printing technology. The microstructure, porosity and water absorption of scaffold were detected. Different strain rates were used to compress the scaffold, and the rate dependent properties of the scaffold were investigated. Constant stress level or constant strain was applied on the surface of scaffold for 3 600 s, and the creep behavior and stress relaxation behavior were investigated.
RESULTS AND CONCLUSION: (1) The prepared scaffolds had three-dimensional porous structure, uniform pore size and good connectivity. The porosity was (85.1±1.6)%. The water absorption expansion rate was (1 071.7±131.6)%. (2) Under different strain rates, the compressive stress-strain curves of cartilage scaffolds did not coincide, which indicated that the compressive mechanical properties of cartilage scaffolds were rate dependent. With the increase of strain rate, the Young’s modulus increased. (3) When the stress level was constant, the creep strain first increased rapidly and then increased slowly. When the stress level increased, the creep strain also increased. (4) When the compression strain was constant, the stress of scaffold decreased rapidly at first and then slowly with the relaxation time. With the increase of the compression strain, the stress at different times increased. (5) The mechanical properties of the collagen type II-silk fibroin-hyaluronic acid composite scaffolds are similar to those of host cartilage, which means that the prepared scaffold is a kind of nonlinear viscoelastic material.
Key words: cartilage scaffold, type II collagen, silk fibroin, sodium hyaluronate, rate dependent, creep, stress relaxation