Macroporous poly(L-lactic acid)/chitosan nanofibrous scaffolds through cloud point thermally induced phase separation for enhanced bone regeneration
After immersed in 70% acetone solution for 1h, the PLLA scaffolds with nanofibers architectures (-80℃ scaffold from CP-TIPS) showed high elasticity and flexibility, while the platelet-like structure scaffolds (-80℃ scaffold from TIPS) were friable. The nanofibrous network was believed to be responsible for the good flexibility.
Steps to reproduce
The porous scaffolds were fabricated by a modified TIPS which we name it as cloud point TIPS (CP-TIPS) in a PLLA/dioxane/ H2O ternary system. Briefly, 4% (W/V) clear solution was obtained by dissolving a certain PLLA in dioxane/ H2O mixed solvents with volume ratios of 86/14 and stirring with a magnetic stirrer at 65℃ for 2 h. The solution temperature was firstly decreased to 1~2℃ above the cloud point temperature, and subsequently, the solution was rapidly transferred into a designed phase separation temperature (Tq = 20℃, 4℃, -20℃, -80℃) for 2 h. Solvent exchange was performed at 4℃ after gelation using deionized water and changed three times a day for 2 days. The resultant sample was freeze-dried for 48 h. Previously prepared PLLA scaffolds were immersed into a mixture of acetone/ H2O (7:3) for 1 h.