Effect of annealing on PLCL scaffold fabricated by freeze-drying technique for vascular tissue engineering

Abstract

Biopolymer Poly(l-lactide-co—caprolactone) (PLCL) has been investigated and is a good candidate for vascular tissue applications due to its unique characteristic and suitable for medical usage. In this study, the properties of a PLCL scaffold made by the freeze-drying technique were altered using the annealing technique. Cylindrical PLCL scaffolds were annealed in the oven at various temperatures (37, 60, and 120 °C) and times (4 and 24 h). Physicochemical properties show the remaining properties of the origin PLCL scaffolds, while FE-SEM images show that the geometry of the pores has changed for all annealed specimens. Hydrophilicity testing revealed a slight increase in surface energy for the cylindrical scaffold's inner and outer surfaces. The mechanical properties, in particular, changed significantly with an increase in tensile strength to approximately 957.96 MPa after 4 h of annealing at 120 °C. In comparison to non-annealed scaffold (about 60%), elongation at break decreased to around 42%. The annealing treatment increased burst pressure from approximately 735 mmHg to 840 mmHg (at 120 °C for 4 h). Furthermore, cell viability reveals a strong result of cell growth after 7 days of seeding. In conclusion, the annealing heat treatment improved the mechanical properties of the cylindrical PLCL scaffold and lead to new avenues for vascular tissue engineering applications.