Biomimetic calcium phosphate coating on electrospun poly (ε-caprolactone) scaffolds for bone tissue engineering

The aim of this study is to develop a facile and efficient process to provide electrospun poly(epsilon-caprolactone) (PCL) scaffold with a bone-like calcium phosphate (CaP) coating while maintaining its fibrous and porous structure. Firstly, PCL scaffolds with uniform fibrous structure were fabricated by electrospinning. Before CaP coating, a plasma surface treatment was applied to clean and activate the PCL surface for calcium and phosphate ion grafting. Then, the treated PCL scaffolds were immersed in 10x simulated body fluid (SBF10) for varying time periods. PCL fibers were found to be mineralized after immersion in SBF10 for 2 h (SBF10_2h). After 6 h, the PCL scaffolds (SBF10_6h) were fully covered with CaP coating and the porous structure was lost. The coating of SBF10_2h was determined to consist of a mixture of nano-apatite and dicalcium phosphate dihydrate (DCPD). By continuous immersion in classical SBF for 7 days, the coating transformed into pure calcium deficient type B carbonate apatite with nano-crystallinity, which was similar to biological apatite. The deposited calcium phosphate coatings improved the wettability of the electrospun PCL scaffold. As the mineralized electrospun scaffold has a similar structure as the natural bone, it is expected to be a potential cell carrier in bone tissue engineering. (C) 2007 Elsevier B.V. All rights reserved.