Coating of collagen on a poly(l-lactic acid) sponge surface for tissue engineering

Porous scaffolds play important roles in tissue engineering. Biodegradable synthetic polymers, such as poly(l-lactic acid) (PLLA), frequently are used in the preparation of porous scaffolds. Pretreating the surface of a PLLA porous scaffold is required to increase its wettability for smooth cell seeding due to the hydrophobic property of the scaffoldʹs surface. In this study, a simple coating method was used to modify the surface of the PLLA sponges. The coating method included three steps: filling the PLLA sponge pores with collagen aqueous solution, centrifuging to remove excess collagen, and, finally, freeze-drying. Compared with the uncoated PLLA sponge, the collagen-coated PLLA sponge demonstrated both improved wettability and high water absorption. Cells were smoothly seeded in the collagen-coated PLLA sponges by dropping a cell suspension solution onto the sponges. Cells adhered to the collagen-coated sponge and were distributed homogeneously throughout the collagen-coated PLLA sponge.