Electrospun PCL/phlorotannin nanofibres for tissue engineering: Physical properties and cellular activities

Micro/nanofibrous substrates have been widely used for tissue regeneration because of their similarities to extracellular matrix components and their high surface area, which facilitates attachment and proliferation of cells. Phlorotannin, the main component of the brown alga Ecklonia cava, contains various growth factors that promote the regeneration of various tissues, including bone, by stimulating alkaline phosphatase (ALP) activity and inducing calcium deposition. Despite the benefits of phlorotannin in tissue regeneration, the activity of phlorotannin as a component of micro/nanofibres of various compositions has not yet been investigated. Here, we fabricated electrospun polycaprolactone (PCL)/phlorotannin micro/nanofibres containing different phlorotannin concentrations (1, 3, and 5 wt%) and determined their physical properties, including water contact angle, water absorption, and mechanical properties. Owing to their hydrophilicity and water absorption ability, phlorotannin-containing fibrous mats exhibited outstanding wettability compared with pure PCL fibrous mats. The biocompatibility of the mats was examined in vitro using osteoblast-like cells (MG63). Cell viability, ALP activity, and calcium deposition were assessed. The cells distributed more widely and proliferated to a greater degree on PCL/phlorotannin mats compared with pure PCL mats. In addition, cell viability (at 5 wt% phlorotannin), total protein content, ALP activity, and calcium deposition were higher with PCL/phlorotannin mats than with pure PCL mats. These results suggest that electrospun PCL/phlorotannin is a promising bioactive material for enhancing bone tissue growth.