Sustainable biomaterials for tissue engineering: electrospun polycaprolactone fibers enriched with freshwater snail calcium carbonate and waste human hair keratin

This study focuses on developing a sustainable and biocompatible polycaprolactone (PCL)-based scaffold for bone tissue engineering through electrospinning, utilizing calcium carbonate (CaCO₃) from Pomacea canaliculata shells and keratin from human hair, known for stimulating bone regeneration. The isolated CaCO₃ has been identified to demonstrate two polymorphs, vaterite and calcite, as determined by X-ray diffraction. The isolation of keratin from human hair was confirmed through sodium dodecyl sulfate polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy analysis, revealing the presence of α-keratin structures around 45–50 kDa and β-keratin structures around 55–60 kDa. According to scanning electron microscope observations, the addition of keratin to PCL fibers reduced their diameter from 457 ± 345 to 371 ± 103 nm. Further addition of calcium carbonate led to a mean diameter of 258 ± 76 nm. The melting temperature of PCL fibers containing keratin and CaCO₃ was determined to be 76.17 °C via differential scanning calorimetry, while thermogravimetric analysis, conducted at temperatures up to 600 °C, revealed a remaining ash content of 9.59%. Calcium phosphate accumulation was observed to initiate on PCL fibers containing keratin and CaCO₃ following a 7-day exposure to simulated body fluid. The fibers exhibit cytocompatibility, showing no toxicity while supporting the growth and proliferation of Saos-2 osteosarcoma cells. The results suggest that the innovative incorporation of keratin and CaCO₃ into PCL nanofibers could serve as a bioactive matrix compared to pure PCL matrices, thereby offering enhanced potential for bone tissue engineering applications. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.