Nano carbon dot-collagen peptide – Hydroxyapatite composite coating for bone tissue regeneration

Biological derivatives are the preferred coating materials for enhancing osseointegration in bone implants. The present study aimed to develop a nanocomposite from fish waste, comprising of carbon dots (CD), collagen peptides (CP), and natural hydroxyapatite (HAP), to serve as a coating material for titanium implants, so as to facilitate rapid tissue regeneration. The nanocomposite (CD-CP-HAP) was synthesized using a two-step protocol. Fourier Transform Infrared (FTIR) and UV-Visible spectroscopic studies confirmed the interaction between carbon dots (CD) and collagen peptides (CP) through conjugated C C and OH---NH hydrogen bonding. Additionally, the phosphate (PO₄³⁻) group of hydroxyapatite (HAP) interacted with the NH and OH functional groups of CD and CP, as evidenced by the presence of OH absorption in multiple environments. The titanium strips coated with the nanocomposite demonstrated a significant increase in polarization resistance, highlighting their potential for bone regeneration applications. The cell toxicity assay indicated that the composite is biocompatible, and has the potential to be used as a coating material for bone implants to enhance bone tissue regeneration. • Nano CD-CP-HAP composite was developed using fish waste for titanium implants. • Synthesized CD-CP-HAP composite through a two-step microwave-assisted protocol. • CD-CP-HAP-coated titanium strips exhibited excellent polarization resistance • Cell toxicity assay revealed the CD-CP-HAP as a safe bone implant coating. • Nano CD-CP-HAP composite has potential application in bone regeneration