Bionic Mineralization Method on Designing and Preparation of CS/HA and CMCS/HA Composite Coating and Its Antibacterial Properties Study

Poly(chitosan)/hydroxyapatite (CS/HA) and carboxymethyl poly(chitosan)/hydroxyapatite (CMCS/HA) composite coatings were successfully fabricated via biomimetic mineralization, with their structural characteristics and properties systematically analyzed. As the CS concentration increased during fabrication, the growth morphology of CS/HA coating transitioned from clustered to sheet-like structures, forming dense and uniform composite coating with strong substrate adhesion and excellent biocompatibility. The CMCS/HA coatings exhibited a coral-like structure comprising spherical particles, which ensured higher substrate coverage and demonstrated superior corrosion resistance. At 20 g/L, coatings prepared by mixing pre-calcified solution A with CMCS and then adding biomimetic mineralization solution A (defined as YOCS), or by mixing pre-calcified solution A with a mixture of biomimetic mineralization solution A and CMCS (defined as FOCS), both show optimum structure. Coatings incorporating 30 g/L CS or 20 g/L CMCS in the biomimetic mineralization solution exhibited optimum corrosion resistance, antibacterial activity, and biocompatibility.