| Abstract [eng] |
Calcium hydroxyapatite (CHA) is a biomimetic calcium phosphate that closely resembles the primary mineral component of bones and teeth, renowned for its exceptional biocompatibility and stability. This doctoral research explores the cationic (Mg²⁺, Mn²⁺, Sr²⁺, Ba²⁺, Fe³⁺, Cu²⁺, Zn²⁺) substitution effects on the bioproperties of calcium hydroxyapatite. It analyses cation-substituted calcium hydroxyapatite coatings and bulk samples, and evaluates the antibacterial properties of the obtained samples with potential applications in cosmetics. Doping CHA with these cations significantly alters its phase purity and microstructure. Smaller ions (Mg²⁺, Mn²⁺) were found to have a stronger inhibiting effect on the hydrolysis process of α-TCP as compared to larger ions (Ba2+ and Sr2+). Moreover, increasing the temperature and time of the hydrothermal synthesis increased the crystallinity of the final products. A novel low-temperature dissolution–precipitation method was developed to synthesise uniform CHA coatings. Coatings with Cu²⁺ substituted CHA were successfully synthesised, while the introduction of Zn²⁺ using this method resulted in the formation of a zinc hydroxide nitrate monohydrate coating. Antibacterial tests revealed that pure CHA has no antibacterial effect, but Cu-CHA and Zn²⁺ coatings exhibited apparent antibacterial activity. Finally, metal-doped CHA bulk samples were used to produce cosmetic creams. Notably, Zn²⁺ doping enhanced antimicrobial efficacy but diminished biocompatibility, while Cu-doped CHA combined potent antimicrobial effects with high biocompatibility. These findings, together with CHA’s inherent biosafety, highlight the potential of CHA (especially Cu-doped variants) in cosmetic formulations such as antimicrobial skin creams to improve skin health. |
