Metal-substituted calcium hydroxyapatite: Synthesis and application in the production of cosmetic products
Abstract
"Calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHA) is renowned for its biocompatibility and biodegradability, making it a promising material for bone regeneration. Its versatility extends to the cosmetic industry, where it holds potential for novel product development. Metal-substituted CHA has garnered attention for its antibacterial properties, as well as its utility as an ultraviolet (UV)-protecting agent in cosmetics. In this study, freshly precipitated metal-substituted α-tricalcium phosphate (α-TCP) served as a precursor for synthesizing zinc-, copper-, or iron-substituted CHA samples under hydrothermal conditions. The transition metal ions in the samples corresponded to a Ca substitution level of 0.8 – 1 mol%. The synthesis involved placing 0.3 g of metal-substituted α-TCP powders in 90 mL vessels with 20 mL of water, followed by hydrothermal treatment at 200 °C for 16 h. The resulting samples were filtered, washed, and dried before analysis. Powder X-ray diffraction (XRD) data were collected using a Rigaku MiniFlex II diffractometer with Ni-filtered Cu Kα radiation. Infrared spectra were recorded with a Bruker ALPHA ATR spectrometer, while sample morphology was examined using a Hitachi SU-70 field-emission scanning electron microscope (FE-SEM). Elemental analysis was conducted using a Perkin Elmer Optima 7000 DV ICP-OES system after dissolving the samples in 5% nitric acid. The production of cosmetic products involved three stages: preparation of the oil phase, preparation of the aqueous phase, and combining temperature-sensitive components. The phases were heated to 75 – 80 °C, mixed, and homogenized before cooling and addition of temperature-sensitive ingredients. The introduction of Zn2+, Cu2+, and Fe3+ ions during hydrothermal synthesis significantly influenced the hydrolysis process of α-TCP, enabling control over the morphology of CHA. Furthermore, in vitro analyses assessed the cytotoxic and antimicrobial properties of metal-substituted CHA samples and fabricated cosmetic products. "
Anna Łukowiak
Conference co-Chair
