Abstract
Hydroxyapatite is a material widely used in biomaterial engineering due to its biocompatibility, bioactivity and chemical similarity to the mineral fraction of bone tissue. Despite its numerous advantages, its limited biological activity and mechanical properties prompt the search for modifications that will increase its functionality in clinical applications. One effective approach is ion substitution in the HA crystal structure, which can occur in both cationic (e.g. Ca2+) and anionic (e.g. OH−) sites.
This review article discusses the effect of substitution of selected therapeutic ions – copper (Cu2+), strontium (Sr2+), cobalt (Co2+), zinc (Zn2+) and magnesium (Mg2+) – on the physicochemical and biological properties of hydroxyapatite. Their impact on physical and chemical properties and biological activity was analysed. Ion substitution enables the design of multifunctional materials that can support regenerative processes, prevent infections and modulate cellular response. A review of current literature data confirms that modified HA may be a promising platform for advanced implant systems and drug delivery systems.