Zinc whitlockite (Zn-WH, Ca18Zn2(HPO4)2(PO4)12) is a new synthetic analog of the second most abundant biomineral – magnesium whitlockite (Mg-WH, Ca18Mg2(HPO4)2(PO4)12), which is considered as a potential material for bone regeneration....

In the present work, a series of zinc whitlockite (Ca x Zn y (HPO 4 ) 2 (PO 4 ) 12 ) powders was synthesized by a low-temperature dissolution–precipitation process for the first time. The phase conversion from calcium hydroxyapatite to zinc whitlockite occurred in an acidic medium in the presence of Zn 2+ ions. Variable chemical composition of the synthesis products was achieved by changing Ca-to-Zn molar ratio in the reaction mixture. Investigation of the phase evolution as a function of time demonstrated that phase-pure zinc whitlockite powders can be synthesized in just 3 h. It is also demonstrated that single-phase products can be obtained when the Ca-to-Zn ratio in the reaction medium is in the range from 9 to 30. With higher or lower ratios, neighboring crystal phases such as scholzite or calcium hydroxyapatite were obtained. The morphology of the synthesized powders was found to be dependent on the chemical composition, transforming from hexagonal to rhombohedral plates with the increase of Zn content. Thermal stability studies revealed that the synthesized compounds were thermally unstable and decomposed upon heat treatment.

The present study investigates thermally induced crystallization and phase evolution of amorphous calcium phosphate (ACP) partially substituted with Fe3+ ions (M/P = 1.5 : 1). It was demonstrated that the...

Magnesium whitlockite (Mg-WH, Ca18Mg2(HPO4)2(PO4)12) is a promising candidate for biomedical application in bone regeneration; however, the fabrication of Mg-WH bioceramics by conventional methods is limited. Mg-WH is known to be...

In the present work, analytical method for the determination of trace elements in adipose tissue by means of inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. Adipose tissue from two groups of the patients with obesity (with and without metabolic syndrome) was investigated. The main aim of this study was to reveal some differences and regularities in concentrations of trace elements in adipose tissue between these two groups of the individuals. Moreover, different types of adipose tissue (subcutaneous, preperitoneal, and visceral) were analyzed separately in order to investigate distribution of metals between these types in different groups of obese people. Al, Ba, Ca, Co, Cu, Cr, Fe, K, Li, Mg, Mn, Na, Ni, Sr, and Zn were selected for the quantitative determination. However, only 6 elements (Na, K, Ca, Fe, Mg, and Zn) were determined in all analyzed samples independently of the type of adipose tissue and presence of metabolic disorder of the patient. Concentrations of Ca, Fe, K, and Na were found to be strongly dependent on the type of adipose tissue. Other elements in terms of detection frequency in adipose tissue samples can be arranged in the following sequence Sr (94.7%), Cr (86.2%), Cu (24.6%), Li (18%), Ba (1.8%), Co (0.05%). The concentrations of Al, Mn, and Ni were found to be lower than limit of detection (LOD) in all analyzed samples. Comparison of metal distribution depending on the type of adipose tissue of people with and without metabolic syndrome is discussed in this work.