Selenium-Doped Hydroxyapatite Nanocrystals–Synthesis, Physicochemical Properties and Biological Significance

Abstract

Hydroxyapatites (HAs), as materials with a similar structure to bone minerals, play a key role in biomaterials engineering. They have been applied as bone substitute materials and as coatings for metallic implants, which facilitates their osseointegration. One of the beneficial characteristics of HA, when used to create biocompatible materials with improved physicochemical or biological properties, is its capacity for ionic substitution. The aim of the study was to present the current state of knowledge about HAs containing selenate ions IV or VI. The enrichment of HAs with selenium aims to create a material with advantageous effects on bone tissue metabolism, as well as having anticancer and antibacterial activity. The work is devoted to both methods of obtaining Se-HA and an evaluation of its chemical structure and physicochemical properties. In addition, the biological activity of such materials in vitro and in vivo is discussed.Pure, stoichiometric HA crystallizes in a monoclinic system, space group P2 1 /b [5]. However, it is worth mentioning that HA like this is rare and very difficult to obtain by synthesis.

Selenium-Enriched Brushite: A Novel Biomaterial for Potential Use in Bone Tissue Engineering

“…Our results of λ strongly agree with previous research on the 1 H→ 31 PCP kinetics of brushite [22]. We can assume that both samples are structurally similar.…”

“…A probable reason why selenite ions can be partially adsorbed on to the surface of DCPD is the difference in spacial conformation of both SeO 3 2− and PO 4 3− . Although both ions are characterized by a similar ionic radius (239 pm for selenite and 238 pm for phosphate), PO 4 3− ions are tetrahedral, while SeO 3 2− ions are of a flat trigonal pyramid conformation [22].…”

Dual Energy X-ray Methods for the Characterization, Quantification and Imaging of Calcification Minerals and Masses in Breast

“…The use of balanced filtering in dual energy technique was applied by Saito [29] in order to achieve a signal-to-noise ratio of 5 in the final dual energy subtracted iodine image. Although the appearance of calcifications may indicate breast cancer, the consistency of calcifications will indicate whether they are associated with malignancy or benignancy [69][70][71][72][73][74][75][76][77][78][79][80][81]87]. Martini et al [28] worked on the differentiation of calcifications consisting of minerals found to indicate malignancy and benignancy according to literature [103][104][105].…”

“…The calcifications of Type I are composed calcium oxalate (CaC2O4) crystals [76] and are found to be associated with benign lesions or mostly non-invasive lobular carcinoma in situ [77,78]. The calcifications of Type II are composed of calcium phosphate, mainly hydroxyapatite (Hap) crystals [76,[79][80][81] and in some cases of calcium carbonate (CaCO 3 ). Hydroxyapatite is associated with malignancy including carcinomas, while calcium carbonate crystals [82][83][84][85][86] with benignancy [44,45,70,87].…”

Antibacterial Composite Materials Based on the Combination of Polyhydroxyalkanoates With Selenium and Strontium Co-substituted Hydroxyapatite for Bone Regeneration

“…The level of reactants used was calculated in order to keep the (Ca+Sr):(P+Se) ratio constant at 1.667 and Sr:(Sr+Ca) and Se:(Se+P) molar ratio constant at 0.2. The aimed chemical composition of the produced Se-Sr-HA was Ca 10 – x Sr x (PO 4 ) 6 – y (SeO 3 ) y (OH) 2 – y , where x = 2 and y = 1.2 ( Ravi et al, 2012 ; Pajor et al, 2018 ). Solution B was added dropwise to solution A.…”