Inhibition of hydroxyapatite formation in aqueous solutions by hafnocene dichlorides

The Crystallization of Hydroxyapatite in the Presence of Lysine

“…If introduced at higher concentrations where it is more effective against HAP formation then after a certain period of time given by its elimination kinetics the concentration will be lowered to the physiological level, where its is less effective, with physiological mechanisms. Therefore, lysine can be a calcification inhibitor, though a not very effective one as compared to other known inhibitors (24,(36)(37)(38)(39). The advantage of using physiological substances such as lysine to prevent pathological formation of HAP over the commercial synthetic drugs, which have been accused of being responsible for several side effects, is that the concentration excess of the amino acids in the tissue can be regulated via physiological pathways and therefore the liver function is not charged.…”

Characterization and inhibitive study of gel-grown hydroxyapatite crystals at physiological temperature

“…Therefore, many researchers have studied the growth inhibition of hydroxyapatite [15][16][17][18]. Koutsopoulos et al [19][20][21][22][23][24][25][26] have studied the growth and inhibition of hydroxyapatite by different therapeutic drugs and various amino acids. Recently, Pampena et al [27] have reported the inhibition of hydroxyapatite by osteopontin phosphopeptides (OPN).…”

Inhibition of Hydroxyapatite Crystal Growth by Substituted Titanocenes

“…It is important to note that titanocene difluorides accelerated the initial crystal growth rate of HAP. This observation is controversial, given the general inhibiting behavior of the other metallocene dihalides. − This accelerating phenomenon is attributed to the F - ions, produced from the hydrolysis reactions (eq 6 and 7). , Similar results with other compounds containing fluoride ions have also been reported in the literature . Fluoride ions in concentrations such as 1 ppm are capable of accelerating HAP formation and enchancing reminerallization of the enamel surface. , The results can also be interpreted via possible Ca 5 (PO 4 ) 3 F (FAP) formation, because of the presence of fluoride ions, F - , in the supersaturated solutions (the solutions are supersaturated with respect to this phase).…”

“…; M = Ti, Zr, Hf, and V; and X = F, Cl, Br, and I), are highly effective against Ehrlich ascites tumor cells, sarcoma 180, B16 melanoma, lymphoid leukemia L1210, lymphocytic leukemia P388, and colon 38 carcinoma. − The effectiveness of metallocenes as antitumor agents varies with the position of the metal atom in the periodic table . The carcinostatic activity of metallocenes is mechanistically similar to that other agents such as cisplatin, (NH 3 ) 2 PtCl 2 , targeting the nucleic acid metabolism and mitotic function. − Titanocene dihalides have been clinically tested in the past, and they proved to be drastic therapeutic drugs against arthritis. , Recently, much work has been done in testing these compounds, and physicochemical evidence for the antiarthritic activity of several metallocene complexes has been reported. − …”

“…9,10 Recently, much work has been done in testing these compounds, and physicochemical evidence for the antiarthritic activity of several metallocene complexes has been reported. [9][10][11][12][13][14][15] Hydroxyapatite [HAP, Ca 5 (PO 4 ) 3 OH] is thermodynamically the most stable calcium phosphate salt and is the inorganic component of hard tissues such as bones and teeth. [16][17][18][19][20] On the other hand, HAP formation occurs in several pathological cases of undesirable biological calcification.…”