Calcium-containing crystals and osteoarthritis

Azomethine-clubbed thiazoles as human tissue non-specific alkaline phosphatase (h-TNAP) and intestinal alkaline phosphatase (h-IAP) Inhibitors: kinetics and molecular docking studies

Thiazole derivatives are known inhibitors of alkaline phosphatase, but various side effects have reduced their curative efficacy. Conversely, compounds bearing azomethine linkage display a broad spectrum of biological applications. Therefore, combining the two scaffolds in a single structural unit should result in joint beneficial effects of both. A new series of azomethine-clubbed thiazoles (3a-i) was synthesized and appraised for their inhibitory potential against human tissue non-specific alkaline phosphatase (h-TNAP) and human intestinal alkaline phosphatase (h-IAP). Compounds 3c and 3f were found to be most potent compounds toward h-TNAP with IC₅₀ values of 0.15 ± 0.01 and 0.50 ± 0.01 µM, respectively, whereas 3a and 3f exhibited maximum potency for h-IAP with IC₅₀ value of 2.59 ± 0.04 and 2.56 ± 0.02 µM, respectively. Molecular docking studies were also performed to find the type of binding interaction between potential inhibitor and active sites of enzymes. The enzymes inhibition kinetics studies were carried out to define the mechanism of enzyme inhibition. The current study leads to discovery of some potent inhibitors of alkaline phosphatase that is promising toward identification of compounds with druggable properties.

Calcium orthophosphates (CaPO4): occurrence and properties

The present overview is intended to point the readers' attention to the important subject of calcium orthophosphates (CaPO4). This type of materials is of the special significance for the human beings because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with CaPO4, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenorthophosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of CaPO4. Similarly, dental caries and osteoporosis might be considered as in vivo dissolution of CaPO4. In addition, natural CaPO4 are the major source of phosphorus, which is used to produce agricultural fertilizers, detergents and various phosphorus-containing chemicals. Thus, there is a great significance of CaPO4 for the humankind and, in this paper, an overview on the current knowledge on this subject is provided.

Calcium orthophosphates: occurrence, properties, biomineralization, pathological calcification and biomimetic applications

The present overview is intended to point the readers' attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided.

Calcium Orthophosphates in Nature, Biology and Medicine

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. These materials are of the special significance because they represent the inorganic part of major normal (bones, teeth and dear antlers) and pathological (i.e. those appearing due to various diseases) calcified tissues of mammals. Due to a great chemical similarity with the biological calcified tissues, many calcium orthophosphates possess remarkable biocompatibility and bioactivity. Materials scientists use this property extensively to construct artificial bone grafts that are either entirely made of or only surface-coated with the biologically relevant calcium ortho-phosphates. For example, self-setting hydraulic cements made of calcium orthophosphates are helpful in bone repair, while titanium substitutes covered by a surface layer of calcium orthophosphates are used for hip joint endoprostheses and as tooth substitutes. Porous scaffolds made of calcium orthophosphates are very promising tools for tissue engineering applications. In addition, technical grade calcium orthophosphates are very popular mineral fertilizers. Thus ere calcium orthophosphates are of great significance for humankind and, in this paper, an overview on the current knowledge on this subject is provided.