Phosphate-containing groups

The functionalization of biomaterials, both natural and synthetic, with phosphate-containing groups in order to provide nucleating sites to trigger the biomineralization cascade and produce calcium phosphate phases has been well researched in line with the implication of anionic polymers in in vivo mineralization. Where synthetic polymers are concerned, mineralization studies have led to some apparently contradictory results. Chirila et critically reviewed this topic as well as investigating the calcifi-... 

Figure 7 A novel, phosphate ester linking strategy [22] was used in the synthesis of phenyl phosphate-containing compound libraries, accomplished in 96-deepwell reaction blocks [23], Rigid, nonpeptide templates (A-group) and pY+3 substituents (B-group) satisfied the diversity sites of the molecules.

The carbodiimide of choice used to couple cystamine to carboxylate- or phosphate-containing molecules is most often the water-soluble carbodiimide, EDC hydrochloride Chapter 3, Section 1.1). This reagent rapidly reacts with carboxylates or phosphates to form an active ester intermediate, which is highly reactive toward primary amines. The reaction is efficient from pH 4.7 to 7.5, and a variety of buffers may be used, providing they don t contain competing groups. 

The final step added a group that would interact with the phosphate binding site either directly or via electrostatic interactions. We could not use phosphate itself, because phosphate-containing compounds are not metabolically stable and have difficulty passing through cell membranes intact. Acyclovir diphosphate, which is not membrane permeable and is subject to extracellular metabolism, is a good example. 

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