Synthesis and evaluation of new phosphonic acid-functionalized acrylamides with potential biomedical applications

Phosphorus-containing acidic monomers are able to interact with the inorganic phase of mineralized tissues such as enamel, dentin, and bone. From this perspective, three phosphonic acid-containing acrylamide monomers with different lengths of alkyl chains were synthesized to be used for both self-etching dental adhesives and mineralized hydrogel scaffolds. Monomers were synthesized by the reaction of -aminophosphonates (diethyl aminomethylphosphonate, diethyl 2-aminobutan-2-ylphosphonate, and diethyl 2-aminooctan-2-ylphosphonate) with acryloyl chloride followed by the hydrolysis of phosphonate groups by using trimethylsilyl bromide. The properties such as pH in the range of mild self-etching adhesives, hydrolytic stability, high rate of copolymerizations with 2-hydroxyethyl methacrylate (HEMA) and HEMA/glycerol dimethacrylate, giving high-molecular-weight polymers on thermal polymerization, and strong decalcification ability of hydroxyapatite make these monomers good candidates for self-etching adhesives, although no appreciable effect of the number and size of the -substituents was observed. Hydrogel scaffolds containing phosphonic acid groups were fabricated, characterized, and mineralized. Altogether, the results suggest that these phosphonic acid-containing monomers have suitable properties to be used in fabrication of biomaterials for both dental and bone tissue engineering applications. (c) 2015 Wiley Periodicals, Inc.