Ph.D. 1983, University of California, Los Angeles
In the McFadden lab, we are investigating how minerals accumulate in biological matrices. In one project we are creating mineralized test articles in which intricate passageways of cellulose and polyaromatic compounds are progressively filled with silicates and other minerals in a manner similar to how sol-gel interactions underlie wood petrification and soil humification. In other projects we are examining how fluoride interacts with the hydroxyapatite of tooth enamel in the prevention of tooth decay, how waterborne copper and arsenic penetrate and accumulate in living tissues, and how (and why) certain organisms actively accumulate high levels of arsenic compounds. Our work puts us in close kinship with those who study other biomineralized systems such as bone, mollusk and echinoderm shells as well as the hardened anatomical features of many invertebrates, including rasping and cutting tools for feeding and stingers for defense.