In collaboration with Prof. Jon Goldberg, UConn Health Center, the Mather Research Group is examining the role of synthetic charged polymers in the preparation of silica and hydroxy-apatite (HA) at dental surfaces, particularly for the sealing of dentine tubules critical to successful treatment of cavities without problems of moisture-induced filling failure. Inspired by nature, especially marine life that employs proteins in the catalysis of silica formation (so-called silaffins, and HA precipitation (e.g., amelogenins), we have found that poly(ethylene imine) (PEI) and poly(glutamic acid) (PGA) are suitable substitutes for complex proteins for silica and HA precipitation. However, significant effort is needed to understand (and thus gain control over) the resulting morphology and organic-inorganic interface. Our approach to this work is to synthesize the PEI and PGA with controlled molecular weight and architecture and process the polymers for mineralization studies either by layer-by-layer adsorption onto surfaces or electrospinning as a mineralization scaffold. The figure below shows nanofibers of PEI with poly(vinyl pyrrolidone) (PVP) before and after silicification (Patel et al, 2009).
A.J. Goldberg, M.C. Advincula, T. Komabayashi, P. A. Patel, P.T. Mather, D.G. Goberman and R. B. Kazemi, “Polypeptide Catalyzed Biosilicification of Dentin Surfaces,” J. Dental Res. 88 (4) 366-381 (2009).
P.A. Patel, J. Eckart, M.C. Advincula, A.J. Goldberg, and P.T. Mather, “Rapid Synthesis of Polymer-Silica Hybrid Nanofibers by Biomimetic Mineralization,” Polymer 50 1214-1222 (2009).