Dr Peiyan Shen
CONTACT
E-mail: peiyan@unimelb.edu.au
Tel: +61 3 9341 1563
QUALIFICATIONS
- B.Med.(Shandong Medical University)
- M.Sc. (Shandong Medical University)
- Ph.D.(University of Melbourne)
SHORT HISTORY
- 1997- present: Research Fellow, Oral Health Science, School of Dental Science, University of Melbourne.
- 1991-1996: Research Fellow, Department of Genetics, University of Melbourne.
- 1986-1990: Ph.D. postgraduate in School of Biochemistry and Molecular Biology, University of Melbourne.
RESEARCH INTEREST
Nanobiotechnology – Clinical Studies of Biomineralising Casein Phosphopeptides (CPP)
Casein phosphopeptides (CPP) containing the cluster sequence -Ser(P)-Ser(P)-Ser(P)-Glu-Glu- have a remarkable ability to stabilize amorphous calcium phosphate (ACP) in metastable solution. Through the multiple phosphoseryl residues, the CPP bind to forming clusters of ACP preventing their growth to the critical size required for nucleation and phase transformation. The CPP can be obtained from a tryptic digest of the major bovine milk protein casein by titrating the digest with CaCl2 and Na2HPO4 at pH 9.0 generate ACP and removal of the CPP-ACP complexes formed by microfiltration. The CPP-ACP has been shown to reduce caries activity in specific-pathogen-free rats orally infected with Streptococcus sobrinus. In a human in situ enamel demineralization study a 1% w/v CPP-ACP solution used twice daily by 12 subjects produced a 51 ± 19% reduction in enamel mineral loss caused by frequent sugar-solution exposure. The CPP-ACP solutions have also been shown to significantly remineralize enamel subsurface lesions in vitro where a 1.0% w/v CPP-ACP solution replaced 64 ± 20% of mineral lost. CPP-ACP in sugar-free chewing gum has been shown to significantly remineralize enamel subsurface lesions in situ.
CURRENT RESEARCH PROJECTS
Investigation of casein phosphopeptides in remineralisation
Casein phosphopeptides (tryptic peptides of milk caseins) have a remarkable ability to stabilize amorphous calcium phosphate (ACP) in metastable solution. Casein phosphopeptides amorphous calcium phosphate (CPP-ACP), marketed as Recaldent, have been demonstrated to have anticariogenic activity in laboratory, animal and human in situ experiments. The aim of this project is to investigate the efficacy of CPP-ACP in a beverage to enhance enamel remineralisation and/or prevent demineralization using an in vitro remineralisation model. Techniques include Transversal Microradigraphy (TMR), regarded as a standard method in the remineralisation and demineralisation studies, or the newly developed method Quantitative Light-induced Fluorescence (QLF).
CURRENT PUBLICATIONS
- SHEN P, CAI F, NOWICKI A, VINCENT J, REYNOLDS EC. Remineralization of enamel subsurface lesions by sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate. J Dent Res 80(12):2066-2070 (2001).
- CAI F, SHEN P, MORGAN M, REYNOLDS EC. Remineralization of enamel subsurface lesions in situ by sugar-free lozenges containing casein phosphopeptide-amorphous calcium phosphate. Aust Dent Res 48(4):240-243 (2003).
- REYNOLDS EC, CAI F, SHEN P, WALKER, GD. Retention in plaque and remineralization of enamel lesions by various forms of calcium in a mouthrinse or sugar-free chewing gum. J Dent Res 82(3):206-211(2003).
- REYNOLDS EC, BLACK CL, CAI F, CROSS KJ, EAKINS D, HUQ NL, MORGAN MV, NOWICKI A, PERICH JW, RILEY PF, SHEN P, TALBO G, WEBBER FW. Advances in enamel remineralization: anticariogenic casein phosphopeptide – amorphous calcium phosphate. J Clin Dent X: 86-88 (1999).
- IIJIMA Y, CAI F, SHEN P, WALKER G, REYNOLDS C, REYNOLDS EC. Acid resistance of enamel subsurface lesions remineralized by a sugar-free chewing gum containing casein phosphopeptide – amorphous calcim phosphate (CPP-ACP). Caries Research (in press 2004).