Amelogenin-chitosan matrix promotes assembly of an enamel-like layer with a dense interface.

Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA.
Acta biomaterialia (Impact Factor: 6.03). 04/2013; 9(7). DOI: 10.1016/j.actbio.2013.04.004
Source: PubMed


Biomimetic reconstruction of tooth enamel is a significant topic of study in material science and dentistry as a novel approach for prevention, restoration, and treatment of defective enamel. We developed a new amelogenin-containing chitosan hydrogel for enamel reconstruction that works through amelogenin supramolecular assembly, stabilizing Ca-P clusters and guiding their arrangement into linear chains. These amelogenin Ca-P composite chains further fuse with enamel crystals and eventually evolve into enamel-like co-aligned crystals, anchoring to the natural enamel substrate through a cluster growth process. A dense interface between the newly-grown layer and natural enamel was formed and the enamel-like layer had improved hardness and elastic modulus compared to etched enamel. We anticipate that chitosan hydrogel will provide effective protection against secondary caries because of its pH-responsive and antimicrobial properties. Our studies introduce amelogenin-containing chitosan hydrogel as a promising biomaterial for enamel repair and demonstrate the potential of applying protein-directed assembly to biomimetic reconstruction of complex biomaterials.

Download full-text


Available from: Qichao Ruan, Jan 09, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Laboratory studies have demonstrated that enamel-like mineralised tissue can be regenerated and used to repair enamel loss. This has implications for the management of non-carious tooth loss due to dental erosion, attrition and abrasion. In this study, we designed a hydrogel biomimetic mineralisation model for the regeneration of enamel-like mineralised tissue with a prismatic structure. The mineralised tissue, which was generated by the model on an etched enamel surface in the presence of 500 ppm fluoride, was analysed with a scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and the nano-indentation hardness test. The generated tissue had enamel prism-like layers containing well-defined hexagonal hydroxyapatite crystals. The modulus of elasticity and nano-hardness of the regenerated enamel prism-like tissue were similar to those of natural enamel. Thus, the regeneration of enamel using this hydrogel biomimetic mineralisation model is a promising approach for the management of enamel loss.
    Full-text · Article · Dec 2013 · ACS Applied Materials & Interfaces
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tooth fracture is a major concern in the field of restorative dentistry. However, knowledge of the causes for tooth fracture has developed from contributions that are largely based within the field of mechanics. The present manuscript presents a technical review of advances in understanding the fracture of teeth and the fatigue and fracture behavior of their hard tissues (i.e., dentin and enamel). The importance of evaluating the fracture resistance of these materials, and the role of applied mechanics in developing this knowledge will be reviewed. In addition, the complex microstructures of tooth tissues, their roles in resisting tooth fracture, and the importance of hydration and aging on the fracture resistance of tooth tissues will be discussed. Studies in this area are essential for increasing the success of current treatments in dentistry, as well as in facilitating the development of novel bio-inspired restorative materials for the future.
    No preview · Article · May 2014 · Applied Mechanics Reviews
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the bio-inspired repair process of tooth enamel, it is important to simultaneously mimic the organic matrices induced biomineralization and increase the binding strength at the remineralization interface. In this work, 4(th) generation polyamidoamine dendrimer (PAMAM) is modified by dimethyl phosphate to obtain phosphate-terminated dendrimer (PAMAM-PO3H2) since it has similar dimensional scale and peripheral functionalities to that of amelogenin which plays important role in the natural developing process of enamel. Its phosphate group has stronger affinity for calcium ion than carboxyl group and can simultaneously provide strong HA-binding capability. The MTT assay demonstrates the low cytotoxicity of PAMAM-PO3H2. Adsorption tests indicate that PAMAM-PO3H2 can be tightly adsorbed on the human tooth enamel. Scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to analyze the remineralization process. After being incubated in artificial saliva for 3 weeks, there is a newly generated HA layer of 11.23 μm thick on the acid-etched tooth enamel treated by PAMAM-PO3H2, while the thickness is only 6.02 μm for the carboxyl-terminated one (PAMAM-COOH). PAMAM-PO3H2 can regulate the remineralization process to form ordered new crystals oriented along the Z-axis and obtain enamel prism-like structure, which is similar to that of the natural tooth enamel. The animal experiment also demonstrates that PAMAM-PO3H2 can induce significant HA regeneration in the oral cavity of rats. Thus PAMAM-PO3H2 shows great potential as a biomimetic restorative material for human tooth enamel.
    No preview · Article · May 2014 · Acta Biomaterialia
Show more