Amelotin Promotes Mineralization and Adhesion in Collagen-Based Systems

Yuichi Ikeda; James Holcroft; Eri Ikeda; Bernhard Ganss

doi:10.1007/s12195-022-00722-2

Amelotin Promotes Mineralization and Adhesion in Collagen-Based Systems

Cell Mol Bioeng. 2022 Mar 27;15(3):245-254. doi: 10.1007/s12195-022-00722-2. eCollection 2022 Jun.

Authors

Yuichi Ikeda^{1

2}, James Holcroft¹, Eri Ikeda^{1

2

3}, Bernhard Ganss¹

Affiliations

¹ Faculty of Dentistry and Institute of Biomedical Engineering, University of Toronto, Toronto, Canada.
² Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8549 Japan.
³ Molecular Immunology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.

Abstract

Introduction: Periodontitis is characterized by the destruction of tooth-supporting tissues including the alveolar bone. Barrier membranes are used in dentistry for tissue regenerative therapy. Nevertheless, conventional membranes have issues related to membrane stability and direct induction of bone mineralization. Amelotin (AMTN), an enamel matrix protein, regulates hydroxyapatite crystal nucleation and growth. To apply an AMTN membrane in clinical practice, we investigated the mineralizing and adhesive effects of recombinant human (rh) AMTN in vitro using a collagen-based system.

Methods: Collagen hydrogel incorporated with rhAMTN (AMTN gel) and rhAMTN-coated dentin slices were prepared. AMTN gel was then applied on a commercial membrane (AMTN membrane). Samples were incubated for up to 24 h in mineralization buffer, and the structures were observed. The peak adhesive tensile strength between the dentin and AMTN membrane was measured. Using an enzyme-linked immunosorbent assay, the release kinetics of rhAMTN from the membrane were investigated.

Results: The AMTN gel resulted in the formation of hydroxyapatite deposits both onto and within the collagen matrix. Furthermore, coating the dentin surface with rhAMTN promoted the precipitation of mineral deposits on the surface. Interestingly, site-specific mineralization was observed in the AMTN membrane. Only 1% of rhAMTN was released from the membrane. Hence, the AMTN membrane adhered to the dentin surface with more than twofold greater tensile strength than that detected for a rhAMTN-free barrier membrane.

Conclusions: RhAMTN can accelerate mineralization and adhesion in collagen-based systems. Furthermore, the AMTN membrane could inform the optimal design of calcified tissue regenerative materials.

Supplementary information: The online version contains supplementary material available at 10.1007/s12195-022-00722-2.

Keywords: Bioengineering; Dentin; Enamel biomineralization/formation; Guided tissue regeneration; Hydroxyapatite.