Keratin-Mimetic Mineralized Scaffold: A Breakthrough Biomaterial for Tooth Enamel Regeneration

Journal: Advanced Healthcare Materials

Publication Date: 2025

DOI: 10.1002/adhm.202502465

Author: Sara Gamea, Elham Radvar, Dimitra Athanasiadou, Ryan Lee Chan, and others

Article Abstract

Biomimetic protein-based platforms, with their hierarchical architecture and superior mechanical properties, hold great promise for hard-tissue regeneration, including enamel regeneration. However, obtaining well-ordered, enamel-like apatite nanocrystals from an organic matrix remains challenging. Here, we report a simple organic approach that uses water-based keratin films to recapitulate the hierarchical structure of tooth enamel. These films form fibrous organic networks and birefringent spherulitic structures via disulfide-bond cross-linking, predominantly adopting an ordered β-sheet conformation. The flexible architecture of the keratin template facilitates the reorganization of secondary structures into α-helices during mineralization, thereby guiding the orderly growth of apatite nanocrystals. This system demonstrates potential for repairing early enamel defects, restoring both optical appearance and mechanical properties. This study offers a promising, straightforward, and clinically friendly strategy for developing novel protein-based matrices from abundant natural sources for hard-tissue regeneration.

Dental caries is a globally prevalent oral disease; in 2019, approximately 2 billion cases of untreated permanent tooth caries were reported. As the hardest acellular mineralized tissue in the human body, dental enamel cannot regenerate once it is damaged by caries or abrasion, highlighting the critical clinical need for enamel repair.

Traditional resin fillings and remineralizing agents suffer from limited restorative efficacy and poor structural compatibility. In contrast, keratin, owing to its intrinsic biological properties and biomimetic mineralization capability, has emerged as a novel ideal material in the field of enamel regeneration, offering a new avenue for the repair of early enamel lesions.

I. Natural Biological Advantages of Keratin

Keratin is abundant in source and exhibits excellent biocompatibility. α-Keratin possesses a hierarchical network structure that, through covalent and non-covalent interactions such as disulfide bonds and hydrogen bonds, forms a stable organic network, endowing it with mechanical strength, flexibility, and resistance to degradation. Its unique conformational tunability—characterized by the dynamic interconversion between β-sheet and α-helix structures—and its negatively charged acidic residues enable it to efficiently bind calcium ions, making it ideally suited to meet the requirements of dental enamel biomineralization.

II. Core Mechanism of Biomimetic Mineralization

Studies have demonstrated that keratin can self-assemble into birefringent spherulitic films, forming an ordered organic scaffold via β-sheet conformation and precisely mimicking the organic matrix environment underlying natural tooth enamel formation. The core mechanisms involved include:

III. Verification of Repair Effects

Keratin demonstrates excellent reparative properties for early enamel damage (white spot lesions):

IV. Application Value and Prospects

The keratin-based dental enamel repair system boasts four core advantages—low cost, ease of preparation, biocompatibility, and minimally invasive efficiency—thereby overcoming the bottlenecks associated with conventional biomimetic materials, such as complex fabrication, uncertain biocompatibility, and challenges in clinical translation.

In addition to the repair of early caries, this approach also holds great promise in areas such as dentin hypersensitivity, tooth wear, and bone defect reconstruction, with far-reaching implications for both dentistry and biomedicine.

Keratin, with its intrinsic biological properties, opens a new avenue for enamel regeneration and represents a groundbreaking material of immense translational value in the field of hard-tissue regeneration. It holds promise as a core solution for non-invasive enamel repair, thereby ushering in a new era of biomimetic regenerative dentistry and advancing minimally invasive oral treatments.

Disclaimer

The copyright of the foregoing content belongs to the original author; the views expressed herein are for informational and discussion purposes only and are not intended for commercial use. The opinions presented do not constitute medical treatment recommendations or investment advice.