IADR Abstract Archives
Peptoids Enhance Collagen Biomineralization and Remineralization of Artificial Dentin Lesions
Objectives: Remineralization of artificial dentin lesions via a polymer-induced-liquid-precursor (PILP) process partially restored the reduced elastic modulus (ER) after 28 days (Burwell et al, PLoS One, 2012). Here we evaluated synthetic peptide-like poly-N-substituted glycines (peptoids) to improve collagen mineralization and dentin remineralization.
Methods: Peptoids were screened by turbidity and dynamic light scattering for their effect on calcium phosphate precipitation. Modulation of calcium phosphate nucleation by peptoids was imaged on a monolayer of collagen on mica by real-time in situ AFM (Fig.1), Mineralization was conducted at pH=7.4 (37°C) with 1) BioGide® collagen membrane, 2) 140µm-deep artificial lesions in non-carious human dentin and 3) ~150µm-thick demineralized non-carious dentin discs and remineralized using calcium phosphate solution containing: 1) 27KDa poly-L-aspartate (poly-D), and/or 2) several peptoids as precursor inducing agents. Mineral-matrix ultrastructure, mineral orientation and crystallinity were determined by TEM/selected area electron diffraction (SAED). Cross-sectional fractures were imaged using SEM and occlusal surfaces of remineralized dentin lesions were imaged by AFM. Mechanical property profiles were obtained by nanoindentation. Demineralized and remineralized dentin discs were analyzed by small angle X-ray scattering (SAXS).
Results: Inhibitory peptoid having proteinogenic functional groups regulated mineralization in a manner similar to non-collagenous proteins (Fig.1). When peptoids were combined with poly-D, collagen mineralization was accelerated and enhanced as compared to remineralization with PILP alone. Artificial dentin lesions remineralized with a combination of peptoids and poly-D achieved significant functional recovery and induced remarkable peritubular remineralization with co-aligned pure hydroxyapatite crystals and exceptionally high ER, in comparison with normal dentin (Fig. 2).
Conclusions: A peptoid-enhanced PILP approach promotes collagen mineralization and peritubular remineralization in artificial dentin lesions.
Methods: Peptoids were screened by turbidity and dynamic light scattering for their effect on calcium phosphate precipitation. Modulation of calcium phosphate nucleation by peptoids was imaged on a monolayer of collagen on mica by real-time in situ AFM (Fig.1), Mineralization was conducted at pH=7.4 (37°C) with 1) BioGide® collagen membrane, 2) 140µm-deep artificial lesions in non-carious human dentin and 3) ~150µm-thick demineralized non-carious dentin discs and remineralized using calcium phosphate solution containing: 1) 27KDa poly-L-aspartate (poly-D), and/or 2) several peptoids as precursor inducing agents. Mineral-matrix ultrastructure, mineral orientation and crystallinity were determined by TEM/selected area electron diffraction (SAED). Cross-sectional fractures were imaged using SEM and occlusal surfaces of remineralized dentin lesions were imaged by AFM. Mechanical property profiles were obtained by nanoindentation. Demineralized and remineralized dentin discs were analyzed by small angle X-ray scattering (SAXS).
Results: Inhibitory peptoid having proteinogenic functional groups regulated mineralization in a manner similar to non-collagenous proteins (Fig.1). When peptoids were combined with poly-D, collagen mineralization was accelerated and enhanced as compared to remineralization with PILP alone. Artificial dentin lesions remineralized with a combination of peptoids and poly-D achieved significant functional recovery and induced remarkable peritubular remineralization with co-aligned pure hydroxyapatite crystals and exceptionally high ER, in comparison with normal dentin (Fig. 2).
Conclusions: A peptoid-enhanced PILP approach promotes collagen mineralization and peritubular remineralization in artificial dentin lesions.
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