Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD

Abstract Aspartic acid (Asp) serves as a critical component in surface modification strategies for Ti-6Al-4V dental implants, although the adsorption mechanisms of Asp on Ti-6Al-4V oxide layers remain unclear. Herein, the adsorption mechanisms of Asp on pristine and V or Al doped rutile TiO2 (110) s...

Full description

Saved in:
Bibliographic Details
Main Authors: Yang Yang, Jiu-Ning Wang, Li-Xia Hu, Qasim Qasim, Xue-Cheng Liu, Wei Xu
Format: Article
Language:English
Published: BMC 2025-07-01
Series:BMC Oral Health
Subjects:
Online Access:https://doi.org/10.1186/s12903-025-06397-1
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849389273163235328
author Yang Yang
Jiu-Ning Wang
Li-Xia Hu
Qasim Qasim
Xue-Cheng Liu
Wei Xu
author_facet Yang Yang
Jiu-Ning Wang
Li-Xia Hu
Qasim Qasim
Xue-Cheng Liu
Wei Xu
author_sort Yang Yang
collection DOAJ
description Abstract Aspartic acid (Asp) serves as a critical component in surface modification strategies for Ti-6Al-4V dental implants, although the adsorption mechanisms of Asp on Ti-6Al-4V oxide layers remain unclear. Herein, the adsorption mechanisms of Asp on pristine and V or Al doped rutile TiO2 (110) surfaces are systematically investigated using density functional theory (DFT) and ab initio molecular dynamics (AIMD). Pristine TiO2 exhibits fifteen distinct Asp adsorption configurations, with the more stable configurations primarily governed by synergistic dual-functional group coordination and proton transfer mechanisms, which collectively enhance binding strength. AIMD simulations reveal the dynamic adsorption evolution of the Asp functional group at room temperature, involving molecular reorientation and facile hydroxyl proton migration. Electronic structure analyses demonstrate that localized electron-deficient regions at 5-fold coordinated Ti sites and d-orbital-driven covalent bonding dominate the robust Asp anchoring. The doping of Al or V reduces electron transfer at surface active sites compared to pristine TiO2 following Asp adsorption, thereby weakening the adsorption strength between the substrate and Asp. Al doping at 5-fold coordinated Ti sites directly weakens the adsorption strength because of its reduced electron-donating capacity and diminishing orbital overlap with non-localized sp3-hybridized orbitals of Al (E ads is decreased by ~ 20%). In contrast, V doping at 6-fold coordinated Ti sites induces long-range electronic perturbations, indirectly lowering the adsorption strength of 5-fold coordinated Ti sites (E ads is reduced by ~ 6%). The obtained results indicate that the doped Al and V atoms in TiO2 formed on the Ti-6Al-4V surface detrimentally impacts bioactive molecular coatings, necessitating mitigation strategies. This work provides atomic-scale insights for engineering TiO2-based biointerfaces, balancing dopant effects and adsorption performance in implant design through tailored surface oxidation protocols.
format Article
id doaj-art-b00bf9f7d7a44fae84970fabe9bbdaf2
institution Kabale University
issn 1472-6831
language English
publishDate 2025-07-01
publisher BMC
record_format Article
series BMC Oral Health
spelling doaj-art-b00bf9f7d7a44fae84970fabe9bbdaf22025-08-20T03:42:01ZengBMCBMC Oral Health1472-68312025-07-0125111210.1186/s12903-025-06397-1Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMDYang Yang0Jiu-Ning Wang1Li-Xia Hu2Qasim Qasim3Xue-Cheng Liu4Wei Xu5Department of Stomatology, The First People’s Hospital of Shuangliu District, Chengdu (West China Airport Hospital of Sichuan University)Institute of New Energy and Low-Carbon Technology, Sichuan UniversityDepartment of Stomatology, Chengdu Pidu District Hospital of Traditional Chinese MedicineInstitute of New Energy and Low-Carbon Technology, Sichuan UniversityNational Research Base of Intelligent Manufacturing Service, College of Environment and Resources, Chongqing Technology and Business UniversityNational Research Base of Intelligent Manufacturing Service, College of Environment and Resources, Chongqing Technology and Business UniversityAbstract Aspartic acid (Asp) serves as a critical component in surface modification strategies for Ti-6Al-4V dental implants, although the adsorption mechanisms of Asp on Ti-6Al-4V oxide layers remain unclear. Herein, the adsorption mechanisms of Asp on pristine and V or Al doped rutile TiO2 (110) surfaces are systematically investigated using density functional theory (DFT) and ab initio molecular dynamics (AIMD). Pristine TiO2 exhibits fifteen distinct Asp adsorption configurations, with the more stable configurations primarily governed by synergistic dual-functional group coordination and proton transfer mechanisms, which collectively enhance binding strength. AIMD simulations reveal the dynamic adsorption evolution of the Asp functional group at room temperature, involving molecular reorientation and facile hydroxyl proton migration. Electronic structure analyses demonstrate that localized electron-deficient regions at 5-fold coordinated Ti sites and d-orbital-driven covalent bonding dominate the robust Asp anchoring. The doping of Al or V reduces electron transfer at surface active sites compared to pristine TiO2 following Asp adsorption, thereby weakening the adsorption strength between the substrate and Asp. Al doping at 5-fold coordinated Ti sites directly weakens the adsorption strength because of its reduced electron-donating capacity and diminishing orbital overlap with non-localized sp3-hybridized orbitals of Al (E ads is decreased by ~ 20%). In contrast, V doping at 6-fold coordinated Ti sites induces long-range electronic perturbations, indirectly lowering the adsorption strength of 5-fold coordinated Ti sites (E ads is reduced by ~ 6%). The obtained results indicate that the doped Al and V atoms in TiO2 formed on the Ti-6Al-4V surface detrimentally impacts bioactive molecular coatings, necessitating mitigation strategies. This work provides atomic-scale insights for engineering TiO2-based biointerfaces, balancing dopant effects and adsorption performance in implant design through tailored surface oxidation protocols.https://doi.org/10.1186/s12903-025-06397-1Ti–6Al–4VAspartic acidTiO2Density functional theoryAb initio molecular dynamics
spellingShingle Yang Yang
Jiu-Ning Wang
Li-Xia Hu
Qasim Qasim
Xue-Cheng Liu
Wei Xu
Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
BMC Oral Health
Ti–6Al–4V
Aspartic acid
TiO2
Density functional theory
Ab initio molecular dynamics
title Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
title_full Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
title_fullStr Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
title_full_unstemmed Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
title_short Atomic scale insight into the adsorption mechanism of aspartic acid on Ti-6Al-4V dental implants: a combination of DFT and AIMD
title_sort atomic scale insight into the adsorption mechanism of aspartic acid on ti 6al 4v dental implants a combination of dft and aimd
topic Ti–6Al–4V
Aspartic acid
TiO2
Density functional theory
Ab initio molecular dynamics
url https://doi.org/10.1186/s12903-025-06397-1
work_keys_str_mv AT yangyang atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd
AT jiuningwang atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd
AT lixiahu atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd
AT qasimqasim atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd
AT xuechengliu atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd
AT weixu atomicscaleinsightintotheadsorptionmechanismofasparticacidonti6al4vdentalimplantsacombinationofdftandaimd