Increasing A-type CO32− substitution decreases the modulus of apatite nanocrystals

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials Pub Date : 2025-02-22 DOI:10.1016/j.jmbbm.2025.106962

Stephanie Wong , Abigail Eaton , Christina Krywka , Arun Nair , Christophe Drouet , Alix Deymier

{"title":"Increasing A-type CO32− substitution decreases the modulus of apatite nanocrystals","authors":"Stephanie Wong , Abigail Eaton , Christina Krywka , Arun Nair , Christophe Drouet , Alix Deymier","doi":"10.1016/j.jmbbm.2025.106962","DOIUrl":null,"url":null,"abstract":"<div><div>Biological apatite mineral is highly substituted with carbonate (CO32−). CO32− can exchange for either phosphate, known as B-type, or hydroxyl groups, known as A-type. Although the former has been extensively studied, A-type CO32− substituted apatites are poorly understood. Therefore, A-type CO32− apatites with biologically relevant levels of CO32− (1.7–5.8 wt%) were prepared and characterized. The addition of A-type CO32− into the apatite structure caused the predicted expansion of the a-axis and contraction of the c-axis in the unit cell. This was accompanied by a significant modification in the atomic order, especially along the a-axis plane, and crystallite size. A combination of in situ loading with synchrotron X-ray Diffraction and Density Functional Theory showed that increasing A-type CO32− substitutions also reduced the bulk and elastic moduli of the crystals. These results show that although A-type CO32− may inhibit lattice changes caused by B-type CO32−, A-type CO32− enhances the reduction in crystal order and mineral stiffness. These results help us to identify the possible contributions of A-type CO32− substitutions in biological apatites that contain both A- and B-type CO32−. In addition, this implies that the stiffness of bioapatite may change with increasing A-type CO32− substitutions, potentially altering the fracture mechanics of calcified tissues and biomaterials.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"166 ","pages":"Article 106962"},"PeriodicalIF":3.3000,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Mechanical Behavior of Biomedical Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1751616125000785","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Biological apatite mineral is highly substituted with carbonate (CO₃²⁻). CO₃²⁻ can exchange for either phosphate, known as B-type, or hydroxyl groups, known as A-type. Although the former has been extensively studied, A-type CO₃²⁻ substituted apatites are poorly understood. Therefore, A-type CO₃²⁻ apatites with biologically relevant levels of CO₃²⁻ (1.7–5.8 wt%) were prepared and characterized. The addition of A-type CO₃²⁻ into the apatite structure caused the predicted expansion of the a-axis and contraction of the c-axis in the unit cell. This was accompanied by a significant modification in the atomic order, especially along the a-axis plane, and crystallite size. A combination of in situ loading with synchrotron X-ray Diffraction and Density Functional Theory showed that increasing A-type CO₃²⁻ substitutions also reduced the bulk and elastic moduli of the crystals. These results show that although A-type CO₃²⁻ may inhibit lattice changes caused by B-type CO₃²⁻, A-type CO₃²⁻ enhances the reduction in crystal order and mineral stiffness. These results help us to identify the possible contributions of A-type CO₃²⁻ substitutions in biological apatites that contain both A- and B-type CO₃²⁻. In addition, this implies that the stiffness of bioapatite may change with increasing A-type CO₃²⁻ substitutions, potentially altering the fracture mechanics of calcified tissues and biomaterials.

查看原文本刊更多论文

增加a型CO32−取代会降低磷灰石纳米晶体的模量

生物磷灰石矿物被碳酸盐（CO32−）高度取代。CO32−可以交换成b型磷酸盐或a型羟基。虽然前者已被广泛研究，但对a型CO32−取代磷灰石的了解甚少。因此，a型CO32 -磷灰石的CO32 -生物学相关水平（1.7-5.8 wt%）被制备和表征。在磷灰石结构中加入a型CO32−导致了预期的单位胞内a轴的膨胀和c轴的收缩。这伴随着原子顺序的重大改变，特别是沿着a轴平面，和晶体尺寸。结合原位加载、同步x射线衍射和密度泛函理论表明，增加A型CO32−取代也降低了晶体的体积和弹性模量。结果表明，虽然a型CO32−可以抑制b型CO32−引起的晶格变化，但a型CO32−增强了晶体有序度和矿物硬度的降低。这些结果有助于我们确定A型CO32 -取代在含有A型和b型CO32 -的生物磷灰石中的可能贡献。此外，这意味着生物磷灰石的刚度可能随着a型CO32−取代的增加而改变，可能改变钙化组织和生物材料的断裂力学。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of the Mechanical Behavior of Biomedical Materials 工程技术-材料科学：生物材料

CiteScore

7.20

自引率

7.70%

发文量

505

审稿时长

46 days

期刊介绍： The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials. The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.