Mechanical and cytotoxicity evaluation of nanostructured hydroxyapatite-bredigite scaffolds for bone regeneration

Our plain-English summary of Mechanical and cytotoxicity evaluation of nanostructured hydroxyapatite-bredigite scaffolds for bone regeneration, by M. Eilbagi, R. Emadi, K. Raeissi, et al (Materials Science & Engineering. C, Materials for Biological Applications, 2016).

The study

• Authors: M. Eilbagi, R. Emadi, K. Raeissi, M. Kharaziha, A. Valiani
• Journal: Materials Science & Engineering. C, Materials for Biological Applications
• Published: 2016;68:603-612
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Despite the attractive characteristics of three-dimensional pure hydroxyapatite (HA) scaffolds, due to their weak mechanical properties, researches have focused on the development of composite scaffolds via introducing suitable secondary components. The aim of this study was to develop, for the first time, three-dimensional HA-bredigite (Ca7MgSi4O16) scaffolds containing various amounts of bredigite nanopowder (0, 5, 10 and 15wt.%) using space holder technique. Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction spectroscopy were applied in order to study the morphology, fracture surface and phase compositions of nanopowders and scaffolds. Furthermore, the effects of scaffold composition on the mechanical properties, bioactivity, biodegradability, and cytotoxicity were also evaluated. Results showed that the composite scaffolds with average pore size in the range of 220-310μm, appearance porosity of 63.1-75.9% and appearance density of 1.1±0.04g/cm(3) were successfully developed, depending on bredigite content. Indeed, the micropore size of the scaffolds reduced with increasing bredigite content confirming that the sinterability of the scaffolds was improved. Furthermore, the compression strength and modulus of the scaffolds significantly enhanced via incorporation of bredigite content from 0 to 15wt.%. The composite scaffolds revealed superior bioactivity and biodegradability with increasing bredigite content. Moreover, MTT assay confirmed that HA-15wt.% bredigite scaffold significantly promoted cell proliferation compared to tissue culture plate (control) and HA scaffold. Based on these results, three-dimensional HA-bredigite scaffolds could be promising replacements for HA scaffolds in bone regeneration.

Copyright © 2016 Elsevier B.V. All rights reserved.

In plain English

This article is not about asbestos. It is a laboratory materials-science study from Iran about making porous scaffolds for bone repair. The authors made scaffolds from hydroxyapatite (HA, a calcium phosphate mineral like the mineral part of bone) mixed with 0, 5, 10 or 15 weight percent bredigite, a calcium magnesium silicate ceramic. As bredigite content rose, average pore size fell from 311.1 micrometres (pure HA) to 227.5 micrometres (15 percent bredigite). Compressive modulus, a measure of stiffness, rose from 150 MPa for pure HA to 215.4 MPa for the 15 percent bredigite scaffold. Apatite, a bone-like mineral, formed on the composite scaffolds in simulated body fluid. Weight loss in a buffered salt solution increased with soaking time and with bredigite content. In cell tests with a bone-derived cancer cell line, after 7 days cell growth on pure HA scaffolds was 138 percent of the plastic-dish control, and on the 15 percent bredigite scaffold it was 171 percent. The authors concluded that the 15 percent bredigite scaffold could be a good candidate for bone regeneration.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory materials study: fabrication and testing of ceramic scaffolds, including in vitro (lab dish) cell culture tests
• Who was studied: Ceramic scaffolds containing 0, 5, 10 and 15 wt.% bredigite. Cell tests used the SAOS-II cell line, from the National Cell Bank of Iran, grown on the pure HA scaffold and the HA-15 wt.% bredigite scaffold only, with triplicate wells per group.
• Exposure: No asbestos exposure was studied. The variable studied was the bredigite (Ca7MgSi4O16) nanopowder content mixed into hydroxyapatite: 0, 5, 10 and 15 wt.%.
• Main results:
  • Average pore size was 311.1 plus or minus 8.7 micrometres for HA, 256.7 plus or minus 18.7 for HA-5 wt.% bredigite, 232.8 plus or minus 17.1 for HA-10 wt.% bredigite, and 227.5 plus or minus 20.2 for HA-15 wt.% bredigite.
  • Across all scaffolds, compressive strength ranged from 1 to 1.7 MPa and compressive modulus from 150 to 215 MPa.
  • Compressive modulus increased from 150 plus or minus 3.2 MPa for pure HA to 215.4 plus or minus 3.9 MPa for HA-15 wt.% bredigite.
  • The HA-15 wt.% bredigite scaffold had the highest density, the smallest grain and micropore size, and the least porosity.
  • An apatite layer formed on the surface of the composite scaffolds after soaking in simulated body fluid.
  • Weight loss in buffered saline increased with soaking time and with bredigite content.
  • After 7 days of culture, cell proliferation on the HA scaffold was 138% of control and on the HA-15 wt.% bredigite scaffold was 171% of control (tissue culture plate).
• The authors' conclusion: The authors concluded that the HA-15 wt.% bredigite scaffold, with its compressive strength, bioactivity, biodegradability and cell behaviour, could be a good candidate for bone regeneration.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Tremolite.

Medical terms in this study, explained in our Lexicon: Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD).

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