Magnetic and radio-labeled bio-hybrid scaffolds to promote and track in vivo the progress of bone regeneration.

Elisabetta Campodoni,Sébastien Boutry,George Loudos,Monica Montesi,Penelope Bouziotis,Stavros Xanthopoulos,Monica Sandri,Irene Morales,Samuele M Dozio,Eleftheria Dermisiadou,Eirini Fragogeorgi,Silvia Panseri,Marisela Velez,Maritina Rouchota,Dimitri Stanicki,Patricia De La Presa,Sophie Laurent,Pilar Marín,Anna Tampieri

doi:10.1039/d1bm00858g

Abstract

This work describes the preparation, characterization and functionalization with magnetic nanoparticles of a bone tissue-mimetic scaffold composed of collagen and hydroxyapatite obtained through a biomineralization process. Bone remodeling takes place over several weeks and the possibility to follow it in vivo in a quick and reliable way is still an outstanding issue. Therefore, this work aims to produce an implantable material that can be followed in vivo during bone regeneration by using the existing non-invasive imaging techniques (MRI). To this aim, suitably designed biocompatible SPIONs were linked to the hybrid scaffold using two different strategies, one involving naked SPIONs (nMNPs) and the other using coated and activated SPIONs (MNPs) exposing carboxylic acid functions allowing a covalent attachment between MNPs and collagen molecules. Physico-chemical characterization was carried out to investigate the morphology, crystallinity and stability of the functionalized materials followed by MRI analyses and evaluation of a radiotracer uptake ([99mTc]Tc-MDP). Cell proliferation assays in vitro were carried out to check the cytotoxicity and demonstrated no side effects due to the SPIONs. The achieved results demonstrated that the naked and coated SPIONs are more homogeneously distributed in the scaffold when incorporated during the synthesis process. This work demonstrated a suitable approach to develop a biomaterial for bone regeneration that allows the monitoring of the healing progress even for long-term follow-up studies.

Highlights

AInstitute of Science and Technology for Ceramics-National Research Council (CNR), Radiological Sciences & Technology, Energy &Safety, Ag
In this work we have prepared biomimetic hybrid scaffolds functionalized with magnetic nanoparticles (SPIONs).[1,9]
Before proceeding to its magnetic functionalization, we first confirmed that this hybrid scaffold can promote bone regeneration and that we could follow it in vivo using SPECT and computed tomography (CT) imaging

Summary

Introduction

AInstitute of Science and Technology for Ceramics-National Research Council (CNR), Radiological Sciences & Technology, Energy &Safety, Ag. If the defect caused by a severe pathological condition is too extended, bone healing and repair can fail.[2] Alternatives, in such cases, can be several forms of bone grafts, defined as implantable materials that promote bone healing alone or in combination with other materials, such as ad-hoc designed three-dimensional (3D) porous structures that mimic and share the essential properties of natural bone. These substitute materials should be thoroughly characterized in terms of porosity, compression resistance, biodegradation, biocompatibility and interaction

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Conclusion